Mitsutaka Edanaga

Hemodynamic and bispectral index responses to tracheal intubation during isoflurane or sevoflurane anesthesia

AbstractPurpose. The effects of volatile anesthetics on change in the bispectral index (BIS) due to tracheal intubation are unclear. We investigated hemodynamic and BIS responses to intubation during isoflurane or sevoflurane anesthesia. Methods. After obtaining Institutional Review Board approval and informed consent, we randomly allocated 40 patients of American Society of Anesthesiologists (ASA) physical status I to receive either isoflurane (ISO group; n = 20) or sevoflurane (SEV group; n = 20). The patients were anesthetized with thiamylal and were ventilated with 100% oxygen, using a mask. The inspired concentrations of isoflurane and sevoflurane were gradually increased and maintained at end-tidal anesthetic concentrations of 2 minimum alveolar concentration (MAC) during the study period. Tracheal intubation was performed 15 min after the end-tidal anesthetic concentrations had reached 2 MAC. Mean arterial pressure (MAP), heart rate (HR), and BIS were recorded before induction, at the loss of consciousness, before laryngoscopy, and at 1, 3, and 5 min after intubation. Results. Anesthesia with 2 MAC volatile anesthetics increased HR in the ISO group, and decreased MAP in the SEV group. The BIS value decreased from 95 ± 3 and 96 ± 2 before thiamylal to 39 ± 9 and 38 ± 10 before intubation in the ISO and SEV groups, respectively. MAP and HR were significantly increased in both groups 1 and 3 min after intubation, but BIS remained unchanged. Conclusion. Anesthesia with 2 MAC of isoflurane and sevoflurane was effective to suppress the change in BIS due to intubation but was not sufficient to prevent changes in hemodynamic responses.

Propofol increases pulmonary vascular resistance during α-adrenoreceptor activation in normal and monocrotaline-induced pulmonary hypertensive rats

BACKGROUND:Using isolated perfused lungs of normal or monocrotaline (MCT: 50 mg/kg)-induced pulmonary hypertensive rats, we tested the hypothesis that the pulmonary vascular effects of propofol depend on activation of the &agr;-adrenoreceptor. METHODS:Changes in pulmonary perfusion pressure induced by propofol (10−5 to 10−4 M) were measured with or without phenylephrine (10−6 M) pretreatment. Before phenylephrine administration, we assessed the effects of inhibitors of nitric oxide synthase (N&ohgr;-nitro-l-arginine methylester: 10−4 M), cyclooxygenase (indomethacin: 10−5 M), and protein kinase C inhibitor, bisindolylmaleimide I (10−6 M) or calphostin C (10−6 M). RESULTS:Changes in pulmonary perfusion pressure by phenylephrine after pretreatment of nitric oxide synthase inhibitor and indomethacin in normal rats were significant (5 ± 3 and 7 ± 2 mm Hg), whereas that after pretreatment of bisindolylmaleimide I were small in MCT-rats (2 ± 1 mm Hg). Propofol caused pulmonary vasoconstriction after phenylephrine pretreatment both in normal and MCT-treated rats. In normal rats, the propofol-induced increase in pulmonary perfusion pressure after indomethacin pretreatment was slightly smaller than that in the non-pretreated lungs (P < 0.05). In MCT-treated rats, the propofol-induced increases in pulmonary perfusion pressure after both protein kinase C inhibitors were smaller than that in the non-pretreated lungs (P < 0.05). CONCLUSIONS:Propofol may increase pulmonary vascular resistance during &agr;-adrenoreceptor activation.

Effects of thiopental on bispectral index and heart rate variability.

Background and objective: Thiopental has been reported to reduce sympathetic tone, however, it is not clear whether change in heart rate variability is associated with depth of anaesthesia. The purpose of the present study was to evaluate changes in heart rate variability at different depths of hypnosis during induction of anaesthesia with thiopental. Methods: We studied 17 ASA I patients scheduled for minor surgery. The depth of hypnosis was monitored by the BIS. Spectral analysis of heart rate variability using a maximum entropy method resulted in a characteristic power spectrum with two main regions, a high frequency and a low frequency. Haemodynamics, entropy, low frequency, high frequency and low frequency/high frequency were monitored in an awake state and after the induction of anaesthesia. Results: Heart rate increased in a BIS‐dependent manner, whereas blood pressure showed no significant changes during the study period. High frequency, entropy and low frequency decreased with a reduction in the BIS value. Low frequency/high frequency showed no significant change during the study period. Conclusions: Induction of anaesthesia with thiopental increased heart rate and decreased high frequency, entropy and low frequency in a BIS‐dependent manner, indicating that thiopental reduces cardiac parasympathetic tone depending on the depth of hypnosis.

A case of hemothorax due to traumatic bleeding managed effectively by Sonoclot®-guided blood transfusion

A 71-year-old woman was transported to our hospital due to traumatic bleeding, and an operation was immediately performed for achieving hemostasis. We decided to perform Sonoclot®-guided blood transfusion. When Sonoclot signatures had returned normal values, further bleeding did not occur. We experienced the first case of traumatic bleeding managed effectively by using Sonoclot. We suggest that a Sonoclot analyzer may be useful for the management of severe coagulopathy due to traumatic bleeding like ROTEM and TEG.

The bronchoscopy model LM-092 has educational benefits

Keywords Bronchoscopy LM-092 YounganesthesiologistsTo the Editor:Recent advances in pulmonary segmentectomy havecreated the need for identification of the correct bronchialsegment by bronchoscopy, because a surgeon must confirmthe pulmonary segment by inflating it under bronchoscopicvisualization before its resection [1]. Therefore, accurateknowledge of bronchial anatomy and the technique toadvance the bronchoscope to the correct bronchial segmentare necessary for anesthesiologists. The purpose of ourstudy was to evaluate whether the use of a bronchoscopytraining simulator improved their skills in bronchoscopy,especially identification of the correct bronchial segment.Nineteen volunteers, including residents and younganesthesiologists, were enrolled in this study. We used thebronchoscopy training simulator LM-092 (Koken Co., Ltd,Tokyo, Japan) (Online Resource 1, Fig. 1), which is madeof special siliconized rubber. The trainee attempted toidentify five bronchial segments. Five segments were usedso that the trainees could not memorize a course of bron-chial segments of the simulator. These segments wererandomly decided by the sealed envelope method, and theinvestigator told the trainee to detect the selected bronchialsegment by this statement: ‘‘Please insert the tip of thebronchoscope to B6 in the left lung.’’ After the trainee hadcompleted insertion of the bronchoscope, the investigatortold the trainee which bronchial segment the tip of theinserted bronchoscope had reached. All trainees repeatedthe same examination 1 week and 2 weeks later. The pri-mary outcome was the number of bronchial segmentscorrectly identified. Statistical significance was assessedusing Friedman’s test with Dunn’s method to compare witheach trial. P\0.05 was considered statistically significant.The number of correctly identified bronchial segmentswas significantly higher in the third examination than in thefirst one [median (25–75th percentile), 4 (2–5) versus 2(1–2); P\0.01] (Online Resource 1, Fig. 2).In conclusion, training based on use of the bronchoscopysimulator LM-092 has benefit for anesthesiologists.References

Ultrasound-guided and radiographic monitoring-assisted peripherally inserted central catheterization

Keywords Basilic vein Complications PerioperativeinsertionTo the Editor:Although the first approach to central venous catheter-ization (CVC) under general anesthesia would generally bethe right internal jugular vein, this procedure is dangerouswhen patients are receiving anti-coagulant therapy or havelow platelet counts. We also note that, in the trendelenburgposition, the left internal jugular vein cannot be dilated,and the approach via the left internal jugular vein is alsodangerous for thoracic duct puncture. Central cathetershave been peripherally inserted via the basilic vein sincethe 1970s [1]. The advantages of peripherally insertedcentral catheters (PICCs) are low complication rates, easyaccess, reduced overall nursing required for i.v. mainte-nance, and low cost [2]. Perioperative insertion of a PICCvia the basilic vein would therefore confer some advanta-ges, and ultrasound-guided and radiographic monitoring-assisted insertion adds more safety and provides optimalmanagement. We therefore performed a clinical trial ofperioperative PICC insertion under ultrasound guidanceand radiographic monitoring.Fourteen patients scheduled for surgical repair ofabdominal aortic aneurysms were prospectively enrolled.The basilic vein in the upper arm was visualized using a4-F Groshong catheter (Medicon, Osaka, Japan) and a6- to 13-MHz ultrasound probe (Vivid i ; GE HealthcareJapan, Tokyo, Japan). The position of the PICC tip wasalso confirmed by radiographic monitoring. Briefly, eitherthe right or left upper arm was rotated 90 and then a 14-Gcannula was inserted into the vein under real-time ultra-sound guidance with a jobbing motion. When blood back-flowed from the vein, the PICC was directly inserted intothe basilic vein. The PICC was then advanced or with-drawn under radiographic monitoring to reach the preferredsite location. Forceful aspiration was added to obtain bloodreturn after the removal of the guidewire in the PICC. Anadditional catheter was cut and a sterile dressing waspositioned over the external portion of the PICC.The mean age of the patients was 71 years (range55–82). The tip of the PICC was successfully positioned in11 (78.6 %) of the 14 patients but became dislodged in 3(21.4 %) patients. The PICC tip was not advanced to thesuperior vena cava. Serious complications, such as infec-tion, accidental puncture of an artery, or injury of mediannerve, did not occur during PICC insertion in any patient.We had perioperatively inserted a CVC under landmarkor ultrasound guidance; therefore, the question arose as towhat should be done when a CVC could not be inserted viathe right internal jugular vein. Goldfarb and Lebrec [3]described difficulties with cannulation from the left internaljugular vein. However, both long- and short-term PICCplacement in infants and children has proven safe andeffective [4], although the PICC tip can quite frequentlybecome dislodged. Thus, ultrasound guidance and radio-graphic monitoring are important. Fricke et al. [5] reportedthat PICC placement was more successful with thanwithout radiographic monitoring. The PICC tip becamedislodged in three of our patients in whom the right basilic