COPD exacerbation: a clinical prediction rule could help predict patients at risk of mechanical ventilation

Clinical bottom line (level 2b)

  1. A clinical prediction rule could help identify patients with a COPD exacerbation at risk of requiring mechanicla ventilation.
Bone et al: Am J Med 1978; 65 : 896-902
Expires June 2004

The study

Prospective cohort study with objective outcomes, not adjusted for confounding factors, validated in an independent set of patients.

Setting: 2 acute hospitals, USA

73 patients (aged ?, ?% male) acutely ill with a COPD exacerbation and initially treated with low-flow oxygen (1 l/min)
Retrospective validation of a clinical prediction rule derived in 50 patients in another centre

?100% followed for length of hospital stay

Outcomes studied:
  • required mechanical ventilation

    • Clinical prediction rule: patients will require intubation if pH < 7.66 - 0.000910 pO2 (mmHg)

The evidence

outcome time to outcome number of patients/total number %
(95% CI)		 NNF
(95% CI)
required mechanical ventilation length of hospital stay 16/73 22%
(12% to 31%)		 5
(3 to 8)

    • LR + 5.1 (95% CI: 2.7 to 9.8)
    • LR - 0.22 (95% CI: 0.080 to 0.62)

Citation

  1. Bone RC, Pierce AK, Johnson RL: controlled oxygen administration in acute respiratory failure in chronic obstructive pulmonary disease: a reappraisal. Am J Med 1978; 65 : 896-902
Search Terms: from reference list of AHRQ review
Contributor: Chris Ball, June 2002
Reviewer:

Clinical Question.
Patient COPD exacerbation
Intervention or Exposure blood gas measurements
Outcome mechanical ventilation