Effects of Systemic Administration of Dexmedetomidine on Intraocular Pressure and Ocular Perfusion Pressure during Laparoscopic Surgery in a Steep Trendelenburg Position: Prospective,Randomized, Double-Blinded Study

Increased intraocular pressure (IOP) during surgery is a risk factor for postoperative ophthalmological complications. We assessed the efficacy of systemically infused dexmedetomidine in preventing the increase in IOP caused by a steep Trendelenburg position, and evaluated the influence of underlying hypertension on IOP during surgery. Sixty patients undergoing laparoscopic surgery in a steep Trendelenburg position were included. Patients in the dexmedetomidine group received a 1.0 µg/kg IV loading dose of dexmedetomidine before anesthesia, followed by an infusion of 0.5 µg/kg/hr throughout the operation. Patients in the saline group were infused with the same volume of normal saline. IOP and ocular perfusion pressure (OPP) were measured 16 times pre- and intraoperatively. In the saline group, IOP increased in the steep Trendelenburg position, and was 11.3 mmHg higher at the end of the time at the position compared with the baseline value (before anesthetic induction). This increase in IOP was attenuated in the dexmedetomidine group, for which IOP was only 4.2 mmHg higher (P < 0.001 vs. the saline group). The steep Trendelenburg position was associated with a decrease in OPP; the degree of decrease was comparable for both groups. In intragroup comparisons between patients with underlying hypertension and normotensive patients, the values of IOP at every time point were comparable. Dexmedetomidine infusion attenuated the increase in IOP during laparoscopic surgery in a steep Trendelenburg position, without further decreasing the OPP. Systemic hypertension did not seem to be associated with any additional increase in IOP during surgery. (Registration at the Clinical Research Information Service of Korea National Institute of Health ID: KCT0001482)     

Friedrich Trendelenburg: Historical background and significant medical contributions

Friedrich Trendelenburg's name is widely known today because it is associated with the Trendelenburg position. However, Trendelenburg made many other valuable contributions to the field of medicine, including a test, a gait, and a sign. A historical review of his life helps to elucidate the factors that contributed to his innovative approaches and techniques. Both Trendelenburg's mentors in his early years and the influences upon him throughout his professional career contributed to his development as a pioneer of surgery, anesthesia, and clinical diagnostics. Clin. Anat. 27:815–820, 2014. © 2014 Wiley Periodicals, Inc.     

Lower Extremity Injury While Undergoing Urology Procedures in the Trendelenburg with Lithotomy Position: Three Case Reports

PurposeTo report and discuss the incidence of severe lower extremity injuries associated with robotic procedures in Trendelenburg with lithotomy position.Design and MethodsA case study method was used to describe three cases of patients who underwent robotically assisted urological procedures in Trendelenburg with lithotomy position and developed serious lower extremities injuries resulting in fasciotomies. Furthermore, a literature review was conducted to evaluate risk factors and possible interventions for the prevention of similar injuries.FindingsCase analysis revealed multifactorial causes, including patient comorbidities, long surgical procedures, and blood pressure decreases below the baseline for more than 30 minutes. The severity of lower extremity injury associated with lithotomy position may be underestimated. The etiology of peripheral nerve injury can be attributed to patient comorbidities, positioning, and surgical conditions. Injury prevention should include careful patient and procedural risk assessment, staff education, and communication strategies.ConclusionsExtreme Trendelenburg with lithotomy position for longer periods can lead to serious lower extremities injuries. Preanesthetic screening and multidisciplinary team discussions for additional precautions for high-risk patients are crucial interventions to decrease incidence and severity of lower extremities injuries.     

腰椎穿刺致反常性脑疝一例

对于急性颅高压患者,去骨瓣减压手术是一种可以挽救生命的治疗手段.反常性脑疝是去骨瓣减压术后脑脊液过度引流后出现的罕见并发症,往往被医师漏诊、误诊,危及患者的生命.作者通过典型病例的分析,提高对于反常性脑疝的认识,有助于临床诊断及治疗,进而挽救患者生命.     

Lloyd-davies position with trendelenburg—A disaster waiting to happen?

PURPOSE: Lower limb compartment syndrome has been reported to occur after colorectal, urological, and gynecological procedures during which the patient's lower limbs are elevated for prolonged periods of time. METHOD: We investigated lower limb perfusion in a group of patients undergoing prolonged pelvic surgery both during and immediately after surgery, using intra-arterial blood pressure monitoring, laser doppler flowmetry, and pulse oximetry. RESULTS: Use of the modified lithotomy position was not associated with any demonstrable decrease in lower limb perfusion. The addition of 15° head-down tilt, however, during pelvic dissection, led to an immediate and significant drop in lower limb perfusion (P<0.05; Mann-WhitneyU test). The subgroup of patients analyzed postoperatively showed a ten-fold increase (P<0.01) in perfusion that was confined to the muscle compartment with no demonstrable increase in skin perfusion or intra-arterial pedal blood pressure. CONCLUSION: The use of the modified lithotomy position during pelvic surgery is not associated with lower limb ischemia. Addition of Trendelenburg position, however, causes profound ischemia of the lower limbs, and this is followed during the recovery period by hyperperfusion that is confined to the muscle compartments, which may put patients at risk of developing lower limb compartment syndrome.Presented at The Association of Surgeons of Great Britain and Ireland, Edinburgh, United Kingdom, May 13 to 15, 1998.     

The effect of the Trendelenburg position on lower oesophageal sphincter tone

Measurements were made of gastric, lower oesophageal and barrier pressures in the supine, moderate and steep Trendelenburg positions in 10 healthy female patients during balanced anaesthesia. Adoption of the Trendelenburg position resulted in no significant changes in any measurement, with the exception of a small increase (0.1 kPa) in intragastric pressure in the steep head-down position. We conclude that the steep Trendelenburg position should not predispose to regurgitation in healthy patients.     

头低足高俯卧位降低儿科ICU呼吸机相关性肺炎的效果

目的探讨合理的体位管理方案以降低儿科ICU机械通气患儿呼吸机相关性肺炎(VAP)的发生率。方法选取2013年6月-2017年6月收治于华中科技大学同济医学院附属同济医院儿童重症医学科行机械通气的460例患儿为研究对象。按使用机械通气的前后顺序交替分为观察组(n=230)和对照组(n=230)。两组患儿在对症支持治疗和机械通气常规护理的基础上给予不同的体位管理方案,每2~3小时改变体位1次。观察组给予头低足高倾斜俯卧位与其他体位交替进行,对照组则给予常规仰卧位与侧卧位交替进行。比较两组患儿机械通气前5天痰液引流量、两组患儿胸片改善时间、机械通气持续时间、VAP发生率以及相关并发症发生率。结果观察组患儿机械通气前5天内痰液引流量较对照组更多,观察组患儿胸片改善时间及机械通气持续时间均少于对照组,且VAP发生率均低于对照组(均P<0.05),两组患儿并发症发生率无明显差异(P>0.05)。结论在儿科ICU机械通气患儿中采取头低足高倾斜俯卧位可以显著提高患儿的通气效果,降低机械通气持续时间和VAP发生率,且不会增加相关并发症风险。     

Effect of superior placement of the hip center on abductor muscle strength in total hip arthroplasty

We evaluated 100 limbs in 50 patients who had undergone unilateral primary total hip arthroplasty with a normal contralateral hip. The 50 patients were divided into 2 groups by postoperative acetabular cup position, specifically by inferior and superior placement (inferior and superior groups). Hip abductor muscle strength was evaluated qualitatively by the modified Trendelenburg test and quantitatively by handheld dynamometer. The ratio of normalized strength of the reconstruction side to that of the nonoperated side was calculated (strength ratio). The modified Trendelenburg test was positive in 5 of 23 patients in the inferior group and 11 of 27 in the superior group (P < .05). The strength ratio of the superior group was decreased by 7.7% in comparison with that of the inferior group (P < .01).