Yunseok Jeon

Does remote ischaemic preconditioning with postconditioning improve clinical outcomes of patients undergoing cardiac surgery? Remote Ischaemic Preconditioning with Postconditioning Outcome Trial

AIMS The aim of this study was to evaluate whether remote ischaemic preconditioning (RIPC) combined with remote ischaemic postconditioning (RIPostC) improves the clinical outcomes of patients undergoing cardiac surgery. METHODS AND RESULTS From June 2009 to November 2010, 1280 patients who underwent elective cardiac surgery were randomized into the RIPC with RIPostC group or the control group in the morning of the surgery. In the RIPC with RIPostC group, four cycles of 5-min ischaemia and 5-min reperfusion were administered twice to the upper limb-before cardiopulmonary bypass (CPB) or coronary anastomoses for RIPC and after CPB or coronary anastomoses for RIPostC. The primary endpoint was the composite of major adverse outcomes, including death, myocardial infarction, arrhythmia, stroke, coma, renal failure or dysfunction, respiratory failure, cardiogenic shock, gastrointestinal complication, and multiorgan failure. Remote ischaemic preconditioning with RIPostC did not reduce the composite outcome compared with the control group (38.0 vs. 38.1%, respectively; P = 0.998) and there was no difference in each major adverse outcome. The intensive care unit and hospital stays were not different between the two groups. However, in the off-pump coronary artery bypass surgery subgroup, multivariate logistic regression analysis revealed that RIPC with RIPostC was related to increased composite outcome (odds ratio: 1.54; 95% confidence interval: 1.02-2.30; P = 0.038). CONCLUSION Remote ischaemic preconditioning with RIPostC by transient upper limb ischaemia did not improve clinical outcome in patients who underwent cardiac surgery.

Transesophageal echocardiographic evaluation of ECG-guided central venous catheter placement.

PurposeTo facilitate electrocardiography (ECG)-guided central venous catheter placement by observing the shape and size of the P wave at specific locations of a central venous catheter (CVC)tip.MethodsWe evaluated 54 patients for whom central venous catheterization was planned as part of routine care for their elective surgery. The junction of the superior vena cava (SVC) and the right atrium (RA) was defined as the superior border of the crista terminalis by transesophageal echocardiography. The RA ECGs were recorded while withdrawing the CVC into the SVC or advancing it into the RA at 1 -cm intervals. Saline was used as an electrical conductor via the distal lumen of the CVC.ResultsThe tallest peaked and biphasic P waves [median (interquartile range)] were observed when the CVC tip was located at positions 0.0 cm (-1.0 to 0.0) and -4.0 cm (-5.0 to-3.0) below the SVC/RA junction, respectively. The P wave returned to a normal shape and size at 4.0 cm (3.0 to 4.0) above the SVC/RA junction. Overshoot P waves were observed at — 4.0 cm (-5.0 to -3.0) below the SVC/RA junction in 22 patients, when the CVC tip appeared to be contacting or in close proximity to the RA wall.ConclusionsDuring ECG-guided central venous catheterization, the tallest peaked P wave may be used to place the CVC tip at the SVC/RA junction, the normally-shaped P wave identifies the mid to upper SVC, and biphasic P waves identify RA localization.RésuméObjectifFaciliter la pose d’un cathéter veineux central (CVC) guidée par électrocardiographie (ECG), observant la forme et la taille de l’onde P à des sites spécifiques de la pointe du cathéter.MéthodeNous avons évalué 54 patients après insertion d’un cathéter veineux central, partie des soins courants de l’intervention chirurgicale réglée. La jonction de la veine cave supérieure (VCS) et de l’oreillette droite (OD), définie par échocardiographie transœsophagienne, correspondait au bord supérieur de la crête terminale. Les ECG de l’OD ont été enregistrées lors du retrait du CVC de la VCS ou quand il a été poussé dans l’OD à intervalles de 1 cm. Une solution salée a servi de conducteur électrique passant par la lumière distale du CVC.RésultatsLes ondes P maximales et biphasiques [médiane (écart interquartile)] ont été observées quand la pointe du CVC était respectivement à 0,0 cm (-1,0 à 0,0) et à -4,0 cm (-5,0 à -3,0) sous la jonction VCS/OD. L’onde P a repris une forme et une taille normales à 4,0 cm (3,0 à 4,0) au-dessus de la jonction SVC/OD. Le dépassement des ondes P a été observé à -4,0 cm (-5,0 à -3,0) sous la jonction VCS/OD chez 22 patients au moment où la pointe du CVC paraissait en contact avec la paroi de l’OD ou très près d’elle.ConclusionPendant le cathétérisme veineux central guidé par ECG, l’onde P maximale peut servir à placer la pointe d’un cathéter veineux central à la jonction VCS/OD, l’onde P de forme normale indique la VCS, de son milieu à sa partie supérieure, et l’onde P biphasique situe l’OD.

Pulse pressure variation as a predictor of fluid responsiveness during one-lung ventilation for lung surgery using thoracotomy: randomised controlled study.

Background and objective Pulse pressure variation (PPV) is increasingly advocated as a predictor of fluid responsiveness in patients receiving mechanical ventilation. However, the ability of PPV has never been studied during one-lung ventilation (OLV). Therefore, we evaluated the value of PPV to predict fluid responsiveness in patients receiving conventional and protective OLV using receiver operating characteristic (ROC) analysis, respectively. Methods Forty-nine patients undergoing lung surgery requiring OLV were enrolled in this study. Patients were randomised either to group P [patients receiving protective OLV with tidal volume 6 ml kg−1, inspired oxygen fraction (FIO2) of 0.5 and positive end-expiratory pressure (PEEP) of 5 cmH2O) or group C (patients receiving conventional OLV with tidal volume of 10 ml kg−1, FIO2 of 1.0 and no PEEP). Following OLV, PPV and cardiac output were measured before and 12 min after fluid loading (7 ml kg−1 hydroxyethyl starch 6%). Patients whose cardiac indices increased by at least 15% to fluid loading were defined as the responders. Results The areas under ROC curve for PPV were 0.857 (P = 0.006) in group P and 0.524 (P = 0.839) in group C, respectively. The optimal threshold value given by ROC analysis for PPV was 5.8% in group P. Conclusions PPV could predict fluid responsiveness only during protective OLV, but not conventional OLV. PPV would be helpful for fluid management in patients receiving protective OLV for lung surgery using thoracotomy.

The carina as a useful radiographic landmark for positioning the intraaortic balloon pump.

BACKGROUND:The aortic knob is thought to be the most useful radiographic landmark for the proper positioning of the intraaortic balloon pump (IABP) tip. However, this has not been studied formally. In this study we assessed whether the aortic knob is a reliable landmark for positioning the IABP and compared it with another potential landmark, the carina. METHODS:We measured the distance from the top of the distal aortic arch (aortic knob) to the left subclavian artery (LSCA) on three-dimensional computed tomography angiography in 100 patients. The distance from the level of the LSCA origin to the level of the carina was also measured using three-dimensional computed tomography in 150 additional patients. RESULTS:In 16% of the aortic knob study population, the LSCA to aortic knob distance was <0 cm or 0 cm. The median distance from the LSCA to the carina was 42 mm (range: 30–63 mm). In the carina study population, the origin of the LSCA was 35–55 mm above the carina in 95.3% of patients. CONCLUSION:In 16% of patients, the IABP was too close to the LSCA origin when it was placed at the aortic knob, whereas positioning the IABP at 2 cm above the carina provided an adequate position for the IABP tip (1.5–3.5 cm distal to the origin of the LSCA) in 95.3% of patients. The carina may be a more reliable landmark for positioning the IABP than the aortic knob.

Pulse pressure variation to predict fluid responsiveness in spontaneously breathing patients: tidal vs forced inspiratory breathing

We evaluated whether pulse pressure variation can predict fluid responsiveness in spontaneously breathing patients. Fifty‐nine elective thoracic surgical patients were studied before induction of general anaesthesia. After volume expansion with hydroxyethyl starch 6 ml.kg−1, patients were defined as responders by a ≥ 15% increase in the cardiac index. Haemodynamic variables were measured before and after volume expansion and pulse pressure variations were calculated during tidal breathing and during forced inspiratory breathing. Median (IQR [range]) pulse pressure variation during forced inspiratory breathing was significantly higher in responders (n = 29) than in non‐responders (n = 30) before volume expansion (18.2 (IQR 14.7–18.2 [9.3–31.3])% vs 10.1 (IQR 8.3–12.6 [4.8–21.1])%, respectively, p < 0.001). The receiver‐operating characteristic curve revealed that pulse pressure variation during forced inspiratory breathing could predict fluid responsiveness (area under the curve 0.910, p < 0.0001). Pulse pressure variation measured during forced inspiratory breathing can be used to guide fluid management in spontaneously breathing patients.

Comparison of Thoracic Epidural Pressure in the Sitting and Lateral Decubitus Positions

Background:The hanging drop technique identifies the epidural space using the negative pressure of this space. Although the hanging drop technique is popular at the thoracic level, there is still controversy on the negative epidural pressure at this level. The authors hypothesized that the epidural pressure is more consistently negative in the sitting position than in the lateral decubitus position at the thoracic level. Methods:This study compared the epidural pressures of 28 awake patients in the sitting (sitting group, n = 14) or lateral decubitus (lateral group, n = 14) position. The T5–T6 epidural pressure was measured using a closed pressure measurement system connected to a Tuohy needle. Results:All of the thoracic epidural pressures in the sitting group were negative (median, −5 mmHg; range, −18 to −1; mean, −7.2; SD, 6.3), in contrast to the lateral group (median, 5 mmHg; range, −4 to 13; mean, 5.1; SD, 4.4). The thoracic epidural pressure in the sitting group was significantly lower than in the lateral group (P < 0.001). Conclusions:The thoracic epidural pressure is more negative in the sitting position than in the lateral decubitus position. These results suggest that the patient should be sitting when the hanging drop technique is used to identify the epidural space.

Effect of the bevel direction of puncture needle on success rate and complications during internal jugular vein catheterization

Objective: Artery puncture and hematoma formation are the most common immediate complications during internal jugular vein catheterization. This study was performed to assess whether the bevel-down approach of the puncture needle decreases the incidence of posterior venous wall damage and hematoma formation during internal jugular vein catheterization. Design: Prospective, randomized, controlled study. Setting: A university-affiliated hospital. Patients: Three hundred thirty-eight patients for scheduled for thoracic surgery requiring central venous catheterization in the right internal jugular vein. Interventions: Patients requiring internal jugular vein catheterization were enrolled and randomized to either the bevel-down group (n = 169) or the bevel-up group (n = 169). All patients were placed in the Trendelenburg position with the head turned to the left. After identifying the right internal jugular vein with ultrasound imaging, a double-lumen central venous catheter was inserted using the modified Seldinger technique. Venous entry of the needle was recognized by return of venous blood during needle advance or withdrawal. The internal jugular vein was assessed cross-sectionally and longitudinally after catheterization to identify any complications. A p value of <.05 was considered to be statistically significant. Measurements and Main Results: There was no difference in the incidence of the puncture-on-withdrawal between the two groups (37 of 169 in the bevel-down group and 25 of 169 in the bevel-up group). However, the incidence of posterior hematoma formation was lower in the bevel-down group (six of 169 vs. 17 of 169, p = .031). Additionally, there was less incidence of the posterior hematoma formation associated with puncture-on-withdrawal in the bevel-down group (six of 37 vs. 11 of 25, p = .034). Conclusions: The bevel-down approach of the right internal jugular vein may decrease the incidence of posterior venous wall damage and hematoma formation compared with the bevel-up approach, which implicates a reduced probability of carotid artery puncture with the bevel-down approach during internal jugular vein catheterization.

The influence of neck flexion and extension on the distribution of contrast medium in the high thoracic epidural space.

BACKGROUND:For safe and effective thoracic epidural analgesia (TEA), it is important to control the level of TEA and to identify factors that influence its spread. In this study, we observed the distribution of contrast injected into the high thoracic epidural space during neck flexion and extension. METHODS:An epidural catheter was inserted into the epidural space until its tip was located at the T1–2 intervertebral level. Patients were randomly allocated to three groups (extension, flexion, and neutral groups), and were injected with 5 mL of contrast when the neck was extended, flexed, or in the neutral position. Extent of contrast spread was determined by counting the number of vertebral body units (VBUs) through lateral epidurography. RESULTS:Forty-two patients were equally allocated to the three groups. Radiographic spreads in the cephalad direction (median) was 1.0, 5.5, and 1.5 VBUs in the extension, flexion, and neutral groups, and spread was greater in the flexion than in the other two groups (P < 0.001). Median radiographic caudal spread was 10.0, 10.0, and 7.0 VBUs in the extension, flexion, and neutral groups, respectively, which was not significantly different among groups (P = 0.145). CONCLUSIONS:Cranial spread of contrast in the high thoracic epidural space is limited. However, neck flexion increases cranial spread. These results suggest that when TEA is high, the tip of the epidural catheter should be located at the upper part of the level to be blocked and that neck flexion may cause an unwanted cervical block.

Effect of palonosetron on the QTc interval in patients undergoing sevoflurane anaesthesia

BACKGROUND Palonosetron is a recently introduced 5-HT3 receptor antagonist for postoperative nausea and vomiting. Detailed standardized evaluation of corrected QT (QTc) interval change by palonosetron under sevoflurane anaesthesia is lacking. We evaluated QTc intervals in patients who are undergoing surgery with sevoflurane anaesthesia and receive palonosetron. METHODS Our study included 100 patients who were undergoing elective surgery under sevoflurane anaesthesia. The patients were randomly assigned to two groups: those who received an i.v. injection of palonosetron 0.075 mg immediately before induction of anaesthesia (pre-surgery group, n=50) and those who received it after surgery in the recovery room (post-surgery group, n=50). QTc intervals were measured before operation, intraoperatively (baseline, immediately after tracheal intubation, and at 2, 10, 15, 30, 60, and 90 min after administration of palonosetron or placebo), and after operation (before and at 3, and 10 min after administration of palonosetron or placebo). QTc intervals were calculated using Fridericias, Bazetts, or Hodges formulas. RESULTS The perioperative QTc intervals were significantly increased from the baseline values, but were not affected by the pre- or post-surgical timing of palonosetron administration. CONCLUSIONS There was no significant difference in the QTc intervals during the perioperative period, whether 0.075 mg of palonosetron is administered before or after sevoflurane anaesthesia. Palonosetron may be safe in terms of QTc intervals during sevoflurane anaesthesia. Clinical trial registration ClinicalTrials.gov: NCT01650961.

Comparison of techniques for double-lumen endobronchial intubation: 90° or 180° rotation during advancement through the glottis

BACKGROUND During endobronchial intubation with a double-lumen endobronchial tube (DLT), the DLT is conventionally rotated through 90° when the bronchial tip is just past the vocal cords. This study was performed to investigate if rotation of the DLT through 180° decreases postoperative hoarseness, sore throat, or vocal cord injuries. METHODS Patients (n=164) undergoing thoracic surgery were randomized into two groups. Just after the bronchial tip passed the glottis, left-sided DLTs were rotated 90° (Group 90, n=84) or 180° (Group 180, n=80) counterclockwise and advanced. In the Group 180, DLTs were re-rotated 90° clockwise after the tracheal tip passed the glottis. Resistance during the advance of DLTs was assessed. Hoarseness and sore throat were evaluated for three postoperative days. Vocal cords were examined on the first postoperative day. RESULTS In nine patients allocated to Group 90, the DLT could not be advanced past the glottis because of severe resistance. There was less resistance to advancement of the DLT in Group 180 compared with Group 90 (P<0.001). The incidence of hoarseness was comparable between the two groups. Sore throat and vocal cord injuries occurred less frequently in Group 180 compared with Group 90 (20 vs 40%, P=0.008; 19 vs 47%, P=0.032). CONCLUSIONS Rotation of a DLT through 180° facilitated its passage through the glottis and reduced the incidence of postoperative sore throat and vocal cord injuries.