Bedside evaluation of respiratory distress.

Observations made at the time of the first trial of independent ventilation in 112 episodes of mechanical ventilatory support led to identification of a group of indicators, each of which, when present, was significantly associated (p less than 0.05) with a need for continued mechanical ventilation and/or with death. Six of these were potentially suitable for use in a format for clinical assessment of the risk of respiratory failure: pulse over 120 or under 70 beats per minute, respiratory rate of over 30, palpable scalene muscle recruitment in inspiration, palpable abdominal tensing in expiration, presence of irregular irregularity of respiratory rhythm with apneic pauses of varying duration, and coma or any condition preventing a patient from responding appropriately to commands aimed at producing ventilatory movements like those needed for vital capacity testing. When none of the six signs was present, there was a 90 percent chance of a favorable outcome. With one or two indicators positive, more than 50 percent of the subjects required further ventilatory support or died. There were no favorable outcomes when three or more of the signs were present together.