The impact of universal cardiopulmonary exercise testing on perioperative pathways and short-term patient outcomes following elective pancreatic surgery: A retrospective cohort study.

Background: The utility of Cardiopulmonary Exercise Testing (CPET) to identify higher risk surgical patients remains controversial. There is limited research investigating the value of preoperative CPET to plan perioperative pathways for patients undergoing major pancreatic surgery. Methods: Retrospective cohort study, comprising two groups before and after a change in referral policy for High Risk preoperative anaesthetic clinic with CPET. Period 1 discretionary referral and Period 2: universal referral. The primary aim was to investigate the impact of this policy change on critical care use (planned vs unplanned) on the day of surgery and on delayed critical care admission. Secondary end points included a comparison of the total number of critical care bed days, days in hospital, complication rates and mortality data between the two cohorts. Results: 177 patients were included; 114 in Period 1 and 63 in Period 2. There was a reduction in unplanned day of surgery postoperative admissions to critical care (28.1% vs. 11.1%, p = 0.008). Seven (6.1%) of patients in Period 1 and 1 (1.6%) patient in Period 2 had delayed admission, though no p value was calculated due to the small numbers involved. Complication rates were similar in each group. The median critical care bed days was 1 (range 0-21) days in Period 1 and 1 (0-13) days in Period 2. Conclusions: A universal referral policy for preoperative CPET demonstrated a decrease in unplanned day of surgery critical care admissions and a trend towards reducing delayed (>24 h postop) critical care admission which could be investigated in a larger study. No measurable impact was seen on clinical outcomes.

Clinical assessment before hepatectomy identifies high-risk patients.

BACKGROUND: Liver resection is associated with significant morbidity, and assessment of risk is an important part of preoperative consultations. Objective methods exist to assess operative risk, including cardiopulmonary exercise testing (CPX). Subjective assessment is also made in clinic, and patients perceived to be high-risk are referred for CPX at our institution. This article addresses clinicians' ability to identify patients with a higher risk of surgical complications after hepatectomy, using selection for CPX as a surrogate marker for increased operative risk. MATERIALS AND METHODS: Prospectively collected data on patients undergoing hepatectomy between February 2008 and November 2013 were retrieved and the cohort divided according to CPX referral. Complications were classified using the Clavien-Dindo system. RESULTS: CPX testing was carried out before 101 of 405 liver resections during the study period. The median age was 72 and 64 in CPX and non-CPX groups, respectively (P < 0.001). The resection size was similar between the groups. No difference was noted for grade III complications between CPX and non-CPX tested-groups; however, 19 (18.8%) and 28 (9.2%) patients suffered grade IV-V complications, respectively (P = 0.009). There was no difference in long-term survival between groups (P = 0.63). CONCLUSIONS: This study attempts to assess clinicians' ability to identify patients at greater risk of complications after hepatectomy. The confirmation that patients identified in this way are at greater risk of grade IV-V complications demonstrates the value of preoperative counseling. High-risk patients do not have worse long-term outcomes suggesting survival is determined by other factors, particularly disease recurrence.

Impaired functional capacity in potential liver transplant candidates predicts short-term mortality before transplantation.

Liver transplantation (LT) is a lifesaving treatment. Because of the shortage of donor organs, some patients will not survive long enough to receive a transplant. The identification of LT candidates at increased risk of short-term mortality without transplantation may affect listing decisions. Functional capacity, determined with cardiopulmonary exercise testing (CPET), is a measure of cardiorespiratory reserve and predicts perioperative outcomes. This study examined the association between functional capacity and short-term survival before LT and the potential for CPET to predict 90-day mortality without transplantation. A total of 176 patients who were assessed for nonacute LT underwent CPET. Ninety days after the assessment, 10 of the 164 patients who had not undergone transplantation were deceased (mortality rate = 6.1%). According to a comparison of survivors and nonsurvivors, the Model for End-Stage Liver Disease score, UK Model for End-Stage Liver Disease (UKELD) score, age, anaerobic threshold, and peak oxygen uptake (VO(2)) were significant univariate predictors of 90-day mortality without transplantation, but only the UKELD score and peak VO(2) retained significance in a multivariate analysis. The mean peak VO(2) was significantly lower for nonsurvivors versus survivors (15.2 ± 3.3 versus 21.2 ± 5.3 mL/minute/kg, P < 0.001). According to a receiver operating characteristic (ROC) curve analysis, peak VO(2) performed well as a diagnostic test (area under the ROC curve = 0.84, 95% confidence interval = 0.76-0.92, sensitivity = 0.90, specificity = 0.74, P < 0.001). The optimal cutoff value for predicting mortality was ≤17.6 mL/minute/kg. The positive predictive value of a peak VO(2) ≤ 17.6 mL/minute/kg for 90-day mortality was greatest for patients with high UKELD scores: 38% of the patients with a UKELD score ≥ 57 and a peak VO(2) ≤ 17.6 mL/minute/kg died, whereas only 6% of the patients with a UKELD score ≥ 57 and a peak VO(2) > 17.6 mL/minute/kg died (P = 0.03). In conclusion, patients assessed for LT with an impaired functional capacity have poorer short-term survival; this is particularly true for individuals with worse liver disease severity.

Serum arterial lactate concentration predicts mortality and organ dysfunction following liver resection.

BACKGROUND: The aim of this study was to determine if the post-operative serum arterial lactate concentration is associated with mortality, length of hospital stay or complications following hepatic resection. METHODS: Serum lactate concentration was recorded at the end of liver resection in a consecutive series of 488 patients over a seven-year period. Liver function, coagulation and electrolyte tests were performed post-operatively. Renal dysfunction was defined as a creatinine rise of >1.5x the pre-operative value. RESULTS: The median lactate was 2.8 mmol/L (0.6 to 16 mmol/L) and was elevated (≥2 mmol/L) in 72% of patients. The lactate concentration was associated with peak post-operative bilirubin, prothrombin time, renal dysfunction, length of hospital stay and 90-day mortality (P < 0.001). The 90-day mortality in patients with a post-operative lactate ≥6 mmol/L was 28% compared to 0.7% in those with lactate ≤2 mmol/L. Pre-operative diabetes, number of segments resected, the surgeon's assessment of liver parenchyma, blood loss and transfusion were independently associated with lactate concentration. CONCLUSIONS: Initial post-operative lactate concentration is a useful predictor of outcome following hepatic resection. Patients with normal post-operative lactate are unlikely to suffer significant hepatic or renal dysfunction and may not require intensive monitoring or critical care.