Anesthesia & Co-existing Disease

Pre-operative Oral Care and Cancer Surgery Outcome

Oral hygiene may be linked to aspiration of oro-pharyngeal secretions and this study concludes that preoperative oral care by a dentist significantly reduced postoperative complications in patients who underwent cancer surgery.They found reduced pneumonia and even mortality rates. Limitations of the study include its retrospective nature and analysis of an administrative claims database. It clearly deserves further study.

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Spinal Hip Fracture Surgery and Sedation

A randomized study suggests limiting sedation, at least in those with low comorbidity scores, during hip fracture repair under spinal anesthesia to reduce delirium.  They conclude: “In the primary analysis, limiting the level of sedation provided no significant benefit in reducing incident delirium. However, in a prespecified subgroup analysis, lighter sedation levels benefitted reducing postoperative delirium for persons with a Charlson comorbidity index of 0“.

Whereas benzodiazepines are increasingly out of favour, this study used Propofol for sedation. The current winner for sedation is Dexmedetomidine and needs further study, as does the relationship of comorbidity to delirium, a serious issue linked to outcome and mortality.

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Acute Kidney Injury, Fluids and Norepinephrine

Norepinephrine is being used to help limit excessive fluid administration in keeping with current enhanced recovery protocols. This study shows that while this agent was not harmful, too restrictive an approach to administration of crystalloids was associated with an increased risk for AKI, particularly in older patients, those receiving antihypertensive medication, and those whose surgery was prolonged. Perhaps “modestly liberal” is the best again as in the Relief trial blog link

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Frailty and Surgery Outcome

Something immensely important is being missed if frailty isn’t a major preoperative assessment element.

This study aimed to compare the accuracy of the modified Fried Index (mFI) and the Clinical FrailtyScale (CFS) to predict death or patient-reported new disability 90 days after major elective surgery.

“Older people with frailty are significantly more likely to die or experience a new patient-reported disability after surgery. Clinicians performing frailty assessments before surgery should consider the CFS over the mFI as accuracy was similar, but ease of use and feasibility were higher“.

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Erythropoietin (EPO) in Cardiac Surgery

A retrospective study compares outcomes in cardiac surgery in those who declined transfusion and received EPO  with those who did not receive EPO or transfusion. Allowing for the limitations of retrospective design, they found no difference in mortality, MI, stroke, thromboembolism, kidney injury, extubation time, ICU or hospital length of stay. The results are encouraging for those who decline transfusion such as Jehovah Witnesses but further larger prospective trials are needed. EPO remains off-label for this use.

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Blood: Choosing Wisely

Some recommendations of relevance to anesthesia and perioperative care on anemia and blood usage:

Delay elective surgery in patients who have correctable anemia

To reduce iatrogenic anemia, don’t order blood tests unless they are clinically indicated.

Don’t transfuse if there is no active bleeding or laboratory evidence of coagulopathy.

To manage surgical bleeding, use early antifibrinolytic drugs like tranexamic acid rather than blood transfusion if possible.

In nonemergent settings, avoid transfusion when other interventions are available. Discuss alternative strategies during the informed consent process.

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Postoperative Cognitive Dysfunction and Noncardiac Surgery

An immense challenge for anesthesia and surgery is the entire spectrum of mild cognitive impairment, dementia, delirium, and post operative cognitive dysfunction POCD, this latter being less clearly described. There are predisposing factors like age,  pre-existing cognitive impairment, low education level and contributions from cardiovascular co-morbidity.

Inflammation seems a potential mechanism. No agent or anesthetic including regional techniques are proven either causative or helpful and it’s unknown if duration of anesthesia contributes. Simple factors like hypotension and hypoxia are not usually present.

Disentangling deterioration from natural progression of underlying cognitive impairment is difficult.  This review surveys the current landscape in this important area, and the future term may be ‘Perioperative Neurocognitive Disorder’

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Anti-platelet Agents and Non-cardiac Surgery

In the past it was conventional to continue aspirin and withhold other antiplatelet agents like Plavix before surgery. However recent studies do not tend to show any particular benefit. One study showed increased bleeding without benefit but this new Cochrane review shows neither harm nor benefit in terms of bleeding, ischemic events or mortality.

Clearly a more nuanced approach may be needed for those with coronary stents or where neuraxial anesthesia is being considered ( blog link )

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Opioid-Induced Adrenal Insufficiency

An important reminder of the endocrine effects of chronic opioid use, namely opioid induced adrenal insufficiency. Symptoms of adrenal insufficiency include fatigue, nausea, vomiting, weight loss, dizziness, and muscular aches, many of which overlap with or may compound symptoms related to chronic pain syndrome.  The etiology, diagnosis and management are discussed in this Mayo Clinic review. The possibility should be considered in all anesthesia and critically ill patients, and appropriate steroid supplementation instituted.

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Cardiac Risk Prediction

A retrospective observational study compared well established cardiac risk prediction models: (i)the Revised Cardiac Risk Index, (ii)American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator, and (iii)the Myocardial Infarction or Cardiac Arrest calculator.

While agreement was better between the latter two (ACS NSQIP and MICA), there was 30% discordance between assigning high or low risk compared to the RCRI.

The NSQIP certainly seems more modern and comprehensive than the RCRI but the divergence in risk assessment certainly needs to be borne in mind.

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