PubMed Health⌕ Search

Biomedical subjects

Shigeho Morita

Publications and source records attributed to Shigeho Morita.

12 recordsLinked to original sources
PubMed2006

Hypertension and anesthesia.

PURPOSE OF REVIEW: There are still many controversies about perioperative management of hypertensive patients. This review aims to provide relevant instruction based on evidence regarding the treatment of those patients. RECENT FINDINGS: Mild to moderate hypertension is not independently responsible for perioperative cardiac complications. The position is less clear for severely hypertensive patients. A randomized study shows no benefit of the traditional practice of delaying elective surgery in severely hypertensive patients until better control of blood pressure is achieved. Perioperative use of beta-blockers or alpha-2 agonists has been shown to maintain perioperative hemodynamic stability and thereby to prevent major cardiac complications. SUMMARY: Delaying surgery only for the purpose of blood pressure control may not be necessary, especially in the case of mild to moderate hypertension. Strict care, however, should be taken to ensure perioperative hemodynamic stability because labile hemodynamics, rather than preoperative hypertension per se, appears to be more closely associated with adverse cardiovascular complications. Delaying surgery in hypertensive patients may be justified if target organ damage exists that can be improved by such a delay or if (suspected) target organ damage should be evaluated further before the operation.

Anesthesia↗
PubMed2005

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.

Adult↗
PubMed2005

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.

Analgesics, Opioid↗
PubMed2005

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.

Abdomen↗
PubMed2004

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.

Coronary Stenosis↗
PubMed2003

Tetraplegia after coronary artery bypass grafting.

UNLABELLED: The authors present a rare case of a cervical cord dysfunction after uncomplicated coronary artery bypass grafting. The preoperative neurological examination did not reveal any abnormalities; however, the postoperative magnetic resonance image showed significant spinal canal stenosis at the same levels as high signal lesions. Although the pathophysiological basis of the case was impossible to determine retrospectively, it seems probable that placing the neck in an extended position during surgery might have aggravated a preexisting spinal canal stenosis to produce cervical injury. IMPLICATIONS: The authors present a rare case of tetraplegia after coronary artery bypass grafting. It is suggested that neck extension during surgery might have aggravated an occult preexisting cervical spinal canal stenosis to produce cervical injury.

Anesthesia↗
PubMed2003

Preoperative information management system using wireless PDAs.

Personal Digital Assistant (PDA) and wireless communication are currently available in clinical settings. We developed wireless PDA software that assists anesthesiologists in pre-operative patient assessment. The device communicates with the hospital information system through a wireless LAN and is equipped with pre-programmed data entry templates for pre-operative assessment. As a preliminary test of the device, we randomly assigned residents in preoperative assessment to an intervention and a control arm and compared the results.

Anesthesiology↗
PubMed2002

Pollution of the medical air at a university hospital in the metropolitan Tokyo area.

STUDY OBJECTIVE: To investigate the quality of medical air in a hospital in the metropolitan area. DESIGN: Prospective study. SETTING: University hospital in the metropolitan Tokyo area. INTERVENTIONS: Medical air introduced into a bio-clean operating room was sampled. MEASUREMENTS: The concentrations of nitric monoxide (NO), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), and carbon monoxide (CO) in the medical air were measured every 30 minutes for 15 days. MAIN RESULTS: The concentrations (mean +/- SD) of NO, NO(2), SO(2), and CO were 34.4 +/- 35.0 ppb (range 0-200 ppb), 7.7 +/- 5.5 ppb (0-29 ppb), 33.8 +/- 2.9 ppb (21-46 ppb), and 1.65 +/- 0.87 ppm (0.5-7.5 ppm), respectively. The concentrations of these gases peaked at rush hours within a day. CONCLUSIONS: In the metropolitan area, we occasionally provide our patients with medical air of poor quality.

Air Pollution, Indoor↗
PubMed2002

The minimum alveolar concentration of xenon in the elderly is sex-dependent.

BACKGROUND: The minimum alveolar concentration (MAC) of xenon in the elderly has not been determined. Moreover, because xenon inhibits the activity of the N-methyl-D-aspartate receptors, and because N-methyl-D-aspartate receptor antagonists such as ketamine and MK-801 exert sex-dependent actions, we hypothesized that the MAC of xenon would also be sex-dependent. METHODS: Forty-eight patients of both sexes (24 patients of each sex), who were aged 65 yr or older and were undergoing elective laparotomy, were anesthetized with inhalational induction of xenon. Those who demonstrated marked agitation received supplemental propofol intravenously. After tracheal intubation, the end-tidal concentration of xenon was maintained at 45 (women only), 50, 55, 60, 65, 70, or 75% (men only) for at least 15 min before skin incision. These concentrations were randomly allocated to four patients of each sex. Each patient was monitored for the presence or absence of any purposeful bodily movement for 1 min following skin incision. The MAC of xenon was calculated separately for men and women using logistic regression analysis. RESULTS: The MAC of xenon was 69.3% (95% CI, 63.0-75.6%) for men and 51.1% (44.6-57.6%) for women. The two 95% confidence intervals did not overlap, indicating a statistically significant difference (P < 0.05). CONCLUSIONS: The MAC of xenon in the elderly is higher in men than in women.

Aged↗