Accuracy of Catheter Positioning during Left Subclavian Venous Access: A Randomized Comparison between Radiological and Topographical Landmarks.

Left subclavian venous access increases the risk of vascular damage and thrombosis based on the catheter course and location of the catheter tip. We investigated the accuracy of tip positioning with conventional landmarks using transesophageal echocardiography. The carina as a radiological landmark and the right third intercostal space as a topographical landmark were selected for tip positioning within the target zone, defined as 2 cm above and 1 cm below the right atrial junction. A total of 120 participants were randomized into two groups. The catheter insertion depth was determined as 1.5 cm more than the distance between the venous insertion point and the carina via the right first intercostal space in the radiological group, and between the venous insertion point and the right third intercostal space via the right first intercostal space in the topographical group. The determined insertion depth and actual distance to the right atrial junction of the radiological and topographical groups were 19.5 cm and 20.5 cm, and 19.8 cm and 20.4 cm, respectively. Acceptable positioning was more frequent in the topographical group (96.4% vs. 85.7%; p = 0.047). The catheter tip is more accurately positioned in the distal superior vena cava using topographical landmarks than radiological landmarks.

Retrospective lumbosacral CT analysis and prospective observational study of the ipsilateral tunnel view technique for fluoroscopy-guided selective S1 transforaminal epidural injection.

BACKGROUND: The purpose of this study was to retrospectively observe the anatomic relationship between dorsal S1 foramen (DS1F) and ventral S1 foramen (VS1F) through computed tomography (CT) analysis and to prospectively determine the optimal angle of ipsilateral tunnel view technique for performing S1 transforaminal epidural steroid injection (S1-TFESI). METHODS: The axial lumbosacral CTs taken between in 208 consecutive patients and the following measurements were obtained on both sides: (1) the α-angle was defined as an angle between a sagittal line passing through the center of the sacrum and an imaginary line passing through the center of DS1F, (2) the largest diameter of DS1F and VS1F. The fluoroscopy was adjusted to show the largest L5/S1 intervertebral disc space, which was defined as the cephalad angle, and tilted to the ipsilateral oblique side until the entrance of DS1F had a well-defined, round shape, which defined as the ß-angle in 40 humans. RESULTS: CT measurements showed that the α-angle was 26.3 ± 3.3 degrees (15-38 degrees) and the diameter of DS1F was 7.1 ± 0.7 mm (4-10.9 mm), which was significantly smaller than the diameter of VS1F, 10.1 ± 1.0 mm (7.2-13.8 mm). The ß-angle was 24 ± 4.6 degrees, which was not much different from the α-angle and the cephalad angle was 23 ± 4.6 degrees. The success rate of S1-TFESI was 100% and there were no procedure-related complications. CONCLUSIONS: The entrance of DS1F is easily identified with an ipsilateral 25 degrees-tunnel view technique while performing S1-TFESI, and it is a clinically applicable approach.

Risk factors for intraoperative massive transfusion in pediatric liver transplantation: a multivariate analysis.

Background: Pediatric liver transplantation (LT) is strongly associated with increased intraoperative blood transfusion requirement and postoperative morbidity and mortality. In the present study, we aimed to assess the risk factors associated with massive transfusion in pediatric LT, and examined the effect of massive transfusion on the postoperative outcomes. Methods: We enrolled pediatric patients who underwent LT between December 1994 and June 2015. Massive transfusion was defined as the administration of red blood cells ≥100% of the total blood volume during LT. The cases of pediatric LT were assigned to the massive transfusion or no-massive transfusion (administration of red blood cells <100% of the total blood volume during LT) group. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors associated with massive transfusion in pediatric LT. Kaplan-Meier survival analysis, with the log rank test, was used to compare graft and patient survival within 6 months after pediatric LT between the 2 groups. Results: The total number of LT was 112 (45.0%) and 137 (55.0%) in the no-massive transfusion and massive transfusion groups, respectively. Multivariate logistic regression analysis indicated that high white blood cell (WBC) count, low platelet count, and cadaveric donors were significant predictive factors of massive transfusion during pediatric LT. The graft failure rate within 6 months in the massive transfusion group tended to be higher than that in the no-massive transfusion group (6.6% vs. 1.8%, P = 0.068). However, the patient mortality rate within 6 months did not differ significantly between the massive transfusion and no-massive transfusion groups (7.3% vs. 7.1%, P = 0.964). Conclusion: Massive transfusion during pediatric LT is significantly associated with a high WBC count, low platelet count, and cadaveric donor. This finding can provide a better understanding of perioperative blood transfusion management in pediatric LT recipients.

Dexmedetomidine for sedation in pediatric patients who received more than 20 sessions of radiation therapy: two cases report.

Dexmedetomidine is a highly selective α2-adrenoceptor agonist that demonstrates anxiolytic and analgesic properties without inducing respiratory compromise, which makes it a suitable agent for procedural sedation and imaging studies. In our current case reports, intravenous dexmedetomidine infusion was used to provide sedation to 2 pediatric patients over more than 20 sessions of radiation therapy. On both occasions, dexmedetomidine provided adequate sedation without respiratory depression. However, the required dosage increased with repeated radiation therapy sessions.

Arrhythmogenic potential develops rapidly at graft reperfusion before the start of hypotension during living-donor liver transplantation.

BACKGROUND: Detailed profiles of acute hypothermia and electrocardiographic (ECG) manifestations of arrhythmogenicity were examined to analyze acute hypothermia and ventricular arrhythmogenic potential immediately after portal vein unclamping (PVU) in living-donor liver transplantation (LT). METHODS: We retrospectively analyzed electronically archived medical records (n = 148) of beat-to-beat ECG, arterial pressure waveforms, and blood temperature (BT) from Swan-Ganz catheters in patients undergoing living-donor LT. The ECG data analyzed were selected from the start of BT drop to the initiation of systolic hypotension after PVU. RESULTS: On reperfusion, acute hypothermia of < 34℃, < 33℃ and < 32℃ developed in 75.0%, 37.2% and 11.5% of patients, respectively. BT decreased from 35.0℃ ± 0.8℃ to 33.3℃ ± 1.0℃ (range 35.8℃-30.5℃). The median time to nadir of BT was 10 s after PVU. Difference in BT (ΔBT) was weakly correlated with graft-recipient weight ratio (GRWR; r = 0.22, P = 0.008). Compared to baseline, arrhythmogenicity indices such as corrected QT (QTc), Tp-e (T wave peak to end) interval, and Tp-e/QTc ratio were prolonged (P < 0.001 each). ST height decreased and T amplitude increased (P < 0.001 each). However, no correlation was found between ΔBT and arrhythmogenic indices. CONCLUSIONS: In living-donor LT, regardless of extent of BT drop, ventricular arrhythmogenic potential developed immediately after PVU prior to occurrence of systolic hypotension.

Cerebral air embolism and subsequent transient neurologic abnormalities in a liver transplant recipient following the removal of the pulmonary artery catheter from the central venous access device: a case report.

Cerebral air embolism is a rare but potentially life-threatening complication. We experienced a living-donor liver transplant recipient who presented with unexpected cerebral air embolism and transient neurologic abnormalities that subsequently developed just after the removal of the pulmonary artery catheter from the central venous access device. One day after the initial event, the patient's neurologic status gradually improved. The patient was discharged 30 days after liver transplantation without neurologic sequelae.

Prediction of hyperdynamic circulation by arterial diastolic reflected waveform analysis in patients undergoing liver transplantation.

OBJECTIVES: In cirrhotic patients with hyperdynamic circulation characterized by a decrease in systemic vascular resistance (SVR) and an increase in cardiac output, cardiac and vascular properties are expressed in peripheral arterial pressure waveforms. We attempted to assess whether the variables derived from the radial artery waveform can predict hyperdynamic circulation in liver transplant recipients. MATERIALS AND METHODS: Before surgical incision, we obtained the simultaneous cardiac index (CI) and SVR determined by a pulmonary artery catheter in 30 liver transplant recipients. We analyzed the diastolic reflected waveform characteristics by calculating the diastolic augmentation index (DAIx, %), which was defined as 100×[peak pressure of diastolic reflected wave-diastolic arterial pressure]/pulse pressure. The time from diastolic arterial pressure to the peak of the diastolic reflected wave, corrected by RR intervals (tDA), was also determined. RESULTS: CI and SVR were correlated with DAIx (r=-0.553, P=0.002 and r=0.617, P<0.001) and tDA (r=0.504, P=0.004 and r=-0.692, P<0.001). The areas under the receiver operating characteristic curves were 0.900 [95% confidence interval: 0.713-0.978 for both DAIx and tDA to predict hyperdynamic circulation (CI>4.0 l/min/m and SVR<800 dynes·s/cm, n=13)]. DAIx less than 35% and tDA more than 484 ms were the best cutoff values for differentiation of hyperdynamic circulation (sensitivity/specificity 92.3%/76.5% and 100%/70.6%, respectively). CONCLUSION: Diastolic reflected waveform characteristics can be used to predict high CI and low SVR in liver transplant recipients. This study suggests that these minimally invasive indicators may also be valuable when pulmonary artery catheterization is not available in patients with a hyperdynamic condition.

Effects of anesthesia on fluid volume kinetics after infusion of colloid solution during blood donation.

BACKGROUND: The fluid kinetics of intravenously infused colloid during inhalation anesthesia and hemorrhage have not been investigated. We therefore assessed fluid space changes during infusion of hydroxyethyl starch solution after hemorrhage in conscious and desflurane-anesthetized individuals. METHODS: Following the donation of 400 ml of blood, 500 ml of hydroxyethyl starch solution was infused over 20 minutes into wakeful and desflurane-anesthetized volunteers. Blood was repeatedly sampled to measure hemoglobin concentration, a marker of plasma dilution, and fluid kinetic analysis was performed to evaluate changes in fluid space. RESULTS: Using a fluid kinetic model, we found that the mean volume of fluid space was 7,724 +/- 1,788 ml in wakeful volunteers and 6,818 +/- 4,221 ml in anesthetized volunteers, and the elimination rate constants were 7.1 +/- 3.5 ml/min and 19.4 +/- 4.6 ml/min, respectively. CONCLUSIONS: Infusion of colloid after mild hemorrhage resulted in similar expansions of plasma volume in desflurane-anesthetized and conscious individuals. During anesthesia, however, the expansion of plasma volume by colloid was decreased and of shorter duration than observed in conscious patients.