Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes: A multicenter prospective observational trial

Background

Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes.

Methods

In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration.

Results

In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation.

Conclusion

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.

Registration of Clinical Trial

DRKS-ID DRKS00014788 ( www.drks.de ).     

Resistencia a los anestésicos locales: ¿verdad o mito?

The report of anesthetic technique failure is crucial and the etiology of the problem should be determined. We describe a case of locoregional anesthesia failure, in which, after excluding its most common causes, the resistance to local anesthetics was considered as the most probable clinical hypothesis. For this reason, a genetic test was performed, as well as the efficacy of other local anesthetics was evaluated, constituting a different approach in the cases of locoregional anesthesia failure. True resistance to local anesthetics is difficult to diagnose so information about this is scarce in the literature. One of the proposed causes is a mutation of sodium channels where local anesthetics bind. If not recognized, the application of locorregional anesthesia in this patient's condition can lead to unpleasant experiences and unnecessary risks, related to toxic levels of local anesthetics. For this reason, the resistance to local anesthetics should be always precluded in cases of strong clinical suspicion. This approach could be applied in similar cases.     

The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study

BackgroundPain assessment is essential for the administration of appropriate analgesia. Currently, clinicians use surrogate methods, such as heart rate or behavioural pain scales, to estimate pain in neonates and infants. The Newborn and Infant Parasympathetic Evaluation (NIPE™) monitor aims to provide an objective numeric value (NIPE index) of pain through a continuous assessment of the patient's parasympathetic activity. The aim of this study was to determine if the intraoperative NIPE index monitoring could predict postoperative pain in neonates and infants.MethodsThis prospective observational pilot study included neonates and infants undergoing elective day-surgical procedures (n = 50). Intraoperatively, NIPE indices at 0 (NIPE₀), 10 (NIPE₁₀), 20 (NIPE₂₀), 30 (NIPE₃₀) minutes and at completion of surgery (NIPEe), were recorded; the median NIPE index (NIPEm) was calculated for the entire procedure. Postoperative Face, Legs, Activity, Cry, Consolability (FLACC) scale scores were calculated by the nursing staff blinded to the intraoperative NIPE indices.ResultsLinear regression documented an association between the NIPEm and postoperative FLACC score at 0 (r = 0.31, p = 0.03) and 10 min (r = 0.36, p = 0.01). No significant associations were observed for FLACC scores at 20 (r = 0.21, p = 0.2) and 30 min (r = 0.36, p > 0.9). Multiple regression analysis revealed that intraoperative NIPE₁₀, NIPE₂₀, NIPE₃₀ and NIPEe also predicted the FLACC score at 0 min (p = 0.003).ConclusionThe intraoperative NIPE index is predictive of pain in the immediate postoperative period. This association was lost at 20 min likely due to nursing intervention to administer analgesia. NIPE monitoring could be useful in facilitating postoperative pain management in infants.Level of evidenceII.Type of studyStudy of Diagnostic Test.     

丙泊酚复合瑞芬太尼喉罩全麻的效果分析与研究

目的 探讨丙泊酚复合瑞芬太尼喉罩全身麻醉(全麻)的效果。方法 62例腹腔镜、泌尿科、骨科、肛肠科、妇科等手术治疗的患者,随机分为实验组和对照组,每组31例。对照组采用常规气管插管静脉复合全麻,实验组给予靶控输注丙泊酚复合瑞芬太尼喉罩全麻。比较两组患者插入喉罩(插管)、插管1 min、插管3 min、拔出喉罩(拔管)1 min、拔管3 min时心率(HR)和平均动脉压(MAP)水平;不良反应发生情况、麻醉效果;全麻起效时间、维持全麻时间、术后苏醒时间。结果 实验组插管时、插管1 min、插管3 min、拔管1 min、拔管3 min的HR水平分别为(77.52±6.36)、(73.26±5.56)、(72.01±4.69)、(75.35±7.63)、(72.34±6.79)次/min,均低于对照组的(92.34±7.85)、(87.97±5.25)、(78.85±5.20)、(95.69±9.21)、(85.63±7.43)次/min,差异均具有统计学意义(P<0.05)。实验组插管时、插管1 min、插管3 min、拔管1 min、拔管3 min的MAP水平分别为(90.25±6.73)、(87.65±7.98)、(88.79±7.65)、(88.09±5.61)、(88.52±5.16)mm Hg(1 mm Hg=0.133 kPa),均低于对照组的(109.51±7.85)、(103.27±12.43)、(102.52±8.21)、(106.74±7.68)、(104.62±7.71)mm Hg,差异均具有统计学意义(P<0.05)。实验组不良反应发生率3.23%低于对照组的19.35%,差异具有统计学意义(P<0.05)。实验组麻醉总有效率96.77%均高于对照组的80.65%,差异均具有统计学意义(P<0.05)。实验组全麻起效、维持全麻、术后苏醒时间分别为(1.61±0.23)、(100.59±6.72)、(17.99±3.52)min,均短于对照组的(2.93±0.41)、(123.61±7.85)、(36.87±4.16)min,差异均具有统计学意义(P<0.05)。结论 针对腹腔镜等手术患者应用丙泊酚复合瑞芬太尼喉罩全麻对血液动力学影响小,不良反应发生率低,麻醉效果良好,降低对机体损伤,值得推广应用。     

全麻复合硬膜外麻醉对肺癌根治术患者外周血T细胞亚群及NK细胞活性的影响

目的探讨全麻复合硬膜外麻醉对肺癌根治术患者外周血T细胞亚群及NK细胞活性的影响。方法收集接受肺癌根治术的84例患者的病历资料,按照患者所行麻醉方式的不同对其进行分组,单纯行全麻者42例归为对照组,行全麻复合硬膜外麻醉者42例纳入观察组,分析不同麻醉方式对患者外周血T细胞亚群及NK细胞活性影响的差异性。结果术后24 h观察组与对照组患者的CD3^+、CD4^+、CD8^+、CD4^+/CD8^+、NK细胞水平均较术前明显降低,且术后24 h相比对照组患者的CD3^+、CD4^+、CD8^+、CD4^+/CD8^+、NK细胞水平,观察组患者以上指标水平明显更高(P<0.05)。术后1周2组患者的CD3^+、CD4^+、CD8^+、CD4^+/CD8^+水平与术前相比并无明显差异(P>0.05),但NK细胞水平较术前明显降低(P<0.05),且术后1周相比对照组患者,观察组患者的NK细胞水平更高(P<0.05)。观察组患者的术后苏醒时间、术后拔管时间、自主呼吸恢复时间均明显短于对照组患者,2组差异有统计学意义(P<0.05)。结论相比单纯全麻,全麻复合硬膜外麻醉对肺癌根治术患者外周血T细胞亚群及NK细胞活性的影响更小,有助于患者术后的恢复。     

围术期非心脏手术呼吸心搏骤停相关麻醉因素回顾性分析

目的回顾性分析聊城市人民医院近7年来,围术期24 h内发生心搏骤停患者的医学资料,为预防这一严重不良事件提供有益信息。方法通过我院手术麻醉电子系统,调阅不良事件上报系统,选取2013-07/2020-12期间在我院手术室接受非心脏手术围术期发生心搏骤停患者的医疗记录进行分析、归纳总结。结果共116152名患者接受非心脏手术麻醉,围术期发生心搏骤停33例(2.8/10000),21例复苏失败,死亡率1.8/10000。麻醉完全相关2例,麻醉部分相关12例,麻醉相关心搏骤停发生率1.2/10000。与麻醉不相关心搏骤停患者基本资料比较,差异无统计学意义。结论围术期心搏骤停原因复杂多样,失血性休克以及感染性休克,是围术期心搏骤停最常见的原因,麻醉医生应熟知各种不同类型心搏骤停病理生理机制,以便实施快速有效的抢救措施。     

Identifying the emergence of the superficial peroneal nerve through deep fascia on ultrasound and by dissection: Implications for regional anesthesia in foot and ankle surgery

Regional anesthesia relies on a sound understanding of anatomy and the utility of ultrasound in identifying relevant structures. We assessed the ability to identify the point at which the superficial peroneal nerve (SPN) emerges through the deep fascia by ultrasound on 26 volunteers (mean age 27.85 years ± 13.186; equal male: female). This point was identified, characterized in relation to surrounding bony landmarks (lateral malleolus and head of the fibula), and compared to data from 16 formalin‐fixed human cadavers (mean age 82.88 years ± 6.964; equal male: female). The SPN was identified bilaterally in all subjects. On ultrasound it was found to pierce the deep fascia of the leg at a point 0.31 (±0.066) of the way along a straight line from the lateral malleolus to the head of the fibula (LM‐HF line). This occurred on or anterior to the line in all cases. Dissection of cadavers found this point to be 0.30 (±0.062) along the LM‐HF line, with no statistically significant difference between the two groups (U = 764.000; exact two‐tailed P = 0.534). It was always on or anterior to the LM‐HF line, anterior by 0.74 cm (±0.624) on ultrasound and by 1.51 cm (±0.509) during dissection. This point was significantly further anterior to the LM‐HF line in cadavers (U = 257.700, exact two‐tailed P < 0.001). Dissection revealed the nerve to divide prior to emergence in 46.88% (n = 15) limbs, which was not identified on ultrasound (although not specifically assessed). Such information can guide clinicians when patient factors (e.g., obesity and peripheral edema) make ultrasound‐guided nerve localization more technically challenging. Clin. Anat. 32:390–395, 2019. © 2019 Wiley Periodicals, Inc.