Delayed Mortality in Patients Receiving Postoperative High-Acuity Care

Abstract

This cohort study compares longer-term postsurgical mortality after advanced recovery room care compared with usual ward care.

The ARRC II study assessed high-acuity postoperative care from arrival in the postanesthesia care unit until the morning of postoperative day 1 using an advanced recovery room care (ARRC) model to treat medium-risk patients who underwent a wide range of elective and emergency surgeries.¹ Findings showed a decrease in major postoperative complications and an increase in postoperative days at home compared with usual ward care. Mortality at 30 or 90 days was numerically, but not statistically significantly decreased, which may reflect type II error as the number of deaths was small.

Short-term postoperative harm (complications) has been shown to be associated with longer-term mortality in large cohort studies.^2,3,4 We hypothesized that longer-term mortality after ARRC might be decreased compared with usual care.

Methods

This cohort study was a post hoc exploratory analysis of the outcomes of ARRC associated with mortality 18 months after surgery. The research ethics committee of Central Adelaide Local Health Network approved the study. The need for informed consent was waived based on evidence of benefit from a pilot study. This study followed the STROBE reporting guideline.

Mortality data from March 1, 2021, to October 14, 2023, were collected via the South Australian Registry of Births, Deaths and Marriages at 18 months after surgery from ARRC II patients. Survival curves were calculated to compare ARRC with usual care for the propensity-matched subgroup for which the original analysis was reported. Because ARRC II was a prospective cohort design, comprehensive propensity score matching was used to address confounding risk. Mortality at 18 months was compared between the 2 groups using the log-rank test. Data were analyzed using R, version 4.2.1 (R Foundation).

Results

The ARRC cohort comprised 348 patients (median [range] age, 72 [19-97] years; 157 female [44%] and 191 male [56%]), and the usual care cohort comprised 348 patients (median [range] age, 72 [19-97] years; 163 female [46%] and 185 male [54%]). National Safety and Quality Improvement Program–estimated 30-day mortality was 1.7% in both groups.¹ Postoperative mortality at 1, 3, 12, and 18 months for the ARRC and usual care groups are shown in the Figure. Mortality over 18 months was significantly lower in the ARRC group (hazard ratio [HR], 0.65; 95% CI, 0.44-0.98; P = .04).

Figure. Survival Analysis for Patients Receiving Advanced Recovery Room Care (ARRC) vs Usual Care for the Propensity Score–Matched Subgroup Analyzed in the Original Report.

Discussion

These findings suggest that reducing early postoperative complications with ARRC is associated with delayed mortality. Observational studies have found an association between postoperative complications in the early weeks after surgery and long-term mortality in populations comparable to ours. Khuri et al² found a 3- to 5-fold mortality increase at 12 months if any early complication occurred. Moonesinghe et al³ found that for elective surgery, prolonged postoperative morbidity conferred an HR of 3.5 for 12-month mortality. Recently, an HR of 1.9 for 12-month mortality was found in lower-risk patients with early complications.⁴

Our data suggest that mortality associated with postsurgical complications may be preventable. The mechanisms are not certain. A previously noted association between early postoperative hypotension and delayed morbidity and mortality suggests that early detection and management may play a role.⁵ At a cellular level, systemic inflammatory response syndrome (SIRS) is known to occur as a result of surgery, and long-term persistence may increase the risk of delayed morbidity and mortality. Treatments for SIRS may alter postoperative outcomes.⁶ Early optimization of a range of physiologic parameters in ARRC may have a positive association with SIRS responses to surgery, with the most common issues managed being blood pressure (hypotension), heart rate, and oxygen saturation.¹ Complications may also prolong recovery, leading to physical debilitation, decreased subsequent activity and exercise levels, and consequent negative health outcomes.

This study shows that ARRC is clinically important and significantly associated with decreased postoperative mortality. However, the study was limited by a small sample size, indicating the need for caution in the interpretation of our findings. This analysis supports the urgent need for a definitive outcome study.

Supplement.

Data Sharing Statement