Intubation and Mechanical Ventilation of the Asthmatic Patient in Respiratory Failure

Methods

Three sets of key words were used for the systematic literature review. The first set included the terms acute asthma, acute severe asthma, acute bronchospasm, acute reactive airways disease, asthma exacerbation, emergency asthma, and status asthmaticus. The second set of key words included the following terms: mechanical ventilation, mechanical ventilator, invasive ventilation, mechanical ventilatory support, continuous mandatory ventilation (CMV), assist-control ventilation, synchronized

Results

The search for the topic of intubation produced 41 randomized controlled trials (RCTs) and 6 meta-analyses. Five RCTs were deemed appropriate for this review. The search for the topic of mechanical ventilation revealed 5 RCTs and 4 meta-analyses. None of these RCTs or meta-analyses was deemed appropriate for this review because they did not deal specifically with mechanical ventilation of asthmatic patients or effects of mechanical ventilation on airway function.

Discussion

The ED task force identified 7 key areas for discussion from the review of the literature and their clinical experience:

• 1

  prevention of intubation,

• 2

  criteria for intubation,

• 3

  recommendations for intubation technique,

• 4

  recommendations for appropriate ventilator settings,

• 5

  management in the immediate postintubation period,

• 6

  medical management of asthma in the ventilated patient, and

• 7

  prevention and treatment of complications.

Summary of Recommendations (All Strong)

• 1

  Criteria for intubation (Evidence Category D)

  • •

    Clinical indications

    • —

      Cardiac arrest

    • —

      Respiratory arrest

    • —

      Altered mental status

    • —

      Progressive exhaustion

    • —

      Silent chest

  • •

    Laboratory indications

    • —

      Severe hypoxia with maximal oxygen delivery

    • —

      Failure to reverse severe respiratory acidosis despite intensive therapy

    • —

      pH <7.2, carbon dioxide pressure increasing by more than 5 mm Hg/h or greater than 55 to 70 mm Hg, or oxygen pressure of less than 60 mm Hg

• 2

  Intubation technique (Evidence Category D)

  • •

    There are 4 choices of