Uribe, Alberto A.

Background: Both perineural and intravenous dexamethasone have been proposed as effective adjuncts that prolong the duration of peripheral nerve blocks. The authors sought to explore whether combining systemic with perineural dexamethasone yields any additive or synergistic effect on the characteristics and analgesic effects of peripheral nerve blocks. Methods: Adult patients having distal radius open reduction and internal fixation and/or carpometacarpal arthroplasty under supraclavicular block were randomized to intravenous dexamethasone, a combination of perineural plus intravenous dexamethasone, or no dexamethasone (control). Sensory block duration was set as the primary outcome. Secondary outcomes included motor block duration; postoperative rebound pain scores as well as worst pain at 8, 16, 24, 32, 40, and 48 h; opioid consumption at 0 to 24 and 25 to 48 h; incidence of nausea/vomiting; and presence of burning sensation in the blocked limb at 24 and 48 h. The null hypothesis was lack of difference in sensory block duration between the three groups. Results: A total of 104 patients were included in the analysis (intravenous dexamethasone, 37; intravenous plus perineural dexamethasone, 34; control, 33). Compared to intravenous dexamethasone alone, adding perineural dexamethasone did not yield any incremental benefits in any of the outcomes examined. The mean ± SD of sensory block duration was 21.3 ± 7.3 h in the intravenous dexamethasone group, 20.6 ± 6.1 h in the perineural plus intravenous group, and 16.8 ± 6.8 h in the control group. The mean difference (95% CI) of sensory block duration was significantly prolonged by 4.5 h (95% CI, 1.3 to 7.7; P = 0.006) in the intravenous dexamethasone group and 3.8 h (95% CI, 0.8 to 6.8; P = 0.015) in the perineural plus intravenous dexamethasone group compared to control; however, no difference was observed when the two dexamethasone groups were compared to each other (0.7 h [95% CI, –2.5 to 3.9]; P = 0.670). Compared to control, both intravenous and intravenous plus perineural dexamethasone similarly reduced 24-h pain scores and opioid consumption and decreased incidence of rebound pain. Conclusions: The authors’ findings suggest that intravenous dexamethasone alone is sufficient to improve analgesic outcomes for patients receiving supraclavicular block for upper extremity surgery. Combining the intravenous and perineural dexamethasone routes does not yield an additive or synergistic effect on the characteristics and analgesic effects of supraclavicular block.

BACKGROUND: Opioid-related adverse events are a serious problem in hospitalized patients. Little is known about patients who are likely to experience opioid-induced respiratory depression events on the general care floor and may benefit from improved monitoring and early intervention. The trial objective was to derive and validate a risk prediction tool for respiratory depression in patients receiving opioids, as detected by continuous pulse oximetry and capnography monitoring. METHODS: PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) was a prospective, observational trial of blinded continuous capnography and oximetry conducted at 16 sites in the United States, Europe, and Asia. Vital signs were intermittently monitored per standard of care. A total of 1335 patients receiving parenteral opioids and continuously monitored on the general care floor were included in the analysis. A respiratory depression episode was defined as respiratory rate ≤5 breaths/min (bpm), oxygen saturation ≤85%, or end-tidal carbon dioxide ≤15 or ≥60 mm Hg for ≥3 minutes; apnea episode lasting >30 seconds; or any respiratory opioid-related adverse event. A risk prediction tool was derived using a multivariable logistic regression model of 46 a priori defined risk factors with stepwise selection and was internally validated by bootstrapping. RESULTS: One or more respiratory depression episodes were detected in 614 (46%) of 1335 general care floor patients (43% male; mean age, 58 ± 14 years) continuously monitored for a median of 24 hours (interquartile range [IQR], 17–26). A multivariable respiratory depression prediction model with area under the curve of 0.740 was developed using 5 independent variables: age ≥60 (in decades), sex, opioid naivety, sleep disorders, and chronic heart failure. The PRODIGY risk prediction tool showed significant separation between patients with and without respiratory depression ( P < .001) and an odds ratio of 6.07 (95% confidence interval [CI], 4.44–8.30; P < .001) between the high- and low-risk groups. Compared to patients without respiratory depression episodes, mean hospital length of stay was 3 days longer in patients with ≥1 respiratory depression episode (10.5 ± 10.8 vs 7.7 ± 7.8 days; P < .0001) identified using continuous oximetry and capnography monitoring. CONCLUSIONS: A PRODIGY risk prediction model, derived from continuous oximetry and capnography, accurately predicts respiratory depression episodes in patients receiving opioids on the general care floor. Implementation of the PRODIGY score to determine the need for continuous monitoring may be a first step to reduce the incidence and consequences of respiratory compromise in patients receiving opioids on the general care floor.