Effect of cerebrospinal fluid drainage pressure in descending and thoracoabdominal aortic repair: a prospective multicenter observational study.

PURPOSE: Cerebrospinal fluid drainage (CSFD) is recommended during open or endovascular thoracic aortic repair. However, the incidence of CSFD complications is still high. Recently, CSF pressure has been kept high to avoid complications, but the efficacy of CSFD at higher pressures has not been confirmed. We hypothesize that CSFD at higher pressures is effective for preventing motor deficits. METHODS: This prospective observational study included 14 hospitals that are members of the Japanese Society of Cardiovascular Anesthesiologists. Patients who underwent thoracic and thoracoabdominal aortic repair were divided into four groups: Group 1, CSF pressure around 10 mmHg; Group 2, CSF pressure around 15 mmHg; Group 3, CSFD initiated when motor evoked potential amplitudes decreased; and Group 4, no CSFD. We assessed the association between the CSFD group and motor deficits using mixed-effects logistic regression with a random intercept for the institution. RESULTS: Of 1072 patients in the study, 84 patients (open surgery, 51; thoracic endovascular aortic repair, 33) had motor deficits at discharge. Groups 1 and 2 were not associated with motor deficits (Group 1, odds ratio (OR): 1.53, 95% confidence interval (95% CI): 0.71-3.29, p = 0.276; Group 2, OR: 1.73, 95% CI: 0.62-4.82) when compared with Group 4. Group 3 was significantly more prone to motor deficits than Group 4 (OR: 2.56, 95% CI: 1.27-5.17, p = 0.009). CONCLUSION: CSFD is not associated with motor deficits in thoracic and thoracoabdominal aortic repair with CSF pressure around 10 or 15 mmHg.

[Two Cases of Large Gynecological Tumor Complicated by Preoperative Deep Vein Thromboembolism and Pulmonary Thromboembolism-Should We Use Inferior Vena Cava Filters ?-].

We experienced two cases of large gynecological tumor resection with co-existing deep vein thrombo- embolism (VTE) and pulmonary thromboembolism (PTE). Despite perioperative anticoagulation, one of the two patients developed dyspnea with massive PTE postoperatively, although the other patient did not have any postoperative complications. To prevent fatal mas- sive PTE, temporary inferior vena cava (IVC) filter might have been effective during perioperative period in these cases. Since there are wide variations among institutes regarding the perioperative application of temporary IVC filters for patients with co-existing VTE and/or PTE before surgery, guidelines or recom- mendations for appropriate usage of perioperative IVC filter are necessary.

Wide discrepancies in activated clotting times measured by two devices were detected for a patient with lupus anticoagulant in a cardiac surgery.

INTRODUCTION:: For a patient with lupus anticoagulant (LA), activated coagulation time (ACT) was measured with two different types of devices (HEMOCHRON® 801 and HEMOCHRON® Jr). CASE REPORT:: ACTs during heparinization measured with the HEMOCHRON® 801 were over the range of measurement, while those with the HEMOCHRON® Jr. reflected an almost normal response to heparin. DISCUSSION:: The phospholipid contained in an activating agent of the HEMOCHRON® Jr was suggested to have counteracted the effect of LA. CONCLUSION:: It was indicated that the coagulation status for LA-positive patients might be better assessed by ACT measured with phospholipid in an activating agent, although careful interpretation is required.

[Mechanobiology and the Heart].

Mechanobiology has been focusing on biological research regarding mechanisms of muscle force generation, or recently sensing and response to the force applied to the tissue or each cell. Therefore, the heart has been one of the target organs and studied extensively for a long time since late 19th century. Its force-length relationship was demonstrated as the Starling's law of the heart, which is one of the most important findings in mechanobiology. In late 20th century, excitation-contraction coupling in the muscle was demonstrated and then, molecular mechanisms are gradually elucidated including calcium homeostasis and signal transductions in various situations: under the effects of catecholamines, other vasoactive agents, or ischemia. Among them, recent findings suggest possible involvement of titin, the giant elastic protein connected with both actin and myosin, with basic mechanism of the Starling's law of the heart Pathological proliferation of the heart as hypertrophic remodeling has also been extensively studied in recent years, and its signal transduction from pressure overload and volume overload to respective morphological changes of the heart chamber are partially clarified.

Nitrogen accumulation during closed circuit anesthesia depends on the type of surgery.

STUDY OBJECTIVE: The aim of this study is to test the hypothesis that the amount of nitrogen that accumulates within the closed breathing system would be greater during open abdominal surgery than during superficial surgery with small wounds. DESIGN: Prospective, comparative study. SETTING: Operating rooms of a university hospital. PATIENTS: Fourteen American Society of Anesthesiologists physical status I and II adult patients scheduled for abdominal surgery (n = 7) or tympanoplasty (n = 7). INTERVENTIONS: After induction of anesthesia and endotracheal intubation, the patients were denitrogenated for 30 minutes using 100% oxygen at a fresh gas flow of 10 L/min. The breathing system was then closed and patients were anesthetized using 60% xenon in oxygen, supplemented with epidural anesthesia in the abdominal surgery group and sevoflurane in the tympanoplasty group. MEASUREMENTS: Nitrogen concentration in the breathing system was determined by gas chromatography immediately before and 2 hours after the breathing system was closed. MAIN RESULTS: The median (range) increase in nitrogen concentration during the 2-hour period of closed circuit anesthesia was greater in the abdominal surgery patients than in the tympanoplasty patients (6.5% [4.0%-10.2%] vs 2.5% [1.4%-8.4%], P = 0.035, Mann-Whitney U test). CONCLUSIONS: The amount of nitrogen accumulation during closed circuit anesthesia is greater during open abdominal surgery than in superficial surgery such as tympanoplasty. We postulate that during open abdominal surgery, nitrogen in the ambient air enters the body across the peritoneum and then diffuses into the alveoli to be exhaled.

The effect of tramadol on serum cytokine response in patients undergoing pulmonary lobectomy.

STUDY OBJECTIVE: To investigate the effect of tramadol on the production of serum interleukin (IL) 6, IL-10, and IL-2 and soluble (s) IL-2 receptor (R), thereby evaluating its effects on the proinflammatory and anti-inflammatory responses and immune function in cancer patients undergoing conventional pulmonary lobectomy. DESIGN: Randomized, double-blinded, placebo-controlled study. SETTING: University hospital. PATIENTS: Forty ASA physical status I and II adult patients scheduled for conventional pulmonary lobectomy. INTERVENTIONS: Patients were randomly divided into 2 groups (n = 20 in each group). Both groups received general anesthesia with enflurane combined with epidural blockade. At 5 minutes before skin incision, patients were given either tramadol 1.5 mg/kg intravenously (IV), followed by a continuous infusion of 0.5 mg/kg per hour until the end of surgery (group I), or IV normal saline (group II). MEASUREMENTS AND MAIN RESULTS: Venous blood samples for the measurement of serum cytokine concentrations were taken before anesthesia and at set intervals until 24 hours after operation. Serum levels of IL-6 and IL-10 in both groups were increased significantly during and after operation compared with baseline levels (P < .05). No statistical differences between groups in terms of IL-6 and IL-10 were observed. Levels of IL-2 were elevated significantly at 4 hours after operation in group I as compared with baseline levels (P < .001), whereas they remained low at 4 and 24 hours after operation in group II (P < .01). There were significant increases in levels of sIL-2R at 4 and 24 hours after operation in group II as compared with baseline levels (P < .05) and at 24 hours after operation in group I (P < .01). Levels of IL-2 were higher at 4 and 24 hours after operation in group I than in group II (P < .01). Levels of sIL-2R were lower at 4 hours after operation in group I than in group II (P < .01). CONCLUSIONS: IV infusion of tramadol does not seem to alter IL-6/IL-10 cytokine response to pulmonary lobectomy. As tramadol was associated with increased IL-2 and delayed enhancement of sIL-2R in our study, it may attenuate to some extent an impaired immune response in pulmonary lobectomy.

The bispectral index predicts responsiveness to verbal commands in patients emerging from nitrous oxide anesthesia supplemented with a subhypnotic concentration of isoflurane.

PURPOSE: Nitrous oxide (N2O) administered alone has minimal effects on the bispectral index (BIS), an electroencephalogram-derived parameter of hypnosis. However, because this gas is commonly supplemented with a volatile anesthetic, we sought to determine how it would affect the BIS when coadministered with a low concentration of isoflurane. METHODS: Twelve patients were anesthetized with 70% N2O + 0.2% isoflurane (all concentrations are end-tidal). Following the end of surgery, the concentration of N2O was decreased in decrements of 10% while isoflurane was continued at 0.2%, and each new concentration of N2O was maintained for 15 min. This procedure was repeated until the patients first opened their eyes or squeezed the investigator's hand on command. RESULTS: N2O 70% + isoflurane 0.2% reduced the BIS to 68 +/- 9 (mean +/- SD). When the concentration of N2O was decreased toward awakening (which occurred at the N2O concentration of 36% +/- 8%), the BIS progressively increased until it reached 93 +/- 5 on awakening. CONCLUSION: The BIS reflects the level of hypnosis during N2O anesthesia supplemented with a low concentration of isoflurane.

Determination of right ventricular function by transesophageal echocardiography: impact of proximal right coronary artery stenosis.

STUDY OBJECTIVE: To investigate whether transesophageal echocardiography (TEE) can provide accurate information on right ventricular (RV) function in patients with right coronary artery (RCA) stenosis, given that a decrease in blood supply from the RCA may invalidate the use of single 2-D echocardiography imaging plane as a guide to RV function. DESIGN: Prospective, nonblinded study. SETTING: University hospital. PATIENTS: 30 adult patients undergoing elective cardiac or vascular procedures. INTERVENTIONS: Patients were classified into two groups according to the presence or absence of the proximal RCA (segment 1 or 2) stenosis. Group A patients had no obstructive lesions in the proximal RCA (n = 15). Group B patients had 75% or greater obstructive lesions in the proximal RCA (n = 15). MEASUREMENTS AND MAIN RESULTS: After induction of anesthesia, RV function was evaluated by both fast-response thermodilution pulmonary artery catheter and TEE. Transesophageal echocardiography-derived RV fractional area change (FAC) and tricuspid annular plane systolic excursion ratio (TAPSE ratio) were compared with thermodilution-derived RV ejection fraction (EF) using linear regression analysis. Transesophageal echocardiography-derived RV end-diastolic area (EDA) was compared with thermodilution-derived end-diastolic volume (EDV). Both methods showed a good correlation in RV, EDV, and EF in Group A, but no correlations in Group B. CONCLUSIONS: Transesophageal echocardiography does not provide reliable information on RVEF and EDV when proximal RCA stenosis is present.