Effect of a temporary lying position on cerebral hemodynamic and cerebral oxygenation parameters in patients with severe brain trauma.

BACKGROUND: Temporary transition from the half-seated position (HSP) to the lying position (LyP) is often associated with an increase in intracranial pressure (ICP) during management of patients with severe traumatic brain injury (TBI). This study was designed to assess the impact of the temporary LyP on cerebral perfusion and oxygenation in cases of severe TBI. METHOD: Patients with a severe blunt TBI with indication of ICP monitoring were prospectively included. Patients underwent standardized management according to the international guidelines to minimize secondary insults. For each patient, a maneuver to a LyP for 30 min was performed daily during the first 7 days of hospitalization. ICP, cerebral perfusion pressure (CPP), mean velocity (Vm), pulsatility index (PI), regional cerebral oxygen saturation (rScO2), jugular venous oxygen saturation (SvjO2)) were compared in the HSP and the LyP. RESULTS: Twenty-four 24 patients were included. The median Glasgow coma scale score was 6 (interquartile range (IQR), 3-8), the median injury severity score was 32 (IQR, 25-48), and the mean age was 39 ± 16 years. On day 1, ICP (+ 6 mmHg (IQR, 4-7 mmHg)) and CPP (+ 10 mmHg (IQR, 5-14 mmHg) were significantly increased in the LyP compared with the HSP. Vm increased significantly in the LyP on the mainly injured side (+ 6 cm/s (IQR, + 0-11 cm/s); P = 0.01) and on the less injured side (+ 4 cm/s (IQR, + 1-8 cm/s); P < 0.01). rScO2 behaved similarly (+ 2 points (IQR, + 2-4 points) and + 3 points (IQR, + 2-5 points), respectively; P < 0.001). Mixed models highlighted the significant association between the position and CPP, Vm, rScO2, with more favorable conditions in the lying position. CONCLUSIONS: Within the first week of management, the temporary LyP in cases of severe TBI was associated with a moderate increase in CPP, Vm, and rScO2despite a moderate increase in ICP.

A new inguinal approach for the obturator nerve block: anatomical and randomized clinical studies.

BACKGROUND: Obturator nerve block is highly recommended for knee surgery in addition to a femoral nerve block. The main disadvantage of the classic approach at the pubic tubercle is low patient acceptance due to pain and discomfort. The authors hypothesized that the use of a new inguinal obturator nerve block technique would reduce pain and discomfort in patients. METHODS: The inguinal approach was simulated in five fresh cadavers. Injection of latex was performed in two cadavers. The location of the needle and the extent of latex solution were analyzed. Fifty patients scheduled to undergo arthroscopic knee surgery were randomly assigned to receive obturator nerve block using either the inguinal (n = 25) or the pubic tubercle approach (n = 25). RESULTS: In all cadavers, the needle was close to the obturator nerve branches, which were surrounded by the latex solution. In the clinical study, visual analog scale pain scores and discomfort of block placement were significantly lower in the inguinal group compared with the pubic tubercle group (P < 0.01). In the inguinal group, there was a significant decrease in block performance time (P < 0.05) and in bolus of propofol and fentanyl used for the procedure (P < 0.01). Twenty minutes after application of the block, adductor strength decrease, occurrence, and location of cutaneous distribution of the obturator nerve were not significantly different between the groups. The incidence of minor complications was significantly increased in the pubic tubercle group (P < 0.05). No major complications were observed. CONCLUSIONS: The new inguinal approach decreases patient discomfort and pain of block placement as well as the time and sedation and analgesics required for a similar quality of sensory and motor block compared with the pubic tubercle approach.

Does the sciatic nerve approach influence thigh tourniquet tolerance during below-knee surgery?

In this prospective, randomized, blinded study we assessed thigh tourniquet tolerance when a Labat's or a posterior popliteal approach of the sciatic nerve was used for below-knee surgery. One-hundred-twenty patients were divided into two groups of 60. A posterior popliteal (Group 1) or a Labat's (Group 2) sciatic nerve block was performed with 25 mL 1% mepivacaine + epinephrine 1:200,000. In both groups, a femoral nerve block was achieved. Patient comfort during block performance, sensory block, success rate, and thigh tourniquet tolerance were recorded. Performance of the block was significantly more comfortable in Group 1 than in Group 2 (P < 0.01). Completeness of the block at t(30 min.) and success rate were comparable in both groups. Thigh tourniquet pain increased with time in both groups. No statistically significant difference was observed between groups. We conclude that despite a complete sensory blockade of the posterior femoral cutaneous nerve in 91% of the patients, Labat's approach of the sciatic nerve provides no better thigh tourniquet tolerance than the popliteal approach. The popliteal approach is as efficient but more comfortable for the patient and is the preferred technique for below-knee surgery.

Postoperative analgesia after total-hip arthroplasty: Comparison of intravenous patient-controlled analgesia with morphine and single injection of femoral nerve or psoas compartment block. a prospective, randomized, double-blind study.

BACKGROUND: The authors compared the analgesic effects and quality of rehabilitation of three analgesic techniques after total-hip arthroplasty in a double-blind, randomized trial. METHODS: Forty-five patients were assigned to 1 of 3 groups, patient-controlled analgesia with morphine (PCA), femoral nerve block (FNB), or psoas compartment block (PCB). At the end of the procedure performed under general anesthesia, nerve blocks using 2 mg/kg of 0.375% bupivacaine and 2 microg/kg of clonidine were performed in the FNB (n = 16) and PCB (n = 15) groups. In the recovery room, all 3 groups received initial intravenous morphine titration if their pain score was higher than 30 on a 100-mm visual analog scale (VAS), and then a PCA device was initiated. Morphine consumption was the primary end point to assess postoperative analgesia. RESULTS: After extubation (H0), morphine titration was higher in the PCA group (P <.05). During the first 4 postoperative hours (H0 to H4), morphine consumption per hour and VAS pain score were lower in the PCB group (P <.05). After H4, there was no difference in morphine consumption and VAS among groups, either at rest or during mobilization. After H4, morphine consumption remained lower than 0.5 mg/h, and VAS remained lower than 30 mm in the 3 groups. In 4 patients of the PCB group, an epidural diffusion was noted. Hip mobility and length of stay in the rehabilitation center were not different among the groups. CONCLUSIONS: PCA is an efficient and safe analgesia technique. FNB and PCB should not be used routinely after total-hip arthroplasty.