Deterioration of respiratory function after intra-hospital transport of critically ill surgical patients

Abstract

Objective: To evaluate the impact of intra-hospital transport of artificially ventilated patients on respiratory function, and to define predictors that may allow estimation of the risk of post-transport pulmonary deterioration.

Design: Prospective observation study.

Setting: Surgical ICU, University Hospital.

Patients: 49 intra-hospital transports (median Apache-score before transport 21, of 28 consecutive patients (all intubated and mechanically ventilated) were studied.

Interventions: 32 transports were destined to the radiology department and 17 to the operating theatre. Patients were ventilated during transportation with a transport ventilator.

Measurements and results: The base-line condition of the patients and any changes of hemodynamic function were noted. Arterial blood gases were determined before transport as well as 0.25, 1, 6, 12, and 24 h after return of the patient to the ICU. Of the transports 41 (83.7%) resulted in a decrease of PO2/FIO2-ratio with a deterioration of more than 20% from baseline in 21 cases (42.8%). The impairment of respiratory function lasted longer than 24 h in 10 subjects (20.4%). Ventilation with positive end-expiratory pressure correlated significantly (r = -0.4) with post-transport change of PO2/FIO2-ratio, whereas initial FIO2, initial PO2/FIO2-ratio, Apache II-score, patients' age or transport time did not distinguish between patients with and without a consecutive decrease of pulmonary function.

Conclusion: Intra-hospital transport of ventilated critically ill patients may result in a considerable and long-standing deterioration of respiratory function. Patients ventilated with positive end-expiratory pressure are at an increased risk and the indication for procedures away from the ICU has to be weighted carefully in these subjects.