Perioperative medicine training resources: U3M9: Complex morbidities and options for optimisation

Abstract
Background: We developed clinical practice guidelines to provide health care providers with evidence-based recommendations for decisions related to the effective management of frailty and pre-frailty using nutrition and physical activity interventions.

Methods: We based the recommendations on two systematic reviews with meta-analyses. Nutrition, physical activity, and combined nutrition and physical activity interventions for adults ≥65y were considered if study populations were identified as frail using a frailty tool or assessment. Risk of bias and certainty of evidence were evaluated. We included physical outcomes, mobility, frailty, cognitive function, activities of daily living, falls, quality of life, diet quality, energy/fatigue levels, health services use, and caregiver outcomes.

Results: Overall, mobility improvements were moderate with nutritional strategies that optimize dietary intake, various types of physical activity interventions, and interventions that combine nutrition and physical activity. Physical outcomes, such as body mass and muscle strength, improved moderately with nutritional strategies and interventions that combined nutrition with physical activity. Frailty status improved with multi-component physical activity interventions. Strong recommendations include optimizing dietary intake, performing physical activity, and adopting interventions that combine nutrition and physical activity. We strongly recommend various types of physical activity including muscle strengthening activities, mobilization or rehabilitation exercises, and multi-component physical activity interventions.

Interpretation: Tailored nutrition and physical activity interventions based on individual goals and health status are associated with improved clinical and physical outcomes. While the recommendations facilitate shared decision-making, we identified sparse application of validated frailty assessments and lack of standardized research outcomes as critical gaps in knowledge.

Abstract
People with diabetes mellitus (DM) undergo more elective surgery than those without DM; however, up to half of the patients are undiagnosed when referred for surgery. This is an opportunity to intervene and instigate a management plan. Preoperative strategies may vary based on coexisting medical diseases such as obesity and the availability of resources with the aim of achieving glycaemic control while also treating coexisting conditions. In the context of obesity, there is substantial overlap in some of the treatment strategies. Guidelines, such as those from the UK Centre for Perioperative Medicine, suggest target glycated haemoglobin levels, preoperative fasting blood glucose levels, and when to defer an elective operation or instigate treatment to proceed if deemed safe. Preoperatively glycaemic control is often achieved pharmacologically, and newer agents, including glucagon-like peptide one receptor agonists (GLP1-RA) and sodium-glucose co-transporter 2 (SGLT2) inhibitors, are emphasised in the preoperative management of diabetes mellitus, particularly if obesity is also present. A very low-energy diet is an underutilised but well-evidenced method of achieving both glycaemic control and weight loss with a particularly dominant effect on liver fat which is helpful for people who are due to undergo abdominal surgery. Bariatric-metabolic procedures are of growing interest as bridging interventions to surgery and are more commonly used for obesity, but they also have a well-recognized impact on the improvement and remission of DM. This review gives an overview of the necessity of preoperative identification of DM and strategies for management. Intra-operative glycaemic control is also discussed, and the role of stress hyperglycaemia perioperatively.

Abstract
Although much is known about surgical risk, little evidence exists regarding how best to proactively address preoperative risk factors to improve surgical outcomes. Preoperative malnutrition is a widely prevalent and modifiable risk factor in patients undergoing surgery. Malnutrition prior to surgery portends significantly higher postoperative mortality, morbidity, length of stay, readmission rates, and hospital costs. Unfortunately, perioperative malnutrition is poorly screened for and remains largely unrecognized and undertreated-a true "silent epidemic" in surgical care. To better address this silent epidemic of surgical nutrition risk, here we describe the rationalization, development, and implementation of a multidisciplinary, registered dietitian-driven, preoperative nutrition optimization clinic program designed to improve perioperative outcomes and reduce cost. Implementation of this novel Perioperative Enhancement Team (POET) Nutrition Clinic required a collaboration among many disciplines, as well as an identified need for multidimensional scheduling template development, data tracking systems, dashboard development, and integration of electronic health records. A structured malnutrition risk score (Perioperative Nutrition Screen score) was developed and is being validated. A structured malnutrition pathway was developed and is under study. Finally, the POET Nutrition Clinic has established a novel role for a perioperative registered dietitian as the integral point person to deliver perioperative nutrition care. We hope this structured model of perioperative nutrition assessment and optimization will allow for wide implementation and generalizability in other centers worldwide to improve recognition and treatment of perioperative nutrition risk.

Abstract
Background: The cardiologist is regularly consulted preoperatively by anaesthesiologists. However, insights into the efficiency and usefulness of these consultations are unclear.

Methods: This is a retrospective study of 24,174 preoperatively screened patients ≥18 years scheduled for elective non-cardiac surgery, which resulted in 273 (1%) referrals to the cardiologist for further preoperative evaluation. Medical charts were reviewed for patient characteristics, main reason for referring, requested diagnostic tests, interventions, adjustment in medical therapy, 30-day mortality and major adverse cardiac events.

Results: The most common reason for consultation was the evaluation of a cardiac murmur (95 patients, 35%). In 167 (61%) patients, no change in therapy was initiated by the cardiologist. Six consultations (2%) led to invasive interventions (electrical cardioversion, percutaneous coronary intervention or coronary artery bypass surgery). On average, consultation delayed clearance for surgery by two weeks.

Conclusion: In most patients referred to the cardiologist after being screened at an outpatient anaesthesiology clinic, echocardiography is performed for ruling out specific conditions and to be sure that no further improvement can be made in the patient's health. In the majority, no change in therapy was initiated by the cardiologist. A more careful consideration about the potential benefits of consulting must be made for every patient.

Abstract
Purpose of Review
The purpose of this article is to provide a brief review of the preoperative pulmonary evaluation of patients undergoing non-thoracic surgery, focusing on risk factor identification, assessment of specific high-risk populations, and strategies to minimize postoperative pulmonary complications (PPCs).

Recent Findings
Along with traditional risk factors, recent risk stratification indices have been developed and validated to help quantify risk of PPCs. Careful history and physical examination are key elements in the pulmonary evaluation of all pre-surgical patients. Patients with chronic obstructive pulmonary disease (COPD) are at increased risk and require more intensive optimization and perioperative monitoring. Well-controlled asthma has not been associated with increased risk of PPCs but the potential for life-threatening bronchospasm and status asthmaticus cannot be ignored. In general, the literature does not support delaying surgery for preoperative diagnosis and management of obstructive sleep apnea (OSA). Exceptions to this rule are patients presenting with evidence of obesity-hypoventilation syndrome or pulmonary hypertension. Recent literature provides more evidence of benefits of regional anesthesia and analgesia to decrease the risk of pulmonary complications, particularly in COPD patients.

Summary
PPCs are major contributors to perioperative morbidity and mortality. A thorough preoperative evaluation must identify high-risk patients, optimize chronic and acute respiratory diseases, and establish a clear perioperative plan to minimize PPCs.

Abstract
Purpose: Care bundles are recommended in patients at high risk for acute kidney injury (AKI), although they have not been proven to improve outcomes. We sought to establish the efficacy of an implementation of the Kidney Disease Improving Global Outcomes (KDIGO) guidelines to prevent cardiac surgery-associated AKI in high risk patients defined by renal biomarkers.

Methods: In this single-center trial, we examined the effect of a "KDIGO bundle" consisting of optimization of volume status and hemodynamics, avoidance of nephrotoxic drugs, and preventing hyperglycemia in high risk patients defined as urinary [TIMP-2]·[IGFBP7] > 0.3 undergoing cardiac surgery. The primary endpoint was the rate of AKI defined by KDIGO criteria within the first 72 h after surgery. Secondary endpoints included AKI severity, need for dialysis, length of stay, and major adverse kidney events (MAKE) at days 30, 60, and 90.

Results: AKI was significantly reduced with the intervention compared to controls [55.1 vs. 71.7%; ARR 16.6% (95 CI 5.5-27.9%); p = 0.004]. The implementation of the bundle resulted in significantly improved hemodynamic parameters at different time points (p < 0.05), less hyperglycemia (p < 0.001) and use of ACEi/ARBs (p < 0.001) compared to controls. Rates of moderate to severe AKI were also significantly reduced by the intervention compared to controls. There were no significant effects on other secondary outcomes.

Conclusion: An implementation of the KDIGO guidelines compared with standard care reduced the frequency and severity of AKI after cardiac surgery in high risk patients. Adequately powered multicenter trials are warranted to examine mortality and long-term renal outcomes.

Keywords: Acute kidney injury; Biomarkers; Cardiac surgery; KDIGO guidelines; Major adverse kidney events; [TIMP-2]·[IGFBP7].

Abstract
Background: Preoperative anemia is a common comorbidity that often necessitates allogeneic blood transfusion (ABT). As there is a risk associated with blood transfusions, preoperative intravenous iron (IV) has been proposed to increase the hemoglobin to reduce perioperative transfusion; however, randomized controlled trials (RCT) investigating this efficacy for IV iron are small, limited, and inconclusive. Consequently, a meta-analysis that pools these studies may provide new and clinically useful information.

Methods/design: Databases of MEDLINE, EMBASE, EBM Reviews; Cochrane-controlled trial registry; Scopus; registries of health technology assessment and clinical trials; Web of Science; ProQuest Dissertations and Theses; Clinicaltrials.gov; and Conference Proceedings Citation Index-Science (CPCI-S) were searched. Also, we screened all the retrieved reference lists.

Selection criteria: Titles and abstracts were screened for relevance (i.e., relevant, irrelevant, or potentially relevant). Then, we screened full texts of those citations identified as potentially applicable.

Results: Our search found 3195 citations and ten RCTs (1039 participants) that met our inclusion criteria. Preoperative IV iron supplementation significantly decreases ABT by 16% (risk ratio (RR): 0.84, 95% confidence interval [CI]: 0.71, 0.99, p = 0.04). In addition, preoperatively, hemoglobin levels increased after receiving IV iron (mean difference [MD] between the study groups: 7.15 g/L, 95% CI: 2.26, 12.04 g/L, p = 0.004) and at follow-up > 4 weeks postoperatively (MD: 6.46 g/L, 95% CI: 3.10, 9.81, p = 0.0002). Iron injection was not associated with increased incidence of non-serious or serious adverse effects across groups (RR: 1.13, 95% CI: 0.78, 1.65, p = 0.52) and (RR: 0.96, 95% CI: 0.44, 2.10, p = 0.92) respectively.

Conclusions: With moderate certainty, due to the high risk of bias in some studies in one or two domains, we found intravenous iron supplementation is associated with a significant decrease in the blood transfusions rate, and modest hemoglobin concentrations rise when injected pre-surgery compared with placebo or oral iron supplementation. However, further full-scale randomized controlled trials with robust methodology are required. In particular, the safety, quality of life, and cost-effectiveness of different intravenous iron preparations require further evaluation.

Abstract
Objective: To assess the association between having a serious mental illness and surgical outcomes for adults, including in-hospital and 30-day mortality, post-operative complications, and hospital length of stay.

Study design: Systematic review and meta-analysis of publications in English to 30 July 2018 of studies that examined associations between having a serious mental illness and surgical outcomes for adults who underwent elective surgery. Primary outcomes were in-hospital and 30-day mortality, post-operative complications, and length of hospital stay. Risk of bias was assessed with the Quality in Prognosis Studies (QUIPS) tool. Studies were grouped by serious mental illness diagnosis and outcome measures. Odds ratios (ORs) or mean differences (MDs), with 95% confidence intervals (CIs), were calculated in random effects models to provide pooled effect estimates.

Data sources: MEDLINE, EMBASE, PsychINFO, and the Cochrane Library.

Data synthesis: Of the 3824 publications identified by our search, 26 (including 6 129 806 unique patients) were included in our analysis. The associations between having any serious mental illness diagnosis and having any post-operative complication (ten studies, 125 624 patients; pooled effect: OR, 1.44; 95% CI, 1.15-1.79) and a longer stay in hospital (ten studies, 5 385 970 patients; MD, 2.6 days; 95% CI, 0.8-4.4 days) were statistically significant, but not those for in-hospital mortality (three studies, 42 926 patients; OR, 1.21; 95% CI, 0.69-2.12) or 30-day mortality (six studies, 83 013 patients; OR, 1.85; 95% CI, 0.86-3.99).

Conclusions: Having a serious mental illness is associated with higher rates of post-operative complications and longer stays in hospital, but not with higher in-hospital or 30-day mortality. Targeted pre-operative interventions may improve surgical outcomes for these vulnerable patients.