Value of a surgical high-dependency unit

A minority of hospitals in the UK have a high-dependency unit (HDU). One reason for this is a lack of evidence supporting its benefit. This study sought to compare the outcomes of patients undergoing major abdominal surgery with regard to HDU utilization.

Data were collected prospectively from two groups of patients over 10 months. Patients in the no-HDU group underwent major abdominal surgery in a hospital without an HDU and returned to a general surgical ward. The other group was managed initially in an HDU. Data collected included Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM) scores, complications, deaths and length of stay.

Physiological and operative scores as calculated on the RAJIS POSSUM software were similar in both groups. The HDU group comprised 121 patients. Sixty-four developed a complication whereas 58.81 were expected to, giving an observed : expected (O : E) ratio of 1.09. Sixteen deaths occurred and 14.54 were expected (O : E ratio 1.10). Some 50 per cent stayed in hospital longer than was predicted. The no-HDU group comprised 71 patients. Fifty-nine developed a complication compared with 33.82 expected (O : E ratio 1.74). Ten deaths occurred, whereas 8.88 were expected, giving an O : E ratio of 1.13. Some 63 per cent stayed longer than predicted. The O : E ratios for morbidity were significantly different (P < 0.0005). The complications that occurred more frequently in the absence of an HDU were chest infection, arrhythmias and hypotension.

Postoperative management on an HDU was associated with fewer cardiorespiratory complications. There was no difference in mortality rate but there was a trend towards shorter hospital stay.