THIS MONTH IN Anesthesiology

Perioperative management of autonomic failure is reviewed.

Ketamine increased genioglossus electromyogram compared to propofol. See the accompanying Editorial View on  page 6 

Pain increase occurs as often as pain decrease after sympathetic blockade. See the accompanying Editorial View on  page 12 

Amniotic fluid embolism, a rare but potentially catastrophic obstetric emergency, is reviewed.

The benefits and potential pitfalls in using continuous glucose monitors are reviewed.

Preoperative consultations may help identify comorbidities and potentially reduce perioperative risks. However, not all patients undergo preoperative consultations. A population-based cohort study was conducted to identify patient-level and hospital-level predictors of consultation using an administrative database. Only 38% of 204,819 surgical patients underwent preoperative medical consultation. Patient and surgery-level factors predicted 5.9% of the variation in consultation rates, while differences in rates across hospitals were large and not explained by procedure, volume, or teaching status. The median odds of undergoing consultation were approximately 3.5 times higher between locations if the location was selected at random. Additional research is needed to understand these discrepancies. See the accompanying Editorial View on  page 3 

Although potentially beneficial, spinal fusion surgery may result in severe complications including ischemic optic neuropathy (ION) leading to visual loss. This multicenter case controlled study compared patients who underwent spinal fusion surgery and did (n = 80) or did not (n = 315) develop ION. The goal of this study was to identify potential risk factors for ION. Multivariate analysis identified male sex, obesity, longer anesthesia duration, Wilson frame use, greater blood loss, and lower percent colloid use as significant and independent risk factors of ION after spinal fusion surgery. See the accompanying Editorial View on  page 1 

Despite its use in patients, no systematic preclinical evaluation of intrathecal methylprednisolone acetate has been reported. The current study evaluated its short- and long-term effects on dog (n = 17) spinal tissue. Dogs implanted with intrathecal catheters received either vehicle (lidocaine), methylprednisolone acetate 20 mg/ml, or methylprednisolone acetate 80 mg/ml via  four injections 7 days apart. The low- and high-dose methylprednisolone acetate groups showed diffuse and severe inflammatory responses, respectively. Six weeks after injections, the severity of inflammation increased with increasing dose. No neuronal injury, demyelination, or gliosis was observed. The observed dose-dependent inflammatory reactions mirrored that reported in humans. Therefore, clinical use of intrathecal methylprednisolone acetate is associated with toxicity.