Characterization of the functional near-infrared spectroscopy response to nociception in a pediatric population.

BACKGROUND: Near-infrared spectroscopy can interrogate functional optical signal changes in regional brain oxygenation and blood volume to nociception analogous to functional magnetic resonance imaging. AIMS: This exploratory study aimed to characterize the near-infrared spectroscopy signals for oxy-, deoxy-, and total hemoglobin from the brain in response to nociceptive stimulation of varying intensity and duration, and after analgesic and neuromuscular paralytic in a pediatric population. METHODS: We enrolled children 6 months-21 years during propofol sedation before surgery. The near-infrared spectroscopy sensor was placed on the forehead and nociception was produced from an electrical current applied to the wrist. We determined the near-infrared spectroscopy signal response to increasing current intensity and duration, and after fentanyl, sevoflurane, and neuromuscular paralytic. Heart rate and arm movement during electrical stimulation was also recorded. The near-infrared spectroscopy signals for oxy-, deoxy-, and total hemoglobin were calculated as optical density*time (area under curve). RESULTS: During electrical stimulation, nociception was evident: tachycardia and arm withdrawal was observed that disappeared after fentanyl and sevoflurane, whereas after paralytic, tachycardia persisted while arm withdrawal disappeared. The near-infrared spectroscopy signals for oxy-, deoxy-, and total hemoglobin increased during stimulation and decreased after stimulation; the areas under the curves were greater for stimulations 30 mA vs 15 mA (13.9 [5.6-22.2], P = .0021; 5.6 [0.8-10.5], P = .0254, and 19.8 [10.5-29.1], P = .0002 for HbO2 , Hb, and HbT , respectively), 50 Hz vs 1 Hz (17.2 [5.8-28.6], P = .0046; 7.5 [0.7-14.3], P = .0314, and 21.9 [4.2-39.6], P = .0177 for HbO2 , Hb, and HbT , respectively) and 45 seconds vs 15 seconds (16.3 [3.4-29.2], P = .0188 and 22.0 [7.5-36.5], P = .0075 for HbO2 and HbT , respectively); the areas under the curves were attenuated by analgesics but not by paralytic. CONCLUSION: Near-infrared spectroscopy detected functional activation to nociception in a broad pediatric population. The near-infrared spectroscopy response appears to represent nociceptive processing because the signals increased with noxious stimulus intensity and duration, and were blocked by analgesics but not paralytics.

Retrospective study comparing outcomes of multimodal epidural and erector spinae catheter pain protocols after pectus surgery.

INTRODUCTION: There are no optimal postoperative analgesia regimens for Nuss procedures. We compared the effectiveness of thoracic epidurals (EPI) and novel ambulatory erector spinae plane (ESP) catheters as part of multimodal pain protocols after Nuss surgery. METHODS: Data on demographics, comorbidities, perioperative details, length of stay (LOS), in hospital and post discharge pain/opioid use, side effects, and emergency department (ED) visits were collected retrospectively in children who underwent Nuss repair with EPI (N = 114) and ESP protocols (N = 97). Association of the group with length of stay (LOS), in hospital opioid use (intravenous morphine equivalents (MEq)/kg over postoperative day (POD) 0-2), and oral opioid use beyond POD7 was analyzed using inverse probability of treatment weighting (IPTW) with propensity scores, followed by multivariable regression. RESULTS: Groups had similar demographics. Compared to EPI, ESP had longer block time and higher rate of ketamine and dexmedetomidine use. LOS for ESP was 2 days IQR (2, 2) compared to 3 days IQR (3, 4) for EPI (p < 0.01). Compared to EPI, ESP group had higher opioid use (in MEq/kg) intraoperatively (0.32 (IQR 0.27, 0.36) vs. 0.28 (0.24, 0.32); p < 0.01) but lower opioid use on POD 0 (0.09 (IQR 0.04, 0.17) vs. 0.11 (0.08, 0.17); p = 0.03) and POD2 (0.00 (IQR 0.00, 0.00) vs. 0.04 (0.00, 0.06) ; p < 0.01). ESP group also had lower total in hospital opioid use (0.57 (IQR 0.42, 0.73) vs.0.82 (0.71, 0.91); p < 0.01), and shorter duration of post discharge opioid use (6 days (IQR 5,8) vs. 9 days (IQR 7,12) (p < 0.01). After IPTW adjustment, ESP continued to be associated with shorter LOS (difference -1.20, 95% CI: -1.38, -1.01, p < 0.01) and decreased odds for opioid use beyond POD7 (OR 0.11, 95% CI: 0.05, 0.24); p < 0.01). However, total in hospital opioid use in MEq/kg (POD0-2) was now similar between groups (difference -0.02 (95% CI: -0.09, -0.04); p = 0.50). The EPI group had higher incidence of emesis (29% v 4%, p < 0.01), while ESP had higher catheter malfunction rates (23% v 0%; p < 0.01) but both groups had comparable ED visits/readmissions. DISCUSSION/CONCLUSION: Compared to EPI, multimodal ambulatory ESP protocol decreased LOS and postoperative opioid use, with comparable ED visits/readmissions. Disadvantages included higher postoperative pain scores, longer block times and higher catheter leakage/malfunction. LEVELS OF EVIDENCE: Level III.

Characterization of 12 polymorphic microsatellite markers in the liverwort Marchantia inflexa (Marchantiaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed in Marchantia inflexa, a haploid liverwort with unisexual individuals, to identify clonal genotypes and measure population genetic variability. METHODS AND RESULTS: Twelve polymorphic primer sets were developed from three enriched genomic libraries. Primers were fluorescently labeled, and alleles were identified by fragment analysis. These primers were tested in four natural populations and revealed a moderate level of genetic variation within four populations, as indicated by the number of alleles per locus (range = 1-5). CONCLUSIONS: Development of polymorphic markers is crucial to the identification of individuals and will allow additional research into this species, particularly on its population genetics and metapopulation dynamics.

Hepatocellular carcinoma metastatic to the scalp.

A case of scalp metastasis from hepatocellular carcinoma (HCC) is reported that was initially diagnosed as a soft-tissue tumor. Attempted excision of the lesion resulted in an open wound requiring soft-tissue reconstruction of the scalp. Results of pathologic examination showed metastatic HCC. The patient returned postoperatively with bleeding, which was unable to be controlled, resulting in his death. Scalp metastases from HCC are very rare but must be considered when treating a patient with known cirrhosis, hepatitis, or HCC.

Trends in Pediatric Pain: Thinking Beyond Opioids.

Trends in pediatric pain management are moving toward thinking beyond opioids. Regional anesthetic techniques, such as quadratus lumborum and erector spinae plane blocks, demonstrate efficacy and safety in pediatric populations. Extremity blocks with motor-sparing characteristics also are used. Adjuvants may be added to pediatric peripheral nerve blocks to increase duration of action and improve block efficacy. For medical management, pediatric pain management frequently uses nonopioid medications. These opioid-sparing medications and regional techniques are used to facilitate enhanced recovery after surgery in pediatric surgical patients. Virtual reality is a field where technology can aid in managing acute pain in pediatric patients.