Pulmonary Obstructive Flashcards
1
Q
Incidence of URI for adult per year? Children?
A
URI adult- 2 /year
Child - 8 /year
2
Q
Risk factors for URI with anesthesia?
A
- Patient
- paternal smoking/passive smoke exposure
- prematurity (<37 weeks)
- history of RAD and parental belief child is “sick”
- Surgery
- ENT sx
- eye sx
- upper abdominal
- cardiac sx
- Anesthetic managmenet
- invasiveness of airway device,
- anesthetic agnet (desflurane)
- provider experience
3
Q
Preop Asessment for URI?
A
- History: onset of symptoms – presence of other pulmonary comorbidities
- Physical Exam – Good upper airway exam & lung auscultation
- Laboratory – CBC if sinusitis or pneumonia is suspected
- Radiology – CXR is unnecessary in the majority of surgical patients
- Medications: continue inhaled beta agonists, anticholinergics, and steroids
4
Q
S/S of mild URTI? MOderate? severe?
A
Mild
- clear runny nose
- dry cough
Moderate
- green runny nose
- dry cough/mild moist cough
Severe
- green runny nose
- severe moist cough
- wheezing
- fever
- lethargy
5
Q
What are some factors that are in favour to proceed with case when patient has URTI?
A
- Team experience
- institutional setting
- previous cancellatins/logistics
- ENT surgery (infectiou soruce contorl)
- non-invasive airway magnamgent
- extedned monitoring possible
6
Q
What are some reasons to cancel case when patietn has URI?
A
- Parental concerns
- Age <1 yo, premature
- Repsiraotyr comorbidity (RSV infeciton, asthma, BPD, current wheeze, passive smoking)
- airway surgery
- endotracheal intubation required
7
Q
How long do you postpone a case if cancelled for URI?
A
2 weeks
8
Q
Premed periop managmeent with URI?
A
- Benzodiazepine – increased risk of preoperative risk for respiratory events
- stay away from benzos
- Alpha-2 antagonists – better suited if premedication is required
- Intranasal, intrabuccal, etc. takes 30-40 minutes for onset, may be too long to be useful
- Albuterol – recommended 10-30 minutes before induction
9
Q
Airway managment with URI?
A
- Lidocaine – topical lidocaine not recommended; IV administration preferred
- Experienced provider – less attempts at airway manipulation
- Regional > Facemask > LMA > ETT (cuffed > uncuffed)
- Safeness wth URI
10
Q
Anesthetic agent with URI?
A
- Induction: Propofol (blunt reflexes) > volatile
- Safest choice unless sick then use ketamine
- Maintenance: volatile (bronchodilator); sevoflurane > desflurane (airway irritant)
- Ventilation: lung protective strategies
11
Q
Emergence with URI?
A
- Higher incidence of respiratory events at emergence because it’s a longer wake up process
- Deep vs awake
12
Q
Postop care for pt with URI?
A
- Monitor for oxygen desat, bronchospasm, and cough
- where to go?
- ICU, admitted over night because born premature?
- have plan before going to OR
13
Q
Asthma characteristics? prevalence?
A
Characterized
-
Reversible expiratory airway obstruction
- Chronic inflammatory changes of airway
- Bronchoconstriction
- Airway hyperreactivity
Prevalence
- Up to 300 million people worldwide
- United States: 3 - 7% of population
- Varies by region
14
Q
Causes for development of asthma?
A
- Genetic
- Environmental
- Mechanical airway stimulation
- Drug induceda
15
Q
Pathophys behind asthma?
A
- Chronic inflammation of the mucosa of the lower airways (intrinsic factor)
- Activation of inflammatory cascade –
- Antigen binding to IgE immunoglobulins on mast cells
- Histamines, bradykinin, prostaglandin D2 & leukotrienes
- Infiltration of eosinophils, neutrophils, mast cells, & T & B cells
- Airway edema – especially the bronchi
- Thickening of the basement membrane
- Activation of inflammatory cascade –
- Overactivity of vagal afferents (extrinsic factor)
- Vagal afferents are sensitive to histamine, cold air, and instrumentation
Larger airways recover before smaller peripheral airways
TLC, RV, & FRC are all increased
Prolonged attacks can markedly increase the work of breathing – gets tired
16
Q
s/s asthma? severity?
A
S/S
- Episodic attacks of
- wheezing
- chest tightness
- dyspnea
- airflow obstruciton is partially reversible with bronchodilators
severity
- depends on diagnostic testing
- medication usage
17
Q
Various diagnostic tests used in asthma?
A
- Peak flow testing
- Pulmonary Function Testing
- Review YouTube videos
- ABG
- Chest X-ray
- CBC with differential
18
Q
Based on SABA use, what is the severity of asthma?
A
- Intermittent asthma <2 days/week
- Mild- >2 days/week but not daily, and not more than 1 x on any day
- moderate- daily use of SABA
- Severe- several times a day
Said we don’t need to memorize chart, but recognize the more someone uses a SABA, the less contorl over the asthma
19
Q
Steps for medication managmenet of asthma?
A
MORE ASTHMA DRUGS THEY ARE ON, MORE SEVERE ASTHMA.
Also look at how often they’re using rescue inhaler
- Step 1- SABA prn
- Step 2-
- Preferred- LOW dose ICS
- Alternatives- cromolyn, LTRA, theophyllin
- Step 3
- preferreed- Low dose ICS + LABA or medium dose ICS
- Alternative- low dose ICS, throphylline, zileuton
- Step 4
- Preferred- medium dose ICS and LABA
- Alternative- medium dose ICS + LTRA, theophyllin, zileuton
- Step 5
- Preferred- High dose ICS and LABA consider omalizumab for patients who have allergies
- Step 6
- Preferred- ICS+ LABA+ oral corticosteroid and consider omalizumab
20
Q
Exampls Beta 2 agonists? MOA beta 2 agonists?
A
Selective:
- Short Acting:
- Albuterol, levalbuterol, or metaproterenol
- Long Acting:
- formoterol & salmeterol
Non-selective:
- Epinephrine, ephedrine, & isoproterenol
MOA
- G-alpha-s which inhibits PKA–> inhibitrs MLCK activity–> bronchodilation
- K efflux from cell–> hyperpolarization–> bronchodilation
21
Q
Anticholinergic example? MOA? SE?
A
Examples
- Ipratropium bromide
- tiotropium
MOA
- NORAMLLY- Ach- mainly working M3
- PLC–> PIP2–> IPC–> increase Ca–> Ca/calmodulin binding and myosin light chain contraction
- Drug-blocks M3
- decrease all the above and get bronchodilation
22
Q
Glucocorticoid use in asthma?
A
- Drug that takes a long tiem to work
- has to diffuse through cell membrane, bind to cytoplasm GR receptor (with immunophli and HSP90?)
- then diffuses through nucleus to have effects on DNA synthesis
- inhibits COX2 transcription and inflammatory cytokines
- work via annexin A1 to inhibit cox 2 and leukotriene
23
Q
How do ICS decrease inflammation?
A
24
Q
Leukotriene pathway inhibitos examples and MOA?
A
- Prevents leukotriene pathway from arachidonic acid
- monetelukast stops develpment LTD4, LTE4 which are mediators that cause bronchoconstriction
25
WHat is omalizumab?
* Binds to circulating IgE, decreasing cell bound Ige
* Decrease expression of high affinity receptors
* Decrease tissue infiltration, decrease mediator release
26
What are degranulation inhibitors?
Cromolyn sodium (rarely used)
* needs to be givne prior to exposure
MOA
* Opens chloride channels
* alters Ca channels
* decreases the release of inflammatory mediators
27
What are methylxanthines? example, se, moa?
* Examples
* theophylline
* rarely used today
* narrow therapetuic window and multipel s/e
* S/E
* nervousness/tremors
* chornotropic/inotropic
* weak diuretic
* increases gastric acid and digestive enzymes
* MOA
* Binds to adenosine receptor and inhbiits Ca influx
* PDE receptor--\> allows amp to build up--\> smooth muscle relxation
28
Asthma considerations for preop assessment?
* Hopefully at least 1-2 weeks prior to scheduled surgery for optimization
* Encourage to stop smoking… optimize before sx
* Severe bronchospasm involving anesthesia: 0.2 – 4.2%
* *biggest chance bronchospams- on emergence*
* Risk factors
* Type of surgery – thoracic, upper abdominal, & oncologic surgery
* Proximity of the most recent asthma attack
* Asthmatic should not be wheezing at time of surgery
29
Things to consider while taking preop hx on asthmatics?
* Baseline breathing?
* *have to take break whle talking, etc*
* Exercise tolerance?
* Type & severity of cough?
* *coughing at night?*
* Quality and quantity of sputum production?
* History of recent URI?
* Latest exacerbation?
* Triggering factors?
* Any recent medication changes?
* Baseline PFT’s?
* Last time to ED? Admitted? ICU admission?
* Last time received systemic steroids?
* *need stress dose if given steroids in past 6 months*
30
What to focus on for physical exam for asthmatics
Focus on respiratory system
* Rate, rhythm, depth, and effort of breathing
* Color
* Listen to breath sounds
* Inspect for inspiratory retractions
31
Preop testing for asthmatics?
* **Patients with well controlled asthma that is NOT steroid depended do not need additional testing beyond that performed for patients without asthma.**
* **NOT predictive of POSTOPERATIVE OUTCOMES**
* Moderate or severe uncontrolled asthma or undergoing lung resection (*patients requiring 2/3 durgs or mutiple use of recue inhalers) get these:*
* Pulse ox
* Pulmonary function testing
* ABG
* CMP
* CXR
* ECG
32
Goals for preop PFT and indicators for pulmonary complications?
* Goal
* Free of wheezing
* PEFR \> 80% personal best
* Indicators for pulmonary complications (remainder bolded red on ppt)
* **Peak flow:**
* **\< 80% of patients personal best**
* **Spirometry:**
* **FEV1(how much can you force out in first second after full inhale) or FVC(FVC= how much can you exahle aftera full inhale\_**
* **\< 70% of predicted**
* **FEV1/FVC ratio**
* **\< 65% of predicted**
33
Lab testing needed for asthmatics?
* CMP/CBC – Maybe required
* B2 agonists may result in hypokalemia, hyperglycemia, & hypomagnesemia
* Eosinophilia
* Parallels inflammation and airway hyperreactivity
* ABG – not routinely indicated, but maybe necessary in severe cases
* Preop PaCO2 \> 45 mmHg is highly suggestive of potential postoperative complications
* **Acute (initially): hypocarbia and respiratory alkalosis**
* **Fatigued: Hypercarbia and respiratory acidosis**
* CXR – Not routinely indicated
* Abnormal is independent predictor of respiratory complication
* Pulmonary hyperinflation and bronchial wall thickening
* ECG – Follow ACC/AHA Guidelines
34
How to manage astma medications perioperatively?
* Asthma medications:
* Continue up to day of surgery except theophylline (stop evening prior; arrhythmias)
* Steroids
* Inhaled
* Replacement not usually required
* May have subclinical HPA axis suppression
* Low dose
* 5 mg PO QAM/QOD
* Replacement not typically required
* High dose
* \> 20 mg QD \> 5 days in the past 6 months (*it takes a long time for HPA xis to repair itself after systemic steroids)*
* **Replacement is required**
* Hydrocortisone 100 mg Q 8 HRS
35
Premedication for asthma pt on way to OR?
* Anxiety can precipitate a bronchospasm
* B2 agonists
* Administer via MDI or nebulizer 20 – 30 minutes prior airway manipulation
* **A2 agonists**
* **Good for sedation, anxiolysis, sympatholytic, and drying of secretions**
* **Benzodiazepines**
* **Use judiciously**
* Anticholinergics
* Dries secretions and decreases airway vagal response
* *Dried secretion can make it harder for pt to cough up secretions*
* _Consideration for increased HR_
36
Choice of anesthetic technique for asthma patients?
* Mask vs LMA vs ETT
* Regional
* Attractive choice when possible
* Brachial plexus block
* Blocking of the phrenic nerve may not be tolerated in patients with severe compromise
* Neuraxial
* Midthoracic or higher may lead to paralysis of accessory muscles of breathing
* Moderate to severe asthmatics may rely on active exhalation for adequate gas exchange
* High levels may provoke anxiety
* *subjective feeling that they're not breathing well, promotes anxiety, may need to then give benzo, and now have resp. depression*
37
What is the goal of anesthesia in patient with asthma?
* Goal – **achieve a depth of anesthesia to -**
* Depress airway reflexes
* Avoid hyperactivity
* Avoid histamine release
* Stimuli that do not ordinarily evoke airway response can precipitate life threatening bronchoconstriction in patients with asthma.
38
Propofol and asthma?
* for hemodynamically stable patient
* Relaxes airway smooth muscles
* Blocks airway reflexes
* Check preservative
* Metabisulfite: may cause bronchoconstriction in asthmatics (hypothetical vs clinical?)
* Ethylenediaminetetraacetic acid (EDTA)
* Newer data….*shows that pt with generic propofol are having higher incidence of bronchospasm*
39
Ketamine in asthmatics?
* for hemodynamically unstable patients
* Ventilatory drive is minimally affected by induction doses
* Racemic ketamine is a potent bronchodilator
* Decreases intracellular Ca+ and induces release of endogenous catecholamines
* Stimulates secretions
* **Good induction agent for asthmatics**
40
Thiopental and methohexital use in asthmatics?
* Thiopental
* Histamine release from skin mast cells has been noted – but not from tracheal mast cells
* Does not increase airway tone, but does not adequately block reflex bronchoconstriction
* Higher level of bronchospasm in both normal patients and asthmatics
* **Methohexital**
* **Does not release histamine (*green on ppt, good to use vs thiopental)***
41
Etomidate use in asthmatics?
* Ventilation is affected less than with barbiturates and propofol
* Apnea does not always result
* Adequate depth of anesthesia is required
42
Use of lidocaine in asthmatics?
* IV (*green on ppt)*
* **Reduces airway responsiveness to noxious stimuli**
* **1 - 1.5 mg/kg**
* LTA
* Is irritating and may cause bronchoconstriction
* Inhaled/nebulized \<-- *red on ppt*
* Produces significant bronchospasm in asthmatics
* Maybe due to reflex local to aerosolized particles
stick to IV in asthmatics...
43
Opioid use in asthmatics?
* Reduce airway reactivity
* Inhibit cholinergic neurotransmission in airways
* Inhibit tachykinin release from sensory nerves
* Synthetic opioids have been safely used in asthmatic patients
* **_Avoids opioids that release histamine_**
* **_Morphine, codeine, & meperidine_**
44
WHat NMB are safe to use? avoid?
* Avoid neuromuscular blocking drugs that release histamine
* Curare, mivacurium, & atracurium
* Safe to use
* Vecuronium, rocuronium, & cisatracurium
45
Succinylcholine use in asthmatics?
* Two acetylcholine molecules linked by an acetyl group
* Can potentially occupy muscarinic receptors
* Increases tracheal smooth muscle tone secondary to parasympathetic stimulation
* In multiple different animal models (isolated tracheas)
* **Has been safely used in asthmatics**
* Few case reports of succinylcholine induced bronchospasm
46
Use of volatiles in asthmatics?
* All are potent bronchodilators
* May Attenuate bronchospasms
* Decrease airway responsiveness
* Reduces resting smooth muscle tone
* Decreases AcH release
* Decreases intracellular Ca++ release
* Depresses afferent pathway to CNS
* Have been used successfully to treat status asthmaticus
* *needs high concentrations VA to do this. may cause BP to decrease*
* High concentrations of volatile anesthetics are often required
* \> 1.5 MAC
*
47
Which VA are safe to use in asthmatics? Caution use of?
* Sevoflurane (halothane)
* Pronounced bronchodilator properties
* Desflurane/isoflurane
* Pungency may increase secretions, coughing, laryngospasm & bronchospasm
* **ESPECIALLY DURING INDUCTION & EMERGENCE**
* Desflurane may increase airway resistance in current smokers
* Nitrous
* Not an airway irritant
* Not a bronchodilator
* Has safely been used in asthmatics who do not require 100% O2
48
Ventilator strategies that are helpful in asthma?
* Designed to prevent air trapping
* Prevent excessive peak airway pressures (\< 40 cm H20)
* Limit plateau pressure \< 30 cm H20
* Pressure controlled ventilation vs. volume controlled ventilation
* Need prolonged expiratory time
* Reduce I:E ratio (1:3)
* Reduce minute ventilation
* Rate : 8 -10
* TV: 6 -8 ml/kg predicted body weight
* PEEP
* Titrate as needed up to 5-8 cm H20
* May actually worsen air trapping
* Recruitment maneuvers
* Every 30 minutes or so
49
What does ETCO2 look like in obstructive processes?
"shark fin"
50
Signs of intraoperative bronchospasm?
* Decreased TV
* Increased positive inspriatory pressur
* decreased pulmonary compliance- *compliance is change volume over change pressure*
* decreased oxygen sat
51
Wheezing differential diagnosis?
* Anesthesia machine/circuit problems
* Foreign body
* Mechanical obstruction- *sampling line bent*
* Light anesthesia
* Aspiration
* Endobronchial intubation
* Pneumothorax
* Pulmonary embolus
* Pulmonary edema
* Acute exacerbation of asthma
* Anaphylaxis
52
How do we manage acute asthma bronchospasm intraop?
* Increase Fi02 to 100%
* Change to hand ventilation
* Assess compliance
* Will the anesthesia bag fill on exhalation?
* Cycle blood pressure
* High – light anesthesia?
* Low – anaphylaxis?
* Auscultate the lungs
* Bilateral vs. unilateral sounds
* Relieve mechanical stimulation
* Suction catheter
* Determine if there is an obstruction, kinking of tube, check depth of ET tube, look at cuff inflation pressure
53
Treatemnt of mild bronchospasm?
* Increase anesthetic depth- *increase respriatory rate, flows after turning up anesthetic*
* Volatile
* Propofol vs. ketamine
* Lidocaine
* Administer Beta agonist
* Albuterol – 8 to 10 puffs
* ET tube
* In-line spacer - *sometimes difficult to find in OR*
* *sometimes just take circuit off, give albuterol in circuit and then reattach*
* *give 4-5 breaths after administer and squeeze bag soft*
* *need to give adequate time to exhale!*
* *can also give narcotic*
54
Treatment of severe bronchospasm?
* Steroids\< *remember these take long to work!!*
* Glucocorticoids (hydrocortisone 100 mg or methylprednisolone 60 – 80 mg iv)
* **Anticholinergics**
* Ipratropim vs glycopyrrolate
* **Anti-histamines**
* H1 (Benadryl) and H2 (Pepcid/zantac/cimetidine)
* Magnesium
* 2 mg IV over 20 min
* Terbutaline
* 0.3 mg SQ
* Aminophylline
* Loading and infusion (rare in OR)
* Epinephrine \<*last ditch resort concentration 1:1000*
* 5 – 10 mcg IV bolus
* 2- 10 mcg/min infusion
* *1:1000 in 100 cc bag makes 1:10*
* *(each cc is 10 mcg)*
* Nitroglycerine\<*-- not high on list*
* Smooth muscle relaxant
* Heliox
* Not very useful – max Fi02 20 – 30 %
* Extracorporeal membrane oxygenation
* Most severe – and refractory to treatment
If patient keeps bronchospasming when trying to wake up to extubate, realize you might need to keep pt intubated and transfer to ICU intead of trying to extubate
55
Reversal agent use in asthma?
* Anticholinesterase/anticholinergic
* **Safe to use when co-administered**
* No significant changes in specific airway resistance
* Suggammadex
* No increase in AcH release
* No affect on isolated smooth muscle tone
* **_Has safely been used in asthmatics_**
* **_In patients with pulmonary disease – 2.6% incidence of bronchospasm_**
* **_Several case reports of bronchospasm have been reported_**
* **_Use cautiously_**
56
Improving emergence in asthmatic patients?
* Smooth and controlled
* Head up
* B2 agonist
* Lidocaine
* Judicious use of opioids
* Dexmedetomidine infusion
* Most should be extubated awake using stringent extubation criteria
* Use of anti-emetics, gastric motility agents, antacids, or OG/NG tube
* Deep extubation- *good for pt in asthma but if patient difficult to intubate, large fluid volume shifts during sx, may not be great candidate for deep extubation*
* PACU vs ICU- *bronchospasm, asthma attack may not be able to go home*
57
Deep extubation in asthmatics?
* No contraindication to mask anesthesia
* Administer B2 agonists and lidocaine
* Get spontaneously breathing
* Deepen the anesthetic
* Suction- *this allows you to assess if pt is deep enough*
* Remove ETT- *on exhalation*
* Place on facemask
* **Can still bronchospasm**
* **May be unable to manage secretions or aspirates**
58
Postop mgmt of patient with asthma
* Prevention of postoperative pulmonary complication
* Adequate pain control
* Regional
* Avoid ASA and NSAIDS
* Why?-*pushes AA into leukotriene pathway*
* Bronchodilator therapy
* Incentive spirometry
* Deep breathing maneuvers
* Early mobilization
59
Asthmatic patient in trauma, OB?
Trauma
* Securing airway take precedence
* However, still maybe time to conduct basic H/P and administer B2 agonist
* May need to rule out tension pneumothorax, pulmonary hemorrhage, etc..
* *Ketamine is great chocie*
Obstetric
* Epidural/spinal preferred
* General anesthesia for emergent section
* Continue medications throughout admission
* Give B2 agonist prior to induction
* Ensure adequate depth of anesthesia
* _**Hemabate is contraindicated- *cause bronchoconstriction and cause asthma attack***_
60
COPD characteristics and prevalence?
Characteristics
* Important risk factors for postoperative pulmonary complication
* Disease of progressive loss of alveolar tissue and progressive airflow obstruction that is not reversible
Prevalence
* 210 million worldwide
* 3rd leading cause of death by 2030
* Smokers – 14%
* Former smokers – 7%
* Male \> female
* 70% have at least one other comorbid condition
61
Risk factors COPD?
* Smoking
* \>60 pack years
* Double risk of post op pulmonary complications
* Triple risk for pneumonia
* Occupational exposure
* Pollution
* Recurrent respiratory infection
* Low birth weight
* A1 antitrypsin deficiency
62
Pathophys COPD?
* Deterioration of elastic recoil
* Decreased bronchiolar wall rigidity – alveolar collapse on expiration
* Increase in gas flow velocity – narrowed bronchi
* Active bronchospasm
* Globlet cell hypertrophy- *Increased mucus*
* Increased pulmonary secretions
* Enlargement of air sac
63
S/S COPD?
* Dyspnea on exertion – some even at rest
* Chronic cough
* Chronic sputum production
* Expiratory airflow obstruction
* Tachypnea
* Prolonged expiratory times
64
What is the GOLD criteria?
* Definition of COPD: A preventable and treatable disease characterized by progressive pulmonary airflow limitations, not fully reversible and abnormal inflammatory response to noxious gases or particles
* Chronic bronchitis – persistent productive cough for 3 months / year for 2 consecutive years
65
S/S associated with emphysema?
**PINK PUFFERS**
**PaO2 \>60; PaCO2- WNL**
* Thin
* Anxious, purse lips
* Accessory muscles
* Dyspnea
* Scant secretions
* Markedly diminished breath sounds
* Right side heart compromise
* CXR: Hyperinflation & flattened diaphragm
66
S/S associated with bronchitis?
**BLUE BLOATERS**
**PaO2 \<60; PaCO2 \>45**
* Overweight
* Cyanosis
* Cough
* Copious secretions
* Diminished breath sounds
* R-sided heart failure
* CXR: increased bronchovescular markings
* \< 5% of patients
67
Diagnosis of COPD?
* Classification and severity based on PFT results
* Decrease in FEV1/FVC ratio
* Decreased FEF 25-75%
* Increased RV
* Normal to increased FRC and TLC
68
Treatment COPD?
* Smoking cessation – decreases mortality by 18%
* Vaccinations
* Bronchodilator therapy
* **B2 and anticholinergic**
* Inhaled corticosteroids
* Oxygen treatment
* For patients with chronic hypoxia (PaO2 \< 55 mmHg or HCT \> 55%)
* Diuretics
* Control peripheral edema in patients with cor pulmonale
* Pulmonary rehabilitation
* Lung volume reduction surgery
* Lung transplants
69
How can we decrease postop pulm complications preop, intraop and postop iwht COPD?
Preop
* Stop smoking for at least 6 weeks
* Treat respiratory infections
* Education on incentive spirometry
Intraop
* Minimally invasive surgery
* Consider regional
* Avoid surgical procedures likely to last \> 3 hours
Post op
* Volume expansion maneuvers (deep breathing, IS, CPAP)
* Maximizing anesthesia (neuraxial, regional, opioid sparing)
70
What should you note in the physical assessment of pt with COPD?
* Same as with asthma – primarily respiratory
* Exercise tolerance
* Home oxygen use
* Use of NIPPV
* Nutritional status: serum albumin \< 3.5 mg/dL
* *so short of breath that they can't eat*
* However, in contrast to asthma, limited improvement in respiratory function is seen after short periods of intensive preoperative preparation.
* **Smoking cessation for as little as 24 hours can increase oxygen carrying capacity**
* May see some data suggesting that smoking cessation should occur 6-8 weeks before the operation to decrease secretions and reduce pulmonary complications
* *some data shows airway becomes hyperreactive, but shown to be false*
* *stopping smoking is always best option*
71
Preop testing needed in COPD?
* Pulse oximetry
* Baseline values
* Use of oxygen
* Pulmonary function tests
* Not warranted for most surgical procedures
* Intrathoracic – lung resection maybe beneficial
* Pg. 25 for inclusive list
* ABG
* If FEV1 \< 50% of predicted
* Maybe useful for intraoperative/postoperative management
* Need for oxygen therapy
Laboratory
* Standard labs: CMP, CBC, coagulation, albumin levels, etc
* CT Scan
* Better than x-ray, but not commonly used
* Chest X-ray
* No routinely indicated since results rarely impact anesthesia care
* Maybe normal even in the presence of sever disease
* **Maybe useful in:**
* **Patients with _new or worsening respiratory symptoms_, _decreasing exercise tolerance, or new lung auscultation finding_**
* **Patients undergoing thoracic or major abdominal surgery**
72
What to include in preop education of the COPD patient?
Counsel patient regarding potential postoperative complications
* Atelectasis
* Hypercapnia
* Hypoxemia
* Retention of secretions
* Bronchospasm
* **Education on splinting and incentive spirometry before surgery**
* **Potential need for post operative ICU ventilation**
73
Choice of anesthetic in COPD?
* Mask vs LMA vs ETT
* Regional
* Preferred over GA – lower risk of pulmonary complications
* **Interscalene block – ipsilateral phrenic nerve palsy – avoid with severe COPD**
* Up to 25% reduction in pulmonary function
* Avoid large doses of sedative and anxiolytic drugs
* **May be difficult in patients who cannot lie flat**
* Neuraxial
* **CSE has been used for major upper abdominal surgery**
* Limit techniques above T6
* May impair active exhalation – active cough
* Excellent adjunctive technique for pain control
* Especially in thoracic or upper abdominal surgeries
74
MAC anesthesia in COPD?
* Monitoring
* Standard
* Oxygen
* Maintain as close as possible to preop values – (88-92%)
* Medications
* Versed/fentanyl – particularly sensitive to the respiratory depressant effects
* Ketamine - good choice
* Dexmedetomidine – good choice –
* Propofol – profound respiratory depressant – reduce doing in COPD patients
75
Goals of induction of aneshtesia in COPD?
Goals
* Avoid hypoxemia/hypercarbia
* Avoid bronchospasm
* Avoid long acting agents
* Extubate as soon as possible
* Avoid bronchospasm
* Bronchospasm may lead to hemodynamic collapse R/T increase intrathoracic pressure
* Minimize respiration complications
* **_Preoxygenation prior to induction is extremely important_**
* **_Patients often rapidly desaturation following induction_**
* **_Some use CPAP/BiPAP right up to induction_**
76
Which induction agents are good to use/avoid during induction of patient with COPD?
* Propofol
* Attenuates bronchospastic response
* Relative short half life
* Ketamine
* Beneficial sympathomimetic bronchodilator properties
* Profound analgesic properties
* May be undesirable in patients with ischemic heart disease
* Thiopental
* Avoid – may increase airway resistance
* Etomidate
* Caution in patients with COPD – R/T adrenal gland dysfunction
77
Use of lidocaine and opioids in patient with COPD?
* Lidocaine
* Suppresses airway reflexes
* Opioids
* Typically small doses are given (50 – 100 mcg)
* A dose of 5 mcg/kg may be required to completely blunt reflexes
* Avoid histamine releasing agents
* *Recognize you may need high dose opioid in order to blunt reflexes and this might cause hypoventilation*
78
NMB use in COPD pt?
RSI vs standard?
* Neuromuscular blocking agents
* Same as with asthma
* RSI vs Standard
* Individualized to patient and case
79
Inhalational agents in pt with COPD?
ALL Inhibit hypoxic pulmonary constriction – increase shunting
* Sevoflurane
* Preferred – bronchodilator properties
* Desflurane
* Controversial
* Rapid on/off makes desirable
* Extreme pungency and direct irritation of airway make it less desirable
* Isoflurane
* Good bronchodilator but pungent and not ideal for induction
* Nitrous
* Quick on/quick off –typically avoided though
* Increase size of bulla
* Limits FiO2
80
Opioid and pain control in pt with COPD?
Opioids/Pain Control
* Administered in low doses
* Balance cough suppression and respiratory depression
* Short acting synthetic opioids preferred
* Fentanyl, alfentanil, and remifentanil
* Intrathecal administration of low dose opioids
* ERAS
* Ketamine, dexmedetomidine, Tylenol, etc to limit opioid use
81
Intraop management of COPD patient?
* Low threshold for a-line placement
* **Hemodynamic support with inotropes may be required for adequate anesthesia**
* Differential diagnosis must include:
* Air trapping (dynamic hyperinflation)
* Increase intrathoracic pressure diminishing preload and displace heart
* Tension pneumothorax
* Bronchopleural fistula
82
Ventilation strategies in COPD patient?
Lung protective
* Minute Ventilation
* Rate: 6 – 10 BPM
* Volume: 5 – 8 ml/kg of body weight
* I:E Ratio - 1:3-5
* **What is baseline PaCO2?**
* **Normal values may lead to metabolic alkalosis**
* Peak inspiratory pressure
* \< 30 cm H20
* Peak plateau pressure
* \< 15 – 20 cm H2O
* Adjust FiO2
* Lowest level to maintain SaO2 \> 88 -90%
* PEEP
* Cautious use of PEEP (5-10 cmH2O)
* Benefits are unpredictable
83
Emergence of patient with COPD?
* Early extubation is beneficial
* **Patients with FEV1 \< 50% may require postoperative ventilation**
* Especially following upper abdominal and thoracic procedures
* Early application of BiPap/CPAP has also shown to be beneficial
* Balance risk of bronchospasm with that of respiratory failure
* Ensure
* Adequate pain control
* Reversal of neuromuscular blocking
* Absence of significant bronchospasm- *Pretreat lidocaine/albuterol*
* Secretions cleared
* Absence of significant respiratory depression
* Normal thermic
