Temporary muscle paralysis for accurate measurement of pulmonary artery occlusion pressure

Succinylcholine, a short-acting neuromuscular blocking agent, was used to accurately measure the pulmonary artery occlusion pressure (PAOP) in eight patients requiring mechanical ventilation for acute respiratory failure, in whom measurement was difficult because of significant respiratory variation in PAOP. The mean decrease in PAOP after paralysis was 9.8 +/- 5.3 mm Hg, with a range of 4 to 20 mm Hg (p less than 0.01). The magnitude of change was closely correlated to the degree of respiratory variation in PAOP observed during spontaneous breathing before paralysis (r = 0.889). Accurate measurement of PAOP affected subsequent management in five of these eight patients. Temporary muscle paralysis with succinylcholine is a useful means of eliminating artifactual elevations in PAOP in patients supported by mechanical ventilation when significant respiratory variation in PAOP is present.