Cardiorespiratory physiotherapy for mechanically ventilated children following cardiac surgery: a prospective observational service evaluation.

Purpose

Children with cardiac conditions often remain intubated and mechanically ventilated during their acute recovery from surgery. Anaesthesia, intubation, surgery and muscle relaxants leave the child´s lungs vulnerable to retained secretions and alveolar collapse.

One role of physiotherapy in cardiac intensive care is to address these sequelae using a number of different techniques, including manual techniques and endotracheal suction. The evidence to support such interventions remains limited and relies on studies with a heterogenous population. Although children post cardiac surgery were included within these populations, lack of subgroup analysis means that the benefits of physiotherapy to this particular group of children are uncertain.

Approach

A prospective observational service evaluation was undertaken at a single tertiary centre.

Children who had undergone cardiac surgery within the previous five days, were intubated and mechanically ventilated, and for whom cardiorespiratory physiotherapy was deemed necessary (assessed by an independent clinical physiotherapist), were observed. Ventilatory and haemodynamic data were documented at one-minute intervals for 15 minutes before and 30 minutes after physiotherapy treatments. During physiotherapy, individual treatment components were observed and recorded.

Outcomes

Twenty two children (seven males) were observed before, during and after physiotherapy. They were aged between 3 days and 17 years (median age 3.9 months). Ten of the children had a delayed sternal closure.

Physiotherapy interventions included positioning, saline instillation, manual hyperinflations with or without chest wall vibrations and endotracheal suction. There were no significant changes in haemodynamic outcomes following physiotherapy.

There was a significant reduction in end tidal CO2 following physiotherapy from mean (SD) 5.04 (0.7) to 4.7 (0.76) kPa, mean change (95% confidence intervals), -0.34 (-0.5 to -0.1), p=0.003.

Minute volume increased significantly from 1.8 (1.3) to 2.0 (1.3) L/min, mean change (95% confidence intervals) 0.11 (0.04 to 0.2), p=0.006, and tidal volume increased significantly from 9.8 (2.6) to 10.4 (2.7) mL/kg, mean change (95% confidence intervals) 0.6 (0.11 to 1.04), p=0.019.

Improvements reached the critical threshold for clinical importance (a change of 10% or more, representing a greater change than that attributable to normal physiological variability) in 8 (36%) children, whilst most others remained within the limits of normal variability. There were brief but clinically important deteriorations following 2 (9%) treatments.

From this small number of children, it can be observed that physiotherapy resulted in statistically significant improvements in terms of ventilatory parameters, without any detriment to haemodynamic stability. The combination of treatment components (positioning, saline, manual hyperinflation, chest wall vibrations and suction), appeared to have a positive effect on end tidal CO2, minute volume and tidal volume for the group, with clinically important improvements in some children.

Implications

Generalisability cannot be assumed, since this was a service evaluation. The findings suggest that physiotherapy was effective for most of these children following cardiac surgery. Advances in technologies, and the use of 'big data,' could provide continuous and accurate measures of respiratory and haemodynamic outcomes, thereby creating a more comprehensive picture of the impact of physiotherapy on the patient's overall recovery, including time to liberation from the ventilator and hospital length of stay.

Funding acknowledgements

This project was undertaken in partial fulfilment of the requirements for an MSc in advanced cardio respiratory physiotherapy from UCL. No additional funds were required.

Additional notes

This work was presented at Physiotherapy UK 2019