Functional near-infrared spectroscopy to assess pain in neonatal circumcisions.

INTRODUCTION: Pain assessment is challenging in neonates. Behavioral and physiological pain scales do not assess neocortical nociception, essential to pain encoding and central pain pathway development. Functional near-infrared spectroscopy (fNIRS) can assess neocortical activation to noxious stimuli from changes in oxy-(HbO) and total-hemoglobin concentrations (HbT). This study aims to assess fNIRS nociceptive functional activation in the prefrontal cortex of neonates undergoing circumcision through changes in HbO and HbT, and the correlation between changes in fNIRS and Neonatal Infant Pain Scale (NIPS), a behavioral pain assessment scale. METHODS: In healthy term neonates, HbO, HbT, and NIPS were recorded during sequential circumcision events 1-Prep before local anesthetic injection; 2-Local anesthetic injection; 3-Prep before incision; 4-Oral sucrose; 5-Incision; 6-Gomco (hemostatic device) attached; 7-Gomco twisted on; and 8-Gomco removed. fNIRS and NIPS changes after each event were assessed with Wilcoxon signed-rank test and summarized as median and interquartile range (IQR). Changes in fNIRS vs. NIPS were correlated with Spearman coefficient. RESULTS: In 31 neonates fNIRS increased (median [IQR] µmol/L) with noxious events: Local injection (HbO: 1.1 [0.5, 3.1], p < .001; HbT: 2.3 [0.2, 7.6], p < .001), Gomco attached (HbO: 0.7 [0.1, 1.7], p = .002; HbT: 0.7 [-0.2, 2.9], p = .02), and Gomco twisted on (HbO: 0.5 [-0.2, 1.7], p = .03; HbT: 0.8 [-0.1, 3.3], p = .02). fNIRS decreased with non-noxious event: Prep before incision (HbO: -0.6 [-1.2, -0.2] p < .001; HbT: -1 [-1.8, -0.4], p < .001). Local anesthetic attenuated fNIRS increases to subsequent sharp stimuli. NIPS increased with subsequent sharp stimuli despite local anesthetic. Although fNIRS and NIPS changed in the same direction, there was not a strong correlation between them. CONCLUSIONS: During neonatal circumcision, changes in fNIRS differed between different types of painful stimuli, which was not the case for NIPS, suggesting that fNIRS may complement NIPS to assess the quality of pain.

A retrospective comparison of thoracic epidural infusion and multimodal analgesia protocol for pain management following the minimally invasive repair of pectus excavatum.

BACKGROUND: Pain management following minimally invasive repair of pectus excavatum is variable. We recently adopted a comprehensive multimodal analgesic protocol that standardizes perioperative analgesic management. We hypothesized that patients managed with this protocol would use more opioids postoperatively, have similar pain control, and shorter length of stay compared to patients managed with thoracic epidural infusion. AIMS: We retrospectively compared opioid consumption, pain scores, and length of stay between a cohort of patients managed with our multimodal analgesic protocol and a cohort managed with a thoracic epidural infusion. METHODS: This retrospective cohort comparison includes patients, 8 to 21 years of age, managed with either thoracic epidural infusion (n = 21) or multimodal analgesic protocol (n = 29) following minimally invasive repair of pectus excavatum from January 1, 2011 through September 15, 2015. The primary outcome, total daily opioid consumption in morphine equivalents, is presented as an average by postoperative day. Secondary outcomes included median daily pain score and length of stay. RESULTS: Patients were similar in age, weight, sex, and physical status. Patients managed with thoracic epidural infusion received less opioid (morphine equivalents-mg/kg) intraoperatively compared to multimodal analgesic protocol (difference of mean [95% confidence interval] 0.22 [0.16-0.28] P ≤ .01) but required more total opioid through postoperative day 3 (difference of mean [95% confidence interval] 1.2 [0.26-2.14] P = .01). We did not observe a difference in pain scores. Median length of stay was 1 day less in patients managed with multimodal analgesic protocol (difference of median [95% confidence interval] 1 [0.3-1.7] P = .003). CONCLUSION: Implementation of a standardized comprehensive multimodal analgesic protocol following minimally invasive repair of pectus excavatum resulted in equivalent analgesia with a modest reduction in length of stay when compared to thoracic epidural. We did not observe an opioid sparing effect in our thoracic epidural which may reflect technique variability.