Hee Jong Lee

Optimal positive end-expiratory pressure during robot-assisted laparoscopic radical prostatectomy

Background Increased intra-abdominal pressure during laparoscopic surgery causes cephalad displacement of the diaphragm, resulting in the formation of atelectasis, which can be overcome by positive end-expiratory pressure (PEEP). The aim of this prospective study was to investigate the level of optimal PEEP to maintain adequate arterial oxygenation and hemodynamics during robot-assisted laparoscopic radical prostatectomy (RLRP). Methods One hundred patients undergoing RLRP were randomly allocated to one of five groups (n = 20) (0, 3, 5, 7 and 10 cmH2O of PEEP). Hemodynamic variables and respiratory parameters were measured at baseline with the patient in the supine position; at 30 min, 1, 2, 3 and 4 h during CO2 insufflation with the patient in the post-Trendelenburg position; and after deflation in the supine position with increasing PEEP. Results The PaO2 levels and alveolar-arterial difference in oxygen tension (AaDO2) were improved in patients with PEEPs compared with patients in whom PEEP was not used. The application of PEEP (10 cmH2O) resulted in higher PaO2 levels compared to those with lower PEEP levels, but excessive peak airway pressure (PAP) was sometimes observed. The application of a PEEP of 7 cmH2O resulted in similar PaO2 levels without causing excessive PAP. There was a significant difference in central venous pressure between the groups, but there were no significant differences in heart rate, mean arterial pressure or minute ventilation between the groups. Conclusions A PEEP of 7 cmH2O is associated with the greater improvement of PaO2 and AaDO2 without causing excessive PAP during RLRP.

Anesthetic consideration for patients with severe tracheal obstruction caused by thyroid cancer -A report of 2 cases-

To achieve safe airway management, it is essential first to predict whether there will be difficulties in intubating or ventilating the patients airway. An enlarged thyroid mass can produce a tracheal obstruction by compression or intraluminal invasion or both. We report two patients with thyroid cancer that obstructed the trachea by compression or invasion. There was no difficulty in endotracheal intubation of the patients with marked thyroid enlargement or in securing passage of the endotracheal tube through the compressed or narrowed portion of the trachea.

Antioxidant effects of methylprednisolone and hydrocortisone on the impairment of endothelium dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta

Background The reperfusion following ischemia produces reactive oxygen species (ROS). We studied the influences of methylprednisolone (MPD) and hydrocortisone (CRT) on ROS effects using the endothelium of rabbit abdominal aorta. Methods Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution. After precontraction with norepinephrine, changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with MPD or CRT at the same concentrations, and the effects of these agents were compared with the effects of ROS scavenger inhibitors: superoxide dismutase inhibitor, diethylthiocarbamate (DETCA), and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results Both MPD and CRT maintained endothelium-dependent relaxation induced by ACh in a dose-related manner in spite of ROS attack. The restored ACh-induced relaxation of MPD and CRT group was not attenuated by pretreatment of 3AT and DETCA. Conclusions MPD and CRT preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a dose-related manner. Endothelial protection mechanisms of MPD and CRT may be not associated with hydrogen peroxide and superoxide scavenging.

A comparison of the accuracy of ulnar versus median nerve stimulation for neuromuscular monitoring.

Background Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve. Methods In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites. Results None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (± 31%) and 26% (± 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve. Conclusions The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.

Rocuronium-induced neuromuscular block after long pretreatment of clonidine in rabbits.

Background Clonidine, an α-2 adrenergic agonist, is used in the perioperative period and in intensive care for the management of hypertension. The in vivo and in vitro effects of clonidine on the actions of nondepolarizing neuromuscular blocking drugs are conflicting. We evaluated the potency and time course of rocuronium-induced neuromuscular block after prolonged pretreatment with clonidine in rabbits. Methods Sixty rabbits were randomly assigned to three groups; control (C) group: normal saline 0.1 ml/kg daily subcutaneous for 6 weeks; S3 group: clonidine 4 µg/kg daily subcutaneous for 3 weeks; S6 group: clonidine 4 µg/kg daily subcutaneous for 6 weeks. The dose-response relations of rocuronium were tested in 30 rabbits (10 from each of the three groups) during ketamine-thiopental anesthesia, while the time course of rocuronium 0.6 mg/kg was examined in 10 rabbits each from the three groups. Results There was no difference in mean arterial pressure and pulse rate among the experimental groups. The calculated ED50 for rocuronium decreased significantly from 64.1 µg/kg (C group) to 50.3 µg/kg (S3 group) and 47.8µg/kg (S6 group) (P < 0.001). There was no difference in the onset and the recovery times after rocuronium. Conclusions Rocuronium after pretreatment with clonidine for three or six weeks may have an increased effect, but no difference in the duration of action compared with control group.

Time course of neuromuscular effects of rocuronium during desflurane anesthesia in patients with or without renal failure

BACKGROUND This study aimed to investigate the neuromuscular effects of 0.6 mg/kg rocuronium under desflurane anesthesia in patients with and without renal failure. METHODS The neuromuscular effects of rocuronium 0.6 mg/kg under desflurane anesthesia were investigated in 20 patients with renal failure undergoing renal transplantation surgery and in 20 patients with normal renal function. Neuromuscular transmission was monitored using acceleromyography with single stimuli at 0.1 Hz. The onset and 25%, 75%, and 95% twitch recovery times, the recovery of the train-of-four ratio to 70% (TOF70), and the recovery index (25-75%) were recorded. RESULTS Block onset was similar in the groups. The 25%, 75% and 95% twitch recovery times, the TOF70 time, and the recovery index were found to be prolonged in patients with renal failure compared to those with normal renal function (e.g. TOF70: 123.1 +/- 49.1 vs. 68.7 +/- 15.5 min) (P<0.001). A very strong association between the time to TOF70 and the diagnostic duration of renal failure was found (R2 = 0.79, P<0.001). CONCLUSIONS The duration of action of a bolus dose of 0.6 mg/kg rocuronium under desflurane anesthesia was increased significantly in patients with end-stage renal failure compared to that of healthy controls and was prolonged according to the duration of renal failure.

Successful transfusion-free pancreatectomy in Jehovah's Witness patients

Backgrounds/Aims Although perioperative therapies have improved greatly, pancreatectomies still often need blood transfusions. However, the morbidity from blood transfusions, the poor prognosis of blood transfused patients, high cost, and decreasing supply of blood products is accelerating transfusion-free (TF) surgery in the patients who have pacreatectomies. The aim of this study was to assess the feasibility of TF pancreatectomies for patients who are Jehovahs Witness. Methods We investigated the possibility of TF pancreatectomies for the Jehovahs Witness patients undergoing pancreatectomies between January 2007 and Februay 2014. There were 4 cases of Whipples operation, 4 of pylorus-preserving pancreaticoduodenectomy, 2 of radical antegrade modular pancreatosplenectomy and 1 of laparoscopic distal pancreatectomy. All were performed by one surgeon. Results Most of the TF pancreatecomies patients received perioperative blood augmentation and intraoperative acute normovolemic hemodilution (ANH). They received no blood transfusions at any time during their hospitalization, and pre- and intra-operative data and outcomes were acceptably favorable. Conclusions To the best of our knowledge, this report is the first successful consecutive pancreatectomy program for Jehovahs Witness not involving blood transfusion. TF pancreatectomy can be performed successfully in selected Jehovahs Witness. Postoperative prognosis and outcomes should be confirmed in follow up studies.

Optimal precurarizing dose of rocuronium to decrease fasciculation and myalgia following succinylcholine administration

Background Succinylcholine commonly produces frequent adverse effects, including muscle fasciculation and myalgia. The current study identified the optimal dose of rocuronium to prevent succinylcholine-induced fasciculation and myalgia and evaluated the influence of rocuronium on the speed of onset produced by succinylcholine. Methods This randomized, double-blinded study was conducted in 100 patients randomly allocated into five groups of 20 patients each. Patients were randomized to receive 0.02, 0.03, 0.04, 0.05 and 0.06 mg/kg rocuronium as a precurarizing dose. Neuromuscular monitoring after each precurarizing dose was recorded from the adductor pollicis muscle using acceleromyography with train-of-four stimulation of the ulnar nerve. All patients received succinylcholine 1.5 mg/kg at 2 minutes after the precurarization, and were assessed the incidence and severity of fasciculations, while myalgia was assessed at 24 hours after surgery. Results The incidence and severity of visible muscle fasciculation was significantly less with increasing the amount of precurarizing dose of rocuronium (P < 0.001). Those of myalgia tend to decrease according to increasing the amount of precurarizing dose of rocuronium, but there was no significance (P = 0.072). The onset time of succinylcholine was significantly longer with increasing the amount of precurarizing dose of rocuronium (P < 0.001). Conclusions Precurarization with 0.04 mg/kg rocuronium was the optimal dose considering the reduction in the incidence and severity of fasciculation and myalgia with acceptable onset time, and the safe and effective precurarization.

Airway management in patient with continuous bleeding lesion of the trachea: a case report.

Hemoptysis requires proper treatment to prevent blood aspiration and asphyxiation. If the patient loses consciousness or is anesthetized, the bleeding inside the trachea may continuously flow into the distal part, which may be fatal. Fatal damage resulting from hemoptysis is mainly caused by asphyxiation, and it is important to find the exact location of the bleeding in order to prevent it from spreading to both lungs. However, endotracheal intubation may increase the bleeding by stimulating the bleeding lesion in the respiratory track, and can make airway management more difficult. We report a successful case of airway management using the cuff and Murphy eye of the endotracheal tube in a patient with tracheal bleeding.

The effect of hand dominance on neuromuscular monitoring at the adductor pollicis muscle

Background Neuromuscular blockade of the adductor pollicis muscle may be influenced by hand dominance resulting in conflicting results of several studies. The current study examined whether hand dominance could influence the measurements of neuromuscular blockade with acceleromyography at the adductor pollicis. Methods The acceleromyographic responses from 0.6 mg/kg of rocuronium were monitored supramaximally in both hands in 31 patients after induction of anesthesia. Onset, maximum effect, and offset of rocuronium were measured and compared in both hands. The train-of-four (TOF) ratios to 0.9 were recorded in all patients. Results In total, 27 patients were right-handed and 4 patients were left-handed. The mean supramaximal threshold or initial TOF ratio was not different between dominant and nondominant hands. No statistically significant differences were found between 716 paired TOF ratios in both hands. A correlation was seen between the dominant and nondominant hand (Nondominant = 0.931·Dominant + 1.714, R = 0.929). The analysis by the Bland-Altman plot showed an excellent agreement with a bias of 1.6% and limits of agreement of -21.2 to 24.5%. Conclusions Dominant and nondominant hands can be used interchangeably for neuromuscular monitoring at the adductor pollicis.