Effect of remifentanil on plasma propofol concentration and bispectral index during propofol anaesthesia.

BACKGROUND: Propofol and remifentanil are commonly administered together in clinical anaesthesia, but the effect of remifentanil on the plasma concentration of propofol has yet to be established. The aim of the present study was to investigate the effect of remifentanil on plasma propofol concentrations (Cp) in the absence of surgical stimulation. METHODS: Thirty-eight patients undergoing elective gynaecologic surgery were randomly assigned to receive one of the three remifentanil doses (0, 0.5, or 1.0 µg kg⁻¹ min⁻¹). Anaesthesia was induced by a target-controlled infusion of propofol. After tracheal intubation, saline or remifentanil infusion was administered for 15 min. Mean arterial pressure (MAP), heart rate (HR), and bispectral index (BIS) were recorded and cardiac index (CI), blood volume, and indocyanine green disappearance ratio (K-ICG) were measured using a dye densitogram analyser before and 15 min after saline or remifentanil infusion. Cp was measured using high-performance liquid chromatography. RESULTS: HR, K-ICG, and BIS were significantly decreased in the remifentanil 0 µg kg⁻¹ min⁻¹ group. The decrease in MAP, HR, CI, and K-ICG was significantly lower in the remifentanil 0.5 and 1.0 µg kg⁻¹ min⁻¹ groups compared with the remifentanil 0 µg kg⁻¹ min⁻¹ group. Cp was significantly increased after remifentanil administration, but this had no influence on BIS. CONCLUSIONS: Remifentanil reduced the CI and increased the Cp, which may be related to a decrease in the K-ICG, but had no significant effect on the BIS.

Rocuronium dose-dependently suppresses the spectral entropy response to tracheal intubation during propofol anaesthesia.

BACKGROUND: The Entropy Module anaesthesia monitor displays two spectral entropy-based indices, response entropy (RE) and state entropy (SE). The difference between RE and SE (RE-SE), which mainly reflects electromyography activation, is thought to indicate the adequacy of antinociception. Little is known, however, about the effects of neuromuscular blocking agents on the RE-SE. We investigated the effects of rocuronium on the RE-SE response to tracheal intubation. METHODS: Forty-four patients were randomly assigned to receive one of four rocuronium doses (0.3, 0.6, 0.9, and 1.2 mg kg(-1)). Anaesthesia was induced by propofol target-controlled infusion. Rocuronium was administered 2 min after anaesthesia induction. Tracheal intubation was performed 7 min after anaesthesia induction. Arterial pressure, heart rate (HR), bispectral index (BIS), RE, SE, and patient movement were recorded. RESULTS: All EEG-derived indices (BIS, RE, SE, and RE-SE) increased after tracheal intubation. The maximum increase in the indices after tracheal intubation was significantly suppressed by an increase in the rocuronium dose. Patient movement after tracheal intubation was suppressed by an increase in the rocuronium dose. All indices were higher in patients who moved during or after tracheal intubation than in those who did not move. Rocuronium dose did not affect the mean arterial pressure or HR in response to tracheal intubation. CONCLUSIONS: The RE-SE response to tracheal intubation was suppressed by increasing the rocuronium dose. Estimates of nociception using RE-SE should be interpreted carefully in different states of muscle paralysis during general anaesthesia.

Relationship between the isoniazid-resistant mutation katGS315T and the prevalence of MDR-/XDR-TB in Osaka, Japan.

OBJECTIVE: To determine the prevalence of katGS315T mutations in isoniazid (INH) resistant Mycobacterium tuberculosis and to elucidate the association of katGS315T mutations with the prevalence of multidrug-resistant tuberculosis (MDR-TB). DESIGN: From 2001 to 2004, 1655 isolates from all newly registered patients who visited the Osaka Prefectural Medical Centre for Respiratory and Allergic Diseases were tested for drug susceptibility. Genotyping was performed using insertion sequence (IS) 6110-restriction fragment length polymorphism (RFLP) in 1629 of 1655 (98.4%) cases. All 145 isolates of INH-resistant M. tuberculosis, including MDR strains, were tested to detect the katGS315T mutation. RESULTS: Five hundred and sixty isolates (34.4%) shared an RFLP pattern. Of the 145 INH-resistant isolates, 18/48 (37.5%) isolates belonging to the RFLP cluster had katGS315T and 23/97 (23.7%) did not have the mutation. Of the 66 MDR-TB cases, 18/29 (62.1%) isolates belonging to the RFLP cluster had katGS315T and 11/37 (29.7%) did not have the mutation. Of the 29 extensively drug-resistant (XDR) TB cases, 17/21 (80.9%) isolates belonging to the RFLP cluster had katGS315T and 3/8 (37.5%) did not have the mutation. CONCLUSION: The clustering rate by IS6110-RFLP was very high among MDR-/XDR-TB isolates with katGS315T. Our study indicates a strong correlation between the katGS315T mutation and the transmission dynamics of MDR-TB, and especially XDR-TB.

Effect of landiolol on bispectral index and spectral entropy responses to tracheal intubation during propofol anaesthesia.

BACKGROUND: beta1-Adrenoceptor antagonists suppress the haemodynamic and arousal responses to tracheal intubation. The Entropy Module shows two spectral entropy-based indices, response entropy (RE) and state entropy (SE). The difference between RE and SE (RE-SE) may reflect nociception during general anaesthesia. In the present study, we investigated the effect of landiolol on entropy indices in response to tracheal intubation. METHODS: A total of 60 patients were randomly assigned to receive saline (Group S), remifentanil (Group R), or landiolol (Group L). Anaesthesia was induced by propofol target-controlled infusion. Two minutes after the induction of anaesthesia, infusion with vecuronium bromide and remifentanil, landiolol, or saline was initiated. Tracheal intubation was performed 7 min after anaesthesia induction. Arterial pressure, heart rate (HR), bispectral index (BIS), and entropy indices were recorded. RESULTS: In Group S, RE increased significantly after tracheal intubation, but there was no significant increase in BIS or SE. These increases in RE were abolished in Groups R and L. RE-SE increased significantly after tracheal intubation in Group S, whereas no increase in RE-SE was observed in Groups R and L. Increases in mean arterial pressure and HR after tracheal intubation were suppressed in Groups R and L compared with Group S. CONCLUSIONS: RE increased in response to tracheal intubation, whereas BIS and SE did not. Landiolol and remifentanil suppressed the increase in RE after tracheal intubation with significant inhibition of RE-SE difference.

Entropy indices vs the bispectral index for estimating nociception during sevoflurane anaesthesia.

BACKGROUND: It is now possible to acquire and process raw EEG and frontal EMG signals to produce two spectral-entropy-based indices (response entropy and state entropy) reflective of analgesic and hypnotic levels during general anaesthesia (with the Datex-Ohmeda S/5 Entropy Module, Datex-Ohmeda, Helsinki, Finland). However, there are no data available on the accuracy of the Entropy Module in estimating nociception during sevoflurane anaesthesia. METHODS: Forty female patients were enrolled in the present study. Each patient was allocated randomly to one of four end-tidal sevoflurane concentration (ET(sev)) groups (1.3, 1.7, 2.1 or 2.5%). A BIS Sensor (Aspect Medical Systems, Newton, MA) and an Entropy Sensor (Datex-Ohmeda) were applied side-by-side to the forehead. The bispectral index (A-2000 BIS Monitor, version 3.4, Aspect Medical Systems), response entropy, state entropy and patient movement were observed after electrical stimulation (20, 40, 60 and 80 mA, 100 Hz, 5 s) and after skin incision during sevoflurane anaesthesia (1.3, 1.7, 2.1 or 2.5%). Accuracy of the EEG variables in differentiating the intensity of electrical stimulation was estimated by the prediction probability (P(K)) values. RESULTS: Response entropy and state entropy [median, (range)] before skin incision were significantly lower in patients who did not move [29 (15-41) and 24 (14-41)] than in those that did [38 (24-53) and 37 (24-52)], but there was no significant difference in BIS. All EEG variables increased significantly (P<0.0001 for all) with increases in the intensity of electrical stimulation. The difference between response entropy and state entropy increased with increases in the electrical stimulation (P<0.0001). However, no EEG variables could differentiate the intensity of the electrical stimulations accurately because of low P(K)-values (P(K)<0.8). CONCLUSION: Noxious stimulation increased the difference between response entropy and state entropy. However, an increase in the difference does not always indicate inadequate analgesia and should be interpreted carefully during anaesthesia.

Beneficial action of candesartan cilexetil plus amlodipine or ACE inhibitors in chronic nondiabetic renal disease.

Although multiple antihypertensive agents are required to control blood pressure (BP) in chronic renal disease, it remains undetermined whether the combination therapy with angiotensin receptor blockers (ARB) plus calcium antagonists or angiotensin-converting enzyme inhibitors (ACEI) confers more preferable action on renal disease than the ARB monotherapy. In the present study, we compared the effect of the combination therapy with ARB plus calcium antagonists/ACEI on proteinuria with that of the ARB monotherapy in chronic nondiabetic renal disease. At 1 month of the drug treatment, the candesartan monotherapy (n=19) reduced BP from 154+/-3/93+/-2 to 146+/-3/88+/-2 mmHg (P<0.05), and a similar magnitude of BP reductions was observed with the combination therapy with candesartan plus ACEI/amlodipine (from 153+/-2/95+/-2 to 144+/-2/88+/-2 mmHg, P<0.05, n=39). The depressor action of these therapies was sustained throughout the 12-month treatment. In contrast, the reduction in proteinuria was greater with the combination therapy (-52+/-3% at 12 months, n=39) than with the candesartan monotherapy (-25+/-3%, n=19), although the baseline values of proteinuria were nearly the same in the candesartan monotherapy group (1.74+/-0.22 g/day) and the combination therapy group (2.10+/-0.19 g/day, P>0.2). Of note, the proteinuria-sparing effect did not differ between the candesartan+ACEI group and the candesartan+amlodipine group. In conclusion, the present study suggests more beneficial action of the combination therapy with ARB plus ACEI/amlodipine than the ARB monotherapy in nondiabetic renal disease. Since the reduction in BP was achieved to the same level, the distinct proteinuria-sparing action of these therapies is attributed to BP-independent mechanisms, which should vary depending on the agents used.

Time required to achieve a stable cuff pressure by repeated aspiration of the cuff during anaesthesia with nitrous oxide.

BACKGROUND AND OBJECTIVE: When the endotracheal tube cuff is repeatedly aspirated to avoid excessive cuff pressure during nitrous oxide anaesthesia, a stable cuff pressure is eventually achieved. We assessed the time required to achieve a stable cuff pressure after repeated cuff deflation. METHODS: During 67% nitrous oxide and oxygen anaesthesia, air-filled cuffs of a standard tracheal tube (Mallinckrodt Hi-Contour) were repeatedly deflated every 30 min for the first 3 or 4 h to inhibit excessive pressure (Groups Def-3 or Def-4, respectively, n = 10 for each); the cuff pressure was monitored for an additional 3 h. In some patients, the study was terminated at 1, 2, 3 and 4 h (n = 6 for each). RESULTS: Cuff pressure in Group Def-3, but not in Group Def-4, > 22 mmHg after stopping cuff aspiration. Intracuff nitrous oxide concentrations increased during repeated cuff deflation and increased further in Group Def-3 during an additional 3 h (from 39.8 +/- 4.7% to 44.3 +/- 3.8%; P < 0.05), whereas intracuff nitrous oxide concentrations at 4 h were not different from those in Group Def-4 at the end of the study (43.7 +/- 4.5% versus 42.3 +/- 4.8%; P = 0.579). CONCLUSIONS: When the air-filled cuff of the standard endotracheal tube is repeatedly deflated every 30 min for 4 h, but not for only 3 h, during nitrous oxide anaesthesia, a stable cuff pressure can be achieved without further deflation of the cuff. Our data also suggest that achieving an equilibrating nitrous oxide concentration in the cuff provides a subsequent stable cuff pressure.

Oxatomide for stable asthma in adults and children.

BACKGROUND: Oxatomide is a histamine H1-receptor antagonist. As an oral agent, oxatomide may be useful in managing asthma. Some guidelines recommend oxatomide for long-term prophylaxis of asthma in children. There is no clear evidence whether children or adults with asthma benefit from oxatomide. OBJECTIVES: To determine whether oxatomide alone, or in combination with other interventions, results in better disease control in people with asthma. SEARCH STRATEGY: The Collaborative Airway Group register and Collaborations trial register CENTRAL were searched using terms: oxatomide* OR Celtect OR Pinset OR KW-4354 OR Tincet. Reference lists of all relevant trials or review articles were checked. Enquiries were made of authors of included studies and relevant pharmaceutical companies. A search of 'Igaku Chuo Zasshi' and 'J-Medicine' were made using the following terms: oxatomide (also in Japanese) or Celtect (also in Japanese) or KW-4354. SELECTION CRITERIA: Studies were randomised, placebo-controlled trials and the interventions were oxatomide or matched placebo given alone or in combination with other asthma-medication for at least 4 weeks. DATA COLLECTION AND ANALYSIS: Four independent reviewers performed assessments of methodological quality and extracted relevant data. MAIN RESULTS: Six studies are included in this review. Three studies were mainly conducted in adults, two were conducted in older children (5-16 years) and one in infants (18-25 months). Trial duration was 4 to 52 weeks. Doses of oxatomide varied between studies, ranging from 1 mg/kg/day for infants to 180 mg/day for adults. Only data on adverse events was suitable for meta-analysis. Although PEF did not change significantly in any of the studies, the FVC and FEV1 improved significantly in two. There was no uniform change in symptom scores. There was no significant difference between oxatomide and placebo treatment in use of inhaled corticosteroid or bronchodilator. Two studies showed significant improvement with oxatomide as judged subjectively by physicians. Adverse events, analysed using data from 4 parallel and one cross over study, showed oxatomide to be associated with a significantly higher risk of any adverse event (OR: 2.97, 95%CI: 1.69 to 5.22) and drowsiness (OR: 5.22,95%CI: 2.53 to 10.74). REVIEWER'S CONCLUSIONS: There is no evidence to show that oxatomide has a significant effect on the control of stable asthma. Some studies reported significant benefits in subjective parameters. There was improvement in some lung function outcomes reported, but this were not consistent across measures or studies and may represent reporting bias. Adverse events, including drowsiness, were significantly greater with oxatomide than placebo.

Cost analysis of paediatric tuberculosis treatment in Japan.

OBJECTIVE: To estimate the cost of treating a tuberculosis (TB) case and to analyse TB-related medical service utilisation, a cost-of-illness study was conducted for all patients with a primary diagnosis of TB admitted to a public hospital in Japan. METHODS: Retrospective analysis by abstracting in- and out-patient medical records of 57 paediatric patients diagnosed with TB during 1993-1998 at a public hospital in Osaka prefecture. Costs were estimated based on third party's payer perspectives according to the service utilisation pattern. In addition to cost data, sociodemographic information and service utilisation pattern were also extracted from the medical records. Cost of preventing a case of TB was abstracted from the published literature. RESULTS: The average cost of treatment was 8384 US dollars (95%CI 5667-11,099), while the average length of hospitalisation was 63 days (95%CI 43-84). Based on 20-80% vaccine efficacy, the cost of preventing a case of TB was 35,950-175,862 US dollars. In univariate analysis, site of TB (P = 0.04) was significantly associated with TB treatment cost, while case-finding method (contact tracing, symptoms, etc.) was associated with length of hospitalisation (P = 0.03). Multivariate regression analysis, however, showed none of the factors to be significant predictors of TB treatment cost and length of hospital stay. CONCLUSION: The cost of treating a case of paediatric TB is much lower than that of preventing one. Japan's universal BCG vaccination policy should be re-examined in the light of economic, social and political issues.

Impact of calcium antagonists on bleeding time in patients with chronic renal failure.

Haemorrhagic diathesis develops in chronic renal failure, in which calcium antagonists are used widely as antihypertensive agents. Although calcium antagonists are reported to impair platelet function, it has not been examined whether calcium antagonists alter bleeding time. The present study was conducted to clarify whether calcium antagonists affect bleeding time in chronic renal failure. Patients with chronic renal failure without and with calcium antagonists were enrolled (n = 156), and bleeding time (Ivy's method) as well as blood parameters (BUN, creatinine, platelet counts, and haemoglobin) were compared in patients with normal and prolonged bleeding time. Among patients not taking calcium antagonists (n = 34), three cases manifested prolonged bleeding time, whereas abnormal bleeding time was observed in 31 patients out of 122. Positive correlations were observed between bleeding time and BUN in both calcium antagonist-untreated (r = 0.46) and -treated groups (r = 0.25). The odds ratio for prolongation of bleeding time in patients taking calcium antagonists was 3.52 (95% CI, 1.01-12.33). In 12 calcium antagonist-treated patients with prolonged bleeding time, the withdrawal of calcium antagonists markedly shortened bleeding time (from 11.3 +/- 0.8 to 5.4 +/- 0.8 min, P < 0.05, n = 12). In contrast, in the additional group (n = 9), the continued treatment with calcium antagonists had no effect on bleeding time (from 11.7 +/- 0.9 to 10.0 +/- 1.0 min). Despite the inhibitory effect of calcium antagonists on bleeding time, no clinically serious events associated with haemorrhagic diathesis developed. In conclusion, calcium antagonists prolong bleeding time in patients with chronic renal failure. The subclinical (laboratory) effect of calcium antagonists however is not necessarily associated with haemorrhagic events of clinical significance.

Divergent renal vasodilator action of L- and T-type calcium antagonists in vivo.

OBJECTIVE: To assess the in-vivo action on the renal microvasculature of the calcium antagonists nifedipine (L-type blocker), efonidipine (L/T-type blocker), and mibefradil (predominant T-type blocker). DESIGN: An intravital needle-type charge-coupled device (CCD) camera videomicroscope was introduced to visualize the renal microcirculation directly in vivo. METHODS: In anesthetized mongrel dogs, nifedipine (0.01-1 mg/kg per min), efonidipine (0.033-0.33 mg/kg per min), or mibefradil (0.01-1 mg/kg per min) was infused intravenously after the insertion of a CCD probe into the kidney. Renal microvascular responses to calcium antagonists were directly evaluated, with concomitant observation of renal clearance. RESULTS: Each calcium antagonist caused modest vasodepressor action without affecting heart rate. Nifedipine (1 mg/kg per min, n = 9) increased renal plasma flow (RPF) (14 +/- 4%, P < 0.05) and glomerular filtration rate (GFR) (19 +/- 5%, P < 0.05), and tended to increase the filtration fraction (5 +/- 2% increment, P = 0.07). Efonidipine (0.33 mg/kg per min, n = 9), however, had no effect on filtration fraction, with 14 +/- 6% increments in RPF (P < 0.05) and 14 +/- 7% increments in GFR (P = 0.08). Rather, mibefradil (1 mg/kg per min, n = 9) elicited 6 +/- 2% decreases in filtration fraction (P < 0.05), with slight increments in RPF (6 +/- 3%) and no changes in GFR. In direct in-vivo microvasculature observations, nifedipine caused predominant (22 +/- 2%) dilatation of afferent arterioles (from 15.5 +/- 0.4 to 18.9 +/- 0.4 microm, n = 5), compared with that of efferent arterioles (10 +/- 2%; from 11.0 +/- 0.4 to 12.1 +/- 0.3 microm). In contrast, efonidipine caused a similar magnitude of vasodilatation (16 +/- 4%) compared with 18 +/- 2%; n = 6), and mibefradil caused greater dilatation of efferent arterioles (20 +/- 4%, n = 7) than that of afferent arterioles (13 +/- 4%). CONCLUSIONS: There exists marked heterogeneity in action of nifedipine, efonidipine and mibefradil on the renal microvascular in canine kidneys in vivo. Furthermore, our current observations suggest an important contribution of T-type calcium channel activity to efferent arteriolar tone in vivo.

Economic evaluation of universal BCG vaccination of Japanese infants.

BACKGROUND: The international controversy surrounding the use and effectiveness of the Bacillus Calmette-Guérin (BCG) vaccine and the low incidence of tuberculosis (TB) among Japanese children prompted this study. METHODS: We compared 'universal BCG vaccination' with 'no vaccination at all' using a cost-effectiveness analysis. The study population was a hypothetical cohort comprising a total of 1.2 million infants born in 1996 at locations all over Japan. A model was developed to calculate the number of TB cases prevented by the vaccination programme. Assuming 40-80% overall vaccine efficacy (64-86% for TB-meningitis) and 10 years of protection, we calculated the cost and number of immunizations required to prevent one child from developing TB, the total number of TB cases averted by vaccination and total costs required for the programme. RESULTS: Based on an assumption of flexible vaccine efficacy (40-80%), we estimated that 111-542 TB cases including 10-27 of TB-meningitis would be prevented during the 10 years after BCG vaccination among the cohort of infants born in 1996. About US$35 950-175 862 or 2125-10 399 immunizations would be required to prevent one child from developing TB. Sensitivity analyses covering a wide duration of protection, incidence of TB, vaccine coverage and discount rate, revealed that other than vaccine efficacy, the cost of preventing a single case of TB is highly sensitive to the duration of BCG protection and TB incidence. CONCLUSION: The cost per case of TB prevented is heavily dependent on vaccine efficacy and the duration of protection, and is high compared with the cost of treating one child who has developed TB.

The effect on intracuff pressure of various nitrous oxide concentrations used for inflating an endotracheal tube cuff.

UNLABELLED: We sought to determine the optimal concentration of nitrous oxide (N(2)O) for inflating endotracheal tube cuffs, to avoid overinflation and air leaks. Female patients undergoing endotracheal intubation (inner diameter 7.5 mm) during anesthesia with 67% N(2)O were randomly assigned to five groups of 25 subjects each, in which cuffs were inflated with 0% (Air), 30% (N30), 40% (N40), 50% (N50), or 67% (N67) N(2)O. The cuff pressure and the N(2)O concentration in the cuff were measured. In an additional 15 patients (N40-a group), pilot balloons were replaced with metal tubes, and the mouths and noses of the patients were wrapped with tape, to minimize N(2)O efflux into the air. Postoperative sore throats were evaluated in double-blinded interviews. Cuff pressures increased significantly in the Air and N30 groups but decreased in the N67 group. Cuff pressures were <22 mm Hg in the N40 and N50 groups, but the N50 group had air leaks. The N(2)O concentration in the cuff in the N40 group was significantly smaller than that in the N40-a group, suggesting N(2)O rediffusion. The incidence of sore throats (40% in the Air group) was reduced significantly in the N40 and N50 groups. Therefore, 40% N(2)O is optimal for filling the cuff during anesthesia with 67% N(2)O. IMPLICATIONS: Nitrous oxide (N(2)O) diffuses into the cuff, equilibrating at a smaller concentration than the gas mixture with which patients are ventilated. Our data indicate that inflation of the cuff with 40% N(2)O is recommended to prevent both excessive endotracheal cuff pressure and air leaks during anesthesia with 67% N(2)O, reducing postoperative sore throats.

[Successful fiberoptic intubation for a patient with lingual tonsillar hyperplasia].

Hypertrophied lingual tonsils are rare, but may cause difficulty or inability in tracheal intubation during induction of general anesthesia. A 39-yr-old woman was scheduled for resection of symptomatic hypertrophied lingual tonsils. In this patient, we examined two methods of oro-tracheal intubation either with rigid laryngoscopy or flexible fiberoscopy using trans-nasal fiberopic monitoring. Direct laryngoscopy failed to expose the trachea because of large hypertrophied tissue, and fiberoscopic intubation was also difficult since a large mass hindered acquiring a suitable view. However, transnasal fiberoscopic monitoring could guide the orotracheal fiber into the trachea for intubation. When an anesthesiologist can predict the abnormality of lingual tonsils, this combination might be recommended for difficult airway and intubation.

[Effect of beclomethasone increment on airflow limitation in asthmatic children treated with high dose beclomethasone].

In order to evaluate the effect of higher dose BDP therapy (1200-1660 micrograms/day), we studied 12 asthmatic children (mean age 9.7 years-old) with airflow limitation on respiratory function test who were asymptomatic with high-dose BDP therapy (800 micrograms/day). After 4 weeks of higher dose BDP therapy, FVC, FEV1 and V50 were significantly improved, but those improvement were insufficient compared with those after salbutamol inhalation. The personal best values after salbutamol inhalation were not different in every parameter of respiratory function test between BDP 800 micrograms/day and 1200 micrograms/day. We conclude that less than 800 micrograms of daily BDP is generally adequate for prevention in most asthmatic children, because higher dose BDP therapy is no more effective on respiratory function in those treated with 800 micrograms of daily BDP, and that the best value of respiratory function after salbutamol inhalation is not always a goal of high dose BDP therapy.

[Decrease in serum propofol concentrations after acute autologous blood letting].

A change in serum propofol concentrations associated with acute autologous blood letting during anesthesia was investigated in seven scheduled surgical patients. Anesthesia was induced with propofol 2 mg.kg-1 and maintained with infusion of propofol 6 mg.kg-1.hr-1 at a constant rate. After achieving a stable anesthesia, about 10 g.kg-1 of autologous blood was withdrawn in about 15 minutes and 20 ml.kg-1 of acetated Ringer's solution was infused to manage the hypotension caused by withdrawal. A blood sample each 4 ml was taken before and 0, 5, 15, 30 minutes after blood withdrawing. Another 7 patients were anesthetized with the same procedure without blood letting to distinguishing the effect of blood letting from rapid infusion therapy of crystalloid. Assay of serum concentration of propofol was performed with HPLC-spectrofluorometry. Concentrations of propofol were significantly decreased from 2.8 micrograms.ml-1 to 2.3 micrograms.ml-1 just after blood letting, and remained at 2.3 micrograms.ml-1 after 30 minutes from letting. Rapid infusion therapy also decreased the concentrations of propofol from 2.4 micrograms.ml-1 to 1.7 micrograms.ml-1. Continuous infusions of propofol may become a major method of general anesthesia with target controlled infusion techniques (TCI) in clinical settings for the accuracy and reliability of prediction of blood concentrations. However, this study demonstrated unexpected decreases of concentration of propofol during acute autologous blood letting similar to surgical mass bleeding, which might be mainly caused by rapid infusion therapy. The rate of infusion of anesthetic should be readjusted to counteract the effect of acute blood loss or volume replacement.

Evaluation of the cardiovascular responses to fiberoptic orotracheal intubation with television monitoring: comparison with conventional direct laryngoscopy.

STUDY OBJECTIVE: To evaluate and compare cardiovascular responses to a new method of orotracheal intubation incorporating TV monitoring, with conventional orotracheal intubation via rigid blade laryngoscopy. DESIGN: Prospective single-blind study. SETTING: Operating room of a medical college hospital. PATIENTS: 90 ASA physical status I and II surgical patients requiring general anesthesia and orotracheal intubation. INTERVENTIONS: Patients were randomly allocated to two groups, one for the new intubation method and the other for conventional intubation using a rigid laryngoscope. In the new method, an anesthesiologist inserted an endotracheal tube alone into the trachea via TV monitoring through the bronchoscope, which was inserted by an assistant through the mouth to the middle larynx. The patient's trachea was intubated without extreme stretching of laryngeal tissues or deep insertion of the tip of the bronchoscope. In the conventional method, orotracheal intubation was performed with rigid direct laryngoscopy. MEASUREMENTS: Noninvasive blood pressure (BP) and heart rate (HR) were measured before arrival at the operating room, and before and after orotracheal intubation. MAIN RESULTS: Although this method was expected to be a minimally invasive fiberoptic intubation technique, the patients showed significant increases in BP and HR. No significant differences between the two groups were observed in cardiovascular responses immediately after intubation: the systolic BP, 169.5 +/- 28.3 versus 167.0 +/- 23.1 mmHg, and HR, 100.2 +/- 18.2 versus 98.8 +/- 16.6 bpm. CONCLUSIONS: Insertion of an endotracheal tube may itself be the most invasive stimulus during intubation procedures.

[Commemorative lecture of receiving Imamura Memorial Prize. Studies on prevention and treatment of childhood tuberculosis].

We performed a retrospective analysis of 394 patients who were treated for active tuberculosis (TB) at our hospital from 1976 to 1997. We had started early BCG vaccination campaign in Osaka Prefecture from 1995 and the coverage of BCG vaccination in infants rose up to about 90%. From that experience, we studied the current situations and measures on prevention and treatment of childhood tuberculosis. Pulmonary TB in children is successfully treated with 6-month standard short-course chemotherapy using isoniazid, rifampin, and pyrazinamide daily for 2 months, followed by isoniazid and rifampin daily for 4 months. Prognosis of childhood tuberculous meningitis (TBM) is poor, early diagnosis and prevention of TBM is important. In order to promote TB control and eliminate childhood TB, especially in infants, the following is necessary; 1) early detection and treatment of adult TB patients, source of infection, 2) prompt and appropriate contact examination and chemoprophylaxis, 3) BCG vaccination during early infancy, 4) protection from MDR-TB are most important.

[Factors for the onset of and the exacerbation of tuberculosis. 3. Clinical factors for the development and the exacerbation of active tuberculosis. a. Children, young adult].

We reviewed the reports about the development and the exacerbation of active tuberculosis and performed a retrospective analysis of 394 patients who were treated for active tuberculosis (TB) at our hospital from 1976 to 1997. The factors for the development and the exacerbation of active tuberculosis were the bacteriological status of the source, the age of the person infected, the degree of tuberculin sensitivity, BCG non-vaccination, non-chemoprophylaxis, the medical condition that increases the risk for tuberculosis, the presence of other infection, poor nutrition.