Bronchospasm: It’ll Take Your (Patient’s) Breath Away

Presenter: Raymond Panketh, MD Mentor: Nabi Khatibi, MD Disclosures None Objectives Case Presentation Case Progression Signs and Differential Diagnosis of Bronchospasm Pathophysiology of Bronchospasm Management of Bronchospasm Role of ETT depth in Bronchospasm Case Management Summary Case Presentation of Patient JB

HPI: – 68 y.o. male with gross hematuria found to have a 1.3cm bladder stone and 1.0cm right kidney stone presenting for bilateral utereroscopy with laser lithotripsy. – PMH: pAF, OSA treated with CPAP, HTN (130s/70s in clinic), DMII (glucose: 133 that AM), GERD, OA, obesity (BMI: 33) – PSH: Left adrenalectomy for adrenal mass, tonsillectomy, cystoscopy and lithotripsy – Allergies: Latex (mild rash), lidocaine, equine containing products (respiratory difficulty) – Meds: Citalopram, Eliquis, Losartan, Metoprolol, Metformin, Pantoprazole, h/o indomethacin – FH: Non-contributory – SH: Never smoker, rare EtOH, no illicit drug use Case Presentation of Patient JB

PE: – Vitals: BP: 139/70 Pulse: 63 Temp: 36.7 °C (98 °F) SpO2: 96% on RA – Ht 170 cm (5’ 7") Wt 99.6 kg (220 lbs) BMI 33.28 kg/m2 – GEN: NAD – PULM: CTAB, no increased WOB – CV: RRR without MRG – NEURO: A&Ox3, no focal deficits – AIRWAY: Multiple intact crowns, Mallampati II, otherwise unremarkable

– EKG: SR at 62 with moderate intraventricular delay QRS: 113ms Case Progression

Pre-induction: 2mg midazolam IV and standard denitrogenation followed by 100mcg fentanyl IV.

Induction: 150mg propofol IV and 160mg succinylcholine IV.

Intubation: Grade I view orally intubated with Mac 3 with a 7.5mm ETT taped at 24 cm at the teeth. Case Progression Case Progression Differential Diagnosis

Causes of increased peak airway pressure during IPPV: – Anesthetic equipment • Excessive tidal volume • High inspiratory flow rates – Airway device • Endobronchial intubation • Tube kinked or blocked • Small diameter tracheal tube – Patient • Obesity • Head down positioning • Pneumoperitoneum • Tension pneumothorax • Bronchospasm Causes of Bronchospasm

Patient – Increased secretions – Vagal-sympathetic tone imbalance – Acute respiratory infection – Pre-existing COPD, asthma, active smoking Environmental – Tobacco – Cold Air – Air pollution, dust, dander Medications – NMBs, antibiotics, beta blockers, protamine, non-synthetic opioids, drug preservatives, ester local anesthetics, carboprost (Hemabate) Hospital Materials – Latex – Invasive ventilatory devices Signs of Bronchospasm

Wheezing on auscultation Slow or incomplete expiration Changes in capnography – Upsloping waveform – “shark fin” – Severely decreased or absent waveform Decreased tidal volume Increased peak airway pressure Decreased oxygen saturation HR of anesthesia provider > SpO2 of patient – High sensitivity / Low specificity Differential Diagnosis

Causes of wheeze during GA: – Bronchospasm – Pulmonary edema – Aspiration of gastric contents – Pulmonary embolism – Tension pneumothorax – Foreign body (such as a tooth) Causes of Bronchospasm Pathophysiology of Reflex Bronchospasm

Irritation of the upper airway/ Noxious stimuli

Afferent sensory pathways via vagus nerve

Solitary nucleus

Efferent vagus nerve pathways

Bronchiolar smooth muscle contraction Crisis Management of Bronchospasm Crisis Management of Bronchospasm Secondary Management of Bronchospasm Steroids: methylprednisolone 125mg IV OR dexamethasone 8mg IV Appropriate ventilation to avoid dynamic hyperinflation: – Longer expiratory time (I:E 1:3-1:5) – Low/normal respiratory rates (8-12/min) – Permissive hypercapnia Adjuncts: – Bronchodilating anesthetics: volatiles, ketamine, propofol – Magnesium sulfate 2g IV over 20min – Heliox (does not reverse bronchospasm, but can be used as a temporizing measure) – Neuromuscular blocking drugs (may improve mechanics of ventilation & lower peak inspiratory pressures) – Extracorporeal membrane oxygenation (ECMO) if severe & refractory to all other treatments ETT: How Far is Too Far? ETT: How Far is Too Far? ETT: How Far Is Too Far? ETT: How Far is Too Far? ETT: Changes in Positioning Case Management

Patient was given 100% oxygen, 100mg IV propofol, isoflurane was increased and albuterol administered via the ETT.

There were no clinical signs of anaphylaxis and the patient remained hemodynamically stable.

Magnesium 2g IV was given over 20 minutes and 30mg of rocuronium was given with appropriate decrease in peak inspiratory pressures.

Patient was reversed with sugammadex followed by uneventful extubation and PACU stay and was discharged home. Summary of Important Points

CALL FOR HELP EARLY – the differential for bronchospasm can be complex, and requires extra eyes and hands!

Although we all strive to have the perfect wake-ups, prematurely lightening the patient while surgery is going on may put our patient’s at higher risk for bronchospasm.

The ”silver standard” should be a combination of observing chest movement, auscultation, and importantly observing tube depth. The gold standard being bronchoscopy.

The optimal depth insertion is about 20cm in women and 22 cm in men and clinicians should be concerned if depth varies much from this, especially in range heights between 150cm and 180cm. References

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