Bronchospasm: It’ll Take
Your (Patient’s) Breath Away
Presenter: Raymond Panketh, MD
Mentor: Nabi Khatibi, MD
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.
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)
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
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
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.
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