Spread of local anaesthetic solution in the paravertebral space after erector spinae plane block (ESPB) is variable. We evaluated whether paravertebral spread of local anaesthetic is affected by patient position after ESPB. We randomised 84 patients to receive ESPB at T₇ with a mixture of 0.375% ropivacaine and radiocontrast dye (30 ml). Participants were positioned supine, prone, or lateral for 30 min after ESPB before computed tomography scanning. The primary outcome was paravertebral space local anaesthetic spread, with secondary assessments of craniocaudal spread and distribution to neural foramina, and intercostal and epidural spaces. Loss of sensation to cold was recorded. Local anaesthetic-contrast mix reached the paravertebral space, intercostal space, and neural foramina in 96.5%, 94.2%, and 77.9% of individuals, respectively. Epidural space spread occurred in 20 cases. Prone positioning consistently allowed paravertebral and intercostal spread in all patients, with more thoracic level spread compared with supine positioning (5.0 [1.9] vs 3.1 [1.7], difference [95% confidence interval, CI]: 1.9 [0.8-3.0] levels, P<0.001 for paravertebral space spread; 2.8 [1.9] vs 1.4 [1.4], difference [95% CI] levels: 1.4 [0.4-2.5], P=0.004 for neural foramina spread; 4.3 [1.3] vs 3.2 [1.5], difference [95% CI] levels: 1.0 [0.1-1.9], P=0.019 for intercostal space spread). Local anaesthetic-contrast extended to the intercostal space further in the prone than in the lateral position group (4.3 [1.3] vs 2.6 [1.5] thoracic levels, difference [95% CI]: 1.7 [0.8-2.6], P<0.001). Sensory block in ventral dermatomes was variable in all participants. Prone positioning after ESPB significantly enhanced local anaesthetic-contrast spread to the paravertebral space, intercostal space, and neural foramina, suggesting that gravity plays a substantial role in spread. Clinical Trials.gov (NCT06142630).

Aim: To evaluate the effect of ultrasound (US) on learning curve and inter-subject performance variability of residents in radial artery cannulation.Material and methods: Twenty non-anesthesiology residents who received standardized training in an anesthesiology department were selected and divided into two groups: anatomy group or US group. After training of relevant anatomy, US recognition and puncture skill, residents selected 10 patients either under US or anatomical localization performing radial artery catheterization. The number and time of successful cases of catheterization were recorded, success rate of first attempt and catheterization, as well as the total success rate of catheterization were calculated. The learning curve and inter-subject performance variability of residents were also calculated. Complications and the residents’ satisfaction for teaching and self-confidence before puncture were also recorded.Results: Compared to the anatomy group, total success rate and the success rate at first attempt were higher in US-guided group (88% vs. 57%, 94% vs. 81%). The average performance time in the US group was significantly less (2.9±0.8 min vs. 4.2±2.1 min) and the mean number of attempts was 1.6, while 2.6 for the anatomy group. With performing cases increasing, the average puncture time of residents in the US group decreased by 19s, while 14s in the anatomy group. More local hematoma occurred in the anatomy group. The satisfaction and confidence degree of residents were higher in US group ([98.5±6.5] vs [68.5±7.3], [90.2±8.6] vs [56.3±5.5]).Conclusion: US can significantly shorten the learning curve, reduce the inter-subject performance variability, improve the first attempt and total success rate of radial artery catheterization for non-anesthesiology residents.

Background: The thyroid cartilage plane (TCP) block is a novel approach for superior laryngeal nerve (SLN) block in awake tracheal intubation (ATI). We aimed to evaluate the efficacy and safety of TCP block for ATI. Materials and methods: Our study included a cadaver dissection and a clinical study. Detailed anatomical dissections were performed on two fresh cadavers after a bilateral TCP block with methylene blue. Sixty patients scheduled for ATI were randomized to receive either bilateral TCP block (TCP group) or fiberoptic bronchoscope-assisted topical anesthesia (FIB group) to anesthetize the vocal cords. A 22-gauge needle was advanced targeting the thyroid cartilage laminae, followed by injection of 2.5 ml lidocaine in the TCP group. Lidocaine spray was applied to anesthetize the remainder of the airway. The primary outcome was quality of airway anesthesia grade during intubation (0, excellent; 1, good; 2, fair; 3, poor; 4, very poor), with secondary outcomes including hemodynamic profile, Ramsay sedation score, and incidence of airway hemorrhage and SLN injury. Results: The methylene blue stained all the internal branches of SLN, with one external branch not stained. In the clinical study, the quality of airway anesthesia was significantly better in the TCP group than in the FIB group (median [IQR], 0 [0–0] vs 1 [0–2], difference [95% CI]: 1 [0–1], P < 0.001). Mean arterial pressure and HR were better maintained during intubation in the TCP group ( P < 0.05). Neither airway hemorrhage nor nerve injury was observed. Conclusion: Ultrasound-guided TCP block is an effective and safe approach for the SLN blockade, providing an alternative for ATI.

We aimed to evaluate the effect of a 16-gauge needle as an introducer in single-operator real-time ultrasound-guided subarachnoid anesthesia. One hundred and two parturients undergoing cesarean section were randomized to undergo real-time ultrasound-guided subarachnoid anesthesia either with (group T) or without (group C) a 16-gauge needle as an introducer. The primary outcome was the number of needle passes required for a successful dural puncture. Secondary outcomes included the number of attempts, first pass/attempt success rate, procedure time, parturients’ pain, puncture depth, periprocedural complications, and the quality of sonographic images. The median number of needle passes and attempts were significantly lower in group T than in group C [1 (1–2) vs. 2 (1–3), median difference (95% CI): 1 (0–1), P < 0.001; 1 (1–1) vs. 1 (1–1), median difference (95% CI): 0 (0–0), P = 0.042]. The first pass/attempt success rates in group T were significantly higher than in group C (70.6% vs. 35.3%, 100% vs. 88.2%; both, P < 0.001). The total procedural time was shorter in group T [108 (94–130) vs. 123 (100–163) seconds, median difference (95% CI): 15 (3–33), P < 0.016]. No intergroup differences of pain, puncture depth, periprocedural complications and quality of sonographic images were seen. The application of a 16-gauge needle as an introducer showed improved efficacy in terms of the number of needle passes/attempts, first pass/attempt success rates, and procedural time in real-time ultrasound-guided subarachnoid anesthesia. The study was registered in the Chinese Clinical Trial Registry (registration date February 27, 2023 registration number ChiCTR2300068702).

As a feasibility study, this study primarily aimed to assess the feasibility of conducting a future randomized controlled trial (RCT) on gastrocnemius plan