Gil, Laura Velez

AbstractPurposeThe purpose of the study was to investigate factors associated with early discontinuation of low‐dose ketamine infusions due to adverse drug events (ADEs).MethodsA retrospective, matched case‐control study of surgical patients who received low‐dose ketamine infusions for postoperative pain over 6 years was conducted. Forty‐seven study patients, who required early discontinuation of their infusion due to ADEs, were included and matched 1:1 with 47 controls, who did not experience ADEs, for a total of 94 patients. The two groups were compared based on surgery type, American Society of Anesthesiologists (ASA) classification, administration of specific perioperative anxiolytic, anesthetic, and analgesic medications, and use of regional anesthesia.ResultsOf the study patients, 44.7% underwent spine procedures (vs. 34% of controls), 27.6% underwent abdominal procedures (vs. 8.5% of controls), 19.2% underwent orthopedic procedures (vs. 46.8% of controls), and 8.5% underwent thoracic procedures (vs. 6.4% of controls). There were no statistically significant differences in ASA classification, pre‐operative gabapentinoid and antidepressant use, average ketamine infusion dose, or postoperative use of peripheral nerve catheters, nonsteroidal anti‐inflammatory drugs (NSAIDs), acetaminophen, muscle relaxants, and nonbenzodiazepine sleep aides. Study patients had higher rates of intra‐operative volatile anesthetic use (78.7% vs. 57.7%, p = 0.03) and more postoperative opioid patient‐controlled analgesia (PCA) use (53.2% vs. 29.8%, p = 0.02) than controls. Control patients had higher rates of preoperative opioid use (76.7% vs. 53.2%, p = 0.02) and premedication with midazolam (89.4% vs. 70.2%, p = 0.02) than study patients.ConclusionPatients who required discontinuation of their low‐dose ketamine infusion due to ADEs were more likely to be opioid naïve, received less pre‐operative benzodiazepines, and had greater postoperative opioid PCA requirements. Control patients, on the other hand, had higher rates of pre‐operative opioid use and experienced fewer ADEs despite greater total ketamine doses.

Over the last two decades, the clinical applications of diagnostic and interventional ultrasound have expanded rapidly. When analyzing the chest wall and thoracic region, ultrasound has previously been shown to reliably identify chest wall pathologies like rib fracture and slipping rib syndrome, as well as having fundamentally changed perioperative management and patient outcomes after the emergence of point-of-care ultrasound. In addition, ultrasound guidance has recently become more popular for multiple blocks in the field of regional anesthesia and pain medicine. In this technical report, we systematize an ultrasound-guided protocol for counting ribs and thoracic levels for both posterior and anterior approaches, which does not require level confirmation by fluoroscopy. With this protocol, we hope to create an effective educational resource to support physicians from any specialty background as they engage in point-of-care ultrasound applications in the thoracic region.