Perioperative care for hepato-pancreato-biliary surgery

Introduction to perioperative medicine

Perioperative medicine is a cross-specialty collaboration focussed on the patient experience from the preoperative period until their discharge home and full recovery. In addition to improving the overall patient experience, good perioperative care can reduce complication rates, average length of hospital stay, mortality, readmission rates and per capita cost.

Evidence-based protocols as part of ERAS pathways are now widely used across a variety of surgical specialties, including liver and pancreatic surgery. ^, They aim to achieve earlier recovery by optimising preoperative physiological function, reducing the surgical stress response and facilitating postoperative recovery. Evidence for ERAS in patients with cirrhosis or obstructive jaundice is still fairly limited.

Focus on the preoperative period has become increasingly important for the surgeon and anaesthetist, with an aim to identify those at particular increased risk for significant perioperative morbidity or even mortality.

Preoperative period

Patient engagement is a vital part of the perioperative journey and starts with the first encounter. ‘Making Every Contact Count’ is a national approach to use the multitude of interactions patients have with the healthcare team to encourage positive change in their physical and mental health and wellbeing. It is important to put patients at the centre of their care and by gaining their confidence, it is hoped they will improve engagement with prehabilitation and preparation for both their operation and the recovery period.

Risk stratification

Preoperative risk scoring systems and risk prediction models can be used in both the elective and emergency settings to estimate adverse postoperative outcomes. These figures can then be used to guide discussions both within the MDT and with the patient to make more meaningful and informed decisions about the proposed procedure.

Child–Pugh scoring was developed in the 1960s to predict mortality in patients with cirrhosis undergoing portosystemic shunts and is still used today as a broad measure of perioperative risk in patients with liver failure. The Child–Pugh score was further developed for use in liver transplantation but has since been replaced with the Model for End-stage Liver Disease (MELD) or United Kingdom Model for End-Stage Liver Disease (UKELD) score, which includes a wider range of variables. ^,

The National Surgical Quality Improvement Program (NSQIP) collects data on morbidity and mortality based on 135 clinical variables for patients undergoing major surgical procedures from the preoperative period to 30 days postoperatively. The data from this large-scale audit has led to the development of the surgical risk calculator, which predicts outcomes based on the proposed surgery and individual patient risk factors. Other perioperative scoring systems used are the ASA (American Society of Anaesthesiology) score, P-POSSUM (Portsmouth Physiological and Operative Severity Score for the enumeration of Morbidity and Mortality) and SORT (Surgical Outcome Risk Tool). These vary in complexity, although the rise in app-based technology makes the majority of these scores quick and easy to calculate.

Risk is also evaluated in the preoperative assessment clinic using a range of techniques designed to determine cardiopulmonary reserve. The 6-minute walk test (6MWT) is a simple test which measures the distance patients can walk on a flat surface at normal pace in 6 minutes. In thoracic and major general surgery, the distance was found to be predictive of postoperative complications and length of stay. Cardiopulmonary exercise testing (CPET) provides an objective assessment of exercise capacity and determines where the limitation lies ( Fig. 3.1 ). During graded exercise on a static cycle, CPET records data on oxygen consumption, anaerobic threshold and extrapolates stroke volume. This can be used to differentiate causes of dyspnoea, prognosticate for cardiopulmonary disease and detail the patient’s functional status.

Information from all of the above can be used to inform MDT decision-making, direct prehabilitation efforts, guide intraoperative anaesthetic and surgical management and assist in the triage of postoperative care.

Preoperative counselling

Whilst there are no studies specifically evaluating the effect of preoperative counselling before hepato-biliary surgery, there is evidence that managing patient expectations and providing written information increases the patient’s engagement with the decision-making process.

The Academy of Medical Royal Colleges host the ‘Choosing Wisely’ campaign—a global initiative aimed at improving conversations between patients and healthcare staff. The framework encouraged for use by patients in consultations is BRAN:

• What are the B enefits?

• What are the R isks?

• What are the A lternatives?

• What if I do N othing?

Following the Montgomery ruling, it is now not only unacceptable but also unlawful to fail to provide patients with adequate information to allow them to make an informed decision and to provide consent for a procedure.

Multidisciplinary team

Shared decision-making is now the cornerstone of patient-centred care. MDT input comprising surgeons, physicians, anaesthetists, oncologists, specialist nurses, physiotherapists and dieticians provides a coordinated approach to the management of the patient and a sharing of expertise. Whilst there is little high-grade evidence to suggest that MDT meetings improve clinical outcomes, they allow discussion of the available options, which may include a non-operative approach such as interventional radiological procedures or chemotherapy. It is imperative that patient’s wishes and expectations are known and that these are considered when planning treatment. Health-related quality of life is of greater importance to the individual patient than many of the traditionally used outcome measures, and there is increasing focus on developing validated tools to assess this.

Optimisation of comorbidities and prehabilitation

Major surgery evokes a stress response, the impact of which varies upon the pre-morbid physiological and psychological reserves of the patient. More vulnerable patients will experience greater morbidity, mortality and longer stays in hospital. Increasing efforts are being made to optimise patients before surgery to improve outcomes with a multimodal prehabilitation approach.

Hypertension

Hypertension is increasingly common in elective surgical patients and if uncontrolled, it increases the risk of perioperative MI, stroke, bleeding and death. Blood pressure should be optimised prior to elective surgery, with sufficient time to allow autoregulatory mechanisms to reset and promote adequate organ perfusion. ACE inhibitors should be withheld on the day of surgery to prevent exaggerated hypotension during induction of anaesthesia. Beta-blockers, if established, should be continued to prevent rebound tachyarrhythmias and an increase in myocardial oxygen demand.

Anaemia

Anaemia is multifactorial and is common in patients presenting for surgery. Even mild anaemia increases postoperative morbidity and mortality, and is associated with longer hospital stay and increased risk of allogenic blood transfusion. The introduction of Patient Blood Management (PBM) has shifted the focus from the use of blood products to optimisation of the patient. The three pillars of PBM strategies are: 1) improving red cell mass with iron or erythropoietin-stimulating agents; 2) minimising blood loss by optimising surgical and anaesthetic techniques; and 3) optimising patient tolerance of anaemia by improving preoperative cardiopulmonary function. Surgery should be delayed where possible to allow for oral iron supplementation. Increasing numbers of centres have the facility to provide intravenous (IV) iron infusions preoperatively. However, in 2020, a randomised controlled trial (RCT) did not show a clinically significant reduction in blood transfusion following preoperative IV iron therapy.

Diabetes

Diabetes affects nearly 10% of the global population, although it is estimated that a far greater number of people are undiagnosed. Diabetes is a multisystem disease, associated with poor surgical outcomes. Improving glycaemic control and optimising associated complications will protect against further insults.

Frailty

Frailty is gaining increasing recognition in perioperative medicine, although remains difficult to quantify. A number of objective assessment techniques, such as the Clinical Frailty Scale (CFS) or Edmonton Frail Scale (EFS) are widely used, but there is no set of agreed criteria for diagnosing frailty. Increasing awareness of the challenges of frailty have led to the introduction of specific perioperative services such as the Proactive care of Older People undergoing Surgery (POPS) clinics which support individuals who would most benefit from prehabilitation services.

Lifestyle interventions