Pulmonary Obstructive Flashcards
Incidence of URI for adult per year? Children?
URI adult- 2 /year
Child - 8 /year
Risk factors for URI with anesthesia?
- 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
Preop Asessment for URI?
- 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
S/S of mild URTI? MOderate? severe?
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
What are some factors that are in favour to proceed with case when patient has URTI?
- Team experience
- institutional setting
- previous cancellatins/logistics
- ENT surgery (infectiou soruce contorl)
- non-invasive airway magnamgent
- extedned monitoring possible
What are some reasons to cancel case when patietn has URI?
- Parental concerns
- Age <1 yo, premature
- Repsiraotyr comorbidity (RSV infeciton, asthma, BPD, current wheeze, passive smoking)
- airway surgery
- endotracheal intubation required
How long do you postpone a case if cancelled for URI?
2 weeks
Premed periop managmeent with URI?
- 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
Airway managment with URI?
- Lidocaine – topical lidocaine not recommended; IV administration preferred
- Experienced provider – less attempts at airway manipulation
- Regional > Facemask > LMA > ETT (cuffed > uncuffed)
- Safeness wth URI
Anesthetic agent with URI?
- Induction: Propofol (blunt reflexes) > volatile
- Safest choice unless sick then use ketamine
- Maintenance: volatile (bronchodilator); sevoflurane > desflurane (airway irritant)
- Ventilation: lung protective strategies
Emergence with URI?
- Higher incidence of respiratory events at emergence because it’s a longer wake up process
- Deep vs awake
Postop care for pt with URI?
- Monitor for oxygen desat, bronchospasm, and cough
- where to go?
- ICU, admitted over night because born premature?
- have plan before going to OR
Asthma characteristics? prevalence?
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
Causes for development of asthma?
- Genetic
- Environmental
- Mechanical airway stimulation
- Drug induceda
Pathophys behind asthma?
- 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
s/s asthma? severity?
S/S
- Episodic attacks of
- wheezing
- chest tightness
- dyspnea
- airflow obstruciton is partially reversible with bronchodilators
severity
- depends on diagnostic testing
- medication usage
Various diagnostic tests used in asthma?
- Peak flow testing
- Pulmonary Function Testing
- Review YouTube videos
- ABG
- Chest X-ray
- CBC with differential
Based on SABA use, what is the severity of asthma?
- 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
Steps for medication managmenet of asthma?
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
Exampls Beta 2 agonists? MOA beta 2 agonists?
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
Anticholinergic example? MOA? SE?
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
Glucocorticoid use in asthma?
- 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
How do ICS decrease inflammation?
Leukotriene pathway inhibitos examples and MOA?
- Prevents leukotriene pathway from arachidonic acid
- monetelukast stops develpment LTD4, LTE4 which are mediators that cause bronchoconstriction
WHat is omalizumab?
- Binds to circulating IgE, decreasing cell bound Ige
- Decrease expression of high affinity receptors
- Decrease tissue infiltration, decrease mediator release
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
What are methylxanthines? example, se, moa?
- Examples
- theophylline
- rarely used today
- narrow therapetuic window and multipel s/e
- theophylline
- 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
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
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
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
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
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
-
FEV1(how much can you force out in first second after full inhale) or FVC(FVC= how much can you exahle aftera full inhale_
-
Peak flow:
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
- Abnormal is independent predictor of respiratory complication
- ECG – Follow ACC/AHA Guidelines