Peri-intubation collapse - ACEM Fellowship Notes

#anaesthetics #tables #cram see also: [[Obesity resus considerations]], [[Tracheostomy|CICO]], [[Awake fiberoptic intubation]], [[Airway]], [[Ventilator strategies|Ventilator strategies table]], [[Aortic stenosis|AS intubation]], [[Cardiac arrest]] [Ventilation_in_special_circumstances](x-devonthink-item://73C66D50-5D35-4744-BE63-5E36BA71F4F8) Precipitous deterioration can occur around the time of intubation in several specific situations. # Special intubation considerations ## aortic stenosis see: [[Aortic stenosis#intubation and RSI with aortic stenosis]] ![[Valvular disorders#Aortic stenosis]] ## metabolic acidosis - Patients typically have respiratory compensation ++, need to match their minute volume peri-intubation or acidosis precipitously worsens → poor myocardial contractility, diminished catechol responsiveness - pre-oxygenate with their spontaneous resps (or NIV-assisted at matched RR), note ETCO2 (and try not to let it climb), RSI but with breaths delivered throughout induction phase (no apnoea), rapid intubation, match previous minute volume Intubation aims: - minimise aponea - maintain high MV to avoid worsening acidosis **strategies:** - pre-oxygenate with BM 15L O2 and PEEP 10 aim SpO2 >96% - position patient upright until induction to maximse tidal volumes - +/- 100 mmol HCO3= prior to induciton - prepare for patient ot arrest -- defib pads on and adrenaline drawn - Induce 0.5-1mg/kg ketamine and 1.2mg/kg roc - 2 hand BVM throughout apoenic period - VL + bougie ETT skilled airway operator - confirm placement - hyperventilate post insertion at rate matching pre-intubation rate without [[Ventilator strategies#Dynamic hyperinflation and auto-PEEP|breath stacking]] ## severe asthma See: [[Asthma#Cardiac arrest in asthma]] - Often ill for quite a while prior to arrival with decreased oral intake so under-volume to begin with - Typically have maximal endogenous sympathetic outflow – this decreases with induction → relative vasodilation - Positive pressure ventilation with inadequate expiratory time → raised intrathoracic pressure, decreased VR etc - Consider pneumothorax >**strategies** >- adequate sedation and muscle relaxation >- ↓ resp rate, titrated to low pH, tolerate ↑ CO2 ~ 6 breaths/min >- I:E ratio 1:5 >- minimise TV to avoid over-distension >- inspiritory flow rate 100L/in aim PAP <40. low PEEP ## acute pulmonary oedema issues: - hypotension (eg from ↓ LV function, nitrates, reduced venous return from IPPV, valvular disease, induction agents treatments: - cease vasodilators - maximise oxygenation - fmall fluid challenge with colloid - inotropic agents if needed ## Right heart failure / pulmonary hypertension see: [Airway management and perioperative decision making in the patient with severe pulmonary hypertension who requires emergency noncardiac surgery. 2012](bookends://sonnysoftware.com/ref/DL/164860) ![[Right heart failure#haemodynamic management for severe right heart failure]] ## intubation for neurocritical eg SAH, stroke, ICH | consideration | management | | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Goals | - avoid spikes in ICH - maintain SBP 110-140 | | prepare | - target BP control prior 110-140 - +/- [[labetalol]] 10-20mg to help with this - +/- need for hypertonic saline 100mL bolus - push-dose vasopressor for perintubation hypotension | | position | - head up 30 deg | | pre-oxygenation | - avoid hypoxia, HFNC apoenic oxygenation | | drugs | - 3-5mcg/kg fentanyl 2-3 min prior to attenuate sympathetic response to laryngoscopy - + low dose ketamine or propofol | | intubation | - gentile with VL | | post-intubation care | - lung protective settings RR 16 TV 6-8, sats >95% - EtCO2 target 35-40 - use minimum PEEP required | ## pregnancy intubation see: [[Pregnant trauma#Pregnancy effect on resus]], [[Cardiac arrest#pregnancy|pregnant ALS considerations]] | consideration | management | | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Issues | - airway: airway oedema, friable, increased obstruction, poor view and anterior, high aspiration risk from gravid uterus and lower oesophageal sphincter tone - breathing: rapid deasutration 2/2 ↓ FRC and O2 demand, difficulty with breasts, needs high O2 - circulation: aortocaval compression → prone to hypotension | | prepare | - IV access - fluid bolus - smaller tube with laryngeal oedema: 6-6.5 | | position | - ramp and sit up as much as possible for lung ventilation and prevent aspiration - tape breasts down - manually displace uterus to left or place wedge on right | | pre-oxygenation | - NRB 15: + HFNC apoenic oxygenation - avoid BVM unless critical hypoxia | | drugs | - N | | intubation | - short handle - VL and bougie +/- d-blade - smaller tube 6 or 6.5 | | post-intubation | - O2 >95% - avoid permissive hypercarbia - se R to match pre-intubation minute ventilation | ## paediatric intubation see also: [[Tracheostomy#CICO age <10]], [[APLS]], [[paediatric airway management]] ETT size: (age/4) + 4 (uncuffed) + 3.5 (cuffed) Length: (age/2) + 12 | consideration | management | | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Issues | | | anatomy | - infants: large head, often neck in flexion when flat → consider towel under shoulder to achieve tragus to sternal notch position up to 1 y old *Airway*: - large tongue - high anterior position - floppy, large u-shaped epiglottis - cricoid ring is narrowest part, tubes may pass cords but not subglottic *Resp:* - small airway diameter → high resistance to flow and increased risk of obstruction - loss of bucket handle movement → reliant on diaphragm for respiration - stomach distension → splinting of diaphragm - short trachea → tube easily displaced - difficult to perform surgical airway: would need needle until age 10 *physiology:* - high metabolic rate and low O2 storage capacity → de-saturate quickly - high surface area/body weight → lose weight - risk of hypoglycaemia | | prepare | - IV access or IO - +/- NGT prior | | position | - aim for tragus to sternal notch, may need pillow under shoulder - avoid pressing of soft tissue of mandible | | equipment | - appropriated sized paeds BCM | | pre-oxygenation | - 15l NRB and HFNC apoenic oxygenation | | drugs | atropie if secondary vagal response during laryngoscopy | | intubation | +/- miller blade to pass over epiglotis | | prepare for failure | needle cric if age <10 | | post-intubation | - secure well - NGT | ## guillain Barre syndrome see [[Guillain-Barré syndrome|GBS]] - hypotension (autonomic dysfunction): - IVF fluid bolus prior - noradrenaline infusion / push-dose pressors - ketamine induciton - autonomic instability - if HTN: fet 3mcg/kg prior - avoid xusamethonium - use roc at lower dose / sugammadex after - aspiration; intubation 30 deg up, early NGT --- # troubleshooting post-intubation hypoxia or hypotension mnemonic:: DOPES, AAHH SHITE ## post-intubation hypoxia **DOPES** - displacement of ETT - Obstruction of ETT - Patient: PTx, PE, bronchospasm, dysynchrony - Equipment (failure in inappropriate settings) - Stacked Breaths **AAHH SHITE** - Acidosis - Anaphylaxis - Heart → tamponade - Heart → pulm HTN - Stacked breaths / autopeep - Hypovolaemia - Induction agents - Tension Ptx - Electrolytes **Aproach** 1. disconnect ventilator and give FiO2 100% in BVM ; note how ventilation feels 2. if asthmatic, allow release of trapped air 3. pass suction cathether 4. check placement of ETT ? length 5. check EtCO2 6. POCUS or CXR: ?PTx, lung collapse, tamponade, single lobe intubation ## causes of high airway pressures - ventilator - bad settings - circuit kinking, pooling of water vapour - ETT displacement, obstruction - patient - bronchospasm - decreased compliance - lung: collapse, consolidation, pulm oedema, ARDS - pleural: Ptx, pleural effusion - chest wall: abdo distension, obesity - patient-ventilator dyssynchrony ## causes of post-intubation hypotension AAHH SHITE issues as above may be disease-specific eg asthma - pneumothorax - anaphylaxis - breath stacking / dynamic hyperinflation [[Ventilator strategies#Dynamic hyperinflation and auto-PEEP|Dynamic hyperinflation]] - induction agent - hypovolaemia