Too much of a good thing? Auditing the prescription and titration of Oxygen on a general ITU at a university teaching hospital
Christopher Hebbes1, Rebecca Perry2, Nathan Sloane2, Andrew Wilkinson2, Alex Keeshan3
Specialty trainee1, Foundation doctor2, and Consultant3 in Anaesthesia and Critical Care
Leicester Royal Infirmary, University Hospitals of Leicester NHS Trust
Oxygen is a commonly used drug in hospital. The complications of inadequate titration and monitoring can affect multiple organ systems and cause poor outcomes in medical and surgical patients
The British Thoracic Society audit in 2015 found that, despite its high usage, prescription and monitoring of targets for Oxygenation in hospital was poor1.
42.5% of patients had no valid Oxygen prescription
69.0% of patients on Oxygen had an SpO2 target outside of the prescribed range
There is increasing evidence that acute exposure to high concentrations of Oxygen can worsen outcomes in myocardial infarction, traumatic brain injury, surgery, and post cardiac arrest.
WHO recommends supplemental Oxygen to reduce Surgical Site Infection2
Hyperoxia may worse outcomes in Myocardial Infarction3
Hyperoxia may worsen mortality in Traumatic Brain Injury4
The recent OXYGEN-ICU1 trial demonstrated a significant reduction in ICU mortality where a SpO2 target of 94-98% (conservative) was used compared to usual treatment 97-100%
Whilst the threshold at which hyperoxia in critical illness becomes deleterious is unknown, this baseline audit aims to evaluate current practice and compliance with the BTS guidelines in target setting and titration of Oxygen therapy in emergency care1. As a secondary aim, we will quantify hyperoxia on a mixed general ITU.
Retrospective audit of all admissions to the intensive care unit at the Leicester Royal Infirmary during March 2017
Reason and time of admission, any risk of hypercapnic respiratory failure, hourly Oxygen saturations were extracted from the notes. Arterial blood gases were downloaded from the blood gas analyser.
Data were coded and analysed using SPSS for Windows and R for Linux. Time to normoxia was analysed using survival curves .
95% of all patients on Oxygen should have an saturation target specified in the ITU medical notes
95% of patients should have an appropriate saturation target documented
Results – Target setting
107 patients admitted to intensive care during March 2017
6726 patient hours audited
5291 on Oxygen, 1435 on room air
44.9% Of all patients had a saturation target specified in the ITU medical notes
24.0% Of all patients with a saturation target had appropriate targets with upper and lower limits at any time during admission
26.5% Of patients not at risk of hypercapnic respiratory failure had a saturation target of 94-98% at any time during admission
60.0% Of patients at risk of hypercapnic respiratory failure had a saturation target of 88-92% at any time during admission
Results - Oxygen titration
Median time to first normoxic ABG 4.8 hours
No difference between medical and surgical patients
Conclusions and action points
Few patients had Oxygen saturation targets specified, and of those, many were not consistent with BTS guidelines
There is a significant time to normoxia for patients which may be improved by Oxygen titration and targeting. Initial hyperoxia is a significant issue
There is increasing evidence that exposure to hyperoxia may cause harm and worsen outcomes in intensive care
Designing and developing training for nurses and junior staff to aid target setting, and titration of Oxygen
Establishing consultant consensus on acceptable default targets for Oxygenation to aid junior staff in target setting setting and prescribing
Troubleshooting guide and flowchart to aid titration of Oxygen added to existing ventilation care bundle