Background:Hypovolemia is a common cause of hypotension and low cardiac index (CI) in cardiac surgery but no hemodynamic parameters reflect this status well. The accurate diagnosis of hypovolemia is important because the wrong treatment will cause ineffectiveness and bad consequences such as severe heart failure, pulmonary edema, ... Objectives: To evaluate the performance of diagnostic characteristics of the trendelenburg 300 test for hypovolemia in cardiac surgery. Subjects and method: The prospective, cross \ufffd?sectional and randomized controlled trial (RCT) study was conducted on 30 patients (18 males, 12 females and average age 47,17 \xb1 13,93) undergoing valvular repair/replacement or coronary revascularization. The Swan \ufffd?Ganz catheters were placed in 20 patients and PiCCO catheters in 10 patients. Trendelenburg 300 test is considered positive if blood pressure (BP), central venous pressure (CVP), CI and intrathoracic blood volume (ITBV) increase. Results: The hypovolemic status in cardiac surgical patients is diagnosed if BP and/or CI increase in trendelenburg 300 position (Se 87.5% and 65.63%; Sp 100% and 75%, area under ROC 0.83 and 0.81, respectively). Conclusion: The increases in BP and CI responding to trendelenburg 300 position are good indicators of hypovolemia in cardiac surgery.
Hypovolemia/ diagnosis ; Head-Down Tilt ; Thoracic Surgery ;

BACKGROUND: It is known that pneumoperitoneum and changes of body position during laparoscopic surgery influenced peak inspiratory pressure (PIP). We asked the question whether oropharyngeal leak pressure (OLP) is changed by changes in intraabdominal pressure and position during laparoscopic surgery with a ProSeal laryngeal mask airway (PLMA). Since gynecological laparoscopic surgery (Lap-Gy) and laparoscopic cholecystectomy (Lap-C) require different surgical positions, we included both surgeries in this study so that we could investigate the effects of various positions on OLP. METHODS: Lap-Gy (n = 15) was performed in the trendelenburg position combined with the lithotomy position, whereas Lap-C (n = 10) was performed in the reverse trendelenburg position. The measured variables were PIP and OLP. We also marked the fiberoptic score to determine the intraoral position (FP) of the PLMA. OLP was measured using a manometric stability test. The variables were measured in a regular sequence as follows: S-0o-0, L-0o-0, L-0o-15, L-(-15o)-15, L-(-30o)-15 in Lap-Gy and S-0o-0, S-0o-15, S-(+15o)-15, S-(+30o)-15 in Lap-C. At each measured point, the capital S means supine and L lithotomy. Intermediate numbers with a 'o' superscript are table angles to the horizontal plane (degrees) , '-' means the trendelenburg position and '+', the reverse trendelenburg position, and the last number represents intraabdominal pressure (mmHg). RESULTS: PIP was significantly increased when L-0o-0 changed to L-0o-15, L-0o-15 to L-(-15o)-15 and L-(-15o)-15 to L-(-30o)-15 in Lap-G, and when S-0o-0 was changed to S-0o-15 in Lap-C (P < 0.05). But, OLP and FP were not significantly altered by changes in postion or intraabdominal pressure in both Lap-Gy and Lap-C. CONCLUSIONS: PIP was affected by pneumoperitoneum and positional changes. But, increases in intraabdominal pressure by pneumoperitoneum and changes in position during laparoscopic surgery had no effect on OLP and FP of PLMA.
Cholecystectomy, Laparoscopic ; Head-Down Tilt ; Laparoscopy* ; Laryngeal Masks* ; Pneumoperitoneum

The effect of anesthetic volume on the spread of hypobaric tetracaine were sutdied after intrathecal injection in thirty patients with prone jackknife and 15 degree Trendelenburg position for perinal surgery. The patients were assigned randomly into the one of three groups divided by the 3, 4, or 5 ml of volume of anesthetic solution. The results show that the volume of tetracaine in distilled water with hypobaric spinal anesthesia in prone jackknife and l5 degree Trendelenburg position had a important effect on the anesthetic dermatomal levels in spite of slightly rapid onset with large. volume. Therefore, we concluded that for the perianal surgery in prone jackknife position, as the volume of the anes- thetic solution with hypobaric spinal anesthesia, 3 or 4 ml of the volume are sufficient to get the adequate anesthetic levels.
Anesthesia, Spinal* ; Head-Down Tilt ; Humans ; Injections, Spinal ; Tetracaine ; Water

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.
Humans ; Head-Down Tilt/physiology* ; Patient Positioning ; Abdomen ; Laparoscopy

BACKGROUND: Unlike the right internal jugular vein (RIJV), there is a paucity of data regarding the effect of the Trendelenburg position on the left internal jugular vein (LIJV). The purpose of this study is to investigate the cross-sectional area (CSA) of the LIJV and RIJV and their response to the Trendelenburg position using two-dimensional ultrasound in adult subjects. METHODS: This study enrolled fifty-eight patients with American Society of Anesthesiologists physical status class I-II who were undergoing general anesthesia. CSAs of both the RIJV and LIJV were measured with a two-dimensional ultrasound in the supine position and then in a 10degrees Trendelenburg position. RESULTS: In the supine position, the transverse diameter, anteroposterior diameter, and CSA of the RIJV were significantly larger than those of the LIJV (P < 0.001). Of 58 patients, the RIJV CSA was larger than the LIJV CSA in 43 patients (74.1%), and the LIJV CSA was larger than the RIJV CSA in 15 patients (25.9%). In the Trendelenburg position, CSAs of the RIJV and LIJV increased 39.4 and 25.5%, respectively, compared with the supine position. However, RIJV changed at a rate that was significantly greater than that of the LIJV (P < 0.05). Of 58 patients, the RIJV CSA was larger than the LIJV CSA in 48 patients (82.8%), and the LIJV CSA was larger than the RIJV CSA in 10 patients (17.2%). CONCLUSIONS: In supine position, the RIJV CSA was larger than the LIJV CSA. The increased CSA in the Trendelenburg position was greater in the RIJV than the LIJV.
Adult ; Anesthesia, General ; Central Venous Catheters ; Head-Down Tilt* ; Humans ; Jugular Veins* ; Supine Position ; Ultrasonography

Common peroneal nerve palsy after surgery with lithotomy position has been widely reported, but it is an unexpected complication after surgery with supine position. We report a patient who developed common peroneal nerve palsy after surgery with supine position. A 55-year old man is planed for robotic assisted laparoscopic right hemicolectomy because of colon cancer. The patient was placed supine with Trendelenburg position at an angle about 5 degrees and tilted left about 15 degrees. The operation is uneventful, but he developed common peroneal nerve palsy on the first postoperative day. The patient was fully recovered with conservative treatment after 2 months. We consider that nerve palsy as a result of compression of common peroneal nerve related to patient positioning. So we should be careful not to develop common peroneal nerve palsy even if the patient was placed in the supine position during robotic assisted surgery.
Colonic Neoplasms ; Head-Down Tilt ; Humans ; Paralysis ; Patient Positioning ; Peroneal Nerve ; Supine Position

BACKGROUND: It has been reported that spinal anesthesia has a sedative effect and so this decreases the hypnotic requirement of intravenous anesthetic. Therefore, we have conducted a prospective randomized study to investigate the effect of the spinal anesthesia level on the hypnotic requirements for conscious sedation. METHODS: Forty adult patients were scheduled to undergo spinal anesthesia, and they were randomly allocated to one of the two groups. After subarachnoid injection of 0.5% hyperbaric bupivacaine 16 mg, the patients in group 1 and group 2 were maintained in a reversed Trendelenburg position and a Trendelenburg position, respectively. After fifteen minutes, the target controlled infusion of propofol was started for achieving a target concentration of 1 microgram/ml, and the mean BIS for 1 min was checked after an effect site concentration (Ce) of 1 microgram/ml was reached. The target controlled infusion of propofol was restarted at a target concentration (Tc) of 1.5 microgram/ml, and the mean BIS for 1 min was checked after the Ce level of 1.5 microgram/ml was reached. RESULTS: The mean BIS at 1 microgram/ml Ce was 90.0 +/- 8.5 and 77.8 +/- 10.3 in group 1 and group 2, respectively. The mean BIS at 1.5 g/ml Ce was 73.6 +/- 19.4 and 60.0 +/- 13.1, respectively. CONCLUSIONS: There was a significant difference in the requirements of propofol for conscious sedation between the below T12 block group and the above T4 block group.
Adult ; Anesthesia, Spinal ; Bupivacaine ; Conscious Sedation ; Head-Down Tilt ; Humans ; Hypnosis ; Hypnotics and Sedatives ; Propofol* ; Prospective Studies

BACKGROUND: The laparoscopy requires CO2 insufflation and posture changes for operational convenience. However, above circumstances affect the cardiopulmonary systems significantly. And then intracranial pressure (ICP) may be also influenced. METHODS: To ascertain the changes of ICP, an experimental study was performed, in which the parameters of hemodynamic status, arterial blood gas components and ICP were measured from twelve cases of Korean mongrel dogs. Pneumoperitoneum was produced by CO2 insufflation(15 mmHg) and then posture was altered from horizontal to head-down tilt of 20, 30 and 40 degree*. The measurements were obtained before (control), after CO2 insufflated horizontal position at 20, 40 and 60 minute in CO2 insufflated tilt** and CO2 deflated horizontal***. RESULTS: MAP and HR were not related to the insufflated time and degree of tilt. CVP and PCWP were significantly increased after CO2 insufflated tilt (p<0.01), but returned to control after deflated supine. PaCO2 was not significantly changed after CO2 insufflated supine, but grdually increased with degree of tilt and time (p<0.01). ICP was increased at 40 and 60 minute of 20degree, and at 20 minute of 30degree(p<0.05), then markedly increased at 40 and 60 minute of 30degree, and at 20, 40 and 60 minute of 40degreetilt (p<0.01). The increment of ICP was parallel with time and degree of tilt. But, ICP was returned to control after deflated supine. CONCLUSIONS: ICP was increased significantly during laparoscopy in head-down tilt, although it was reversible. Therefore, the patient must be given special attention during laparoscopy in whom the increment of ICP may be harmful.
Animals ; Carbon Dioxide* ; Carbon* ; Dogs ; Head-Down Tilt* ; Hemodynamics ; Humans ; Insufflation* ; Intracranial Pressure* ; Laparoscopy ; Pneumoperitoneum ; Posture

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.
Head-Down Tilt ; Humans ; Intraocular Pressure* ; Iron-Dextran Complex ; Male ; Supine Position ; Volunteers

BACKGROUND: The laparoscopy requires carbon dioxide (CO2) insufflation and Trendelenburg position for operational convenience. However, the above circumstances affect the cardiopulmonary systems significantly and intraocular pressure (IOP) may be also influenced. METHODS: In 27 non-glaucoma patients right and left intraocular pressure (RIOP, LIOP) were measured 5 minutes after induction of general anesthesia (control value), 15 and 30 minutes after CO2 insufflation and endelenburg-lithotomy position. RESULTS: The control values of RIOP and LIOP were 11.3 4.7 mmHg and 11.5 4.7 mmHg respectively. At 15 minutes after CO2 insufflation and Trendelenburg-lithotomy position, they increased to 16.6 5.3 mmHg and 17.0 5.9 mmHg (p<0.05). At 30 minutes, 18.4 3.5 mmHg and 18.2 4.1 mmHg (p<0.05). CONCLUSION: CO2 insufflation and Trendelenburg-lithotomy position increase IOP significantly in non-glaucoma patients during laparoscopy.
Anesthesia, General ; Carbon Dioxide ; Head-Down Tilt ; Humans ; Insufflation* ; Intraocular Pressure* ; Laparoscopy*