Deokkyu Kim

Tracheal rupture after endotracheal intubation: A report of three cases

Tracheal rupture is a rare but serious complication that occurs after endotracheal intubation. It usually presents as a linear lesion in the membranous wall of the trachea, and is more prevalent in women and patients older than 50 years. The clinical manifestations of tracheal injury include subcutaneous emphysema and respiratory distress. We report the cases of three female patients of old age presenting tracheal rupture after endotracheal intubation. Two cases received surgical repair without complication and one recovered uneventfully after conservative management. We presume that the tracheal injuries were caused by over-inflation of cuff and sudden movement of the tube by positional change. Therefore, we recommend cuff pressure monitoring during general anesthesia and minimized movement of the head and neck at positional change.

The changes of endotracheal tube cuff pressure by the position changes from supine to prone and the flexion and extension of head

Background The proper cuff pressure is important to prevent complications related to the endotracheal tube (ETT). We evaluated the change in ETT cuff pressure by changing the position from supine to prone without head movement. Methods Fifty-five patients were enrolled and scheduled for lumbar spine surgery. Neutral angle, which was the angle on the mandibular angle between the neck midline and mandibular inferior border, was measured. The initial neutral pressure of the ETT cuff was measured, and the cuff pressure was subsequently adjusted to 26 cmH2O. Flexed or extended angles and cuff pressure were measured in both supine and prone positions, when the patients head was flexed or extended. Initial neutral pressure in prone was compared with adjusted neutral pressure (26 cmH2O) in supine. Flexed and extended pressure were compared with adjusted neutral pressure in supine or prone, respectively. Results There were no differences between supine and prone position for neutral, flexed, and extended angles. The initial neutral pressure increased after changing position from supine to prone (26.0 vs. 31.5 ± 5.9 cmH2O, P < 0.001). Flexed and extended pressure in supine were increased to 38.7 ± 6.7 (P < 0.001) and 26.7 ± 4.7 cmH2O (not statistically significant) than the adjusted neutral pressure. Flexed and extended pressure in prone were increased to 40.5 ± 8.8 (P < 0.001) and 29.9 ± 8.7 cmH2O (P = 0.002) than the adjusted neutral pressure. Conclusions The position change from supine to prone without head movement can cause a change in ETT cuff pressure.

Effect of ketorolac on the prevention of emergence agitation in children after sevoflurane anesthesia.

Background The purpose of this study was to evaluate the effects of ketorolac on the incidence and severity of emergence agitation in children recovering from sevoflurane anesthesia. Methods Eighty-five children aged 3 to 7 years were randomly assigned to the control group or the ketorolac group (1 mg/kg ketorolac). The children were evaluated by the Pediatric Anesthesia Emergence Delirium Scale and a four-point agitation scale. Results The median agitation scores did not differ significantly between the two groups. The overall incidence of emergence agitation was similar in the two groups (41% in the control group vs. 32% in the ketorolac group, P = 0.526). The number of children who received rescue drugs for treatment of emergence agitation was not significantly different between the two groups. Conclusions The administration of 1 mg/kg of ketorolac is not effective in decreasing the incidence and severity of emergence agitation in children aged 3 to 7 years after sevoflurane anesthesia.

Reliability of assessment of nasal flow rate for nostril selection during nasotracheal intubation

STUDY OBJECTIVE To evaluate the reliability of assessments of nasal flow rate for improved nostril selection for nasotracheal intubation. DESIGN Prospective, randomized, double-blinded study. SETTING Operating room of a university-affiliated hospital. PATIENTS 118 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for elective maxillofacial and oral surgery requiring nasotracheal intubation. INTERVENTIONS Patients were randomized to the left or right nostril groups. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)) through the mouth and each nostril were measured before anesthesia induction. MEASUREMENTS The relationship between the rate of airflow through the selected nostril and frequency of epistaxis and navigability of the nasotracheal tube were evaluated. MAIN RESULTS There were no significant differences in the frequency of epistaxis and degree of navigability of the tracheal tube between the left and right nostril groups. In both nostril groups, patients who suffered epistaxis showed significantly less FEV(1) and FEV(1)/FVC values than did patients without epistaxis (P < 0.05). In addition, in both groups patients who passed the tube easily showed significantly higher FEV(1) and FEV(1)/FVC values than did patients who passed the tube with resistance or failed tube passage (P < 0.05). CONCLUSION Measurement of nasal flow rate is a useful clinical method for choosing a nostril for nasotracheal intubation.

The effects of incremental continuous positive airway pressure on arterial oxygenation and pulmonary shunt during one-lung ventilation

Background Although one lung ventilation (OLV) is frequently used for facilitating thoracic surgical procedures, arterial hypoxemia can occur while using one lung anesthesia. Continuous positive airway pressure (CPAP) in 5 or 10 cmH2O to the non-ventilating lung is commonly recommended to prevent hypoxemia. We evaluated the effects of incremental CPAP to the non-ventilating lung on arterial oxygenation and pulmonary shunt without obstruction of the surgical field during OLV. Methods Twenty patients that were scheduled for one lung anesthesia were included in this study. Systemic and pulmonary hemodynamic data and blood gas analysis was recorded every fifteen minutes according to the patients positions and CPAP levels. CPAP was applied from 0 cmH2O by 3 cmH2O increments until a surgeon notifies that the surgical field was obstructed by the expanded lung. Following that, pulmonary shunt fraction (QS/QT) was calculated. Results There were no significant differences of QS/QT between supine and lateral positions with two lung ventilation (TLV). OLV significantly decreased arterial oxygen partial pressure (PaO2) and increased QS/QT compared to TLV. PaO2 and QS/QT significantly improved at 6 and 9 cmH2O of CPAP compared to 0 cmH2O. However, there were no significant differences of PaO2 and QS/QT between 6 and 9 cmH2O CPAP. In 18 patients (90%), surgical fields were obstructed at 9 cmH2O CPAP. Conclusions This study suggests that 6 cmH2O CPAP effectively improved arterial oxygenation without interference of the surgical field during OLV when CPAP was applied from 0 cmH2O in 3 cmH2O increments.

Measurements of the Length and Diameter of Main Bronchi on Three-Dimensional Images in Asian Adult Patients in Comparison With the Height of Patients

OBJECTIVE To measure the length and diameter of the main bronchus using the three-dimensional reconstruction images from the spiral chest computerized tomography scans in Asian adult patients, and to evaluate the relationship between the height of patients and the length and diameter of main bronchi. DESIGN Prospective observational study. SETTING Academic, tertiary care hospital. PARTICIPANTS Two hundred Asian adults undergoing a chest spiral computerized tomography scan. INTERVENTION No intervention. MEASUREMENTS AND MAIN RESULTS The authors measured the anteroposterior and transverse diameters of the mid-portion of the right main bronchus and 2 cm below the carina of the left main bronchus. In addition, the length of both main bronchi was also measured. The length of the left main bronchus was about 3-4 times greater than its right counterpart. The main bronchus of women was oval-shape, with a large anteroposterior diameter, but the main bronchus of men was round-shape. There was no significant correlation between the measurements of main bronchi and the height of patients. CONCLUSIONS The results showed that there is no direct relationship between the length and diameter of main bronchi and the height of patients. The height is not the criterion for choosing DLT size. Therefore, the authors proposed that 3-D images be used to determine the size of the main bronchi. The diameter of main bronchus using the 3-D images can be used to determine the optimal size of the DLT in a clinical setting, although further studies are needed.

Anesthetic management of a pregnant woman undergoing laparoscopic surgery for pheochromocytoma -A case report-

Pheochromocytoma is a rare catecholamine producing tumor. Anesthetic management for the resection of pheochromocytoma is hard and challenging issue to anesthesiologist, because of its potentially lethal cardiovascular complications. It becomes more complicated when the patient is pregnant. Clinicians must keep the safety of both mother and fetus in mind. The timing of surgery for pheochromocytoma in pregnancy is very important for the maternal and fetal safety and depends on the gestational age when diagnosis is made, clinical response to medical treatment, the surgical accessibility of the tumor, and the presence of fetal distress. We report anesthetic experience of a laparoscopic resection for pheochromocytoma in 25th week gestational woman.

A comparison of desflurane consumption according to fresh gas flow

The consumption of volatile agents during general anesthesia can be altered by fresh gas flow (FGF), and it is known to be better to maintain an anesthetic effect with a lesser amount of volatile anesthetics because cost considerations, as long as it does not present a safety problem. A previous study reported that the consumption of sevoflurane and isoflurane was decreased in low FGF anesthesia, and the decreased amount was proportional to the FGF rate [1]. We hypothesized that desflurane consumption would proportionally depend on the FGF rate during anesthetic management in surgery. After obtaining Institutional Review Board approval and informed consent, 42 patients, age 20-60 years and scheduled for oro-facial surgery, were randomly allocated to one of two groups: Group F1 received an FGF 1 L/min and Group F3 received an FGF 3 L/min. After arriving in the operating room, all patients were monitored by non-invasive blood pressure, pulse oximeter, electrocardiogram, Entropy, and Surgical Pleth Index (SPI) (GE Healthcare, Helsinki, Finland). Anesthesia induction was performed using propofol and rocuronium. After intubation, administration of 8% desflurane was initiated with an FGF 6 L/min for the first five minutes and then the FGF was switched to 1 or 3 L/min according to the assigned group. Anesthesia was maintained with only desflurane; no adjuvant drugs including nitrous oxide, opioids, intravenous anesthetics, and anti-hypertensive and vasoactive drugs. Blood pressure was maintained within ± 20% from the baseline value, which was obtained before anesthesia induction, and Entropy and SPI were kept below 50. If blood pressure, Entropy, or SPI were out of the maintenance range, the study was paused and the proper treatment was conducted for the patients safety. Desflurane consumption was measured using an anesthesia machine (Avance CS2™, GE Healthcare, Helsinki, Finland) at 5, 15, 30, and 60 minutes after intubation, when the administration of desflurane was initiated. The analysis was performed using SigmatPlot 12.5 (Systat Software Inc., San Jose, USA). Data were expressed as mean ± SD or median (range; 25-75%). The differences between two groups were analyzed by a t-test or Mann-Whitney rank sum test depending on the results of the normality and equal variance test. Statistical significance was considered at P < 0.05. Five of 42 enrolled patients did not complete the study and were excluded from the statistical results; 18 patients in group F1 and 19 patients in group F3 completed as protocol. There was no statistical difference between the two groups in age, sex, height, weight, the time from intubation to skin incision, the type of surgery, hemodynamic parameters, and anesthetic depth. Desflurane consumption with a FGF 6 L/min for the first five minutes after intubation was 15 (13-15) ml in the F1 group and 14 (12-15) ml in the F3 group, which were not statistically different (P = 0.189). The desflurane consumption for one hour was 54 (49-56) ml in the F1 group and 94 (86-105) ml in the F3 group (P < 0.001, Fig. 1). Fig. 1 The consumption of desflurane for 1 hour. Data are presented as median (range; 25-75%). F1: group received a fresh gas flow of 1 L/min, F3: group received a fresh gas flow of 3 L/min, IT: intubation. *P < 0.05 compared with group F1 at 30 and ... Although the FGF difference was three-fold (1 vs. 3 L/min) in this study, the desflurane consumption during one hour was less than twofold greater (54 vs. 94 ml). Weiskopt and Eger [2] calculated the desflurane consumption with various FGFs through simulation under the assumption that 1 MAC was kept constantly and found that desflurane consumption increased nearly twice - directly proportional to a twofold increase in FGF. However, in our study, the desflurane consumption decreased less than a half with a threefold decrease in FGF. Several hypotheses to explain the cause can be postulated. First, a constant MAC was not maintained during anesthetic management in the present study. Proper anesthetic depth varies depending on the situation, and such factors including preparation for the operation after the anesthetic induction, a difference of surgical stimuli for the entire operation time, and individual variation can affect the depth. Second, relatively high concentrations of volatile anesthetics in low FGFs are required to reach the same anesthetic depth or MAC because the absolute amount of anesthetics to be delivered to the respiratory circuit of the anesthesia machine is decreased when FGF is decreased. In our study, a higher concentration of desflurane should be required in the F1 group compared to the F3 group, when the increasing of MAC was needed during the surgery. Third, although there was no statistically significant difference between 69 (61-78) kg in the F1 group and 63 (56-67) kg in the F3 group, the body weight in the F1 group was higher than that of the F3 group. Desflurane consumption may have increased more than expected due to the 10% body weight difference in the F1 group. It is generally accepted that a low FGF is pharmacoeconomic due to the reduction in the consumption of volatile agents [1,2,3]. However, to reduce the FGF, a device that can monitor the respiratory gases is essential, but the monitoring device can increase the cost. When the FGF is low, the rebreathing fraction through the carbon dioxide absorbent is increased so that carbon monoxide production is increased by the degradation of anesthetics with the absorbent. The cost of carbon dioxide absorbent should also be considered. There are some limitations to our study. Our study was conducted during anesthetic management for surgical stimuli, so it was difficult to maintain an equal anesthetic depth simultaneously in both groups. Second, because we did not record the dial setting of the vaporizer, there is no evidence that a higher dial setting was maintained in the F1 group compared to the F3 group. Third, there were no lower limits for Entropy and SPI, so there is a possibility of desflurane overdose. Fourth, the volatile agent consumption of Avance CS2™ was calculated by a formula [4], not measured by the actual consumption amount. These factors may be a possible source of bias. In conclusion, the desflurane consumption measured by Avance CS2™ for one hour was less in the FGF 1 L/min than in the FGF 3 L/min, and the amount of desflurane saved was less than half during anesthetic management in surgery.

The tip fracture of the Coopdech bronchial blocker during insertion in the patient with lung surgery

Bronchial blockers are simple alternative methods of facilitating placement of devices for one-lung ventilation. The Coopdech bronchial blocker (Daiken Medical, Osaka, Japan) has been clinically introduced to perform one-lung ventilation with a single-lumen tracheal tube [1]. The distal tip of the Coopdech bronchial blocker has a pre-formed angulation. We experienced a case of fracture of the tip of the Coopdech bronchial blocker during insertion for one-lung ventilation. A 65-year-old female was scheduled for video-assisted thoracoscopic surgery and lung biopsy for suspected solitary pulmonary nodule in her right middle and lower lobes. Her medical history was unremarkable except for well-controlled asthma. The patient’s airway examination revealed Mallampati II and a thyromental distance of 4-finger breadths. Her chest computerized tomography revealed no abnormality of the trachea or major bronchi. Her trachea was easily intubated with a 7.5 mm internal diameter (ID) single-lumen tracheal tube (HiLo oral/nasal tracheal tube, Mallinckrodt, Athlone, Ireland). A Coopdech bronchial blocker was then inserted into the tracheal tube, and the length of the blocker was about 40 cm from the tip of the blocker to the connector of the tracheal tube. A pediatric fiberoptic bronchoscope (FI-7RBS, Pentax Medical Company, Montvale, NJ, USA) was passed through the single-lumen tracheal tube, and the tip of the blocker was visualized between the carina and the tip of tracheal tube. Despite repeated attempts under bronchoscopic guidance, the blocker could only be inserted into the left main bronchus. After removing pediatric fiberoptic bronchoscope, the tip of the bronchial blocker was rotated to the right side and then advanced blindly into the right main bronchus. After advancing the blocker for 2–3 cm, the resistance increased abruptly. Tip fracture of the bronchial blocker, which was folded backward, was visualized by reinserted pediatric fiberoptic bronchoscope. Subsequent attempts to withdraw the blocker failed because the bent tip hooked the tracheal tube. Under laryngoscopic guidance, subsequent attempts to remove both the tracheal tube and bronchial blocker also failed because the bent tip hooked the vocal cord. Both the tracheal tube and bronchial blocker were reinserted up to the carina, and the tip of the tracheal tube was positioned 2 cm above the carina, which was a relatively large space, with bronchoscopic guidance. The fractured tip of the bronchial blocker was rotated to the

Desflurane-induced hemodynamic changes in patients with diabetic cardiovascular autonomic neuropathy

BACKGROUND Diabetic cardiovascular autonomic neuropathy (CAN) causes perioperative cardiovascular instability. A rapid increase in the desflurane concentration induces tachycardia and hypertension (HTN). This study examined the effects of the cardiovascular response to desflurane on patients with diabetic CAN. METHODS Forty diabetes mellitus (DM) patients with CAN were divided two groups: one with HTN (DM+HTN group, n = 17) and one without HTN (DM group, n = 23). The control group (n = 20) was composed of healthy patients without DM or HTN. In each group, the concentration of desflurane inspired was increased abruptly to 12.0 vol% 2 minutes after a thiopental injection. The target was to produce an end-tidal concentration of desflurane of 10.0 vol%, which was maintained until the end of the study by adjusting the vaporizer dial setting. The heart rate (HR), mean arterial pressure (MAP), and cardiac index (CI) were measured. RESULTS The HR, MAP and CI increased significantly in all three groups when compared with the baseline (P<0.05). Additionally, the HR and MAP showed did not differ among the three groups at any of sampling times. However, the CI of the DM group and the DM+HTN group differed when compared with the control group at 90 and 120 seconds after intubation (P<0.05). CONCLUSIONS In diabetic patients with CAN, the hemodynamic responses to a rapid increase in desflurane concentration are similar to those in non-diabetic patients before endotracheal intubation. However, after endotracheal intubation, increments in CI are blunted in diabetic patients with CAN.