Anesthesia & Co-existing Disease

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.


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.


Cholecystectomy during Pregnancy

There has been a general opinion and comfort level with the safety of gall bladder surgery during pregnancy. One of the more reassuring findings in this study is that 90% were done after pregnancy, as the findings are not entirely supportive of existing recommendations.

They found “Women who have their gallbladder removed during pregnancy are more likely to experience longer hospital stays, increased 30-day readmissions, and higher rates of preterm delivery than those who delay the operation until after childbirth”. Pre-eclampsia and hemorrhage rates were also higher, as was open surgery.

It should be noted that they only studied third trimester vs. postpartum and not earlier during pregnancy. It certainly is possible that a subset of patients could benefit from cholecystectomy during pregnancy.


EEG guided Anesthesia and Delirium

Some retrospective evidence has lent hope to the attractive notion that reducing anesthesia depth by titrating anesthesia to EEG could also reduce delirium in postoperative elderly patients.

In this study, the primary outcome was incident delirium during postoperative days 1 through 5. While anesthesia agent use was less in the guided group, this randomized study found: These findings do not support the use of electroencephalography-guided anesthetic administration for the prevention of postoperative delirium among older adults undergoing major surgery.

There was no difference in hypotension or awareness under anesthesia, other postulated related outcomes. Lower mortality at 30 days did occur in the EEG guided group, but the significance of this secondary outcome is unclear from this study.


Peripartum Cardiomyopathy

Of interest to obstetric anesthesiologists, a BMJ current review of this rare but serious dilated cardiomyopathy with systolic dysfunction that presents in late pregnancy or, more commonly, the early postpartum period.

Risk factors include black ancestry, pre-eclampsia, advanced maternal age, and multiple gestation pregnancy. Half recover but many more are left with chronic disease and a minority require mechanical support and/or transplantation.

Features are common to heart failure, and also include arrhythmias and thromboembolism (anticoagulation for which will impact neuraxial anesthesia). General treatment measures are discussed and potential specific treatments, including Bromocriptine for Prolactin inhibition, a postulated mechanism in etiology.


Obstructive Sleep Apnea and Ventilatory Depression

It has become axiomatic to state that patients with obstructive sleep apnea (OSA) are more sensitive to opioid induced ventilator]y depression. This small controlled study used Remifentanil infusions to test this theory. They found that obstructive sleep apnea status, apnea/hypopnea events per hour of sleep, or minimum nocturnal oxygen saturation measured by pulse oximetry did not influence the sensitivity to remifentanil-induced ventilatory depression in awake patients receiving a remifentanil infusion of 0.2 μg · kg–1 of ideal body weight per minute.

While this study was on awake patients using a specific ultrashort acting opioid, clinical practice is still likely to be guided by an abundance of caution in administering opioids to OSA patients, especially in the perioperative period, where sedation, sleep, and anesthesia may compound the issue.


Antidepressant and Antianxiety Medications and Post-op Length of Stay

Preoperative antidepressants and anti anxiety medications were studied in this administrative database study and linked to increased postoperative hospital length of stay. They conclude that either due to underlying psychiatric disease or medication effects, patients on preoperative antidepressant and antianxiety medication stay in the hospital longer after surgery and may require greater attention to hasten recovery, including preoperative counseling, postoperative psychiatric consults, or holistic recovery approaches.


Red Cell Transfusion and Storage Duration

Debate has occurred over the years speculating on the benefits of fresher (short storage duration) blood. This Cochrane review included 22 trials across a wide variety of scenarios, e.g. anemia, critical care, general and cardiac surgery, and hematology.

No difference in hospital, ICU, or 30 day mortality was discernible. The conclusion is: “There appears to be no evidence of an effect on mortality that is related to length of storage of transfused RBCs. However, the quality of evidence in neonates and children is low”. Blood bank practice of using the oldest blood first appears appropriate.


Anesthesia and Cancer

There are many studies that have documented the potential harmful effects of inhalational anesthetics and opioids on cancer spread and recurrence via immunological mechanisms. They are retrospective studies with inherent limitations but suggest total intravenous anesthesia (TIVA) with Propofol, local and regional anesthesia, and perhaps using NSAIDS may have protective effects, with minimization of systemic opioids.

The BJA provides another review of this topic, stressing the need for confirmatory randomized trials.


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”.