Mortality in Patients Intubated on the Medical High Dependency Unit
Duncan GJ Philp Core Trainee in Anaesthesia @happymarmot
Andrew J Clarkin Consultant in Anaesthesia & Critical Care @ajclarkin
General Intensive Care Unit, Aberdeen Royal Infirmary, Aberdeen, UK
The Medical High Dependency Unit (MHDU) in Aberdeen Royal Infirmary is geographically remote from the Intensive Care Unit (ICU). Patients in MHDU can be supported with high flow nasal oxygen (HFNO), continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV). We hypothesized that this ability to provide significant respiratory support may delay referral to ICU and invasive ventilation, and that delayed referral may necessitate intubation in MHDU prior to transfer with the attendant risks.
All patients admitted to ICU from MHDU between January 2015 and December 2016 were identified using the WardWatcher database. Patients who were not invasively ventilated were excluded. WardWatcher and the electronic patient record were then used to determine the number of days from hospital admission to ICU admission, location of intubation, and the in-hospital mortality.
There were 121 patients admitted from MHDU to ICU of whom 39 did not require intubation, leaving 82 patients. Of these 27% were intubated in MHDU prior to transfer. There was a statistically significant increase in mortality associated with intubation on MHDU (p=0.03).
There are several possible explanations including speed of patient deterioration, physiology at the time of intubation (and so complications during intubation), or delay in intubation and invasive ventilation. Our data also showed that a quarter of the ICU admissions from MHDU were on the first day of their hospital stay. This suggests inappropriate admission to MHDU rather than ICU.
Improvement is required and a comprehensive action plan has been produced to address these issues. Further scrutiny of these patients and future re-audit will help to clarify the interplay between the contributing factors and quantify the resulting improvement.