Preoperative cardiopulmonary exercise testing improves risk assessment of morbidity and length of stay following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are the standard treatment for selected patients with peritoneal malignancy. The optimal means of assessing risk prior to these complex operations is not known. This study explored the associations between preoperative cardiopulmonary exercise testing (CPET) variables and postoperative outcomes following elective CRS and HIPEC. This study included patients who underwent routine preoperative CPET prior to elective CRS and HIPEC at Royal Prince Alfred Hospital in Sydney between July 2017 and July 2020. CPET was performed using a cycle ergometer and measured peak oxygen uptake (VO₂ peak) and anaerobic threshold (AT). Outcomes included in-hospital morbidity, length of intensive care unit (ICU) stay and hospital stay. The associations between preoperative CPET variables and postoperative morbidity were assessed using univariate and multivariate analyses. A total of 129 patients were included. Mean age was 56 years (standard deviation (SD) 12.5 years), and colorectal cancer was the most common indication for CRS and HIPEC. The overall complication rate was 69%, and two (1.6%) patients died in hospital. Patients who did not develop any postoperative complication had slightly higher preoperative AT and VO₂ peak and shorter length of hospital stay. Data in this study support the role of CPET prior to CRS and HIPEC as an adjunct to improve risk assessment.

Nutritional prehabilitation: physiological basis and clinical evidence

In this narrative review, we describe the physiological basis for nutritional prehabilitation and evaluate the clinical evidence for its current roles in the perioperative period. Surgical stress and fasting induce insulin resistance as a result of altered mitochondrial function. Insulin resistance in the perioperative period leads to increased morbidity in a dose-dependent fashion, while preoperative carbohydrate loading attenuates insulin resistance, minimises protein loss and improves postoperative muscle function. Carbohydrate loading is an established practice in many countries and a key component of enhanced recovery after surgery (ERAS) programs, yet its independent effects on clinical outcomes remain unclear. Amino acid supplements may confer additional positive effects on a number of markers of clinical outcomes in the perioperative period, but their current role is also poorly defined. Clinical studies evaluating nutritional interventions have been marred by conflicting data, which may be due to small sample sizes, as well as heterogeneity of patients and surgical procedures. At present, it is known that carbohydrate loading is safe and improves patients' wellbeing, but does not appear to influence length of hospital stay or rate of postoperative complications. This should be appreciated before its routine inclusion in ERAS programs.

The role of prehabilitation in frail surgical patients: A systematic review

INTRODUCTION

Increasing emphasis is being placed on the detection of frailty in the pre-operative setting given its association with surgical morbidity and mortality. Prehabilitation seeks to increase the physiological reserve of frail patients, attenuating the risk of irreversible functional decline following surgery.

AIM/HYPOTHESIS

This systematic review appraises the evidence available for prehabilitation in frail surgical patients. We proposed that exercise prehabilitation would especially benefit frail patients, with improvements in pre-operative functional capacity, and reductions in complications and length of hospital stay.

METHODS

A literature search was conducted in MEDLINE, PubMed and CINAHL databases. Studies were included if they consisted of a prehabilitation intervention in frail patients undergoing surgery and specified a frailty model/index. Eight studies were included for analysis, 2 of which are ongoing studies.

RESULTS

In 3 studies, prehabilitation consisted of an exercise intervention alone. There was a high feasibility of prehabilitation and a trend to improved pre-operative function, however, no evidence of improved post-operative functional recovery was there. In 2 studies, prehabilitation consisted of both exercise and nutritional interventions. Reductions in mortality and duration of hospital stay were reported, but the quality of evidence was judged to be very low. There was a lack of evidence of improved outcomes following pre-operative inspiratory muscle training in frail patients.

DISCUSSION

This systematic review focuses on prehabilitation in frail surgical patients and reports that evidence supporting any outcome is limited, despite high feasibility and acceptability. There is a need for large randomised controlled trials to better establish the effects of prehabilitation in frail patients.

Endothelial glycocalyx: basic science and clinical implications

The classic Starling principle proposed that microvascular fluid exchange was determined by a balance of hydrostatic and oncotic pressures relative to the vascular wall and this movement of water was regulated by gaps in the intercellular spaces. However, current literature on the endothelial glycocalyx (a jelly-like protective layer covering the luminal surface of the endothelium) has revised Starling's traditional concepts. This article aims to summarise the literature on the glycocalyx related to its basic science, clinical settings inciting injury, protective strategies and clinical perspectives. Perioperative damage to the glycocalyx structure can increase vascular permeability leading to interstitial fluid shifts, oedema, and increased surgical morbidity. Pathological shedding of the glycocalyx occurs in response to mechanical cellular stress, endotoxins, inflammatory mediators, atrial natriuretic peptide, ischaemia-reperfusion injury, free oxygen radicals and hyperglycaemia. Increased understanding of the endothelial glycocalyx may change perioperative fluid management, and therapeutic strategies aimed at its preservation may improve patient outcomes.