First Edition CCSG writing group
With further expert input from:
Second Edition CCSG writing group:
With further expert input from:
Prone positioning is an intervention used in Acute Respiratory Distress Syndrome (ARDS) with the aim of improving oxygenation, preventing ventilator associated lung injury and, in combination with a protective ventilation strategy, has been shown to decrease mortality1. Placing the patient in the prone position is a strategy frequently undertaken for patients with COVID-19, particularly in mechanically ventilated patients during the first surge2.
Whilst there is little published evidence regarding enteral feeding in the prone position it has historically been thought to carry some risk of aspiration of gastric contents. In addition to the usual challenges of providing adequate nutrition in critically ill patients, feeding the patient in the prone position may pose an additional challenge due to decreased enteral feeding tolerance compared with patients in the supine position3.
As medical treatments for patients with COVID-19 evolve, prone positioning in awake patients is now increasingly undertaken. More recently, the ICS published guidance for ‘Prone Positioning of the Conscious COVID Patient, 2020’3. This recent guidance recommends 30 minutes to two hourly timed position changes for patients undergoing the ‘conscious prone position process’ with periods of ‘flat-bed positioning’. However, ICU’s may use different positioning techniques, with duration dependent on clinical need and resource.
Where evidence is lacking, recommendations have been based on the consensus of best practice by expert critical care dietitians within the British Dietetic Association CCSG and Critical Care Organisations.
The aims of this document are to:
1. Tube position
2. Feed Delivery
3. Choice of feed
4. Monitoring feed tolerance
5. Managing Feed Intolerance
Follow recommendations as above in the ‘enteral feeding in the intubated patient’ section, with the additional considerations:
1. Reducing aspiration risk
2. Maximising feed delivery
3. Additional positioning considerations
Six studies were identified investigating enteral feeding in the prone postion4-9. All were small in sample size and based primarily on observational study designs. The quality of the available evidence is therefore low and should be interpreted with these limitations in mind. Three international guidelines on nutrition in COVID-19 were identified10-12 and five review articles which provided clinical insights13-17.
All international guidelines for nutrition in COVID-19 support the use of EN whilst in the prone position and advocate the use of post pyloric tubes if tolerance is an issue10-13. Due to the aerosol generating risks associated with post pyloric tube placement endoscopically or via interventional radiology, a case-by-case decision is recommended. No difference in micro-aspiration was observed between gastric and post-pyloric tube feeding in patients undergoing rotational positioning for ARDS5. All other studies in the prone position used gastric feeding tubes, and no increased incidence of ventilator associated pneumonia was observed in comparison with those in the supine position4;6.
No published studies were identified comparing the risk of aspiration based on different GRV thresholds whilst in the prone position. Most commonly a GRV of 250mls has been used whilst feeding in the prone position4;6,9.
All international guidelines for nutrition in COVID-1910-12 advocate for continuous enteral feeding using pumps with an incremental increase in rate over the first 4-7 days to avoid gastro-intestinal complications and risks associated with overfeeding. The safe maximum feeding rate whilst in the prone position has been suggested to be between 65 ml/hr4 to 85 ml/hr6.
Episodes of vomiting and aspiration have been witnessed particularly when turning the patients from supine to prone position and vice versa15. Cessation of NG feeding for 1hr prior to position change has been suggested as a way of overcoming complications11;15;18.
Patients in the supine position on HFNO or NIV experience difficulties in meeting their nutritional requirements orally10. It can therefore be assumed that the prone position will further amplify this problem. Due to the lack of evidence to support decision making, an individualised approach to feeding whilst receiving NIV support in the prone position is required, taking into account nutritional risk, oral intake, resources and degree of respiratory compromise10.
The CCSG writing group have written these guidelines based on the evidence available and clinical experience. We acknowledge that enteral nutrition of those in the prone position, especially whilst on NIV, is not without risk. We recommend all feeding decisions are made in agreement with the local critical care team, including a local risk assessment.