Postoperative pain control for primary cleft lip repair in infants: is there an advantage in performing peripheral nerve blocks?

Background: Primary cleft lip repair is performed in infants under 1 year of age. The efficacy of an infraorbital nerve block vs intravenous fentanyl was compared in our prospective, randomized controlled trial. Methods: Forty‐six infants scheduled for primary cleft lip repair were prospectively randomized to one of two groups: group F that received 2 mcg·kg^?1 of fentanyl intravenously and an infraorbital nerve block with 0.5 ml on each side of preservative‐free normal saline, and, group B that received bilateral infraorbital nerve blocks with 0.5 ml on each side of 0.25% bupivacaine and 2 ml of preservative‐free saline solution intravenously after induction of anesthesia but prior to surgical incision. Patients were observed by a blinded observer for (i) pain scores using neonatal infant pain score; (ii) need for rescue medication in the anesthesia care unit (PACU), in the short stay unit (SSU) and at home and (iii) feeding parameters including difficulty in feeding, time to first feeding and volume of feeds in the PACU, SSU and at home. Results: There were no significant differences in pain scores between the two groups over time (P = 0.98); there were no differences between groups in the number of rescue medications in the PACU, in the SSU as well as at home; however, the time to first rescue medication was greater in the block group compared with the fentanyl group (P = 0.07). There were no significant differences in feeding volumes between groups in the PACU (P = 0.46), SSU (P = 0.57) and at home (P = 0.15). There were no differences in time to initiate feeding between the two groups (P = 0.81). However, there was difficulty with feeding in the block groups compared with the fentanyl group (P = 0.01). Conclusions: The infraorbital nerve block can be effectively used for pain control in infants undergoing primary cleft lip repair. Although children undergoing a nerve block experienced minor difficulties in feeding, there were no differences in feeding volumes or other feeding parameters. This study has shed light into postoperative outcomes besides pain control on children undergoing cleft lip repairs.     

Essential role of endothelial nitric oxide synthase in vascular effects of erythropoietin

Erythropoietin (EPO) fosters tissue oxygenation by stimulating erythropoiesis. More recently, EPO has been recognized as a tissue-protective cytokine. In this study, we tested the hypothesis that endothelial NO synthase (eNOS) plays a key role in the vascular protective effect of EPO. A murine model of wire-induced injury of carotid artery was used to examine the effect of EPO on endothelial repair and arterial wall architecture. Recombinant human EPO (1000 U/kg, SC, biweekly) was administered for 2 weeks in wild-type and eNOS-deficient mice after which reactivity of isolated carotid arteries was studied in vitro, and the vasculature was histologically assessed. Injured arteries exhibited impairment of endothelium-dependent relaxations to acetylcholine (P<0.05). This was associated with increased medial cross-sectional area (P<0.05). EPO upregulated expression of phosphorylated Ser1177-eNOS and normalized the vasodilator response to acetylcholine (P<0.05). Furthermore, EPO prevented the injury-induced increase in medial cross-sectional area (P<0.05). The vascular protective effects of EPO were abolished in eNOS-deficient mice. Most notably, EPO significantly increased systolic blood pressure and enhanced medial thickening of injured carotid arteries in eNOS-deficient mice (P<0.05). Our results demonstrate that EPO prevents aberrant remodeling of the injured carotid artery. The protective effects of EPO are critically dependent on activation of eNOS.     

Anatomical location of the bifurcation of the sciatic nerve in the posterior thigh in infants and children: a formula derived from MRI imaging for nerve localization

BACKGROUND AND OBJECTIVES: Sciatic nerve block is performed at the popliteal fossa for various surgical procedures in infants and children. The aim of this study is to review magnetic resonance imaging scans in children of various ages to assess the location of the division of the nerve in the posterior thigh. METHODS: After Institutional Review Board approval was obtained, measurements of the bifurcation of the sciatic nerve in the posterior thigh were recorded from magnetic resonance images that were previously obtained in children of various ages. Data were recorded in a database and parametric and nonparametric statistical analysis was performed. RESULTS: Measurements were recorded from 59 patient images. Using a linear regression model, we were able to arrive at a formula for determining the point of bifurcation of the sciatic nerve at the posterior thigh. The mathematical formula derived from the linear regression equation was: CONCLUSIONS: We speculate that this knowledge will assist practitioners who use nerve stimulation techniques for sciatic nerve blocks in children of all ages.     

Intensive care management of head injury patients without routine intracranial pressure monitoring

Background: Head injury contributes significantly to mortality and morbidity in India. Evaluation of the available trauma care facilities may help improve outcome. Aim: To evaluate the factors influencing the mortality of patients with head injury who had intensive care management and evolve strategies to improve outcome. Setting and Design: Retrospective study in a tertiary hospital where intracranial pressure monitoring (ICPM) is not routinely practiced. Materials and Methods: All patients with head injury managed in the intensive care unit in a two-year period were included. The factors evaluated were age, vital signs, Glasgow Coma scale score (GCS) at admission, pupillary light reflex (PR), oculocephalic reflex (OCR), hemodynamic stability, computerized tomography (CT) findings, diabetes mellitus, anemia, infections and abnormalities of serum sodium. Results: We analyzed 208 patients (202 without ICPM). In-hospital mortality was 64 (31%). Only 24 (11.5%) patients were admitted within one hour of injury, while one-third arrived after six hours. The clinical factors (at admission) that influenced mortality included age, GCS, PR, OCR and diastolic blood pressure (DBP). Effacement of the basal cisterns in the initial and repeat CT scans, hyperglycemia, hemodynamic instability and serum sodium imbalances were associated with higher mortality. The independent predictors of mortality by logistic regression were initial GCS, DBP, hemodynamic instability and effacement of cisterns on repeat CT. Conclusions: Mortality following head injury is high. Pre-hospital emergency medical services are disorganized. The key to reducing mortality within the limitations of our current trauma system is maintenance of DBP>70 mmHg and SBP> 90 mmHg from the time of first contact.     

Preparatory activity in premotor and motor cortex reflects the speed of the upcoming reach

Neurons in premotor and motor cortex show preparatory activity during an instructed-delay task. It has been suggested that such activity primarily reflects visuospatial aspects of the movement, such as target location or reach direction and extent. We asked whether a more dynamic feature, movement speed, is also reflected. Two monkeys were trained to reach at different speeds ("slow" or "fast," peak speed being approximately 50-100% higher for the latter) depending on target color. Targets were presented in seven directions and at two distances. Of 95 neurons with tuned delay-period activity, 95, 78, and 94% showed a significant influence of direction, distance, and instructed speed, respectively. Average peak modulations with respect to direction, distance and speed were 18, 10, and 11 spikes/s. Although robust, modulations of firing rate with target direction were not necessarily invariant: for 45% of neurons, the preferred direction depended significantly on target distance and/or instructed speed. We collected an additional dataset, examining in more detail the effect of target distance (5 distances from 3 to 12 cm in 2 directions). Of 41 neurons with tuned delay-period activity, 85, 83, and 98% showed a significant impact of direction, distance, and instructed speed. Statistical interactions between the effects of distance and instructed speed were common, but it was nevertheless clear that distance "tuning" was not in general a simple consequence of speed tuning. We conclude that delay-period preparatory activity robustly reflects a nonspatial aspect of the upcoming reach. However, it is unclear whether the recorded neural responses conform to any simple reference frame, intrinsic or extrinsic.