Respiratory monitoring without machinery

The clinical examination remains an important tool for monitoring respiratory function in the critically ill. Noninvasive monitors appear to offer little additional accuracy for precision to the results of clinical examination for the assessment of airway function, ventilatory drive, and ventilatory muscle function. Moreover, the clinical examination coupled with the chest radiograph remains the cornerstone for evaluation of both parenchymal and pleural disease. On the other hand, technology has clear advantages over the clinical examination in providing the necessary accuracy and precision for the assessment of oxygen and carbondioxide tensions. Pulmonary-vascular and right-heart function can be evaluated reasonably well by clinical examination, but invasive monitoring is still needed for definitive answers. In the critically ill patient, continuous noninvasive monitoring appears to have a distinct advantage over clinical spot-check measurements because such continuous monitoring provides information on patient-ventilator system integrity (redundant systems should include pressure, flow, and, perhaps, CO2 sensors); ventilatory pattern during sleep (pneumograms, thermistors, exhaled CO2); ventilation during weaning attempts; and ventilation during administration of sedatives, analgesics, or paralytics. The only other useful continuous monitor appears to be a heart rate monitor to serve as a nonspecific early warning system for a variety of impending changes that need more careful clinical assessment. In conclusion, the clinical examination remains one of the best systems for nininvasive monitoring. Moreover, the clinical examination should determine when technical monitoring is indicated, and not vice versa. Finally, it hould be remembered that just as technical monitors require careful construction, calibration, and maintenance, clinicians require proper training, retraining, and ongoing development of their skills to remain effective.

Duke Scholars

Author Neil Ross MacIntyre Jr. Medicine, Pulmonary, Allergy, and Critical Care Medicine