Non-infectious Disorders Flashcards

Question

Most common location of recurrent respiratory papillomatosis

Answer 1

1) HPV 11 2) Age <3 3) Trach 4) previous invasive procedure

Answer 2

1) Progressive hoarseness 2) Stridor 3) Breathing difficulty

Answer 3

Bronchoscopy | white polypoid lesions with clean, smooth surface

Answer 4

``` Mainstay = surgical excision Adjuncts = interferon, antivirals, retinoids, inhibitors of oxygenase-2 cycle ```

Answer 5

1) >4 surgical procedures per year 2) rapid recurrence with airway compromise 3) distal multisite spread

Answer 6

Altered state of hemoglobin where ferrous irons of heme are oxidized to ferric state and are unable to reversibly bind oxygen ** left shift of the curve

Answer 7

Methemoglobin absords light at 2 wavelengths - the high concentration of methemoglobin causes O2 sat to display 85% regardless of true saturations *blood gas will give falsely high level of O2 sat

Answer 8

Peak cough >360-400 l/min for healthy person | Minimum = >270 l/min

Answer 9

1) Air stacking/volume recruitment 2) Chest compression 3) Mechanical insufflation/exsufflation

Answer 10

1) Exclude patients with perinatal lung disease 2) Within 7 days of known insult 3) Respiratory failure not explained by cardiac failure or fluid overload 4) Imaging findings of new infiltrates 5) classified as mild, moderate, severe using OI and OSI

Answer 11

1) Exudative 2) Fibroproliferative 3) Fibrosis 4) Recovery

Answer 12

- lower tidal volumes - lower plateau pressure - higher PEEP - lower delta P - lower FiO2 - lower PaO2, lower pH, higher PaCO2 goals

Answer 13

- Low surface tension, low viscosity, high volatility - Allows it to spread easily and more readily into distal airspaces - Increased surface tension by inhibiting surfactant - Volatility allows it to spread rapidly to alveoli and interfere with gas exchange **worry about severe pneumonitis

Answer 14

- Necrosis of bronchial, bronchiolar, and alveolar tissue - Atelectasis - Interstitial inflammation - Hemorrhagic pulmonary edema - Vascular thrombosis - Necrotizing bronchopneumonia - Hyaline membrane formation - Alveolitis

Answer 15

- Different pressure/volume curves for inflation and deflation - Less compliant with inflation (same pressure, lower volume) - Less expected pressure for deflation - Inflation -> with expansion of the alveoli, surfactant concentration decreases so more unopposed surface tension

Answer 16

Changes in surfactant activity (greater surface tension during inspiration) Others: Stress relaxation, redistribution of gas, recruitment of alveoli

Answer 17

- Stiff, less compliant chest wall - Decreased lung growth - Decreased respiratory muscle strength (because of how they're connected)

Answer 18

- Severe: restrictive with low TLC (low FVC proportional to low TLC) - *Important to compare volumes pre and post op - Greater angle of curve = greater decrease in FVC - Decrease MIP (correlates with decreased FVC) *check pre-op - Decreased expiratory flow - Normal FEV1/FVC ratio - Lower airway obstruction may be seen

Answer 19

- Improved lung volume - no change in lung function - no change in vital capacity - increased residual volume

Answer 20

- <25 + low risk of progression = monitor - <25 + progression = bracing; if progression with bracing = surgery - >50 = surgery

Answer 21

Normal residual volumes + FRC so increased because TLC is decreased

Answer 22

Occurs with neuromuscular weakness - chest wall and abdomen move in opposite directions DMD: diaphragm weak compared to intercostals = outward chest and inward abdomen with inspiration, FVC and MIPS more affected than MEPS SMA: Intercostal weakness with diaphragm sparing = inward chest and outward abdomen (chest sucked in due to diaphragm)

Answer 23

1) Residual injury to the peripheral airways | 2) Small airway obstruction and gas trapping = decreased FEV1 and increased RV/TLC

Answer 24

``` Blowing into the eyes Poor mask and headgear fit High leak Inappropriate settings Not desensitized to mask Poor sensing - dyssynchony Lack of humidification ```

Answer 25

1) Exclude patients with perinatal lung disease 2) Within 7 days of known clinical insult 3) Respiratory failure not fully explained by cardiac failure or fluid overload 4) Chest imaging findings of new infiltrates consistent with acute pulmonary parenchymal disease 5) Oxygenation (severity): CPAP >5, OI ≥ 4

Answer 26

``` (BTS): complete resolution and then minimum 7 days prior to flying Underlying conditions (ie. CF) and pneumomediastinum = 2 weeks ```

Answer 27

Triglycerides >1.1 mmol/dl Total count >1000 cells;>80% lymphocytes Chylomicrons + --not usually tested for though Sudan 3 + staining for fat globules Exudate- Pleural fluid LDH > 2/3rd of upper limit of normal or > 0.6 of serum LDH, Pleural fluid Protein > 0.5 of serum protein (2-6 g/dl) (Light’s) Electrolytes and glucose same as plasma

Answer 28

Loud P2 Pan systolic murmur in right sternal border ( TR murmur) and ejection murmur in pulmonic area HEPATOMEGALY/raised JVP Left parasternal heave

Answer 29

Both types of nonfatal drowning result in: - decreased lung compliance - ventilation-perfusion mismatching - intrapulmonary shunting, leading to hypoxemia that causes diffuse organ dysfunction. Previously: Salt water: caused plasma to be drawn into the pulmonary interstitium and alveoli, leading to massive pulmonary edema and hypertonic serum. Fresh water: aspirated hypotonic fluid rapidly passing through the lungs and into the intravascular compartment, leading to volume overload and dilutional effects on serum electrolytes.

Answer 30

Left lung dependent: Relative lucency (L), Normal (R) Right lung dependent: Normal (L), Decreased volume (R) Affected dependent lung will be hyperlucent. Normal lung will compress and partially collapse and appear denser (Normal).

Answer 31

Hypothermia Electrolyte imbalance Trauma Hypoxic-ischemic damage

Answer 32

1) Supportive care – oxygen, ventilator support and diuretics; if sick and features of ARDS, treat as ARDS 2) Broad spec Abx 3) Surfactant 4) Steroids 5) Multi-organ supportive care

Answer 33

NSR Reactive pupils Neurologic responsiveness at the scene Observed event

Answer 34

1) Pool fencing 2) Public education campaigns 3) Swimming programs for infants and toddlers less than four years of age should not be promoted as being an effective drowning prevention strategy. 4) Children less than four years of age do not have the developmental ability to master water survival skills and swim independently. 5) Swimming instruction should be carried out by trained instructors in pools that comply with current standards for design, maintenance, operation, and infection control 6) Residential pools should be fenced on all four sides, and must include a self- closing, self-latching gate. 7) Constant arms-length adult supervision is recommended for toddlers and infants near water 8) Government-approved personal flotation devices (PFDs) should be used for all young children and those who cannot swim. 9) Parents and pool owners should be encouraged to receive first aid and cardiopulmonary resuscitation (CPR) training, and to maintain an emergency action plan

Answer 35

Suspected when respiratory symptoms don’t disappear promptly when treated with usual treatment (expectorants, bronchodilators, antibiotics)

Answer 36

``` Ipsilateral compression of normal aerated lung Widening of intercostal spaces Flattening/descent of diaphragm Mediastinal shift away from lesion Wheeze ```

Answer 37

CXR U/S: can locate and help with needle aspiration of pleural effusions CT: Best able to provide detail for Mediastinal pulmonary and diaphragmatic densities MRI: Distinguishes between vascular and mediastinal structures and more sensitivity than CT in detecting intraspinal extension Echo Aortograms: Useful for identification of bronchial arteries, Can rule out vascular lesions, rings, sequestrations and other malformations Bronchoscopy: Allows evaluation of tracheobronchial tree, vocal cords, laryngx, trachea, and major bronchi/segmental bronchi

Answer 38

Disease in right lung drains into the right scalene lymph node Disease in left lung drains into either right or left scalene lymph nodes

Answer 39

Lymph nodes are within triangular fat pad | Bound by internal jugular vein (medial), subclavian vein inferior), posterior belly of the omohyoid muscle (superior

Answer 40

Benign tumour Consist of cartilage, with epithelium, fat and muscle Typically located in periphery (can be seen with intermediate/primary bronchi) “Popcorn like” calcification is pathognomonic

Answer 41

Carcinoid (90%) | Cylindromatous (10%)

Answer 42

Typically multiple lesions HPV plays a role in pathophysiology (serotypes 6 and 11 implicated in recurrent papillomatosis) Juvenile forms do not undergo malignant transformation Laser CO2 ablation most commonly used as treatment

Answer 43

Depends on location and size Dyspnea, hoarseness, stridor are most common (2/3 of cases) Cough (initially dry, then productive) Lesions may be attached by pedicle à oscillate in and out of orifices during inspiration/expiration May be asymptomatic if slow growing and high within the airway Wheeze is earliest sign of tracheal papilloma Eventually develops into stridor, with associated slowly developing dyspnea May see obstructive emphysema, atelectasis, pneumonia, abscess, empyema and bronchiectasis

Answer 44

Congenital hemangiomas are one of the most common tumors of the airway in children Usually located below vocal cords Typically flat, sessile 90% of patients have development of symptoms @ 6 months o Suggests proliferative phase at this age ``` Dx: Best done with bronchoscopy DO NOT biopsy Tx: - Tracheostomy necessary for severe obstruction - Steroids - Beta blockers ```

Answer 45

Insidious onset Stridor, retractions, dyspnea, wheeze, +/- cyanosis and cough o Intermittent symptoms and labile Absence of leukocytosis and fever

Answer 46

Anterior: Sternum Posterior: Vertebrae Superior: Suprasternal notch Inferior: Diaphragm Encapsulated by parietal pleura

Answer 47

From angle of sternum, to the intervertebral disk between T4/5

Answer 48

Portion of mediastinum anterior to the anterior plane of trachea

Answer 49

Portion containing the heart and pericardium, ascending aorta, lower segment of the SVC, bifurcation of the pulmonary artery, trachea, main bronchi, and bronchial lymph nodes

Answer 50

Portion that lies posterior to the anterior plane of the trachea

Answer 51

AKA: foregut duplication cysts - Classified as tracheal, hilar, carinal esophageal, and miscellaneous - Usually located in middle of mediastinum, but can be anywhere in mediastinum - May contain any or all of the normally present tissues in trachea and bronchi

Answer 52

Typically asymptomatic May be frequent URTI, sternal discomfort, respiratory difficulty (cough, noisy breathing, dyspnea, cyanosis) If located below carina, can cause severe respiratory distress, due to mainstem bronchi compression Need to identify early

Answer 53

Single, smooth bordered, spherical mass o Similar density to cardiac shadow o Unusual to have calcification o Can show air fluid levels due to communication with tracheobronchial tree § Can see connection with bronchoscopy if communication exists o Moves with respiration (seen on fluoroscopy) o Occasionally seen on prenatal U/S

Answer 54

Located in posterior mediastinum o Most typically on the right, intimately associated with the wall of the esophagus Characteristic type: Resembles adult esophagus with cyst lined by noncornified stratified squamous epithelium, Well defined muscularis mucosa and striated muscle in the wall May be associated with dyspnea and regurgitation Barium swallow shows smooth indentation of esophagus Esophagoscopy shows indentation of normal mucosa by soft, pliable movable extramucosal mass

Answer 55

Arises from foregut, typically lies in posterior mediastinum against vertebrae - Typically posterior and lateral from the esophagus - Male > Female - Lining is generally ciliated if arises from embryonic esophagus - Can be relatively certain that a posterior mediastinal cyst is enteric if microscopic exam shows gastric or intestinal type of epithelium Typically symptomatic due to pressure on thoracic structures, or rupture into the bronchi This can lead to massive hemoptysis and death

Answer 56

Thymic hyperplasia

Answer 57

Normally, see thymic shadow during first months of life, typically disappearing by 1 year Common to see cervical extension

Answer 58

Results from faulty embryogenesis of thymus, or local disclocation during embryogenesis - AKA mediastinal dermal cyst - Contains ectodermal tissue (hair, sweat glands, sebaceous cysts, teeth), mesodermal and endodermal tissue

Answer 59

Neurogenic Mediastinal Tumors

Answer 60

Neuroblastoma Ganglioneuroma/ Ganglioneuroblastoma Pheochromocytoma Chemodectoma

Answer 61

TB, fungal, bacterial or inflammatory lung disease (sarcoid)

Answer 62

Teratoma Thymoma Terrible Lymphoma (or T cell Lymphoma) Thyroid

Answer 63

``` Esophageal Parathyroid Adenoma Bronchogenic cysts Foregut duplication cyst Tracheal tumours ```

Answer 64

Neurogenic Tumours | Neuroendocrine Tumours

Answer 65

``` Yes Carcinoid tumors (40%), Bronchogenic carcinoma (17%), and Pleuropulmonary Blastoma (15%) ```

Answer 66

Plasma cell granuloma (most common) | Hamartoma

Answer 67

``` Bronchial adenoma (most common) Bronchial carcinoid Cylindroma Mucoepidermoid tumour Mucous-gland adenoma Primary carcinoma of the lung Undifferentiated carcinoma Adenocarcinoma Squamous cell carcinoma Pleuropulmonary blastoma ```

Answer 68

``` Wilm’s tumour Osteosarcoma Ewing’s sarcoma Rhabdomyosarcoma Hepatocellular carcinoma Hepatoblastoma Neuroblastoma Germ cell Tumours ```

Answer 69

Slow growing, locally invasive Represent an inflammatory response to previous infectious or traumatic insult Only 20% of patients have a clear documented pulmonary insult prior Presentation varies: o 30% are asymptomatic o Fever (22%) and cough (20%) are common o Hemoptysis, pain and pneumonitis

Answer 70

Occurs only in children (Distinct from pulmonary blastoma of adults) - Embyonic neoplasm from thoracopulmonary mesenchyme - Aggressive with poor prognosis Classification: o Type 1: Cystic o Type 2: Cystic and Solid o Type 3: Purely solid - Microscopically seen areas of high mitotic activity with areas of undifferentiated loose medsenchymal spindle cells o Type 1 has rhabdomyoblastic differentiation o Type 2 and 3 have cartilaginous differentiation - History of childhood neoplasms or congenital dysplasia (lung, kidney, thyroid) in 25% of cases

Answer 71

Cough, breathlessness o May have fever o Often discovered after failed treatment with antibiotics for “chest infection” o Type 1 tends to present earlier

Answer 72

Chest wall configuration (scoliosis, overdistension etc.) Pattern of spontaneous breathing - Thoracic and/or abdominal breathing - Paradoxical thoracoabdominal movements: inspiratory rib cage retraction, paradoxical inspiratory abdominal retraction (unilateral or bilateral) Specific Maneuvers - Maximum variation in thoracic circumference - Maximal excursion or diaphragm (inspection and percussion) - Cough strength

Answer 73

- Spirometry (esp FVC) - annual - MIP (mouth or sniff), MEP - Peak Cough - annual (<160-200 L/m = ineffective) -DLCO - Pulse Ox and End-tidal CO2 - Overnight assessments: Oximetry + CO2, or PSG - FVC 40-60% = low risk noctural hypovent - FVC <40% or diaphragm weakness= ↑ risk - Annual assessment is FVC <60%, or symps Peak cough <160-200 L/min = ineffective (teens/adults) -↑risk of resp infection, failure

Answer 74

-Optimize: nutrition, oxygenation, electrolytes -Treat non-related resp d/o: asthma, allergy, T&As, etc. -Prevent lung infections: Avoid smoke-exposure, large daycares. Flu shot. 23-valent vaccine. -Respiratory muscle training useful in some d/o -Assisted cough and lung-recruitment - either manual or mechanical - esp. If recurrent infctns -Ventilatory support: Nocturnal BiPAP recommended in NMD w/ alveolar hypoventilation Consider if FTT or recurrent infection (>3/yr) -Consideration for tracheostomy

Answer 75

1) Central drive of breathing 2) Upper motor neuron 3) Lower motor neuron 4) NM junction 5) Respiratory muscles 6) Nonmuscular, chest wall structures

Answer 76

-Leads to Restrictive pulmonary disease: ↓ FVC & FEV1, Normal V1/VC ratio -↓ Strength of resp muscles (high variability) -↓ Ventilatory response w/ exercise -RV Normal or Increased (if weak exp ms) -When resp muscle strength <50% predicted, the decr in VC is greater than expected due to ↓ed compliance of both the lungs (atelectasis) and chest wall (constovertebral/costosternal jt anyklosis) -Daytime hypercapnia usually present when resp muscle strength <25% (can occur sooner) -Less severe weakness may still have noctural ↑CO2 or hypercapnia with illness, anesthesia, etc

Answer 77

``` SCI CP SMA SMA with Resp distress type 1 Phrenic nerve injury Guillan Barre ```

Answer 78

AR disorder of the SMN1 gene (survival motor neuron) - essential to motor neurons -Mutation leads to primary degeneration of anterior horn cells +/- bulbar nuclei

Answer 79

SMA-1 SMA-2 SMA-3

Answer 80

symptoms manifest by 6-months, can manifest in-utero (↓ fetal mvmt) ○ Incidence 1:10,000; 2nd most common severe childhood NMD (behind DMD) ○ Impaired head control, weak cry, cough ○ Paradoxical breathing due to intercostal muscle weakness ○ Diaphragm relatively spared ○ Chest radiograph: bell-shaped, small volumes ○ At risk for swallowing dysfxn, aspiration, recurrent resp failure w/ illness/virus ○ Poor prognosis - 95% mortality by 18mo (respiratory failure) w/o intervention Respiratory mgmt = highly controversial - palliative vs. life-prolonging ■ Chronic non-invasive used increasingly oftern 16+ hrs/day ■ Non-invasive recommended over tracheostomy ○ Mechanical in-exsufflation, minimum BID ■ Used as often as necessary to maintain SaO2 >95% w/ illness ■ Used to maintain sats >95% during illness

Answer 81

Type 2 = intermediate form, largest group of SMA pts ○ Present btw 6mo-1year ○ Able to sit, cannot walk ○ At risk of respiratory failure due to: ■ Aspiration, reflux, recurrent atelectasis, resp infctn, weak cough, scoliosis ○ Recurrent infections usu precede nocturnal hypox/hypovent ○ With resp support (non-invasive, cough-assist, prevention) good QOL and lifespan into early adulthood expected

Answer 82

Onset after 18 months, able to walk, resp involvement usu minimal

Answer 83

- Presents in first weeks of life w/ acute life-threatening resp distress & diaphragmatic paralysis - Autosomal recessive, of gene encoding immunglobulin μ binding protein 2 - Peripheral muscle weakness initially just in lower limbs, and not generally a presenting feat - Prenatal testing/diagnosis possible

Answer 84

1) Disorders of Innervation 2) NM Junction 3) Muscle disorders 4) Disorders of Anatomy 5) Idiopathic

Answer 85

Injury due to thoracic/neck surgery Most occur on right side; bilateral = 10% Manifests as elevation of the hemidiaphragm In neonates - freq causes resp failure Older patients, often asymptomatic

Answer 86

Sniff test or spont breathing shows paradoxical diaphragm movement

Answer 87

Asymptomatic pts = no therapy | Symptomatic = ventilatory support, +/- plication

Answer 88

``` Acute, inflammatory demyelinating disease of peripheral nerves Autoimmune dz (likely) triggered by infection- CMV, EBV, Varicella, Mycoplasma, campylobacter flu vaccine ``` Diagnosis clinical: tingling paresthesia of distal extremities, proximal muscle weakness, pain Respiratory failure may develop: aspiration, impaired cough, Resp muscle weakness Early Rx w/ IVIG, Plasma exchange may hasten resolution. Steroids = no effect.

Answer 89

X-linked AR mutation to dystophin gene = most common severe muscular dystrophy (DMD = lack of dystophin, Becker MD = expression of mutant dystorphin ) Restrictive lung dz 2° to muscle weakness, scoliosis, chest wall ankylosis, obesity Maximal FVC typically occurs at age 10-12

Answer 90

FVC, MIP/MEP, peak cough, Blood Gases / CO2s, and O/N pulse oximetry to monitor progression

Answer 91

First decade: Prevent infxns (Flu, 23-valent vax), exercise, Rx other resp problem (asthma, T&A) Second decade: Volume recruitment, mechanical ventilation will be reqd Scoliosis can impact FVC, muscle strength - therefore aggressive management recommended -Early surgery = Rx of choice: when Cobb angle >20degrees, FVC >40%

Answer 92

1) During infection: Assisted cough PRN and NIMV to maintain SaO2 > 95% (R/A) 2) Oxygen used with caution, can mask hypoventilation 3) Early antibiotics 4) Inability to maintain SaO2 >95% in R/A = indication of admission 5) If intubation reqd, protocols for extubation = highly successful (extubate to NIV and cough assist) 6) Written action plan for all DMD pts

Answer 93

1) Early Rx w/ long-term steroid: Slows decline in muscle strength/fxn → slows loss of ambulation 2) prevents scoliosis and retards respiratory decline 3) May improve cardiac fxn 4) Recommended once child reaches plateau phase in motor skills (age 4-8yrs) 5) Recommended to continue daily steroid Rx even after loss of ambulation Deflazacort (0.9 mg/day) recommended over Prednisone (0.75mg/day) -Deflazacort = less wt gain, ↓ behavioral effects

Answer 94

Severe neonatal form affects 10-15% w/ Myotonic Dystrophy Presents: generalized hypotonia (w/o myotonia), respiratory & feeding difficulties CXR = thin ribs, right hemidiaphragm elevation -Significant diaphragmatic weakness at birth Associations: Polyhydramnios, prematurity, hydrops w/ effusion and pulmonary hypoplasia may contribute to pulmonary morbidity

Answer 95

Autoimmune d/o vs neuromuscular junction Characterized by autoantibodies vs. acetylcholine receptor (AchR) or sometimes MuSK protein Abn muscle fatigability Myasthenic crises → respiratory failure; triggers include: infection, fever, stress, meds Diagnosis: Response to Acetylcholinesterase inhibitor, eclectorphysio studies, ciculating Abs Long-term mgmt: Acetylchoinesterase meds (pyridostigmine) and immune-suppressants

Answer 96

Distorts thoracic cage → cardiopulmonary dysfxn may impact QOL, lifespan “Thoracic Insufficiency Syndrome” = spine or chest wall d/o which impact pulm fxn or growth Cobbs angle >50-60 = restrictive dz (rare before this) ↓FVC>↓RV → mild ↑RV/TLC (Minority show obstruction → mainstem distortion) Cobbs > 60 = ↑ risk Nocturnal hypoventilation Most common form of scoliosis = idiopathic (85%)

Answer 97

Controversial Congenital/infantile scoliosis: decreased alveolar multiplication Juvenile/Adolescent: decreased Alveolar size Potential assoc btw early scoliosis & pulmonary hypoplasia Congenital & Infantile = serious condition → progression to deformed/rigid chest affects lung dev

Answer 98

Most common immediate post-op morbidity & mortality Include: atelectasis, hemo/pneumothorax, pulm edema, UA obstructn, fat emboli NIMV and mechanical in/exsuff = valuable to decrease duration of intubation (in congenital scoliosis) Improvement in lung volume, arterial oxygenation occurs late after surgery -May take >2-yrs for measureable improvement postop, can sometimes worsen pulm fxn

Answer 99

Most common form of Hypoplastic Thorax Syndromes Autosomal recessive d/o - narrow hypoplastic ribcage, short-limb dwarfism Assoc: pelvic & pharyngeal abn, polydactyly, liver & kidney abn, ↓plt, Shwachman synd Diagnosed clinically at birth: thorax circumference <75% of head, tachypnea CXR: narrow rib cage, high clavicles, short horizontal ribs, flaring costochondral jxns CT: “Four-leaf clover” caused by foreshortened ribs Most die shortly after birth from resp failure; highly variable in survivors Improvement may occur w/ age → justifying life support (long-term vent) early

Answer 100

Includes 2 d/o =Spondylocostal dysostosis & spondylothoracic dysplasia Broadening, bifurcation & fusion of ribs, congenital scoliosis & short vertebral ht Manifests as shortened thoracic height, fanlike rib configuration, fusion costovertebral junctions Both AD & AR inheritance

Answer 101

Overinflation → mech.l disadvantage: flattens diaphragm, ribs more horizontal = ↓power

Answer 102

↓FRC due to mass load of adipose tissue on rib cage / abdomen With morbid obesity FRC can reach RV → therefore marked ↓ERV, ↑IRV Decreased pulmonary compliance - due to dependent atelectasis, increased pulm blood flow, ↓FRC ↓ Physical performance = ↑ metabolic cost of exercise, ↑ fatigue, +/- ↑ exercise induced bronchospasm Association with OSA

Answer 103

1) Diaphragm insertion into ribcage more perpendicular → inward displacement of lower ribs 2) ↑ compliance of ribcage → inward displacement w/ deep inspiration 3) If intercostal muscles relax (ie REM sleep) → even normal resp leads to inward displacement 4) Inward displacement = ↓ Tidal Volume, Paradoxical breathing 5) Rapid breathing, w/ limited diaphragmatic excursion - to overcome increased tendency to fatigue (During dz states RR ↑s - limits contraction strength - reduces diaphragm fatigue) 6) Newborns prevent resp failure by increasing resting alveolar gas stores (ie End Expiratory Volume) - Done via: - ↑ RR - limits time for expiration - Braking the expiratory flow by breathing vs. closed glottis - Progressive post-inspiratory decontraction of the diaphragm

Answer 104

Mean PAP ≥ 25 mmHg (new guideline = 20) Normal pulmonary artery wedge pressure (≤ 15mmHg) Elevated PVR PAH (by definition) occurs in the pre-capillary vessels and thus requires normal PA wedge pressure and excludes causes of pulmonary venous HTN

Answer 105

1) Pulmonary Arterial HTN (includes PPHN, PVOD) 2) Pulmonary HTN caused by left heart disease 3) Pulmonary HTN caused by lung diseases and/or hypoxia 4) Chronic Thromboembolic Pulmonary HTN 5) Pulmonary HTN with unclear multifactorial mechanisms

Answer 106

Unique form of PAH – often resolves completely with proper intervention/support, vs most other PAH requiring lifelong Tx ▪ Almost always transient Characterized by elevated PVR, R-L shunt, severe hypoxemia Often associated with pulmonary parenchymal abnormalities (ie. Mec asp, sepsis, pneumonia, difficult transition), or with hypoplasia, perinatal stress etc Suspect ACD/MPV if: 1) PPHN that’s refractory to Tx or brief response to iNO/IV epoprostenol 2) Late onset presentation (12- 24 hours after birth) 3) Other non-lethal congenital malformations (Ie. Cardiac (HLH), GI (malrotation/atresia), Renal)

Answer 107

Characterized by progressive PA vascular obliteration and RV overload Meet criteria for IPAH if you have PAH, and other causes are ruled out

Answer 108

1) Vasoconstriction Abnormalities include: prostacyclin pathway, endothelin system and NO production/availability Vasoconstriction -> medial hypertrophy of vascular bed -> intimal fibrosis (adolescents/adults) -> plexiform vascular lesions and other non-reversible changes (adults) As you progress, your vasculature is less responsive to vasodilator therapy 2) Endothelial dysfunction Key factor in mediating the structural changes in the pulmonary vasculature seen in PAH Leads to the release of: vasoconstrictive agents, vasoproliferative substances, chemotactic substances attracting SM cells into vascular walls, thrombogenic substances

Answer 109

BMPR2 ALK-1 Endoglin

Answer 110

Normal PVR decreases after birth and within 4 – 6 weeks of life reaches normal adult levels - Normal pulmonary vascular bed is low pressure, low resistance - Highly distensible and can accommodate large increases in pulmonary blood flow PAH -> unable to accommodate increase pulmonary blood flow -> increase PAP at rest and more-so on exertion -> RV hypertrophy (compensatory and initially help deal with increased RV afterload) -> septum flat, then bow into left heart (RVH now becomes detrimental)-> left sided diastolic dysfunction which in severe cases may cause worsening of PH and RV failure With exercise, patients unable to increase CO to meet O2 demands and thus feel exertional dyspnea and may have exertional/post-exertional syncope

Answer 111

1. Progressive RV failure – progressive dyspnea and decrease in CO 2. Sudden death – from dysrhythmia, likely secondary to hypoxemia May also have PE, pulmonary arterial aneurysm rupture, pulmonary hemorrhage, RV ischemia Illnesses (Ie pneumonia) can be fatal, as alveolar hypoxia causes hypoxic pulmonary vasoconstriction, leading to inability to maintain adequate cardiac output → cardiac shock and death

Answer 112

Symptoms: highly variable (Most common, dyspnea, fatigue, +/- chest pain) Infants: low CO (tachypnea, tachycardia, poor appetite, FT, lethargy, diaphoresis, irritability) Cyanosis with exertion (R→L shunt via PFO or other shunt) Dyspnea/syncope on exertion Chest pain (crying spells in infants) Peripheral edema

Answer 113

Loud single P2 – from high RVSP Murmur from tricuspid insufficiency (pan-systolic) – from high RVSP Murmur from pulmonary insufficiency (high pitched diastolic) – from high pulmonary pressures RV gallop May be S3 or S4 RV failure – elevated JVP (rare), hepatomegaly, peripheral edema Clubbing Signs/symptoms of systemic disease

Answer 114

EKG, CXR Echo (look for left heart disease, septal bowing) PFTs (should be normal except for low DLCO) V/Q scan BW PSG Cardiac Cath (should be done prior to initiation of PH-specific drug therapy)

Answer 115

Cardiac Catheterization Gold standard for assessing severity and prognosis Do vasodilator therapy during cath (iNO, IV epoprostenol) Positive response = reduction in mean pulm art. pressure by at least 20% Brisk acute vasodilator response predicts response to CCB Duration of symptoms prior to Dx not appear to correlate with likelihood of acute response or lack thereof Marked variability in biology

Answer 116

No cure, no single therapeutic approach that works for all patients Pulmonary vasodilator must be balanced with potential effects on systemic circulation Huge effect of hypoxic vasoconstriction with illness Vaccines for influenzae and pneumococus Antipyretics for fever (minimized metabolic demands on compromised Cardio/Resp system) Low threshold for vasodilators (iNO) in face of acute illness with hypertensive crisis May need antitussive medication to reduce pulm arterial pressures Avoid decongestants with pseudoephedrine Prevent constipation

Answer 117

Ensure fully vaccinated, peds patients have much more reactive vascular bed, thus simple resp infection can cause V/Q mismatch, hypoxemia and subsequent catastrophic PH crisis Anti-pyretics to be given aggressively iNO for acute PH crisis Avoid decongestents with pseudoephedrine

Answer 118

Indication comes from observational data in adults – IPAH and APAH lungs often have thrombotic lesions, some patients have underlying coagulopathy, poor RV function can lead to stasis and thrombus formation data limited, but supportive for chronic anti-coagulation Some people favour warfarin in patients with R-sided failure to achieve INR of 1.5, care with toddlers and trauma (adults target 1.5 – 2) Contraindication to warfarin – can use LMWH

Answer 119

‘responder’ = decrease in mean PAP ≥ 20% from baseline with no clinically significant decrease in CO and decrease or no change in ratio of PVR to SVR

Answer 120

L-arginine → NO (by NO synthase) Selectively relaxes pulmonary vessels (versus the other vasodilators mentioned) When inhaled, it’s inactivated by Hgb thus no systemic response May help as antiproliferative agent Tx for PPH, exacerbation of IPAH, peri/post-operative PH and other forms of PAH

Answer 121

Phosphodiesterase 5 inhibitors prevent breakdown of cGMP, thus increasing cGMP which potentiates vasodilation with NO - Sildenafil (PO, TID)

Answer 122

1. PH, no physical activity limitation; ordinary physical activity does not cause undue dyspnea, fatigue, chest pain or near syncope 2. Slight limitation of physical activity. Comfortable at rest, but ordinary activity causes undue dyspnea, fatigue, chest pain or near syncope 3. Marked limitation physical activity; comfortable at rest, but less than ordinary activity causes undue dyspnea or fatigue, chest pain or near syncope 4. Inability to carry out any physical activity w/o symptoms; signs of R-sided failure; dyspnea, fatigue may be present at rest; discomfort increased by any physical activity

Answer 123

= Pulmonary Heart Disease clinically useful definition: involvement of the RV (hypertrophy, dilatation or failure) as detected by clinical signs, CXR, ECG, echo, cardiac cath or autopsy, which is caused by altered pulmonary structure and function and not due to diseases primarily involving the left or right side of heart

Answer 124

- 16th week of gestation → all bronchial airway generations have formed along with accompanying pulmonary arteries - 3rd trimester → pulmonary vascular surface area increases 10 fold with concomitant development of distal airway, alveolar ducts and saccules - Larger arteries develop muscle coat earlier whereas small arteries have minimal smooth muscle and develop muscular coat with normal postnatal growth - Fetal pulmonary circulation receives < 8% of ventricular output due to high PVR (most RV output crosses the dutus arteriosus to the aorta) - During late gestation, pulmonary blood flow increases in proportion to lung weight and increased vascular cross-sectional area but mean PAP increases as well → PVR increases with GA

Answer 125

Lack of gas-liquid interface and rhythmic distension of the lung Low oxygen tension (fetal PaO2 is 20-25 mmHg) Low basal production of endogenous dilators (prostacyclin and NO) Increased production of vasoconstrictors (endothelin-1 and leukotrienes)

Answer 126

At birth pulmonary blood flow increases 8-10 fold and PAP decreases to levels about 50% of systemic → stimulation of NO production contributes substantially to fall in PVR

Answer 127

Pulmonary circulation: RV outflow tract, main PA, major branches to left and right lung, lobar branches, intrapulmonary arteries, arterioles, capillaries, venules, veins -3 types of pulmonary arteries ● Elastic PAs (> 1000 um external diameter) – central and extralobular ● Muscular PAs (100-1000 um) – accompany bronchioles within lobules ● Pulmonary arterioles ( <100 um) – terminal branches of the PA tree and supply alveolar ducts and alveoli 2 types of small pulmonary artery branches ● Conventional branches – travel alone and usually smaller, branch from main arterial channels and extend to the periphery at the end of the respiratory bronchioles (numbers fixed after 18 months) ● Supernumerary branches – more numerous, present at birth and can participate in gas exchange (increase with septation and formation of new alveoli up to 3 years)

Answer 128

- Receives 1-2% of total cardiac output - Supplies airways, pulmonary nerves and ganglia, walls of elastic and some muscular pulmonary arteries and veins, lymph nodes and connective tissue septa and pleura - Flow may increase substantially with pathology causing chronic inflammation and injury (e.g. CF, BPD, bronchiectasis) and acute increases may contribute to lung edema - Marked variability of branching patterns → 40% have one bronchial artery to each lung -Bronchial veins empty into azygos, hemiazygos or intercostals veins → right atrium - 1/4-1/3 of blood goes from bronchial veins to RA and remainder flows from pulmonary veins to LA

Answer 129

Zone 1: alveolar pressure > pulmonary artery pressure and pulmonary venous pressure = pulmonary capillaries are collapsed (thus no perfusion) Zone 2: pulmonary artery pressure > alveolar pressure > pulmonary venous pressure = flow determined by difference between pulmonary artery and alveolar pressures (flow begins at top of zone 2) Zone 3: pulmonary artery and venous pressures > alveolar pressure = flow determined by difference between pulmonary artery and venous pressures (most of the lung is zone 3) o Largest contribution to resistance is in the capillaries of the alveolar septum > arterioles

Answer 130

Passive vascular distention Recruitment of small pulmonary arteries Vasodilation

Answer 131

During exercise Increased CO increases PAP because of high flow through restricted vascular bed and inability to dilate -With severe PHTN, CO is unable to increase → fatigue, dyspnea on exertion, syncope or sudden death

Answer 132

RV is has a thinner wall and greater volume and surface area than LV → highly compliant chamber that better accommodates increases in filling pressure but poorly designed to handle rapid increases in high systolic ejection pressure → abrupt rise in RV afterload markedly increases RV end-diastolic pressure, decreasing ejection fraction and RV output Sudden rise in PVR rapidly dilates RV → right heart failure → hepatomegaly, peripheral edema, venous distention Attempt to compensate by muscle hypertrophy → reduces compliance and increases RV end- diastolic and right atrial pressure LV function is generally preserved in most with chronic lung dx but high PVR can impair CO (RV dilation distorts LV and impedes filling) High PVR causes LV dysfunction by decreasing preload and causing paradoxical interventricular septal motion (ventricular interdependence)

Answer 133

Increased RV wall thickness, chamber size, flattening or paradoxical motion of IVS, Delayed opening and early closure of pulmonic valve, incomplete tricuspid valve closure Tricuspid insufficiency jet reflects the pressure difference between the RV and the RA and using Bernoulli principle (pressure = 4V2 where V is the peak systolic velocity), is a good estimate of RVsp

Answer 134

Oxygen Hypoxia is the most common cause of progressive PHTN in CLD → O2 is the mainstay of therapy BTS recommends targeting O2 sat > 93%

Answer 135

Dx requires echo confirming R-L shunting at ductus or PFO in the absence of anatomic heart disease Clinical features highly suggestive: 1) marked or labile hypoxemia 2) differences in preductal and postductal paO2 at least 5-10 mmHg (not present if shunting primary at PFO) 3) clinical improvement with hyperventilation Treatment: high FiO2, hyperventilation, sodium bicarb (for alkalosis), inotropes (CVS support), prostaglandins (side effects are hypotneison, worsening R-L shunting and V/Q mismatch), iNO, HFO, ECMO Poor responders may have lung hypoplasia (think ACD), surfactant def, or other lung disorders

Answer 136

BPD with PHTN are prone to recurrent pulmonary edema, frequent chest exacerbations, congestive heart failure and morbidity from viral infections or sudden death Cardiac complications include LVH, systemic hypertension Pulmonary circulation characterized by pulmonary vasoreactivity, hypertensive vascular remodeling (increased muscularization with adventitial thickening), decreased arterial number, decreased septation (simple alveoli) Treatment: Maintain O2 sat > 94-95% → according to BTS guidelines this appears to reduce pulmonary hypertension Also in CLD: O2 sat < 90% is associated with incr risk of ALTE while O2 sat of ≥ 93% was not O2 sat < 92% associated with suboptimal growth O2 sat ≤ 90% impairs sleep quality while > 93% does not

Answer 137

1. Chronic hypoxia (secondary to severe V/Q mismatch from lung disease) 2. Chronic hypercarbia with acidosis may cause intermittent spikes in PAP leading to vascular remodeling 3. Severe bronchiectasis with progressive interstitial disease decreases alveolar-capillary surface area 4. Chronic infection/inflammation can alter pulmonary vascular reactivity and structure

Answer 138

PaO2 < 50, PCO2 > 45, FVC < 60%, RAD on ECG

Answer 139

Occurs when ascending to altitudes usually > 2400 m → alveolar hypoxia disrupts alveolo-capillary barrier → lung inflammation → vasoconstriction → worsening VQ mismatch → overperfusion of some nonconstricted capillaries causes stress failure → vascular injury and increased interstitial and alveolar edema Sx are severe dyspnea, fatigue, weakness, dry cough, anxiety, hemoptysis On exam are tachypneic, tachycardic, cyanotic, and have diffuse crackles CXR shows fluffly densities, PA enlargement ECG shows tachy, peaked p waves, RAD, ST-T changes, RV hypertrophy BAL shows high concentration of albumin → permeability edema

Answer 140

Caused by repeated episodes of hypoxia

Answer 141

Severe dyspnea on exertion, SOB, clubbing, cyanosis, orthodeoxia (hypoxia aggravated in upright position) spider nevi Diagnostic criteria: ▪ Liver disease ▪ Oxygenation defect where PaO2 80 or A-a O2 gradient ≥ 15 ▪ Pulmonary vascular dilatation seen on lung perfusion scan or bubble echo o CXR may be normal or show increased markings more prominent at bases o PFTs may demonstrate restrictive or mixed abn but low DLCO o Chest CT shows increased central and peripheral vascularity Dx confirmed by lung perfusion scans (labelled albumin) that show increased activity in extrapulmonary sites or bubble echo Main cause of refractory hypoxia is intrapulmonary shunting through dilated vessels in the microcirculation = arterioles and capillaries (also have some VQ mismatch) Severity of liver disease does not correlate Treatment: liver transplant

Answer 142

Injury to pulmonary circulation → increased permeability → pulmonary edema and surfactant inactivation + decreased lung compliance + decreased gas exchange Also get PHTN → worsens V/Q mismatch and accelerates pulmonary edema formation Tx: iNO has been shown to lower PAP and improve oxygenation but not to improve mortality or ventilator free days!

Answer 143

1) Obstruction of Large Airways 2) High Pulmonary Blood Flow from L to R shunts 3) High Pulmonary venous pressure

Answer 144

Associated with CHD (usually cyanotic heart disease after fontan), lymphangiectasia, asthma, ABPA, sickle cell anemia, collagen vascular disease Formation of large airway casts that plug and obstruct medium-sized or small airways Present with dyspnea, wheeze, pleuritic chest pain, +/- fever CXR shows focal collapse with compensatory hyperinflation Dx usually made with bronch Treatment empirical with bronchodilators, ICS, DNase/NAC

Answer 145

Uncommon - Usually blunt trauma - Penetrating injury – gunshot, stabbing are rare - > 75% are MVC and rest largely sports injury, physical abuse and fall from height - B/C high chest wall compliance in peds, you can get significant thoracic trauma without associated fracture - Follow ATLS guidelines - If hemodynamically stable, child may be sent to CT for assessment of potentially missed injuries

Answer 146

High chest wall compliance in peds More rounded chest with less muscles More flexible Elastic rib cage With this, pediatric patients can have anterior and posterior curvatures of ribs contact each other w/o fracture Thus blunt injury may cause significant damage to visceral structures without characteristic external findings Peds mediastinum is much more mobile than adults, so more resistant to injury Lack of pre-existing vascular disease protects great vessels from injury Conditions such as tension pneumothorax or hemothorax are very poorly tolerated and must be recognized and addressed Massive gastric distension can compromise pulmonary reserve

Answer 147

Require high compression crush injury Exam: local tenderness, ecchymosis, peculiar concavity or paradoxical respiratory movement; dyspnea, cyanosis, tachycardia and hypotension may be evidence of underlying heart contusion o Require ICU, monitoring, r/o cardiac injury and tamponade o Markedly displaced fragments should be reduced under GA o If significant paradox respiration – mech vent

Answer 148

Very rare in kids, b/c so flexible o Multiple rib # with destruction of thoracic skeleton can give you ‘flail chest’ motion o Unsupported area of chest moves in w/inspiration and out w/expiration result → paradox o This leads to dyspnea; coughing has little result in this situation o Clinically: local pain, tenderness, edema, ecchymosis o CXR–see fracture Tx: uncomplicated fracture - pain control to allow normal resps o Physiotherapy to augment cough & mucus clearance o Severe fracture - analgesia, intermittent PPV and if PTX/hemoTX → chest tube immediately o Flail chest → consider mech vent (to avoid ARDS – as have airway obstruction, atelectasis and pneumonia) o Immediate fixation rarely required

Answer 149

▪ Control secretions ▪ Decrease dead space ▪ Control obstructed airway ▪ Mech vent can be applied

Answer 150

1. Pneumothorax 2. Hemothorax 3. Tracheobronchial trauma 4. Pulmonary compression injury 5. Posttraumatic atelectasis

Answer 151

Atmospheric air enters and exits unimpeded – huge problem, b/c get severe paradox, mediastinal flutter and if large, more air exchanged at this site then trachea; mediastinum moves like pendulum, compressing contralateral lung on inspiration and ipsilateral on expiration → completely ineffective ventilation w/increase dead space, low Tidal V

Answer 152

- A, B, C, D, E - Monitors, IV access, bloods - tension – insertion of needle (biggest you can find to fit) in the 2nd ICS, MCL - Traumatic valvular leak need → occlude (ie. stabbing) - Persistent leak – insert chest tube - Persistent air leak may need surgical repair versus resection of affected segment *OPEN PTX – immediate occlusion of open wound with sterile occlusive dressing, CT insertion connected to underwater seal (prevent conversion of open to tension) → when stable, to OR to debride and surgically close

Answer 153

Hemothorax

Answer 154

- A, B, C, D, E - IV access, monitors, bloods - large chest tube to drain air/blood - persistent bleed > 1 ml/kg/min w/hemodynamic instability despite resuscitation → take to OR (or at surgeons discretion) - may get clotting, loculation or infexn w/retained hemothorax - Fibrothorax (unevacuated pleural blood organized into fibrous tissue) is infection risk and cause chronic cardiorespiratory changes as lung incarcerated and CW immobilized → may require thoracotomy and decortication

Answer 155

Ruptured trachea/bronchus = rare – secondary to severe compression injury Big leak distal cause bilateral PTX; proximal more pneumomediastinum, S/Q emphysema

Answer 156

- Resp distress, hemoptysis, hemodynamic compromise depending on location (ie. bilat tension PTX) - CXR – see air leak, tracheobronchogram suggestive; CT better delineate anatomy, bronch gold standard

Answer 157

- A, B, C, D, E, monitors, IV access, BW etc - Maintain airway, chest tubes as needed - Emergency bronch and immediate repair (thoracotomay and primary repair of defect); if small tracheal injury – temp trach may be very useful

Answer 158

- Pulmonary contusion - Alveolar disruption → interstitial emphysema, PTX may follow - Damage to vessels → venous distension → extravasation of blood into head/neck → purplish edema here +/- increase ICP due to venous return obstruction

Answer 159

- A, B, C, D, E, IV access, monitors, BW | - treat supportively and other comorbidities accordingly

Answer 160

Chest trauma → PTX or HTX or contusion etc gives increased secretion production with decreased clearance secondary to pain or airway obstruction or ineffective cough → atelectasis with risk of infection (syndrome called ‘wet lung’)

Answer 161

- A, B, C, D, E, IV access, monitors and BW - Frequent position change - Encourage airway clearance - Abx - Mech vent if needed - Cautious hydration

Answer 162

1. CW fractures – sternal and rib 2. Pulmonary pathology – traumatic PTX and hemothorax, tracheobronchial trauma, pulmonary compression injury, post-traumatic atelectasis, 3. Cardiac/great vessel injury 4. Esophageal injury 5. Diaphragmatic injury and thoracoabdominal injuries

Answer 163

rare – but suspect in any penetration or blunt trauma of chest/neck/upper abdo Myocardial contusion to vessel rupture o clinically contusion: arrhythmia, hypotension, severe cases – aneurysm with myocardial wall weakness o monitor w/serial EKG o Tx – supportive – tx dysrhythmia, defib, CPR – if persistent dysrhythmia do echo Perforation – blood loss varies from minimal to exsanguination with or w/o tamponade o Acute tamponade: distended neck veins, distant HS, low systolic BP with narrow pulse pressure and elevated venous pressure and pulsus paradoxus o Dx: echo o Tx – needle aspiration (sub-xyphoid approach), resuscitation

Answer 164

Rupture of thoracic aorta

Answer 165

See w/penetrating injury, forceful retching/blunt trauma, iatrogenic (instrumenting esophagus), ingestion of caustic agents, in delivery room from PPV, spontaneous has been described Clinically – fever, hypotension, chest and neck pain, pneumomed/PTX/SC emphysema and hematemesis Dx: X-ray, contrast esophagram - Tx: A, B, C, D,E as above, CT’s as needed, NPO, Abx, nutrition and operative repair (open and endoscopic options depend on location, severity, clinical practice at center etc)

Answer 166

Penetrating trauma or severe blunt trauma can cause rupture - L > R (90% on L) - ? secondary to strength on right, liver on right and weak points of embryonic fusion on left - Most small w/very non-specific presentation of cardio-resp Sx/Sx - CXR: abn diaphragm contour; contrast swallow to confirm stomach in thorax; CT helpful - Tx: Surgery (reduce organs into abdomen and closure of defect) and most do via abdomen to assess for intra-abdo injuries

Answer 167

Combined injuries seen in MVC, violent sudden/jolting impact - splenic/hepatic laceration common - Clinically: RUQ/LUQ pain/tenderness, rigid abdo, peritoneal signs with elevated lab values - Tx: A, B, C, D, E, IV access, BW, NG-tube drainage, Abx, hemorrhage or perforation in abdo → surgical exploration as soon as stable

Answer 168

“an episode that is frightening to the observer” and has ≥1 of following: (1) apnea, usually central (less commonly obstructive); (2) colour change, usually to blue or pale (less often to red and plethoric) (3) sudden limpness; (4) choking or gagging

Answer 169

Apnea of infancy (by definition idiopathic) is a type of ALTE because it frightens parents. Infants are beyond term postconceptional age when apnea is first noted. The components of an ALTE are usually present, except perhaps choking or gagging.

Answer 170

(1) It “may be warranted” in selected prems until “43 wks postmenstrual age,” or until “extreme episodes” of apnea, bradycardia, and hypoxemia resolve; (2) infants who are usually supported at home by mechanical ventilation through a tracheotomy should be monitored. AAP doesn't recommend monitoring for kids who have ALTE or who had siblings w/SIDS Monitoring doesn't prevent SIDS

Answer 171

``` Preterm birth <37 weeks Male sex African-American race Maternal parity more than 2 Late or no prenatal care Mother < 20 Smoking during pregnancy Never breastfed Upper respiratory infection Winter peak Age at death (89% >2 weeks but less than 23 weeks) ```

Answer 172

``` Side sleeping Soft bedding Not using a pacifier Bed sharing Being inexperienced sleeping prone Head covered during sleep Out of home child care ```

Answer 173

``` RSV, pertussis Sepsis with apnea Syndrome compromising the upper airway Breath-holding spells Seizures Intracranial hemorrhage Exaggerated laryngeal chemoreflex +/- GERD Drugs Tachyarrhythmias Inborn errors of metabolism Hypoventilation during bed sharing or because nose and mouth become covered with bedding ```

Answer 174

Duration of the event Time of day Adequacy of lighting Infant's position within his or her surroundings, and whether the episode began while awake or asleep. The infant's color, tone, and the need for and type of resuscitation must be noted. Was blood or pink froth coming from the infant's mouth or nose? Family history of seizures, sudden death, or serious illness with coma among young people must be ascertained. Was the infant in the early stages of a respiratory illness, or was he or she having coughing paroxysms?

Answer 175

muscle tone, alertness, bruising or scalp swelling or disuse of extremities, and fundoscopic evidence of retinal hemorrhages. Evidence of stridor, stertor, chest wall retractions, poor skin perfusion, and cardiac murmurs or dysrhythmias. Infants younger than 2 months of age should be considered at risk for bacteremic sepsis when they present with apnea or hypotonia and should be treated accordingly.

Answer 176

baseline: glucose, lytes, bicarb, hemoglobin and WBC,diff, cultures blood/urine; NP swab (RSV) and pertussis; CXR, blood gas (high bicarb may suggest resolved acidosis) If the infant continues to be limp or if apnea recurs, one should measure ABG, lactate, ammonia, as well as screening the urine for abnormal levels of amino and organic acids and drugs. Appears ill or w/ altered mental status w/o other cause, video-EEG & imaging CNS (MRI > CT)

Answer 177

laryngeal chemoreflex apnea (LCRA) Reflex apnea may be elicited during GER in susceptible infants, particularly when reflux reaches the pharynx, and this apnea may put these infants at risk for an ALTE if not sudden death. Reflexes (LCRA) elicited only if reflux passes the supraesophageal sphincter Milk, water, and non-acid secretions/reflux are capable of eliciting profound apnea/LCRA.

Answer 178

Infants attempt to clear fluid that elicits LCRA by laryngeal closure and swallowing during a central apnea. After the central apnea, any breaths attempted are obstructed so long as upper airway closure persists. When swallowing presumably clears the fluid, the upper airway is opened with a return to eupneic breathing. The LCR sequence in more mature infants and experimental animals does not involve prolonged apnea, and is as follows: cough, swallowing, arousal if asleep. The cough-swallow-arousal sequence is much less common when elicited during sleep in immature subjects. In infants, should swallowing be delayed or fail to occur, the apneic phase of the laryngeal chemoreflex can be prolonged, extending over 20 seconds and causing hypoxemia. Duration of the apneic phase of the LCR seems to be inversely proportional to postnatal age. These findings suggest that in immature subjects airway protection from aspiration takes precedence over ventilation in some circumstances when even small quantities of fluids (~0.1 mL) come in contact with the larynx

Answer 179

1. LCRA and nicotine: pre and postnatal cigarette smoke exposure significantly ↑s risk of sudden unexpected infant death 2. Acute infection with RSV has been associated with apnea, esp prone infants. Evidence of a recent RSV inf also markedly ↑the risk for SIDS among prone infants. - Thought is ↑ secretions in RSV trigger LCRA, & IL’s produced that ↑the LCRA duration.

Answer 180

Most apnea among prem infants is “idiopathic” - attributed to immaturity of ventilatory control Important episodes of apnea: - Cessation of airflow for 10-20 seconds or longer, OR - Shorter pauses assoc. w/decreases in Spo2% <90% or in HR<100 beats/m (if apnea<10 sec, we don't know what SpO2 decrease is worrisome).

Answer 181

- ICH - Sedation crossing the placenta - Sepsis +/- meningitis - Heat/cold stress - PDA - Hypoglycemia - Lyte abnormalities (esp. hyponatremia) - Anemia - NEC - Feeding-related apnea - Heart block or failure lowering cerebral perfusion - Excessive sedating meds

Answer 182

Mixed 1. Upper airway obstruction, for which the infant has shorter and weaker “load compensation,” is preceded by brief central apnea, or leads to longer central apnea. 2. Infants with a lower minute volume response to increasing CO2 become progressively more hypercarbic and hypoxemic. 3. The development of hypoxemia further blunts CO2 response, and the increasing CO2 makes the activities of the diaphragm and genioglossus asynchronous, perpetuating the cycle of obstructive and central (i.e. mixed apneas).

Answer 183

Yes - Swallowing interrupts LCRA. - Prem infants swallow more frequently during apnea than during eupneic breathing - Suggests exaggerated LCRA, possibly caused by pooling of saliva, may explain some apneic episodes. - LCRA = mixed apnea, similar to the most frequent type of AOP.

Answer 184

Excessive periodic breathing After onset of periodic breathing, transient upper airway obstruction at pharynx common during the first inspiratory effort after the apneic pause. Periodic breathing has both central & obstructive apneic components (i.e., mixed).

Answer 185

Apnea of prematurity does eventually resolve, later prems generally resolves by term, may last longer in earlier prems Late prems (33-37wks) can have ventilatory / autonomic instability, + incr risk of apneas/brady; are frequently admitted after PMA 40 wks for excessive apneas, periodic breathing or hypoxemia.

Answer 186

1st line: methylxanthine (caffeine), w/75% prems responsive. Caffeine recommended for premature infants 500-1250 grams, even before onset of apnea Not clear how caffeine given prophylactically might reduce the incidence of CLD. If failed caffeine → often respond to nasal CPAP or nasal intermittent PP ventilation. Enthusiasm for using high flow nasal cannula instead of CPAP or caffeine Prems at incr risk of serious apneas post-anesthesia, even at 46+ wks, esp if ventilation/CLD hx Monitoring prems at home: AAP says monitoring for prems who have apneas until 43 wks PMA.

Answer 187

"The sudden death of an infant <1 yr age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history.”

Answer 188

1. Infant @ risk 2. Exogenous factors 3. Vulnerable period (developmentally).

Answer 189

1. Baby’s face in the bedding/pillow while sleeping prone (asphyxia & brain hypoperfusion) 2. Failure of arousal 3. Hypoxic coma 4. Brady&gasping 5. Failure for autoresuscitation/death Death results from one or more failures in protective mechanisms against a life-threatening event during sleep in the vulnerable infant during a critical period

Answer 190

1. Infants at increased risk for SIDS have been shown to have abnormal arousal, hypoxic drive, and airway protective reflexes, among other physiologic aberrations. 2. Infants at greater statistical risk for SIDS compared with controls may have diminished arousal to breathing hypoxic and hypercarbic gases & longer obstructive apnea before arousal and resumption of eupneic breathing. 3. Infants at risk for SIDS may have blunted ventilatory responses. 4. The ventilatory responses of normal infants may be less when prone than when supine

Answer 191

Higher ambient temp (28 deg vs 24 deg) increases the arousal threshold to sound in infants about 3 m of age Arousal response to sound stimuli and air jets applied to the face, is decreased among sleep-deprived infants, prone-sleeping term & prem infants, & prone infants w obstructive apnea. Thermal stress: (exp animals) increasing core temperature prolongs LCRA; - Interactive effect of hyperthermia and cigarette smoking in further prolonging the apneic phase of the LCR.

Answer 192

When baby sleeps w/parent = ↑risk of death;, and esp if mom smoker! Sharing beds = increased risk of suffocation; thermal stress.

Answer 193

necrosis of bron- chial, bronchiolar, and alveolar tissue, atelectasis, intersti- tial inflammation, hemorrhagic pulmonary edema, vascular thromboses, necrotizing bronchopneumonia, and hyaline membrane formation

Answer 194

acute alveolitis that is most severe at 3 days, subsides at 10 days, and is fol- lowed by a chronic proliferative phase that may take weeks to resolve.9 Rats develop hyperemia and vascular engorge- ment of both large and small blood vessels within 1 hour of aspiration.10 At 24 hours, there is a focal bronchopneumo- nia with microabscess formation. By 2 weeks, the process largely resolves Pulmonary lesions are believed to be caused by direct aspiration into the airways

Answer 195

Low surface tension Low viscosity - allows it to spread more readily and deeper Low surface tension - allows it to spread throughout the TB tree High volatility - increases the likelihood of CNS involvement

Answer 196

Inhibit surfactant - predisposes to alveolar instability and atelectasis

Answer 197

- Cough may appear within 30 min or may be delayed for hours - normal or decreased breath sounds - severe injury - hemoptysis and pulmonary edema develop rapidly and resp failure can happen within 24 hours - can get features of chemical pneumonitis

Answer 198

Can vary from punctate, mottled densities to pneumonitis or atelectasis and tend to predominate in dependent areas Can also get air trapping, pneumoatoceles, pleural effusions Peak within 72 hours and usually clear within days

Answer 199

Hypoxemia without hypercapnia - V/Q mismatch or diffusion block Destruction of the epithelium of the airways together with bronchospasm adds to teh ventilation-perfusion abN and displacement of alveolar gas by the hydrocarbon vapours adds to the hypoxemia

Answer 200

Bronchopneumonia Atelectasis Salicylate overdose Other toxic inhalation

Answer 201

Important to avoid emetics of gastric lavage If no sx and normal CXR - observe for 6 hours Blood gas if abN exam or CXR noted Repeat CXR in 24 hours Oxygen if needed Maintain hydration but be careful of too much

Answer 202

petroleum solvents, dry-cleaning fluids, lighter fluids, kerosene, gasoline, and liquid polishes and waxes (mineral seal oil)

Answer 203

Medullary depression and respiratory paralysis

Answer 204

Displacement of alveolar gas by the inhaled substance

Answer 205

Thermal and chemical Thermal - primarily affects supraglottic airways Generation of noxious and irritant gases Production of high levels of CO and CO2 Soot particles can cause acute bronchospasm

Answer 206

Smoke inhalation - Most common Poorly functional home heating systems INadequate ventilation for fuel burning systems Motor vehicles idling

Answer 207

Results from the combination of CO with Hgb to form COHb leading to severely impaired tissues oxygenation CO displaces oxygen from Hgb reducing the delivery of O2 to the tissues and shifts the curve to the left **Although oxygen content of art blood is low, partial pressure of oxygen is not reduced - ventilation may not be stimulated until acidosis develops ***If suspicion of CO poisoning - NEED to do art gas along wth COHb levels CO also binds to myoglobin - anoxia of muscle cells

Answer 208

Higher altitude | Anemia

Answer 209

Tracheobronchitis (severity related to tidal volume of smoke) Acute pulmonary edema (causes by increased pulmonary vascular permeability) Atelectasis

Answer 210

Severe damage to upper airway = stridor and increase extrathoracic resistance (usually within 24 hours) Alveolar hypoventilation INflammatory changes in the ariways - V/Q mismatch Altered surfactant function Pulmonary edema Oxidants directly from the products of combustion also contribute to airway damage, closure and atelectasis

Answer 211

Focus on Hypoxemia May have facial burns, singed nasal hairs, carbonaceous sputum, soot in airway Blistering, edema of OP, hoarseness, stridor, mucosal lesions of upper A/W Give oxygen Resp failure can happen as the result of A/W obstruction - NEED To assess upper airway!

Answer 212

Focus on reversing CO poisoning CO levels may be reduced by half in about an hour when the patient breathes 100% oxygen. If alveolar hypoventilation, mechani- cal ventilation is necessary Controversy exists regarding the importance of, and need for, hyperbaric oxygen in the management of CO poisoning - The potential risks of the hyperbaric chamber include oxygen toxicity to the lung,

Answer 213

1) Severe burns of the nose, face, mouth (as high risk for nasopharyngeal edema and obstruction) 2) Edema of the vocal cords with laryngeal obstruction 3) Difficulty handling secretions 4) Progressive respiratory insufficiency 5) Altered mental status that decreases minute ventilation and diminishes the protective reflexes of he airway

Answer 214

Hypoventilation secondary to muscle weakness Chronic ILD Aspiration pneumonia Pulmonary HTN