Advances in the Clinical Application of Trendelenburg Position / 中国医学科学杂志(英文版)

The Trendelenburg position and reverse Trendelenburg position are frequently employed during lower abdominal surgery to achieve optimal surgical field visualization and complete exposure of the operative site, particularly under pneumoperitoneum conditions. However, these positions can have significant impacts on the patient's physiological functions. This article overviews the historical background of Trendelenburg position and reverse Trendelenbury position, their effects on various physiological functions, recent advancements in their clinical applications, and strategies for preventing and managing associated complications.

Positioning of a morbidly obese patient during retinal surgery

A body mass index (BMI) ?35 kg/m2 is classified as obese, and a BMI ?40 kg/m2 is classified as morbidly obese. Obese people are at a higher risk for developing cardiovascular complications like ischemic heart diseases, congestive cardiac failure, hypertension, type 2 diabetes mellitus and obstructive sleep apnea (OSA) among other health issues. Central obesity can also increase the pleural pressure and cardiac filling pressures, thus increasing the intracranial (ICP) and intraocular pressure (IOP). These clinical co-morbidities can make retina surgeries, which require patient in supine position for 45-90 minutes, a challenging task. We present our experience in the intraoperative positioning of such a patient who underwent surgery for retinal detachment.

Reverse trendelenburg position can alleviate postoperative nausea and vomiting in thyroid surgery: from Logistic multivariate analysis / 中华内分泌外科杂志

Objective To assess the clinical significance of reverse trendelenburg position in preventing postoperative nausea and vomiting(PONV)in thyroid surgery.Methods 110 patients with papillary thyroid carcinoma(PTC) admitted from Feb.2013 to Mar.2014 were prospectively divided into experimental group and the control group according to whether reserve trendelenburg position was adopted.Univariate and multivariate method were used to analyze relations between PONV and surgical position,gender,age,body mass index,hypertension,surgical time,ASA classification,anesthesia,and motion sickness.Results Of the 110 cases of PTC,the incidence of PONV was 16.28％ (7/43) in the experimental group while it was 37.31％ (25/67) in the control group.The difference had statistical significance(P ＜ 0.05).Statistical analysis showed that PONV was related to patients'gender,surgical position,surgical time,and motion sickness,while only surgical position and motion sickness was the independent risk factors.Conclusion Reverse trendelenburg position surgery can help to prevent PONV and promote recovery.

Postural Intraocular Pressure Change at Trendelenberg Position Measured by Rebound Tonometer

PURPOSE: This study was carried out to evaluate the postural intraocular pressure (IOP) change in Trendelenburg, reverse Trendelenburg, and supine positions in healthy young males. METHODS: We measured the IOP values of 5 healthy young male volunteers (10 eyes) using an Icare PRO rebound tonometer in sitting, Trendelenburg, reverse Trendelenburg, and supine positions. RESULTS: The mean IOP in the supine position (18.63 mm Hg) was significantly higher (p < 0.01) than in the sitting position (15.31 mm Hg). When maintaining the Trendelenburg position, IOP gradually increased. CONCLUSIONS: In our study, the Trendelenburg position significantly increased the IOP compared to that in the supine position. The effects of increased IOP should be considered in situations that require Trendelenburg positioning, such as exercise or surgery.

The correlation between the Trendelenburg position and the stroke volume variation / 대한마취과학회지

BACKGROUND: The stroke volume variation (SVV), based on lung-heart interaction during mechanical ventilation, is a useful dynamic parameter for fluid responsiveness. However, it is affected by many factors. The aim of this study was to evaluate the effects of SVV on Trendelenburg (T) and reverse Trendelenburg (RT) position and to further elaborate on the patterns of the SVV with position. METHODS: Forty-two patients undergoing elective surgery were enrolled in this study. Fifteen minutes after standardized induction of anesthesia with propofol, fentanyl, and rocuronium with volume controlled ventilation (tidal volume of 8 ml/kg of ideal body weight, inspiration : expiration ratio of 1 : 2, and respiratory rate of 10-13 breaths/min), the patients underwent posture changes as follows: supine, T position at slopes of operating table of -5degrees, -10degrees, and -15degrees, and RT position at slopes of operating table of 5degrees, 10degrees, and 15degrees. At each point, SVV, cardiac output (CO), peak airway pressure (PAP), mean blood pressure, and heart rate (HR) were recorded. RESULTS: The SVV was significant decreased with decreased slopes of operating table in T position, and increased with increased slopes of operating table in RT position (P = 0.000). Schematically, it was increased by 1% when the slope of operating table was increased by 5degrees. But, the CO and PAP were significant increased with decreased slopes of operating table in T position, and decreased with increased slopes of operating table in RT position (P = 0.045, 0.027). CONCLUSIONS: SVV is subjected to the posture, and we should take these findings into account on reading SVV for fluid therapy.

The effects of hip abduction with external rotation and reverse Trendelenburg position on the size of the femoral vein; ultrasonographic investigation / 대한마취과학회지

BACKGROUND: Femoral vein (FV) catheterization is required for critically ill patients, patients with difficult peripheral intravenous access, and patients undergoing major surgery. The purpose of this study was to evaluate the effects of hip abduction with external rotation (frog-leg position), and the frog-leg position during the reverse Trendelenburg position on diameter, cross-sectional area (CSA), exposed width and ratio of the FV using ultrasound investigation. METHODS: Ultrasonographic FV images of 50 adult subjects were obtained: 1) in the neutral position (N position); 2) in the frog-leg position (F position); 3) in the F position during the reverse Trendelenburg position (FRT position). Diameter, CSA, and exposed width of the FV were measured. Exposed ratio of the FV was calculated. RESULTS: The F and FRT positions increased diameter, CSA and exposed width of the FV significantly compared with the N position. However, the F and FRT positions had no significant effect on exposed ratio of the FV compared with the N position. The FRT position was more effective than the F position in increasing FV size. CONCLUSIONS: The F and FRT positions can be used to increase FV size during catheterization. These positions may increase success rate and reduce complication rate and, therefore, can be useful for patients with difficult central venous access or at high-risk of catheter-related complication.