Irradiation of true pelvis for bladder and prostatic carcinoma in supine, prone or Trendelenburg position

Small bowel transit was performed in 50 patients with bladder or prostatic carcinoma. The patients were all examined in supine and prone positions; some were also studied in 25 degrees Trendelenburg position and 25 degrees inclined procubitus to investigate the effect of the various positions on the displacement of the small bowel loops out of the true pelvis. The prone position proved to be superior to the supine position in 78% of patients. A mean displacement of 0.9 cm was obtained. Greatest shifts generally were found in the Trendelenburg position and inclined procubitus, with a mean displacement of 1.9 and 2.0 cm, respectively. The patients' height, weight, maximal abdominal circumference and Quetelet's index were analyzed with regard to the shifts of bowel loops under the various conditions. Only weight and Quetelet's index were correlated with the shifts in the Trendelenburg and inclined procubitus positions. The shifts were generally larger in case of heavier patients. We conclude that pelvic irradiation should preferably be done in the Trendelenburg or inclined procubitus position, especially in case of obesity.     

Hemodynamic changes due to Trendelenburg positioning and pneumoperitoneum during laparoscopic hysterectomy

More prolonged gynecological laparoscopic operations are being performed in recent years, and a steeper head-down position is required. The early reports of hemodynamic changes during gynecologic laparoscopy are conflicting, and the effects of anesthesia, head-down tilt and pneumoperitoneum have not been clearly separated. Invasive hemodynamic monitoring was carried out in 20 female ASA Class I-II patients who underwent laparoscopic hysterectomy. Baseline measurements were made in the supine, supine-lithotomy and Trendelenburg (25 30 degrees) positions in awake patients. Measurements were repeated in the supine-lithotomy and Trendelenburg positions after induction of anesthesia, during laparoscopy 5 minutes after the beginning of peritoneal CO₂-insufflation (intra-abdominal pressure 13–16 mmHg) and at 15-minute intervals thereafter, after laparoscopy in the Trendelenburg and supine positions, after extubation and in the recovery room at 30-minute intervals. Patients received balanced general anesthesia with isoflurane in 35% O₂ in an oxygen/air mixture. End tidal PGO₂ was maintained between 4.5–4.8 kPa (33—36 mmHg) by changing the minute volume of controlled ventilation. The Trendelenburg position in awake and anesthetized patients increased pulmonary arterial pressures (PAP), central venous pressure (GVP) and pulmonary capillary wedge pressure (PCWP). These pressures increased further at the start of CO₂-insufflation, decreased towards the end of the laparoscopy and reached pre-insufflation levels after deflation of pneumoperitoneum. The mean arterial pressure (MAP) increased at the beginning of laparoscopy in comparison with the pre-laparoscopic values. Heart rate (HR) was quite stable during laparoscopy. The cardiac index (CI) decreased with anesthesia from 3.8 to 3.2 1 · min^-1 · m^-2 and further during laparoscopy to 2.7 1 · min^-1 · m^-2, returning to pre-insufflation values soon after deflation. The stroke index (SI) changed in concert with the GI changes. The right ventricular stroke work index decreased during laparoscopy more than the left ventricular stroke work index. The right atrial pressure (GVP) exceeded the PCWP more often during laparoscopy than during any other phase of the procedure. Anesthesia and the Trendelenburg position increased the CVP, PCWP and pulmonary arterial pressures and decreased cardiac output. Pneumoperitoneum increased these pressures further mostly in the beginning of the laparoscopy, and cardiac output decreased towards the end of the laparoscopy. The risk of systemic CO₂-embolus was increased during laparoscopy.     

长时间CO2气腹和Trendelenburg体位对中老年患者直肠癌根治术中脑氧饱和度的影响

目的评估腹腔镜下直肠癌根治术中长时间CO2气腹和Trendelenburg体位对中老年患者脑氧饱和度(rSO2)的影响。方法选择拟行腹腔镜下直肠癌根治术患者38例,男19例,女19例,年龄45~80岁,BMI 18~25kg/m2,ASAⅠ或Ⅱ级。根据年龄分为两组:45~64岁为中年组(M组),65~80岁为老年组(O组)。两组均常规全麻插管,记录诱导结束后10 min(T0)、Trendelenburg体位后30 min(T1)、1 h(T2)和2 h(T3)的HR、MAP、PETCO2、PaCO2、PaO2、rSO2等。采用Pearson检验分析rSO2与年龄的相关性。记录术后3 d内急性脑卒中和术后谵妄(POD)等神经系统相关不良反应的发生情况。结果与T0时比较,T1-T3时两组rSO2均明显升高(P<0.05)。T0时M组rSO2明显高于O组(P<0.05)。不同时点两组HR、MAP、PETCO2、PaCO2、PaO2差异无统计学意义。T0时rSO2与年龄呈明显负相关(r=-0.650,P<0.05)。T1、T2时rSO2与年龄未见明显相关性。T3时rSO2和年龄之间呈明显正相关(r=0.488,P<0.05)。两组术后无一例急性脑卒中和POD等神经系统相关不良反应发生。结论在需要Trendelenburg体位的腹腔镜手术中,尤其对于老年患者,应该加强rSO2监测,避免脑氧供氧需失衡带来的神经系统并发症。     

改良抬胸Trendelenburg位对腹腔镜结直肠癌根治术老年患者脑氧代谢和早期术后认知功能的影响

目的 观察改良抬胸位对腹腔镜结直肠癌根治术老年患者的脑氧代谢和早期术后认知功能的影响.方法 择期拟行腹腔镜结直肠癌根治术患者80例,年龄60～82岁,体重44～69 kg,ASA分级Ⅰ、Ⅱ级,性别不限,按随机数字表法分为2组(每组40例):M组加用定制体位垫使患者呈改良抬胸Trendelenburg体位(简称T位),T组采用T位.于常规全身麻醉插管后平卧位5 min(T1),气腹改良抬胸T位/T位即刻(T2)、30 min(T3)、60 min(T4)和90 min(T5),气腹放气平卧位15 min(T6),分别采集桡动脉和颈静脉球血样,记录血气分析、血糖、乳酸值及MAP等,计算脑动静脉氧含量差(arteriovenous O2 content difference,Ca-jv DO2)及脑葡萄糖摄取(arteriovenous O2 glucose difference,Da-jvglu)等;并于麻醉前,麻醉结束后2、6、24、48、72 h时,采用简易智能量表(mini-mental state exam,MMSE)进行认知功能评分.结果 与T1时比较,两组患者动脉血二氧化碳分压(arterial partial pressure carbon dioxide,PaCO2)在T3-6时均显著升高,MAP在T2时显著降低,两组患者在T3～5时颈静脉球血氧分压(jugular venous partial pressure oxygen,PjvO2)显著升高,T4-5时颈静脉球血氧饱合度(jugular venous oxygen saturation,SjvO2)显著升高(P＜0.05);M组MAP在T4-6时显著升高,T组在T3-6时显著升高(P＜0.05);T组在T6时SjvO2[(75±9)％]显著升高,T5时Caa-jvDO2[(5.2±1.5)％]显著下降,而颈静脉球血乳酸(jugular venous lactate,Lacjv)[(2.0±0.5) mmol/L]显著上升(P＜0.05).与T组比较,M组MAP在T4-6时上升较慢,Ca-jvDO2[(5.9±1.6)％]在T5时无明显下降,Da-jvglu气腹前后差异无统计学意义(P＞0.05),SjvO2 [(75±9)％]和Lacjv[(1.5±0.5) mmol/L]无显著上升,而PaCO2[(34±3) mmHg(1 mmHg=0.133 kPa)]在T6时显著降低(P＜0.05).与T组比较,M组麻醉结束后6、24 h时MMSE评分明显较高;与麻醉前比较,麻醉结束后2h两组MMSE评分显著降低(P＜0.05).结论 改良抬胸T位缓解了气腹后期脑氧供需失衡,麻醉结束后24 h内认知功能下降的发生率明显降低,有利于较长时间手术的安全.     

Epidural blood patch in Trendelenburg position pre‐medicated with acetazolamide to treat spontaneous intracranial hypotension

Background: Spontaneous intracranial hypotension (SIH) is characterized by orthostatic headache, diffuse pachymeningeal enhancement on brain magnetic resonance imaging (MRI) and low cerebrospinal fluid (CSF) pressure. Treatment ranges from conservative management, such as bed rest, overhydration and caffeine, to invasive procedures, such as the autologous epidural blood patch (EBP), computed tomography (CT)‐guided fibrin glue injection at the site of the leak and open surgical intervention. EBP has emerged as the treatment of choice for SIH when initial conservative measures fail to bring relief. Methods: Forty‐two patients with SIH were treated with lumbar autologous EBP in Trendelenburg position preceded by pre‐medication with acetazolamide. Results: A complete recovery was obtained in all patients after one (90%), two (5%) or three (5%) EBPs. After EBP, two patients (5%) also performed evacuation of bilateral chronic subdural hematoma with mass effect. Conclusions: Spontaneous intracranial hypotension can be effectively cured by lumbar autologous EBP in Trendelenburg position pre‐medicated with acetazolamide.     

Hip Abductor Strengths After Total Hip Arthroplasty Via the Lateral and Posterolateral Approaches

A retrospective control study was carried out to compare the postoperative hip abductor strengths after primary total hip arthroplasties via the lateral (lateral group; 38 hips) and posterolateral (posterior group; 40 hips) approaches. At a minimum of 2 years after total hip arthroplasty, abductor muscle strength was evaluated qualitatively by the Trendelenburg test and quantitatively using a dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The Trendelenburg test was positive in 10 of 38 patients in the lateral group and in 11 of 40 patients in the posterior group. The average strength ratios of the lateral and posterior groups were 86.1% and 87.3%, respectively (P = .67). Strength ratio was positively correlated to femoral offset within both groups.     

An innovative approach to orotracheal intubations: the Alexandrou Angle of Intubation position

Visualization of the vocal cords is paramount during orotracheal intubations. We employed a novel patient position in this derivation study. The Alexandrou Angle of Intubation (AAI) position is defined as a 20°-30° incline where the supine patient's head is elevated in relation to the body and legs. Our study participants were blinded to the goals of the research as well as our novel technique. Using intubation manikins, our participants ranked their preference for visualizing the vocal cords between the Flat, Trendelenburg, and AAI positions. A majority (58.8%) of our study participants preferred the AAI for visualizing the vocal cords over the other two positions. Future studies will reveal whether AAI will play a significant role in emergent airway management.     

Effect of age on pulmonary gas exchange during laparoscopy in the Trendelenburg lithotomy position

BACKGROUND: Physiological changes in respiratory mechanics caused by aging may lead to a deterioration in pulmonary gas exchange, an increase in the alveolar-arterial oxygen gradient [(A-a)D(O2)] and a difference between the arterial carbon dioxide (CO(2)) tension (P(a)(CO(2))) and expired end-tidal CO(2) tension (P(ET)(CO(2))) [P((a-ET))(CO(2))] during laparoscopy in the Trendelenburg lithotomy position (TLP). METHODS: The subjects were 51 gynecologic patients. Pressure-controlled ventilation was used to maintain P(ET)(CO(2)), measured by the side stream method, within the range 4-4.67 kPa. During laparoscopy with CO(2) insufflation in TLP, the tidal volume was increased to keep P(ET)(CO(2)) within +/- 20% of the pre-insufflation value. The subjects were divided into three groups by age: young group (< 45 years); middle-aged group (45-64 years); and elderly group ( > or = 65 years). RESULTS: Before pneumoperitoneum (PPN), significant differences were found between the young and elderly groups in the arterial oxygen tension (P(a)(O(2))), (A-a)D(O(2)), P(a)(CO(2)) and P((a-ET))(CO(2)). In all groups, the peak inspiratory pressure and P(a)(CO(2)) increased progressively during PPN in TLP. P((a-ET))(CO(2)) increased gradually after starting CO(2) insufflation in TLP only in the elderly group. CONCLUSIONS: An increase in P((a-ET))(CO(2)) was seen during PPN in TLP in the elderly group. With CO(2) insufflation in TLP, the setting of mechanical ventilation based on the value of P(ET)(CO(2)) (measured by the side stream method) should be determined with caution in elderly patients.     

Compartment syndrome of the leg associated with lithotomy position for cytoreductive surgery

BACKGROUND: Compartment syndrome is seen in patients who have ischemic damage to muscle that is contained within a fascial compartment. A pathologic cycle is initiated when tissue injury produces swelling and compromises muscle perfusion. Patients undergoing cytoreductive surgery combined with intraperitoneal chemotherapy are required to be in the lithotomy position for many hours. Compartment syndrome can develop necessitating fasciotomy. METHODS: In a study of 473 operative procedures to perform cytoreductive surgery and intraperitoneal chemotherapy, eight patients required fasciotomy on an emergency basis to treat compartment syndrome and were recorded in a prospective database over a 4-year time period. RESULTS: During the hospitalization five of the eight patients developed venous thrombotic complications. In order to prevent movement of the patient on the operating table during steep Trendelenburg position, shoulder braces were used in the subsequent 250 patients and no episodes of compartment syndrome occurred. CONCLUSION: Compartment syndrome in patients undergoing cytoreductive surgery may be related to changes in position on the operating table induced by steep Trendelenburg position. Minimizing this change in position has reduced the likelihood of developing Compartment syndrome.     

Trendelenburg position with hip flexion as a rescue strategy to increase spinal anaesthetic level after spinal block

BACKGROUND: When the level achieved by a spinal anaesthetic is too low toperform surgery, patients are usually placed in the Trendelenburgposition. However, cephalad spread of the hyperbaric spinalanaesthetics may be limited by the lumbar lordosis. The Trendelenburgposition with the lumbar lordosis flattened by hip flexion wasevaluated as a method to extend the analgesic level after theadministration of hyperbaric local anaesthetic. METHODS: When the pinprick block level was lower than T10 5 minafter intrathecal injection of hyperbaric bupivacaine (13 mg),patients were recruited to the study and randomly allocatedto one of the two positions: the Trendelenburg position withhip flexion (hip flexion group, n = 20) and the Trendelenburgposition without hip flexion (control group, n = 20). Each assignedposition was maintained for 5 min and then patients werereturned to the horizontal supine position. Spinal block levelwas assessed by pinprick, cold sensation, and modified Bromagescale at intervals for the following 150 min. RESULTS: The maximum level of pinprick and cold sensory block [median(range)] was higher in the hip flexion group [T4 (T8–C6)and T3 (T6–C2)] compared with the control group [T7 (T12–T4)and T5 (T11–T3)] (P < 0.001). The maximum motor blockademedian (range) was not different between the two groups being3 (3–3) in the hip flexion group vs 3 (0–3) in thecontrol group. CONCLUSIONS: When the level of spinal anaesthesia is lower than required,flexion of the hips in the Trendelenburg position may be usefulas a strategy attempt to increase the level of the block.