Pre-operative

Cricoid Pressure and Aspiration

A study throws doubt once again on the utility of cricoid pressure in preventing aspiration of gastric contents.

“The inclusion criteria were patients 18 years and older with a full stomach (<6 hours fasting) or the presence of at least 1 risk factor for pulmonary aspiration (emergency conditions, body mass index >30, previous gastric surgery [sleeve, bypass, or gastrectomy], ileus, early [<48 hours] postpartum, diabetic gastroparesia, gastroesophageal reflux, hiatus hernia, preoperative nausea/vomiting, and pain)”.

There was no difference in aspiration compared with a sham procedure but cricoid made intubation slower and more difficult. The authors caution that further study is needed in Obstetrics and outside the Operating Room.

However this study had a non-inferiority design that was underpowered with the low aspiration rates as well as defining a 50% difference threshold. It is unlikely to consign cricoid pressure to the history books but will perhaps confirm biases in the anti-cricoid camp!

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Anticoagulants and antiplateles in hip fracture surgery

Delay in hip fracture surgery can increase mortality (link ).

A Scottish Consensus statement on the management of patients on anticoagulants (and antiplatelet agents) presenting for hip fracture surgery incorporates current knowledge and views on when to proceed and how to expedite anticoagulant reversal with Vitamin K and/or Prothrombin Complex Concentrate, as well as antiplatelet agent considerations. Caution may also be needed with neuraxial techniques in such patients.

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Colorectal Infection Reduction

A network meta-analysis looks at various combinations or omissions of mechanical  bowel preparation and oral antibiotics before elective colorectal surgery. The accepted conclusion by now is:

“Mechanical bowel preparation with oral antibiotics is the best approach to reduce surgical site infections in patients undergoing colorectal surgery.”

 

Prediction of Disability Free Survival

This sub-study sought to evaluate the 6 Minute Walk Test prediction of disability free survival. Of the risk assessment tools analysed, the Duke Activity Status Index was the most predictive of  disability free survival. “The 6MWT was safe and comparable with cardiopulmonary exercise testing for all predictive assessments. Future research should aim to determine the optimal 6MWT distance thresholds for risk prediction”.

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See previous study also: link

 

Preoperative geriatric assessment increases 90 day survival

Preoperative geriatric assessment was performed in only 2.8% of elective non-cardiac surgeries in adults over 65 years of age in this study but was associated with a higher 90 day survival. Given the increasing importance of managing multiple comorbidities, polypharnacy and in particular evaluating frailty and functional status, further randomized studies are needed to verify these findings.

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Systemic Inflammation and myocardial injury

Inflammation is thought to be central in the pathogenesis of cardiovascular disease and this study found that one indicator, the Neutrophil-Lymphocyte Ratio > 4 is associated with perioperative myocardial injury, independent of conventional risk factors. The role of inflammation and its possible modification to reduce myocardial injury is an interesting area for future study.

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Timing of Routine Preoperative Blood Testing

This study concludes: “In American Society of Anesthesiologists physical status I and II patients, risk of 30-day morbidity and mortality was not different with blood testing up to 2 months before surgery, suggesting that it is unnecessary to retest patients shortly before surgery”.

The premise of “routine” testing in healthy patients seems at odds with the Choosing Wisely campaign, as most healthy patients require little or no blood tests pre-operatively.

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OSA Screening in Pregnant Obese

Pregnant patients 24-35 weeks with BMI > 40 were given Obstructive Sleep Apnea (OSA) screening questionnaires (Berlin, American Society of Anesthesiologists checklist, and STOP-BANG), and the Epworth sleepiness scale. They underwent overnight sleep apnea testing; 24% had OSA.

“Established OSA screening tools performed very poorly to screen for OSA in this cohort. Age, BMI, neck circumference, frequent witnessed apneas and highly likely to fall asleep while driving were most strongly associated with OSA status in this cohort.”

OSA screening tools may need to be refined in this population.

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Gastric Volume/Content in Elective Pediatric Surgery

This prospective cohort study aimed to identify “at risk” stomachs – with solid content or more than 1.25ml/kg in elective pediatric surgery. Median duration of fasting was 4 hours for liquids and >13 hours for solids. They found only 1% of elective children had potentially increased risk for pulmonary aspiration, but none had solid contents

While the overall findings are reassuring, they also draw attention to the often prolonged fasting times in pediatric surgery.

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Sleep Apnea and Peri-operative Oitcomes

Obstructive Sleep Apnea is a red flag for surgery and anesthesia and ASA guidelines exist to identify and manage it peri-operatively, based on factors such as its severity, type/magnitude of surgery and need for postoperative opioids. The present study, although based on administrative data, is noteworthy as it involved a common ambulatory procedure, shoulder arthroscopy.

There was an increased risk of pulmonary complications, myocardial infarction, and an increased odds of requiring postoperative ventilation, hospital admission, and intensive care unit admission. These are significant for an ambulatory procedure and emphasize the need for caution in this population.

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