Quality of Studies

Conclusions

Following a systematic review of the literature; critical appraisal of identified studies; the following conclusions were reached:

Quality of studies

·  Three case series have been published with no control (Chang et la 2005; Martin et al 2002; Sprague et al 2003)

·  Only one RCT could be identified (Caruso et al 2005)

·  Internal validity of studies is a problem scoring 3-4 on Pedro scale.

·  The only experimental study published scored 4/11 on the PEDRO scale. Data was not analyzed on an intention to treat basis; patients were lost to follow up and the study sample size was underpowered.

Background

·  The physiologic rationale for IMT is not sound as there are numerous factors influencing successful weaning from mechanical ventilation (Jubran 2006; de Jonge et al 2004)

·  It is unsure whether decresead inspiratory muscle strength is the cause of prolonged ventilation or the outcome (Chang et al 2005).

Summary of evidence

·  Even though the small study reported a trend toward a lower reintubation rate and weaning duration, the inspiratory strength in this group tended to decrease during mechanical ventilation suggested a lack of beneficial effect on the IMT (Caruso et al 2005)

·  No adverse effects were reported in any of the studies.

RECOMMENDATIONS

·  IMT is not currently regarded as standard care in the management of critically ill patients and questions have been raised as to the physiological basis of this intervention. There is insufficient evidence to make any recommendations with regards to the implementation of an IMT program at this time. In the one RCT identified there was no effect on re intubation rate or TOV between the intervention group or the control group. This study was however not sufficiently powered; patients were lost to follow up; there was insufficient blinding and data was not analyzed on an intention to treat basis. Good quality studies are urgently required in this area.