Ultrasonography versus palpation for spinal anesthesia in obese parturients undergoing cesarean delivery: a randomized controlled trial.

INTRODUCTION: Ultrasonography may facilitate neuraxial blocks in obstetrics. This randomized controlled trial aimed to compare preprocedural ultrasonography with landmark palpation for spinal anesthesia in obese parturients undergoing cesarean delivery. METHODS: 280 American Society of Anesthesiologists (ASA) physical status II-III parturients with body mass index ≥35 kg/m2, full-term singleton pregnancy, undergoing elective cesarean delivery under spinal anesthesia, were randomly assigned to two equal groups (ultrasonography and palpation); preprocedural systematic ultrasound approach and conventional landmark palpation were performed, respectively. Patients and outcome assessors were blinded to the study group. All ultrasound and spinal anesthetic procedures were performed by a single experienced anesthesiologist. The primary outcome was the number of needle passes required to obtain free cerebrospinal fluid (CSF) flow. Secondary outcomes were the number of skin punctures required to obtain free CSF flow, success rate at the first needle pass, success rate at the first skin puncture, duration of the spinal procedure, patient satisfaction and incidence of vascular puncture, paresthesia, failure to obtain CSF flow and failed spinal block. RESULTS: There were no significant differences in primary or secondary outcomes between the two groups. The median (IQR) of the number of needle passes required to obtain free CSF flow was 3 (1-7) in ultrasonography group and 3 (1-7) in palpation group; p=0.62. CONCLUSIONS: Preprocedural ultrasonography did not decrease the number of needle passes required to obtain free CSF flow or improve other outcomes compared with landmark palpation during spinal anesthesia performed by a single experienced anesthesiologist in obese parturients undergoing cesarean delivery. TRIAL REGISTRATION NUMBER: NCT03792191; : https://clinicaltrials.gov/ct2/show/NCT03792191.

The Influence of Different Degrees of Temperature of Intrathecal Levobupivacaine on Spinal Block Characteristics in Orthopedic Surgeries: A Prospective Randomized Study.

BACKGROUND AND AIMS: The temperature of the local anesthetics may affect the distribution of spinal anesthesia. The aim of the current study is to compare the effects of different degrees of intrathecal levobupivacaine 0.5% on the spinal anesthesia characteristics and shivering in orthopedic surgery. MATERIALS AND METHODS: A randomized, prospective, and controlled trial was conducted on 120 patients aged 40-70 years with American Society of Anesthesiologists Classes I and II and who scheduled for orthopedic surgery; they were randomly distributed into three groups: Group 1 (L 24°C) - levobupivacaine 0.5% warmed to 24°C; Group 2 (L 30°C) - levobupivacaine 0.5% warmed to 30°C; and Group 3 (L 37°C) - levobupivacaine 0.5% warmed to 37°C. Every patient had received 3 mL of 0.5% levobupivacaine intrathecally. Sensory blockade was tested using the loss of pinprick sensation, whereas the motor block was tested using the modified Bromage scale. The onset and grading of shivering after spinal anesthesia were recorded. RESULTS: The use of intrathecal levobupivacaine 0.5% warmed to either 30°C or 37°C resulted in a significant acceleration of the onset of either sensory or motor blockade with a significant prolongation in the duration in addition to significant delay in the onset of shivering and the time of the first analgesia requirement in comparison to those of spinal anesthesia with levobupivacaine at room temperature (24°C). Notably, a nonsignificant difference in the spinal block characteristics and shivering was observed between Group L 30°C and Group L 37°C. CONCLUSION: The increasing the temperature of levobupivacaine 0.5% to 30 °C attains more rapid onset of sensory and motor blocks , with prolongation of the onset of shivering. It could be considered as effective equivalent to warming levobupivacaine 0.5%to 37°C in spinal anesthesia.

Effect of Switching between Pressure-controlled and Volume-controlled Ventilation on Respiratory Mechanics and Hemodynamics in Obese Patients during Abdominoplasty.

BACKGROUND: The ideal intraoperative ventilation strategy in obese patients remains obscure. This prospective, randomized study was designed to evaluate the effect of pressure-controlled ventilation (PCV) before or after volume-controlled ventilation (VCV) on lung mechanics and hemodynamics variables in obese patients subjected to abdominoplasty operation. PATIENTS AND METHODS: The study included forty patients with body mass index 30-45 kg/m2 subjected to abdominoplasty. All patients were randomly allocated in two groups after the induction of general anesthesia (twenty patients each), according to intraoperative ventilatory strategy. Group I (P-V): started with PCV until the plication of rectus muscle changes into VCV till the end of surgery. Group II (V-P): started with VCV until the plication of rectus muscle changes into PCV till the end of surgery. Lung mechanics, hemodynamics variables (heart rate and mean blood pressure), and arterial blood gases (ABGs) were recorded. RESULTS: No significant difference in the hemodynamics and ABGs were recorded between the studied groups. The use of PCV after VCV induced the improvement of lung mechanics. CONCLUSION: Switching from VCV to PCV is preferred to improve intraoperative oxygenation and lung compliance without adverse hemodynamic effects in obese patients.