Noninvasive positive-pressure ventilation to treat hypercapnic coma secondary to respiratory failure

Chest. 2005 Mar;127(3):952-60. doi: 10.1378/chest.127.3.952.


Introduction: Hypercapnic coma secondary to acute respiratory failure (ARF) is considered to be a contraindication to the use of treatment with noninvasive positive-pressure ventilation (NPPV). However, intubation exposes these patients to the risk of complications such as nosocomial pneumonia, sepsis, and even death.

Patients and methods: We performed a prospective, open, noncontrolled study to assess the outcomes of NPPV therapy in patients with a Glasgow coma scale (GCS) score of </= 8 points due to ARF. The primary goal of the study was to determine the success of NPPV therapy (defined as a response to therapy allowing the patient to avoid endotracheal intubation, and to survive a stay in the ICU and at least 24 h on a medical ward) in patients with hypercapnic coma, compared to those who started NPPV therapy while awake. The secondary goal of the study was to identify the variables that can predict a failure of NPPV therapy in these patients.

Results: A total of 76 coma patients (80%) responded to NPPV therapy, and 605 patients with GCS scores > 8 responded to therapy (70%; p = 0.04). A total of 25 coma patients died in the hospital (26.3%), and 287 noncoma patients died in the hospital (33.2%; p = 0.17). The variables related to the success of NPPV therapy were GCS score 1 h posttherapy (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.53 to 3.53) and higher levels of multiorgan dysfunction, as measured by the maximum sequential organ failure assessment index score reached during NPPV therapy (OR, 0.72; 95% CI, 0.55 to 0.92).

Conclusions: We concluded that selected patients with hypercapnic coma secondary to ARF can be treated as successfully with NPPV as awake patients with ARF.

MeSH terms

  • Acute Disease
  • Aged
  • Coma / complications*
  • Coma / mortality
  • Contraindications
  • Female
  • Glasgow Coma Scale
  • Hospital Mortality
  • Humans
  • Hypercapnia / complications*
  • Male
  • Positive-Pressure Respiration* / adverse effects
  • Positive-Pressure Respiration* / instrumentation
  • Positive-Pressure Respiration* / methods
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / mortality
  • Respiratory Insufficiency / therapy*
  • Survival Rate
  • Treatment Failure
  • Treatment Outcome