Effects of intensivist coverage in a post-anaesthesia care unit on surgical patients' case mix and characteristics of the intensive care unit

Abstract

Introduction: There is an increasing demand for intensive care in hospitals, which can lead to capacity limitations in the intensive care unit (ICU). Due to postponement of elective surgery or delayed admission of emergency patients, outcome may be negatively influenced. To optimize the admission process to intensive care, the post-anaesthesia care unit (PACU) was staffed with intensivist coverage around the clock. The aim of this study is to demonstrate the impact of the PACU on the structure of ICU-patients and the contribution to overall hospital profit in terms of changes in the case mix index for all surgical patients.

Methods: The administrative data of all surgical patients (n = 51,040) 20 months prior and 20 months after the introduction of a round-the-clock intensivist staffing of the PACU were evaluated and compared.

Results: The relative number of patients with longer length of stay (LOS) (more than seven days) in the ICU increased after the introduction of the PACU. The average monthly number of treatment days of patients staying less than 24 hours in the ICU decreased by about 50% (138.95 vs. 68.19 treatment days, P <0.005). The mean LOS in the PACU was 0.45 (± 0.41) days, compared to 0.27 (± 0.2) days prior to the implementation. The preoperative times in the hospital decreased significantly for all patients. The case mix index (CMI) per hospital day for all surgical patients was significantly higher after the introduction of a PACU: 0.286 (± 0.234) vs. 0.309 (± 0.272) P <0.001 CMI/hospital day.

Conclusions: The introduction of a PACU and the staffing with intensive care staff might shorten the hospital LOS for surgical patients. The revenues for the hospital, as determined by the case mix index of the patients per hospital day, increased after the implementation of a PACU and more patients can be treated in the same time, due to a better use of resources.

Figure 1

Distribution of patients by LOS in the ICU before and after the introduction of the PACU. Values are mean number of treatment days per month. P-values: LOS <24 hours <0.001, LOS 1 to 7 days: P = 0.31, LOS >7 days: P = 0.001, PACU w/o intensivist (20 months): n = 3,293 patients, PACU with intensivist (20 months): 2,676 patients.

Figure 2

Distribution of the patients of a month according to the TISS-28 score. Average number of patient days per month before and after the introduction of a PACU staffing with an intensivist. P-values: TISS <20: <0.001; TISS 20 to 35 no vent: <0.001; TISS 20 to 35 on vent: <0.001; TISS 36 to 60: n.s.; TISS >60: n.s.

Figure 3

Mean length of stay in PACU for all PACU-patients in days. Data for quarters of year, from 1 January 2008 to 30 April 2011; n = 3,317 patients.

Figure 4

Mean CW per hospital day, before and after staffing the PACU with an intensivist. Values for all surgical patients treated in the PACU and surgical patients without treatment in PACU. PACU-Cases n = 3,317, no-PACU cases: n = 47,773.