Anaesthesiology intensive therapy最新文献

The physiological transformations accompanying pregnancy, compounded by the implications of obesity, pose intricate challenges for anaesthesiologists attending to obese parturients. Obesity makes it harder to successfully provide epidural analgesia to a parturient. This narrative review explains the most recent data on the safety and complications of providing labour epidural analgesia in obese expectant mothers. We have emphasised the evidence-based approaches that are the most effective for obese pregnant mothers receiving labour epidural analgesia.

Introduction: Hypovolaemia is presumed to be a common risk factor of postinduction hypotension (PIH), despite worldwide improvement in preoperative volume optimization. Correct assessment of fluid status in patients undergoing general anaesthesia remains a major challenge for anaesthesiologists. Bioimpedance analysis (BIA) is a sensitive method that allows objective assessment of patient fluid status as it can detect subclinical changes. The study's main purpose was to determine the correlation between the preoperative BIA assessed fluid status and PIH.

Material and methods: This was an observational single centre study that included patients undergoing elective surgery. We defined PIH as the blood pressure decrease occurring during the first 10 minutes after induction of anaesthesia and orotracheal intubation before surgical incision. We standardized BIA evaluation, patient pre anaesthetic and preoperative preparation, technique and monitoring of anaesthesia.

Results: Our study included 115 patients. The mean age of the population was 58.1 years and the median values for total and intracellular water were 35.1 L and 19.3 L, respectively. In the univariable and multivariable analysis, only total body and intracellular water were associated with different definitions of PIH. There was no correlation between any of the BIA-derived parameters of fluid status and the duration of PIH.

Conclusions: Our study shows that in elective surgery, bioimpedance could detect subtle, subclinical fluid parameters that are associated with PIH.

Introduction: The superior vena cava collapsibility index (SVC-CI) is a potential marker of fluid responsiveness (FR) in mechanically ventilated patients. Few studies reporting its diagnostic performance are currently available.

Material and methods: A systematic search, using the PRISMA approach, was performed using the Medline and EMBASE databases. Prospective studies evaluating the SVC-CI as a marker of FR in ventilated adult patients were included. A bivariate random-effect model was utilised to generate the summary receiver operating characteristic (SROC) curve. The area under the ROC curve (AUC), the sensitivity and specificity of the curve operating point were calculated.

Results: We included eight studies with a total of 857 patients, in whom SVC-CI was evaluated a total of 1083 times prior to the volume expansion trial. In 609 (56.23%) trial cases FR was present. The SROC curve demonstrated that the test's operating point has a sensitivity and specificity of 80.8% (95% CI: 66.3-90%) and 81.4% (95% CI: 76.4-85.5%), respectively. The model's AUC was equal to 0.848 (95% CI: 0.824-0.863) with P < 0.001. No significant inter-study heterogeneity was found (I 2 = 0%). A subgroup analysis revealed a significantly lower sensitivity of SVC-CI in patients with higher levels of positive end-expiratory pressure (PEEP) (> 5 cm H 2 O) (χ 2 = 7.753, df = 2, P = 0.0207). The study setting and type of intervention for volume expansion did not significantly change the performance of the test.

Conclusions: SVC-CI is a reliable predictor of FR for mechanically ventilated patients in intensive care units and operating rooms. A PEEP level exceeding 5 cm H 2 O may impair the sensitivity of the test.

Background: The effect of both propofol and sevoflurane on bupivacaine cardiac toxi-city has not been conclusively defined. The goal of this study was to investigate the effects of propofol vs sevoflurane general anesthesia (GA) on bupivacaine-induced arrhyth-mias.

Material and methods: Ten rabbits were randomized to two groups: propofol- or sevoflurane-based GA. At the maintenance stage of anesthesia heart rate and QRS/QT durations were recorded as "baseline" and an intravenous (i.v.) bupivacaine 0.25% infusion at the rate of 1.0 mg kg -1 min -1 was initiated. Blood samples were obtained when predefined electrocardiographic (ECG) changes were observed and when the heart rate (HR) reached 75%, 50%, and 25% of the baseline and 0 bpm.

Results: The mean time to first predefined ECG changes was 131 ± 25.02 s for the propofol group and 223 ± 34.11 s for the sevoflurane group ( P = 0.001). Time of progression of bradycardia in both groups was evaluated as a percentage of the initial HR for the understanding of the dynamics of changes during the local anesthetic systemic toxicity (LAST). The 25% HR time was shorter for the propofol group (480 ± 117 vs. 673 ± 146 s, P = 0.05). Time to asystole was shorter in the propofol group (110.7 ± 22.22 vs. 226.6 ± 98.61 s, P = 0.047). Mean serum bupivacaine concentration was lower for the propofol group during the occurrence of the first ECG changes (2.542 ± 1.415 vs. 6.997 ± 2.197 mg mL -1 , P = 0.005) and asystole (110.7 ± 22.22 vs. 226.6 ± 98.61 mg mL -1 , P = 0.047).

Conclusions: It seems that sevoflurane-, but not propofol-based anesthesia reduces the risk of LAST during GA combined with peripheral nerve blocks. Sevoflurane-based anesthesia may protect the myocardium from the toxic effects of bupivacaine.

Introduction: Visualisation and separate blockade of the four primary constituent nerves (radial, median, ulnar, musculocutaneous) increases the success rate of ultrasound-guided brachial plexus block at the axillary level. However, the upper limb is still positioned as if performing the landmark-oriented approach described by Winnie, with the shoulder and elbow at 90o. Thus, we aimed to find the optimum arm position for visualisation of the brachial plexus at the axilla using ultrasound.

Material and methods: After the Institutional Ethics Committee's approval, this prospective observational study was conducted on 36 consenting individuals more than 18 years of age. The ultrasound probe was placed on a short axis at the intersection of the pectoralis major muscle and the biceps brachii muscle, with just enough probe pressure to cause light compression of veins. Each arm was placed in three different positions - shoulder at 90º and elbow at 90º, shoulder at 90º and elbow at 0º, and shoulder at 120º and elbow at 90º - in which the nerves were assessed using a six-point visibility scale. The path of each nerve was traced down for confirmation. Distance from the skin to axillary artery, skin to individual nerves, and artery to nerves was measured.

Results: Visibility scores of the individual nerves and the distances measured in the three positions were comparable ( P > 0.05). The skin artery and skin nerve distances were the shortest in the 120/90 position, and the radial nerve was more often located in this position.

Conclusions: Arm position with 120º shoulder and 90º elbow had favourable results. Further studies will confirm its clinical utility and block success rate.

Introduction: Neuraxial anaesthesia is a common choice for most hip and lower limb operations. Pain associated with positioning is often a deterrent, and the vast literature suggests different regional blocks and opioids for these patients. Patients with acetabular fractures may experience increased pain, and thus are more difficult to position for the neuraxial block. We conducted a randomized controlled pilot study to assess and compare the analgesic efficacy of ultrasound-guided suprainguinal fascia iliaca block (SFICB) versus systemic fentanyl to facilitate positioning for combined spinal epidural (CSE) anaesthesia in patients undergoing acetabular fracture surgery.

Material and methods: Twenty patients referred for surgical repair of acetabular fractures were randomly assigned to receive either ultrasound-guided SFICB (group B) or intravenous fentanyl (group F). Changes in visual analogue scale (VAS) scores in supine and sitting position, improvement in sitting angle (SA), positioning quality, rescue analgesic requirement, total opioid consumption, comfort VAS scores, and complications were noted to compare both groups.

Results: The post-intervention VAS score in the sitting position was significantly lower in group B than in group F (5.9 ± 2.1 vs. 3.5 ± 1.5, P = 0.01). Group B also had more significant improvement in SA (27.5° (20.75-36.5°), in comparison to group F (10 (5-18.75), P = 0.006). The positioning quality was better in group B, with 70% of patients achieving an optimal position compared to only 10% in group F ( P = 0.02).

Conclusions: Ultrasound-guided SFICB, as compared to systemic fentanyl, provided better analgesia and helped to achieve a better and more comfortable position to perform the neuraxial block.

Introduction: The Air-Q Self Pressurized Airway Device with Blocker (SP Blocker) was compared to the Proseal Laryngeal Mask Airway (PLMA) during positive pressure ventilation regarding the primary outcome (oropharyngeal leak pressure [OLP]), secondary outcomes (peak inspiratory pressure [PIP], inspired tidal volume [ITV], expired tidal volume [ETV], leak volume [LV] and leak fraction [LF]), insertion time, ventilation score, fiber-optic glottis view score, and postoperative laryngopharyngeal parameters (LPM).

Material and methods: Adult healthy female patients scheduled for elective gynecological laparotomies under general anesthesia using controlled mechanical ventilation were recruited to a prospective randomized comparative clinical trial. Exclusion criteria were body mass index (BMI) ≥ 35 kg m -2 , El-Ganzouri score ≥ 5, upper airway problems, hiatus hernia or pregnancy. Patients were classified into an SP Blocker group ( n = 75) and a PLMA group ( n = 75). Primary and secondary outcomes were assessed initially and at fixed time points after successful insertion of devices.

Results: Initially after successful device insertion: the SP Blocker group showed statistically significant higher mean OLP (cmH 2 O) (29.46 ± 2.11 vs. 28.06 ± 1.83 respectively; 95% CI: -2.037 to -0.76, P < 0.0001), lower mean PIP (cmH 2 O) (15.49 ± 0.61 vs. 17.78 ± 1.04 respectively; 95% CI: 2.02 to 2.56, P < 0.0001), higher mean ITV (mL) (411 ± 30 vs. 403 ± 15 respectively; 95% CI: -15.65 to -0.347, P = 0.041), higher mean ETV (mL) (389 ± 12 vs. 354 ± 11 respectively; 95% CI: -38.72 to -31.29, P < 0.0001), lower mean LV (mL) (22 ± 18 vs. 49 ± 10 respectively; 95% CI: 22.3 to 31.7, P < 0.0001) and lower mean LF (%) (5 ± 2.04 vs. 12 ± 6.8 respectively; 95% CI: 5.38 to 8.62, P < 0.0001) than the PLMA group. Mean insertion time (seconds) was shorter in the SP Blocker group than the PLMA group (16.39 ± 2.81 vs. 18.63 ± 3.44 respectively; 95% CI: 1.23 to 3.25, P < 0.0001). The SP Blocker group offered a better fiber-optic glottis view score than the PLMA group without differences concerning ventilation score and LPM.

Conclusions: SP Blocker provided as safe anesthesia during controlled mechanical ventilation as PLMA.