Regional Anesthesia

Perioperative Epidurals and Delirium

A secondary observational non-randomized analysis of the PODCAST trial found that “postoperative epidural use was not associated with a reduced overall incidence of delirium. However, longitudinal analysis revealed reduced adjusted odds of experiencing an episode of delirium in the epidural group. Epidural use was also associated with reduced postoperative pain and opioid consumption”.

This study lends support to further randomized studies to study Epidural analgesia and delirium, even though previous work does not strongly support any particular form of anesthesia for delirium prevention.

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General Anesthesia for Cesarean

This retrospective study spanned a decade but included nearly half a million Cesarean Sections in New York State.

5.7% were classified as GA without a recorded indication. The study found: “The use of potentially avoidable general anesthesia in these patients is associated with an increased risk of anesthesia-related complications, surgical site infection, and venous thromboembolism, but not death or cardiac arrest”. The odds were quite significantly higher.

Risk factors for GA included age less than 19, racial or ethnic minority, Medicaid or Medicare beneficiaries, preexisting or pregnancy-associated conditions, nonelective admission, and admission during weekend, teaching hospital, neonatal level-of-care designation 1 or 3, lower use of neuraxial techniques during labor and vaginal deliveries, higher annual volume of deliveries, and higher proportion of women with a comorbidity index greater than 2.

Neuraxial anesthesia is established as the standard of care in Cesarean anesthesia absent contraindication. Higher labor epidural rates appeared to be the most actionable factor to encourage and increase the odds of neuraxial anesthesia.

Many of the other factors are either known or subject to the limitations of this retrospective study, and may be subject to coding inaccuracy, malfunctioning epidural catheters, or patient request.

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Erector Spinae Block for Rib Fractures

Another study uses an arguably simpler block than paravertebral for rib fractures. It quantified incentive spirometry pre and post block.

The majority had continuous catheters and the study found that erector spinae plane blocks were associated with improved inspiratory capacity and analgesic outcomes following rib fracture, without haemodynamic instability.

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Rib Fractures and Paravertebral Catheters

This retrospective study over four years showed almost half of patients with rib fractures had ultrasound guided paravertebral catheters inserted by the fourth year. Only minor complications were reported. The conclusion was that “paravertebral catheters are a safe and effective technique for rib fracture analgesia; however, our data were insufficient to demonstrate any improvement in mortality.”

They seem clearly useful as part of an opioid free or sparing approach to rib fractures.

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Carbetocin in Elective Cesarean Section

Maternal postpartum hemorrhage is a common complication and indeed accounts for the highest fraction of global maternal mortality (35%).

Routine uterotonics are recommended after delivery as they significantly reduce hemorrhage. Oxytocin is well known, but SOGC recommended a single 100 μg i.v. bolus dose of carbetocin over 1 min (in lieu of an oxytocin infusion) as the uterotonic agent of choice to prevent PPH after elective caesarean delivery; the rationale is that its duration of action is 4 to 7 times that of Oxytocin. This dose comes from manufacturers recommendations.

This randomized non-inferiority design study tested 20mcg vs. 100mcg Carbetocin in elective Cesarean under Spinal Anesthesia.

Uterine tone at 2mins did not meet criteria but 20mcg was non-inferior to 100mcg at 5 mins in terms of uterine tone and hemorrhage as well as the need for further uterotonics.

The numerical rating score for uterine tone may be operator dependent and subjective but the authors suggest further studies to assess the clinical significance of their findings, as all other side effects were basically similar. The study may be underpowered in terms of numbers.

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Colloid and Crystalloid for Cesarean Spinal

There seems (yet again) little rationale for giving colloids, this time in co-loading fluid for Cesarean Section under spinal anesthesia. This study found that the combination of 500-mL colloid preload and 500-mL crystalloid coload did not reduce the total ephedrine dose or improve other maternal outcomes compared with 1000-mL crystalloid coload, although vena caval diameter changes were noted with ultrasound. Neither were there any significant differences in the incidence of hypotension and severe hypotension, the time to the first ephedrine dose, and neonatal Apgar scores at 1 and 5 minutes.

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Epidural Analgesia for Pediatric Thoraco-Lumbar Spine Surgery

This Cochrane review compared postoperative systemic analgesia with epidural analgesia for spine surgery in children and adolescents.

They found a small advantage in that there is moderate‐ and low‐quality evidence that there may be a small additional reduction in pain up to 72 hours after surgery with epidural analgesia compared with systemic analgesia.

The findings are somewhat underwhelming but there may be an added advantage in earlier return of bowel function. No meaningful data on time to ambulation or length of stay is provided. Patients were more satisfied with epidurals.

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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.

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Pain Management for Ambulatory Arthroscopic ACL Reconstruction

Multimodal, and especially opioid-free, analgesic techniques are now the norm in enhancing recovery in ambulatory surgery such as knee anterior cruciate ligament reconstruction. Femoral nerve block, adductor canal block, and local instillation analgesia are variously employed and this guideline from the Society for Ambulatory Anesthesia sought to determine the optimal balance of technique with risks. “Based on the evidence available, local instillation analgesia provides the best balance of analgesic efficacy and associated risks”. Where not employed they provide a weaker recommendation for adductor canal or femoral nerve block.

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