Efficacy of femoral periarterial block in preventing thigh tourniquet pain: a randomized controlled trial.

BACKGROUND: Tourniquet pain, described as a dull, tight, poorly localized aching sensation, is common in conscious patients. Although various pain-reduction methods have been implemented, none are completely effective. Femoral periarterial block (FAB) has been shown to attenuate tourniquet-induced hypertension in patients undergoing general anesthesia. We aimed to test the feasibility of FAB in inhibiting thigh tourniquet pain in orthopedic patients under conscious sedation. METHODS: Forty-two patients (aged 18-64 years and ASA I-II) scheduled for below-knee orthopedic surgeries with an anticipated tourniquet duration of more than 40 min were recruited and received FAB (Group 1) or not (Group 2). The primary outcome was the occurrence of tourniquet pain. The onset time and severity of the tourniquet pain were recorded. Total doses of sedatives and analgesics administered intraoperatively and hemodynamic changes were documented. The occurrence of local anesthetic systemic toxicity was recorded. RESULTS: Kaplan-Meier time-to-event curves indicated an improved tourniquet tolerance and delayed pain onset. Tourniquet pain occurrence was lower in Group 1 than in Group 2 (30% vs. 95.5%, P=0.02). Tourniquet pain onset was delayed in Group 1 (80[67,84] min vs. 58[51.5,60] min, P<0.01). Fewer patients in Group 1 experienced severe pain (3(15%) vs. 18(81.8%), P<0.01), and less hemodynamic changes (2(10%) vs. 12(54.5%), P<0.01). Local anesthetic systemic toxicity was absent. CONCLUSIONS: FAB, applied with regional anesthesia in patients undergoing below-knee orthopedic surgeries, could reduce thigh tourniquet pain, stabilize blood pressure and heart rate, and prolong tourniquet duration.

Identification of the popliteal sciatic nerve through the above-knee lateral approach provides superior echogenicity and ultrasound visibility: a patient volunteer trial.

BACKGROUND: Distinguishing light-echoed nerves from surrounding structures is challenging but may be important in nerve block administration. We evaluated the effect of patient characteristics on the echogenicity or visibility of the popliteal sciatic nerve (PSN). METHODS: This study included adult patients who presented to the operating room as volunteers. The primary outcome was the success rate of nerve identification by ultrasound using different PSN access paths. The secondary outcome included the PSN visibility score (VIS), scan time, and PSN depth. Logistic regression analysis was used to identify factors associated with the PSN identification success rate. The Body Mass Index (BMI) proximal-based cut-off was used to compare the PSN identification success rate through different access paths. RESULTS: The PSN was successfully identified in 89.7% of the volunteers. The access paths (P<0.01) and BMI (P=0.01) were identified as independent predictors of successful PSN identification. A higher PSN identification success rate (P=0.01), a higher VIS (P<0.01), a more superficial PSN depth (P<0.01), and a shorter scan time (P<0.01) were observed in the above-knee lateral approach. Among volunteers with BMI≥26.77 kg/m2, the PSN identification success rate through the above-knee lateral approach was significantly higher (P<0.01), and PSN depth was shallower (P<0.01) than through the medial approach. CONCLUSIONS: The ultrasound-guided above-knee lateral approach for PSN block improved the PSN identification success rate, ensured a more superficial nerve location, and provided a clearer image.

Association of acute normovolemic hemodilution with decreased length of hospital stay in rhesus-negative patients undergoing major cancer surgeries: a retrospective study.

BACKGROUND: Shortages of allogeneic blood supplies for rhesus (Rh)-negative patients who are scheduled for major cancer surgeries may cause delays in surgical procedure, resulting in a prolonged length of hospital stay (LOHS). This study investigated the relationship of acute normovolemic hemodilution (ANH) with LOHS in this patient population. METHODS: Rh-negative patients who underwent major cancer surgeries between January 2015 and April 2020 were included in this retrospective study. The primary outcome was LOHS. The secondary outcomes were length of preoperative stay (LOPS), perioperative laboratory data and allogeneic blood transfusion (ABT), and postoperative adverse events. Furthermore, relationships between these perioperative variables and LOHS were examined by both univariate analyses and multiple linear regression analysis. RESULTS: Seventy patients were divided into ANH (n=30) or Control (n=40) group. The two groups were well-matched for baseline data. LOHS, LOPS, perioperative ABT amount, and the overall rate of postoperative adverse events were all significantly lower in the ANH group (P=0.004, P=0.009, P<0.001, P=0.023, respectively). In the ANH group, levels of hemoglobin and hematocrit decreased on postoperative day 1 (P=0.023, P=0.012, respectively). Univariate analyses revealed significant association between LOHS and the following perioperative variables: ANH, body mass index, types of surgery, intraoperative colloids infusion, and perioperative ABT. Multiple linear regression analysis with correction for diagnosis identified ANH, intraoperative colloids infusion, and perioperative ABT as independent predictors. CONCLUSIONS: ANH was associated with the decreased LOHS in Rh-negative patients undergoing major cancer surgeries.