From the Guidelines
Ventilator management for asthma patients should prioritize a lung-protective strategy with low tidal volumes, permissive hypercapnia, and low PEEP to minimize barotrauma and auto-PEEP, as recommended by the most recent guidelines 1. The goal of ventilator management in asthma is to provide adequate oxygenation while minimizing the risk of complications such as barotrauma and auto-PEEP.
- Initial ventilator settings should include a low tidal volume of 6-8 mL/kg ideal body weight,
- Respiratory rate of 8-12 breaths/minute,
- Longer expiratory times with an I:E ratio of at least 1:3 to prevent dynamic hyperinflation. Permissive hypercapnia is recommended, allowing pH as low as 7.2 to avoid excessive ventilatory pressures 1.
- PEEP should be kept low (0-5 cmH2O) as asthma patients already have intrinsic PEEP from air trapping.
- Plateau pressures should be maintained below 30 cmH2O to prevent barotrauma. Sedation with propofol (starting at 5-50 mcg/kg/min) or dexmedetomidine (0.2-0.7 mcg/kg/hr) is often necessary, with neuromuscular blockade using cisatracurium (0.15-0.2 mg/kg bolus followed by 1-3 mcg/kg/min infusion) reserved for severe cases 1. Concurrent aggressive bronchodilator therapy is essential, including continuous albuterol nebulization (10-20 mg/hr), IV magnesium sulfate (2 g over 20 minutes), and systemic corticosteroids (methylprednisolone 60-125 mg IV every 6 hours) 1. Monitor for complications such as pneumothorax, hypotension from dynamic hyperinflation, and auto-PEEP by performing periodic expiratory hold maneuvers. If conventional ventilation fails, consider alternative modes like pressure-controlled ventilation or airway pressure release ventilation, with extracorporeal membrane oxygenation as a last resort for refractory cases 1.
It is essential to consult with or comanage by a physician expert in ventilator management, as ventilation of patients with severe asthma is complicated and risky 1. Intubation should be done semielectively and before respiratory arrest occurs, with the patient transferred to an intensive care unit appropriate to the patient’s age 1. Intravascular volume should be maintained or replaced during intubation, and high ventilator pressures should be avoided to minimize the risk of barotrauma 1.
Overall, the key to successful ventilator management in asthma is to prioritize a lung-protective strategy while providing adequate oxygenation and minimizing the risk of complications.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Ventilator Management Guidelines
The guidelines for ventilator management in patients with asthma (bronchial asthma) are as follows:
- Non-invasive ventilation (NIV) can be used in severe asthma attacks to decrease the need for intubation and support pharmaceutical treatments 2, 3.
- NIV has been shown to be effective in reducing bronchial obstruction and symptoms in patients with acute asthma 4.
- The use of bi-level positive airway pressure and nebulization can help reverse bronchial obstruction in patients with acute asthma 4.
- NIV can be safely used in acute severe asthma, with no instances of haemodynamic compromise or need for escalation to invasive ventilation 5.
Patient Selection
- Selecting the appropriate patients for NIV use is a key factor in successful NIV application, but the process is still controversial 2.
- Patients with severe asthmatic attacks who are at an increased risk of developing respiratory failure may benefit from early respiratory support in the form of NIV 6.
- Further work is needed to delineate the precise patient selection process for NIV in acute severe asthma 5.
Ventilator Settings
- The use of low pressure delta and high positive pressure at the end of expiration may be more efficacious in reversing bronchial obstruction 4.
- The inspiratory positive airway pressure and expiratory positive airway pressure used in NIV for acute severe asthma were 11.9 ± 1.4 and 5.8 ± 1.2 cmH2O, respectively 5.