Low-dose ketamine infusion reduces postoperative hydromorphone requirements in opioid-tolerant patients following spinal fusion: A randomised controlled trial.

BACKGROUND: The current opioid epidemic highlights the urgent need for effective adjuvant therapies to complement postoperative opioid analgesia. Intra-operative ketamine infusion has been shown to reduce postoperative opioid consumption and improve pain control in opioid-tolerant patients after spinal fusion surgery. Its efficacy for opioid-naïve patients, however, remains controversial. OBJECTIVE: We hypothesised that low-dose ketamine infusion after major spinal surgery reduces opioid requirements in opioid-tolerant patients, but not in opioid-naïve patients. DESIGN: Randomised placebo-controlled study. SETTING: Single-centre, tertiary care hospital, November 2012 until November 2014. PATIENTS: A total of 129 patients were classified as either opioid-tolerant (daily use of opioid medications during 2 weeks preceding the surgery) or opioid-naïve group, then randomised to receive either ketamine or placebo; there were thus four groups of patients. All patients received intravenous hydromorphone patient-controlled analgesia postoperatively. INTERVENTION: Patients in the ketamine groups received a ketamine infusion (bolus 0.2 mg kg over 30 min followed by 0.12 mg kg h for 24 h). Patients in the placebo groups received 0.9% saline. MAIN OUTCOME MEASURES: The primary outcome was opioid consumption during the first 24 h postoperatively. The secondary outcome was numerical pain scores during the first 24 h and central nervous system side effects. RESULTS: Postoperative hydromorphone consumption was significantly reduced in the opioid-tolerant ketamine group, compared with the opioid-tolerant placebo group [0.007 (95% CI 0.006 to 0.008) versus 0.011 (95% CI 0.010 to 0.011) mg kg h, Bonferroni corrected P < 0.001]. There was no difference in hydromorphone use between the opioid-naïve groups (0.004 and 0.005 mg kg h in the opioid-naïve ketamine and placebo group, respectively, P = 0.118). Pain scores did not differ significantly between the opioid-tolerant ketamine group and the opioid-naïve groups. There was no significant difference in side effects among groups. CONCLUSION: Postoperative low-dose ketamine infusion reduces opioid requirements for the first 24 h following spinal fusion surgery in opioid-tolerant, but not in opioid-naïve patients. TRIAL REGISTRATION: NCT03274453 with clinicaltrials.gov.

Total Joint Arthroplasty in Ambulatory Surgery Centers: Analysis of Disqualifying Conditions and the Frequency at Which They Occur.

BACKGROUND: The frequency of total joint arthroplasties (TJAs) performed in ambulatory surgery centers (ASCs) is increasing. However, not all TJA patients are healthy enough to safely undergo these procedures in an ambulatory setting. We examined the percentage of arthroplasty patients who would be eligible to have the procedure performed in a free-standing ASC and the distribution of comorbidities making patients ASC-ineligible. METHODS: We reviewed the charts of 3444 patients undergoing TJA and assigned ASC eligibility based on American Society of Anesthesiologists (ASA) status, a set of exclusion criteria, and any existing comorbidities. RESULTS: Overall, 70.03% of all patients undergoing TJA were eligible for ASC. Of the ASA class 3 patients who did not meet any exclusion criteria but had systemic disease (51.11% of all ASA class 3 patients), 53.69% were deemed ASC-eligible because of sufficiently low severity of comorbidities. The most frequent reasons for ineligibility were body mass index >40 kg/m2 (32.66% of ineligible patients), severity of comorbidities (28.00%), and untreated obstructive sleep apnea (25.19%). CONCLUSION: A large proportion of TJA patients were found to be eligible for surgery in an ASC, including over one-third of ASA class 3 patients. ASC performed TJA provides an opportunity for increased patient satisfaction and decreased costs, selecting the right candidates for the ambulatory setting is critical to maintain patient safety and avoid postoperative complications.

Preoperative Evaluation Clinic Visit Is Associated with Decreased Risk of In-hospital Postoperative Mortality.

BACKGROUND: As specialists in perioperative medicine, anesthesiologists are well equipped to design and oversee the preoperative patient preparation process; however, the impact of an anesthesiologist-led preoperative evaluation clinic (PEC) on clinical outcomes has yet to be fully elucidated. The authors compared the incidence of in-hospital postoperative mortality in patients who had been evaluated in their institution's PEC before elective surgery to the incidence in patients who had elective surgery without being seen in the PEC. METHODS: A retrospective review of an administrative database was performed. There were 46 deaths from 64,418 patients (0.07%): 22 from 35,535 patients (0.06%) seen in PEC and 24 from 28,883 patients (0.08%) not seen in PEC. After propensity score matching, there were 13,964 patients within each matched set; there were 34 deaths (0.1%). There were 11 deaths from 13,964 (0.08%) patients seen in PEC and 23 deaths from 13,964 (0.16%) patients not seen in PEC. A subanalysis to assess the effect of a PEC visit on deaths as a result of failure to rescue (FTR) was also performed. RESULTS: A visit to PEC was associated with a reduction in mortality (odds ratio, 0.48; 95% CI, 0.22 to 0.96, P = 0.04) by comparison of the matched cohorts. The FTR subanalysis suggested that the proportion of deaths attributable to an unanticipated surgical complication was not significantly different between the two groups (P = 0.141). CONCLUSIONS: An in-person assessment at the PEC was associated with a reduction in in-hospital mortality. It was difficult to draw conclusions about whether a difference exists in the proportion of FTR deaths between the two cohorts due to small sample size.