An evaluation of a single chest physiotherapy treatment on mechanically ventilated patients with acute lung injury

BACKGROUND AND PURPOSE: Acute lung injury is a lung pathology that presents frequently on the intensive care unit. Chest physiotherapy, in the form of endotracheal suction, alternate side-lying and manual hyperinflation, is usually given to patients with this condition with the intention of removing retained pulmonary secretions and recruiting collapsed distal lung units. Despite this common practice there is insufficient research on the effects of chest physiotherapy in patients with acute lung injury being ventilated mechanically. The aim of the present study was to further understanding of the effects of three modes of treatment in chest physiotherapy in an acute lung injury patient group. METHOD: This randomized, controlled trial investigated all mechanically ventilated patients with acute lung injury admitted to the adult intensive care unit at Guy's and St Thomas' NHS Trust between August 1996 and July 1997, who matched the inclusion criteria. Patients were randomized into one of three treatment groups: Group 1 (suctioned only); Group 2 (positioned and suctioned); and Group 3 (positioned, manually hyperinflated and suctioned). Baseline and 10, 30 and 60 minutes' post-treatment data were recorded for dynamic pulmonary compliance, arterial blood gases and haemodynamic variables. Results were analysed by use of an SPSS software package with a repeated-measures analysis of variance (ANOVA). RESULTS: Eighteen patients fitted the inclusion criteria. Significant changes were observed in both PaCO2 (p = 0.026) and dynamic compliance (p = 0.019) over time for all three groups. The arterial oxygen to fraction of inspired oxygen ratio (PaO2:FiO2) did not alter significantly in any of the groups. With respect to other oxygenation parameters, mixed venous oxygen saturation (SvO2) showed a significant difference between the groups. Heart rate (HR) and systemic blood pressure (BP) showed statistically significant, but not clinically significant differences over time. CONCLUSIONS: Patients with acute lung injury are notably complex to nurse and may require protracted physiotherapy intervention, which may take many forms. As de-recruitment was the single most important event that occurred in the present study population, a prescriptive chest physiotherapy approach to treating mechanically ventilated patients with acute lung should be questioned and adapted accordingly.