Breathing pattern and gas exchange in emergency and elective abdominal surgical patients

To evaluate the effects of intra-abdominal surgical emergency on breathing pattern and gas exchange and compare it with the changes induced by elective abdominal surgery.

Prospective clinical study.

Abdominal surgical departments in a university hospital.

Patients operated for intra-abdominal emergency (n = 10, EAS), elective upper abdominal (n = 19, UAS).

Breathing pattern and gas exchange were measured with a respiratory inductive plethysmograph and a gas exchange monitor. EAS patients had pre-operatively a classical rapid shallow breathing pattern and increased ventilatory demand due to increased energy expenditure. The operation improved the breathing to normal pattern (frequency, 26 +/- 5/min and 17 +/- 3/min, p < 0.01; tidal volume, 439 +/- 128 ml and 541 +/- 165 ml, NS., before and after surgery, respectively). Sighing was absent before and after EAS and strictly reduced after elective surgery (p < 0.01 for UAS). The operation restricted the abdominal-diaphragmatic breathing movement which was reflected as increased contribution of the rib cage to VT (%RC: from 37% +/- 15 to 57% +/- 15 for UAS p < 0.001; from 47% +/- 16 to 61% +/- 14 for EAS NS.). After EAS and UAS hypoxemia was common (p < 0.001) with frequent radiological pathology. We conclude that intra-abdominal surgical emergencies increase the ventilatory demand and challenge the respiratory system to marked adaptive changes both pre- and post-operatively.