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Biomedical subjects

T Asai

Publications and source records attributed to T Asai.

At least 19 recordsLinked to original sources
PubMed2003

Use of the laryngeal tube in 100 patients.

BACKGROUND: The laryngeal tube has a potential role during anaesthesia, but there have been only a few studies assessing its efficacy during the entire course of anaesthesia, and all previous studies used prototypes. We studied 100 patients to assess the efficacy of a new laryngeal tube during the entire course of anaesthesia. METHODS: After induction of anaesthesia, the laryngeal tube was inserted (up to two times) and adequacy of ventilation was assessed. The airway pressure at which gas leaked around the device was measured. The device was used during anaesthesia, while ventilation was controlled. The device was removed after the patient had opened the mouth to verbal command. Any complications during and after anaesthesia were recorded. RESULTS: Ventilation was possible at the first attempt in 90 patients, at the second attempt in another seven patients, and adequate ventilation failed after two attempts in three patients. Median (interquartile range) leak pressure was 28 (22-30) cmH2O. In all 97 patients, the laryngeal tube was used until the end of surgery. However, in two of the 97 patients the airway was partially obstructed during anaesthesia and it was necessary to reposition the device. The laryngeal tube was tolerated well during emergence from anaesthesia. No hypoxia, regurgitation, vomiting or laryngospasm occurred in any patient. On removal of the laryngeal tube, no blood was detected on the device and no apparent ischaemic changes to the tongue were observed in any patient. Post-operatively, six patients complained of a mild sore throat, and no patient complained of difficulty in swallowing or numbness of the oropharynx. CONCLUSION: The laryngeal tube can be useful for maintaining a patent airway during anaesthesia.

Adolescent↗
PubMed2003

Inhibition of NFkappaB activation using cis-element 'decoy' of NFkappaB binding site reduces neointimal formation in porcine balloon-injured coronary artery model.

Application of DNA technology to regulate the transcription of disease-related genes has important therapeutic potential. The transcription factor NFkappaB plays a pivotal role in the transactivation of inflammatory and adhesion molecule genes, leading to vascular lesion formation. Double-stranded DNA with high affinity for NFkappaB may be introduced as 'decoy' cis elements to bind NFkappaB and block the activation of genes mediating inflammation, resulting in effective drugs for treating intimal hyperplasia. In this study, we tested the feasibility of NFkappaB decoy therapy to treat neointimal formation in a porcine coronary artery balloon injury model as a pre-clinical study. An angioplasty catheter was introduced into the left anterior descending coronary artery of the pig to cause vascular injury. First, we tested the feasibility of transfection of FITC-labeled NFkappaB decoy ODN using a hydrogel balloon catheter. Fluorescence due to NFkappaB decoy ODN could be detected throughout the medial layer. Therefore, we transfected NFkappaB decoy ODN into the balloon-injured LAD using a hydrogel catheter. Histological evaluation demonstrated that the neointimal area in the balloon-injured artery was significantly reduced by NFkappaB decoy ODN as compared to scrambled decoy ODN at 1 week after single transfection, accompanied by a significant reduction in PCNA-positive stained cells (P < 0.01). Interestingly, the reduction of ICAM-positive staining was observed, accompanied by the inhibition of migration of macrophages. Of importance, intravascular ultrasound (IVUS) confirmed that neointimal area in the balloon-injured artery was significantly reduced by NFkappaB decoy ODN at 4 weeks after transfection (P < 0.01). Interestingly, the inhibition of neointimal area was only limited to the lesion transfected with NFkappaB decoy ODN, while other lesions without NFkappaB decoy ODN demonstrated a marked increase in neointimal formation. Here, we report the successful in vivo transfer of NFkappaB decoy ODN using a hydrogel catheter to inhibit vascular lesion formation in balloon-injured porcine coronary artery.

Angioplasty, Balloon, Coronary↗
PubMed2003

Prevalence of a training module for difficult airway management: a comparison between Japan and the United Kingdom.

To examine the education of trainees with regard to difficult airway management, we sent a questionnaire to all 89 Japanese University Departments of Anaesthesia (to be answered by a person who was responsible for teaching trainees) and all 280 Royal College of Anaesthetists' Tutors in the UK. The presence or absence of a formal training module for difficult airway management, timing and methods of training, types of airway devices that should be taught, and tutors' expertise with various techniques and devices were surveyed. Sixty-seven of the 89 Japanese tutors (75%) and 167 of 280 UK tutors (60%) replied to the questionnaire. Only 19 of 67 (28%) Japanese anaesthetists and 33 of 167 (20%) UK anaesthetists who replied, indicated that they had a difficult airway training module. In six Japanese departments (9%) and 115 (69%) UK departments, equipment for percutaneous transtracheal ventilation was readily available. Airway devices and techniques that tutors considered necessary to be mastered in the first 2 years of training, differed considerably between Japan and the UK, with notable differences in the use of gum elastic bougies and awake intubation. A training module for difficult airway management is often not provided and equipment for emergency transtracheal ventilation is often unavailable in both countries.

Anesthesiology↗
PubMed2003

Comparison of two Macintosh laryngoscope blades in 300 patients.

BACKGROUND: There are two forms of Macintosh laryngoscope blade. Compared with the standard blade, the English blade is longer, its curve is more continuous across the entire length of the blade, the flange of the blade continues much closer to the blade tip, and the height of the flange is shorter. METHOD: We studied 300 patients to compare the ease of laryngoscopy with each type of Macintosh laryngoscope blade. In a random crossover design, after induction of anaesthesia and neuromuscular block, the two blades were inserted in turn, and the views of the glottis at laryngoscopy (Cormack and Lehane scores) were compared. RESULTS: There was a difference in the view of the glottis in 80 patients. Among these patients, the view was better for the English blade for 63 patients and the standard blade was better for 17 patients. Laryngoscopy was difficult (grade 3 or 4) for at least one blade in 42 of 300 patients (14%). In these 42 patients, there was a difference in the score between the blades in 28 patients; the view was better for the English blade in 25 patients (60%) and for the standard blade in three patients (7%). The view was significantly better for the English blade than for the standard blade (P<0.001; 95% confidence interval 45-74%). CONCLUSIONS: In patients in whom laryngoscopy was unexpectedly difficult, the English blade provided a better glottic view significantly more frequently than the standard blade.

Adolescent↗
PubMed2003

Randomized comparison of laryngeal tube with classic laryngeal mask airway for anaesthesia with controlled ventilation.

BACKGROUND: Only a prototype laryngeal tube has been compared with the classic LMA for brief periods of anaesthesia. We compared the new laryngeal tube (which had several improvements in design) with the classic LMA. METHODS: We randomly allocated 72 patients to receive either the laryngeal tube or an LMA, and compared adequacy of controlled ventilation during anaesthesia (good: clear airway without complications; fair; clear airway with complications or suboptimal airway; or failed), leak pressure and the incidence of postoperative complications. RESULTS: Insertion was successful within 2 attempts in all 36 patients for the classic LMA and in 35 patients for the laryngeal tube. The mean leak pressure for the laryngeal tube (28 cm H(2)O) was significantly greater than that for the classic LMA (21 cm H(2)O) (P<0.001; 95% CI 3.6-10.0 cm H(2)O). Ventilation was good in 25 cases, fair in 11, and failed in no patients with the classic laryngeal mask airway; and good in 23, fair in 11 and failed in two for the laryngeal tube. There was no significant difference in adequacy of ventilation between the groups. The median peak airway pressure for the laryngeal tube (17.5 cm H(2)O) was greater than that for the classic LMA (16 cm H(2)O) (difference: 2 cm H(2)O; 95% CI 0-5 cm H(2)O). There was no significant difference in the incidence and severity of the postoperative complications between the two groups. CONCLUSION: The laryngeal tube was as effective as the classic LMA during anaesthesia with controlled ventilation. There were similar operative and postoperative complications.

Adult↗
PubMed2003

[Non-compromised grafting policy in off-pump coronary artery bypass].

BACKGROUND: The off-pump coronary artery bypass (OPCAB) has been prevalent around the world. However the most optimal selection of graft conduits has still been controversial. METHODS: Between January 2002 and April 2003, 126 consecutive isolated coronary artery bypass procedures were attempted to performed without cardiopulmonary bypass. A mean age of the patients was 69.3 (47-90). Fifteen patients were operated on emergently and 16 were urgently, including 15 patients requiring preoperative intra-aortic balloon pumping (IABP). Five patients underwent reoperative coronary bypass. RESULTS: All procedures were completed without cardiopulmonary bypass. The mean number of grafts per patient was 3.23 (range, 1 to 6). The skeletonized arterial conduits were aggressively used [117 left internal mammary artery (LIMA) to 155 sites, 70 right internal mammary artery (RIMA) to 79 sites, 57 right gastro-epiploic artery (RGEA) to 82 sites and 49 saphenous vein (SV) to 91 sites]. Cardiac-related hospital mortality was none. Angiographic assessment of grafts demonstrated that patency of LIMA, RIMA, RGEA and SV were 98.6%, 100%, 100%, and 97.6% respectively. CONCLUSION: OPCAB with skeletonized in situ arterial conduits is secure and feasible.

Aged↗
PubMed2002

Molecular strategy using cis-element 'decoy' of E2F binding site inhibits neointimal formation in porcine balloon-injured coronary artery model.

Transcription factor E2F plays a pivotal role in the transactivation of cell cycle regulatory genes, leading to vascular lesion formation. Double-stranded DNA with high affinity for E2F as 'decoy' cis elements may block the activation of genes mediating the cell cycle, resulting in an effective therapeutic agent for treating intimal hyperplasia. In this study, we tested the feasibility of E2F decoy therapy to treat neointimal formation in a porcine coronary artery balloon injury model. An angioplasty catheter was inserted in the left anterior descending coronary artery of pigs to cause vascular injury. Initially, we tested the feasibility of transfection of FITC-labeled E2F decoy ODN using a hydrogel balloon catheter. Fluorescence due to E2F decoy ODN could be detected throughout the medial layer. Therefore, we transfected E2F decoy ODN into the balloon-injured artery using hydrogel catheter. Of importance, intravascular ultrasound (IVUS) and histological evaluation demonstrated that plaque area in the balloon-injured artery was significantly reduced by E2F decoy ODN compared with mismatched decoy ODN at 1 month after a single transfection (P < 0.01). In contrast, luminal and total vessel areas were significantly increased in vessels treated with E2F decoy ODN as compared with mismatched decoy. Endothelial function after angioplasty was not affected by E2F decoy transfection. Finally, we tested the acute toxicity of E2F decoy ODN in monkeys, and no apparent side-effects were detected. Here, we report the successful in vivo transfer of E2F decoy ODN using a hydrogel catheter to inhibit vascular lesion formation in balloon-injured porcine coronary artery without any apparent side-effects.

Angioplasty, Balloon, Coronary↗
PubMed2002

Efficacy of catheter needles with safeguard mechanisms.

There has been considerable interest in using safeguarded needles to reduce needlestick injury. In a randomised design, we studied the efficacy and safety of two such needles (the Insyte AutoGuard and the Protective Acuvance), by comparing them with a conventional catheter needle (Insyte), for intravenous cannulation (18 G) in 150 patients and for intra-arterial cannulation in another 150 patients (20 G). For intravenous cannulation, the success rates were similar in the three groups but insertion of the AutoGuard or Acuvance catheter was significantly more difficult than the conventional catheter. For the Acuvance, the back-flow of blood into the chamber was sometimes too slow. For intra-arterial cannulation, insertion of the AutoGuard was significantly more difficult than the other two devices, mainly because the backflow chamber of the AutoGuard was too short so that the chamber often filled with blood before cannulation. Insertion of the Acuvance was significantly more difficult than the conventional catheter. For both intravenous and intra-arterial insertion, handling of the withdrawn needle was judged significantly safer in the AutoGuard group than the other two groups, whereas there was no significant difference in the safety between the Acuvance and conventional groups. In five subjects from the AutoGuard group, blood splashed on retraction of the needle. Blood contamination during needle withdrawal occurred frequently in the control and Acuvance groups, but rarely occurred in the AutoGuard group. Therefore, the AutoGuard needle is more suitable for intravenous cannulation, and the Acuvance is more suitable for intra-arterial cannulation.

Adolescent↗
PubMed2002

Effect of cricoid pressure on the ease of fibrescope-aided tracheal intubation.

We studied the reasons for difficulty with tracheal intubation over a fibrescope, and whether cricoid pressure facilitated intubation, in 50 patients. After induction of anaesthesia and neuromuscular blockade in 10 patients (phase 1), we attempted to clarify the reasons for difficulty in advancing a tracheal tube over an orally-inserted fibrescope, by observing through another fibrescope that was inserted nasally into the pharynx. In the next 40 patients (phase 2), we studied the effect of cricoid pressure on the success rate of tracheal intubation over the fibrescope. After a fibrescope (with a tracheal tube over it) had been inserted orally into the trachea, patients were randomly allocated to receive either criocoid pressure or sham pressure, and the success rate of intubation within 60 s was assessed. In phase 1, the tube was advanced into the trachea without difficulty in three of 10 patients. In the remaining seven patients, the tube impacted on the epiglottis in one patient and on the arytenoid cartilage in another two patients, and the tube migrated into the hypopharynx in the remaining four patients. In phase 2, tracheal intubation was successful within 60 s in seven of 21 patients (33%) without cricoid pressure, compared with 12 of 19 patients (63%) when cricoid pressure was applied (95% CI for difference 2-59%; p = 0.04). We conclude that cricoid pressure facilitates fibrescope-aided tracheal intubation.

Adolescent↗
PubMed2002

Efficacy of the ProSeal laryngeal mask airway during manual in-line stabilisation of the neck.

The laryngeal mask airway has a potential role during cardiopulmonary resuscitation, but its placement becomes more difficult during manual in-line stabilisation of the neck, and the device cannot reliably prevent pulmonary aspiration. The ProSeal laryngeal mask airway has a theoretical advantage of reducing aspiration because of its drainage tube, but its ease of placement during stabilisation of the neck is unknown. We studied 20 patients to compare ease of placement and the sealing effect between the standard and ProSeal laryngeal mask airways. In a randomised cross-over fashion, after induction of anaesthesia and neuromuscular blockade, the standard and ProSeal laryngeal mask airways were placed in turn. Placement was significantly easier for the ProSeal laryngeal mask airway (successful at the first attempt in 16 patients and at the second attempt in the remaining four patients) than for the laryngeal mask airway (successful at the first attempt in 12 of 20 patients and at the second attempt in three patients, and failed (> two attempts) in the remaining five patients; p = 0.04). The airway pressure at which gas leaked around the device was greater for the ProSeal than the laryngeal mask airway (mean difference 5.8 cmH2O; 95% CI 2.9-8.7 cmH2O; p = 0.0008).

Adolescent↗