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.

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.

Objective To establish the feasibility and acceptability of a preoperative exercise program, and to obtain pilot data on the likely difference in key surgical outcomes to inform the sample size calculation for a full-scale trial. Design Pilot randomized controlled trial. Setting Royal Prince Alfred Hospital, Sydney, Australia. Subjects We included patients undergoing elective pelvic exenteration or cytoreductive surgery aged 18 to 80 years, who presented to the participating gastrointestinal surgeon at least 2 weeks prior to surgery. Patients presenting cognitive impairment, co-morbidity preventing participation in exercise, inadequate English language, currently participating in an exercise program or unable to attend the exercise program sessions were excluded. Methods Participants were randomized to a 2–6 weeks preoperative, face-to-face, individualised exercise program or to usual care. Feasibility was assessed with consent rates to the study, and for the intervention group, retention and adherence rates to the preoperative exercise program. Acceptability of the exercise program was assessed with a semi-structured questionnaire exploring the advice received and the amount, duration and intensity of the exercise program. In addition, postoperative complication rates (Clavien-Dindo), length of hospital stay and self-reported measures of health-related quality of life (SF-36v2) were collected at baseline, day before surgery and in-hospital up to discharge from hospital. Results Of 122 patients screened, 26 (21%) were eligible and 22 (85%) accepted to participate in the trial and were randomized to the intervention (11; 50%) or control group (11; 50%). The median age of the include participants was 63 years. Adherence to the preoperative exercise sessions was 92.7%, with all participants either satisfied (33%) or extremely satisfied (67%) with the overall design of the preoperative exercise program. No significant differences in outcomes were found between groups. Conclusions The results of our pilot trial demonstrate that a preoperative exercise program is feasible and acceptable to patients undergoing major abdominal cancer surgery. There is an urgent need for a definite trial investigating the effectiveness of a preoperative exercise program on postoperative outcomes in patients undergoing major abdominal cancer surgery. This could potentially reduce postoperative complication rates, length of hospital stay and subsequently overall health care costs. Trial registration ACTRN12617001129370. Registered on August 1, 2017, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373396&showOriginal=true&isReview=true