Peri-operative pharmacy services and the enhanced recovery pathway

Pharmacists can play a crucial role within surgical enhanced recovery pathways. This article discusses some of the strategies that can be employed in optimising long-term conditions peri-operatively to achieve the best possible patient outcomes

The World Health Organization has estimated that approximately 234 million surgical procedures are performed worldwide each year.¹ Although most of these procedures are uncomplicated, an increasing number of individuals are at risk of adverse outcomes because of comorbid conditions and poor functional capacity. At age 65, 50% of the UK population has multi-morbidity (two or more long-term conditions), and this proportion rises with age and deprivation.² Complications which prolong length of stay occur after approximately 15% of inpatient operations, which can be mitigated by optimising patients for surgery.³   

Optimising patients for surgery

One of the key stages of enhanced recovery (ER) is optimising patients for surgery. The concept of ER was first pioneered in Denmark in the late 1990s for patients undergoing colorectal surgery.⁴ Since their introduction in the UK in the early 2000s, ER pathways have been successfully implemented within various surgical specialities in the UK, the primary aim being to reduce the length of stay while still providing a high-quality package of care. Fundamental to all aspects of ER is that patients are ‘partners in their own care’ and are kept fully informed throughout their surgical journey.

Pre-operative assessment

It is crucial that assessment and preparation for surgery starts as soon as possible adopting a multi-modal, trans-disciplinary approach.² Primary care physicians can play a major role in identifying the modifiable causes of increased morbidity; for example, smoking, reduced physical activity, excess alcohol and poor nutrition prior to referral for surgery. 

Pre-assessment clinics (nurse-, anaesthetist- and pharmacist-led) are also crucial in identifying these ‘high-risk’ patients with multiple comorbidities at risk of post-operative complications: for example, pre-existing anaemia, diabetes, cardiovascular and respiratory disease. 

Implementation of an ER pharmacist service: a local example

In line with the ER initiative, a pharmacist-led Enhanced Surgical Medicines Optimisation Service (ESMOS) was implemented in a large 1200-bedded tertiary hospital in Central Manchester in September 2017 to mitigate the risks of post-operative complications and optimise post-operative care.⁵ The goals of the ESMOS service are to identify high-risk surgical patients once they are listed for surgery and get them in the best possible state for surgery by focusing on optimising their pre-existing comorbidities.

During the pre-operative phase, patients are reviewed in a virtual pharmacist clinic whereby patients’ pre-existing medical comorbidities are recorded by pharmacists along with any high-risk medication the patient is taking.^6,7 The goal at this stage is to optimise long-term conditions prior to surgery. The ESMOS was initially rolled out to four main general surgical sub-specialties: hepato-pancreato-biliary (HPB); upper gastrointestinal (GI); lower GI; and vascular surgery. 

The results of the 12-month follow up study following implementation of the ESMOS service demonstrated a significant reduction in length of stay and post-operative complications.⁶ 

Preparation for surgery 

Pharmacists can play a key role in identifying patients with co-morbid conditions and optimising these prior to surgery as time allows. Figure 1 summarises the key areas of optimisation. 

Over the next section, strategies that can be employed in optimising these comorbid conditions are discussed in more detail. 

Optimising cardiac function 

Thorough assessment of cardiac morbidity is particularly important for high-risk surgical patients. The revised cardiac risk index is one of the most validated and widely used risk assessment tools for predicting peri-operative risk in patients with cardiac comorbidities.⁷ 

Hypertension alone is only a minor independent risk factor for adverse cardiac events in non-cardiac surgery.⁷ Postponement of planned surgical procedures due to elevated blood pressure is a common reason to cancel necessary surgery. 

The Joint Guidelines from the Association of Anaesthetists of Great Britain and Ireland and the British Hypertension Society have produced a consensus statement stating patients with clinic blood pressures below 180mmHg systolic and 110mmHg diastolic should not have their surgical procedure delayed.⁸ Patients with stage 3 hypertension (BP >180mmHg systolic /110mmHg diastolic) should have their surgery delayed with BP optimisation and allowing a minimum of 4-6 weeks of treatment following the National Institute for Health and Care Excellence/British Heart Society CG127 algorithm.⁸ Patients presenting with stage 1 (BP 130–139mmHg systolic or 80–89mmHg diastolic) or stage 2 hypertension (BP >140mmHg systolic or 90mmHg diastolic) are considered safe to proceed to surgery.⁸ 

It should be noted that patients with diastolic pressure ≥110mmHg immediately before surgery have been shown to have increased risk of complications including myocardial infarction and renal failure.⁹ 

Heart failure is a global problem, with at least 26 million people affected.¹⁰ The prevalence of heart failure is also increasing as the population ages, and more patients with congestive heart failure will present for surgery.¹¹ In patients with acutely decompensated heart failure (New York Heart Association class IV), surgery should be postponed, if possible, and the opinion of a cardiologist sought for titration of heart failure medication.⁷ Pharmacists can play a vital role in up-titration of heart failure medication in this crucial period. 

Optimising respiratory function 

Pre-operative optimisation of lung function helps to reduce post-operative pulmonary complications.¹² Patients are advised to stop smoking for a period of 4–6 weeks. This reduces airway reactivity, improves mucociliary function and decreases carboxy-haemoglobin.¹² Pharmacists can help promote smoking cessation advice to these ‘at-risk’ patients. 

Incentive spirometry pre-operatively has also proved to be effective in reducing post-operative pulmonary complications.¹³ Pharmacists can further support patients by providing the appropriate counselling on correct inhaler technique and checking compliance. Patients with symptomatic asthma should have their treatment increased until symptom control is achieved.¹⁴ Approximately 4.5% of the UK population aged over 40 years are affected by chronic obstructive pulmonary disease (COPD).¹⁵ For the care of COPD, the updated National Institute for Health and Care Excellence (NICE) guidance emphasises ‘five fundamentals’ of chronic obstructive pulmonary disease care: offer treatment and support to stop smoking; offer pneumococcal and influenza vaccinations; offer pulmonary rehabilitation for people with COPD (if indicated); co-develop a personalised self-management plan; and optimise treatment of comorbidities.¹⁶ Postponement of surgery is advisable only after a recent exacerbation.¹³ 

Optimising diabetes control

Peri-operative hyperglycaemia, whether the cause is known diabetes, undiagnosed diabetes or stress hyperglycaemia, is a risk factor for harm, increased length of stay and death.^17,18 

The Centre for Peri-operative Care (CPOC) in the UK has published guidance on the peri-operative care for patients with diabetes mellitus undergoing elective and emergency surgery.¹⁹ 

Ideally, diabetic patients should be optimised at the time of referral from primary care.¹⁷ In situations where this is not possible, advice from the diabetes team should be sought as soon as possible to facilitate optimisation. 

The key recommendations from the CPOC guideline are that pre-operative assessment clinics should refer all patients with a HbA1C of 69mmol/mol and above, an insulin pump or a continuous subcutaneous insulin infusion (CSII) to a specialist diabetes team for treatment optimisation.¹⁹  Another recommendation from this document is that pre-assessment clinics should work where possible, with the pharmacy team to ensure medicines reconciliation prior to admission to reduce medication errors including a system for patients to report changes to their medication between their pre-operative assessment and date of surgery. Ideally, diabetic medication should be pre-prescribed prior to admission and for best practice rescue treatment should also be pre-prescribed for looming hypo- or hyper-glycaemia.¹⁹  

Pharmacists can use this vital time adequately to promote lifestyle interventions such as smoking cessation, lifestyle modification, reduction in alcohol intake, optimal nutrition and weight management. 

Optimising pre-existing anaemia 

It has been estimated that approximately 40% of patients presenting for surgery are anaemic.²⁰ Pre-operative anaemia is associated with significantly higher rates of morbidity and mortality and increased need for blood transfusion. 

Patients undergoing major surgery (defined as blood loss >500ml expected or possible) should be optimised if their haemoglobin concentration is less than 130g/l on screening.

Detection of pre-operative anaemia should be carried out as soon as possible, at least 14 days before elective surgery.²¹ 

Figure 2 suggests a treatment algorithm for different types of anaemia from diagnosis to surgery based on an international consensus statement as described by Munoz et al.²² 

Treatment of iron deficiency anaemia should be carried out with iron supplementation, and there is good evidence that this results in higher haemoglobin concentrations, lower transfusion rates and better quality of life.²¹ When the interval between investigation and surgery is sufficient (>6 weeks), oral iron treatment may be considered.²¹ 

Pharmacists can play a key role in optimising pre-operative anaemia by identifying affected patients in the first instance, interpreting laboratory results and working with the wider multi-disciplinary team to ensure a management plan is in place to correct the anaemia. 

Optimising anticoagulation control 

An increasing number of patients considered for surgery are on anticoagulants hence it is important that these are managed appropriately in the peri-operative period to reduce the incidence of thrombotic events. The British Society of Haematology has published guidelines on the peri-operative management of anticoagulation.²³ Pharmacists can support pre-assessment clinics by ensuring these patients have an appropriate management plan in place. 

For those patients on warfarin, this should be stopped for five days prior to surgery and bridging-dose heparin should be considered in high-risk patients, with the last dose at least 24 hours prior to surgery for those on a once-daily regimen. 

For patients on direct oral anticoagulants, the peri-operative management approach is based on an approximate calculation of the half-life of the drug and renal function. This is combined with consideration of the bleeding risk of the proposed procedure and a clinical evaluation of the patient’s individual risk factors for bleeding and thrombosis. Where available, local guidelines should be consulted and advise sought from specialist haematology teams in complex patients. 

Conclusion

This article summarises some of the strategies that can be employed in this crucial pre-operative period to optimise patients for surgery to achieve the best possible patient outcomes. It is recognised that the surgery waiting lists in the UK already under pressure have been further increased by the COVID-19 pandemic. These waiting lists provide a unique opportunity for multidisciplinary teams to work collaboratively, further supporting the concept of enhanced recovery. 

References

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