Pre-operative

Heart Failure and Surgical Mortality

Heart Failure is a recognized red flag for surgical risk. This retrospective study sought to quantify the risk in over 600,000 patients undergoing non-cardiac surgery. The findings showed that crude 90-day mortality for patients with heart failure and symptoms was 10.1%; for patients with heart failure and no symptoms, 4.9%; and for patients without heart failure, 1.2%.

The important message is that in heart failure even without symptoms, mortality is higher.

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Routine Preoperative Testing for Cataract Surgery

This Cochrane review summarizes the evidence that has been found in that “Preoperative medical testing did not reduce the risk of medical adverse events during or after cataract surgery when compared to selective or no testing”.

There was no difference in medical adverse events, cancellation rates or eye complications. Costs however were 2.5 times higher.

Although the findings do not preclude specific circumstances, the overall findings do not support preoperative testing before cataract surgery as medically or economically effective, despite the usually older population with frequent comorbidities.

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Difficult Intubation Prediction

Anesthesiologists take an intuitive eyeball approach to anticipating difficult intubations, but many formal scores and assessment tools of varying sensitivity and specificity exist, like the Mallampati or Wilson scores. This full text JAMA review looks at some of these in predicting difficult intubation.

The best predictors were an inability to bite the upper lip with the lower incisors, a short hyomental distance, retrognathia, or a combination of findings based on the Wilson score.

The inability to bite the upper lip with the lower teeth was the best predictor.

A good full text review at this link

High Flow Nasal Oxygen vs. Facemask Preoxygenation

Two studies compare high flow nasal oxygen (HFNO) with facemask preoxygenation, one in obstetrics. Both reach the same conclusion in that HFNO is inferior to standard facemask preoxygenation.

HFNO, or simply a maximally cranked nasal cannula placed under the facemask have both been shown to increase apnea time and desaturation during difficult intubations but as a stand-alone measure are inadequate to optimize oxygenation prior to anesthesia induction.

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Psychological Factors and Surgical Outcome

Anaesthesia publishes this interesting discussion of what is a somewhat heterogeneous literature on how psychology and mental health may impact surgical recovery and outcome. It discusses how anxiety and catastrophizing impacts pain, and how depression may predict longer term pain and recovery trajectory. Attitudinal factors, particularly self‐efficacy, a positive outlook and patient‐perceived control have been associated with earlier functional recovery.

The authors discuss how education, stress control, behavioural training, and multimodal prehabilitation including exercise can improve functional recovery, although traditional surgery outcome gains may not be as apparent from available literature.

There is a need for further study and for now it is suggested that “it may be that a stratified approach is required, targeting patients with abnormal mood and low self‐efficacy for prehabilitation”.

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Elderly and Frail Patient Pre-op Optimization

Anaesthesia provides this focus on the important issue of frail and elderly patients presenting for surgery. Beyond basic medical assessment, it emphasizes assessment of non-traditional aspects now clearly linked to worse outcomes, like frailty, balance and gait, nutritional status, cognitive issues, mental health, functional status, medications and polypharmacy, social and family supports.

Pre‐operative comprehensive geriatric assessment is now enshrined in many programs, reference being made to programs at Guy’s and St Thomas’, Nottingham, Duke and Michigan.

Review of several Frailty assessment tools is provided, including the Fried Scale, Rockwood Index, Clinical Frailty Score, and Edmonton Scale.

Nutritional assessment and optimization are discussed, as well as current opinion on the prevention and management of delirium and post-operative cognitive dysfunction.

The importance of (often absent) advance directives and proxy decision makers is stressed, and the need to involve patients and families in shared decision making that goes beyond simple surgical risk, but encompassing patient-centred outcomes such as functional decline, loss of independence and the subsequent care burden

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Preoperative Cardiac Optimization

Another Anaesthesia review discusses the approach to preoperative cardiac risk stratification, hypertension, heart failure, murmurs, beta-blockers and other medication management, and implantable electronic cardiac devices.

Also discussed is the role of preoperative investigation such as EKG, CXR, and Echocardiography, as well as serial monitoring of Troponins and BNP. Some evidence for exercise therapy as a preoperative cardiac prehabilitation is reviewed.

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Emergency Laparotomy Preoptimization

Anaesthesia journal continues its preoptimization series. More than half of emergency laparotomies are over 70 years old and have an ASA status > 3. Bowel obstrction, adhesions, peritonitis, perforation, among others comprise a large proportion. The preoptimization window is smaller for emergency surgery.

Timely antibiotics, standard or geared for sepsis are needed. Balanced crystalloids for fluid sequestration in the bowel are preferred over normal saline for better renal outcome. Starches are out of fashion for similar renal adverse effects and mortality in sepsis, gelatins reported as potential allergic reactions, and Albumin not of proven benefit. Concomitant distributive shock from sepsis may require vasopressors like Norepinephrine, and CVP (and newer cardiac output and volume assessment tools) may be needed. Electrolytes, especially Potassium may need replacement.

Acute hemorrhage necessitates blood rather than excessive fluids. Cardiovascular medications need review and management, and nephrotoxic agents eliminated due to the high incidence of renal injury in this scenario.

Nutritional supplementation should begin early. Diabetes needs insulin infusion usually, but overly tight control is now discouraged, aiming for around 8mmol/L.

The National Emergency Laparotomy Audit (NELA)  2016-2017 identified delays, and timely Operating Room transfer is important. (It also flagged early antibiotics, presence of senior attending physicians and failure to refer for geriatric assessment. Risk assessment was recommended using tools such as P‐POSSUM model or the NELA risk prediction model).

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OR Fires

Another (gated) review seeks to bring attention to the issue of Operating Room fires. It reviews the “fire triangle” of ignition, fuel and oxidizer; the contribution and risks of such factors as electrosurgery, laser, drills, fibreoptic light sources, defibrillators, alcohol skin prep, intestinal gas, drapes and oxygen.

Oxygen is one of the key modifiable factors and advice is to maintain FiO2 below 30%. Over 80% of all OR fires are in surgery on the head, neck and upper chest and a similar percentage under sedation, where local oxygen concentrations can easily increase with nasal cannula flow above (or even less with draping) 4l/min. A lethal combination of oxygen, drapes and alcohol based preps can develop waiting for the cautery to spark a fire, particularly lethal near the patient airway.

Should a fire occur, recommendations are to stop the flow of all airway gases, disconnect the breathing circuit, remove tracheal tubes in airway fires and irrigate with saline, and remove burning materials, extinguish the fire and restore room air breathing.

Fire risk should be included in checklists at briefing and/or timeouts.

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A (free!) guideline is also available from the FDA here