Effectiveness of apnoeic oxygenation during intubation: systematic review and meta-analysis.

Annals of Emergency Medicine;2017:x:1-12

Presented by: Dr M. Gallagher

Background

  • Concept-> administration oxygen during apnoeic period of intubation.
  • Rationale->  ability of alveoli to capture oxygen via passive process without ventilation.
  • Importance-> higher risk hypoxaemia during the intubation of the critically ill patient in ICU or ED setting.

Design & Setting

  • Systematic review and meta-analysis
  • Study overall effect of apnoeic oxygenation during emergency intubation on

1) hypoxaemia

2) ‘first pass’ success intubation

3)  lowest oxygen saturation

Inclusion criteria

  • Oxygenation during apnoeic period via

– nasal cannula (NO DESATURATION)

– high flow oxygen nasal cannula (THRIVE)

– nasopharyngeal catheter or modified laryngoscope.

  • Intubations performed in ICU or ED settings.
  • RCT’s and observational studies in the last 10 years.

Exclusion criteria

  • Intubations in ‘out-of hospital’ settings or in theatres.

Outcomes

  • Lowest SpO2 peri-intubation
  • ‘First pass’ success
  • Incidence hypoxaemia
    1. SpO2 <93%
    2. SpO2 < 80%
    3. SpO2 <70%
  • Duration of mechanical ventilation
  • ICU length of stay and mortality

Results

  • Included 8 emergency department or intensive care based studies
  • Total 1837 patients
    • Apnoeic oxygenation 982 patients
    • No apnoeic oxygenation 855 patients
  • High flow oxygen nasal cannula (NO DESAT) most studies.
  • Standard nasal cannula in ED.

For apnoeic oxygenation

  • Lowest peri-intubation SpO2 was higher than for standard oxygenation.
  • Associated with increased ‘first pass- success rates.
  • Decreased risk of incidence SpO2 < 93%.
  • Not associated with SpO2 < 805 or <70%.
  • No association with duration of mechanical ventilation.
  • Decreased length of stay on ICU.
  • No association with ICU mortality.

Subgroup analysis

  • Overall no difference between study design or  risk of bias.
  • Apnoeic oxygenation favoured trainees ‘subgroup when proceduralist expertise was evaluated.
  • Results were not statistically significant

Conclusions

  • No adverse effects for very simple procedure -> ?beneficial in emergency scenarios particularly when a trainee is intubating.
  • Different techniques used
    • Emergency Department = standard nasal cannula
    • Intensive Care Unit = high flow nasal cannula.
  • No clear overall consensus in the literature.

Strengths

  • Meta-analysis-> good use of statistical analysis to try overcome any bias.
  • Relevant to patient groups in question

Weaknesses

  • Quality of included studies (low-moderate).
  • Clinical heterogenitcity ( clinical setting, context for intubation, methods of pre-oxygenation and apnoeic oxygenation).
  • Not able to assess publication bias.

Implications

  • Potentially a useful adjunct in emergency intubation

Potential for impact

  • Seems to be of benefit
  • Relatively simple and safe intervention with few complications
  • Evidence surrounding apnoeic oxygenation still not certain and some concerns raised about quality of available studies