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Biomedical subjects

Kohei Murao

Publications and source records attributed to Kohei Murao.

18 recordsLinked to original sources
PubMed2006

Pulmonary nodules: estimation of malignancy at thin-section helical CT--effect of computer-aided diagnosis on performance of radiologists.

PURPOSE: To evaluate the effect of a computer-aided diagnosis (CAD) system on the diagnostic performance of radiologists for the estimation of the malignancy of pulmonary nodules on thin-section helical computed tomographic (CT) scans. MATERIALS AND METHODS: The institutional review board approved use of the CT database; informed specific study-related consent was waived. The institutional review board approved participation of radiologists; informed consent was obtained from all observers. Thirty-three (18 malignant, 15 benign) pulmonary nodules of less than 3.0 cm in maximal diameter were evaluated. Receiver operating characteristic (ROC) analysis with a continuous rating scale was used to compare observer performance for the estimation of the likelihood of malignancy first without and then with the CAD system. The participants were 10 board-certified radiologists and nine radiology residents. RESULTS: For all 19 participants, the mean area under the best-fit ROC curve (A(z)) values achieved without and with the CAD system were 0.843 +/- 0.097 (standard deviation) and 0.924 +/- 0.043, respectively. The difference was significant (P = .021). The mean A(z) values achieved without and with the CAD system were 0.910 +/- 0.052 and 0.944 +/- 0.040, respectively, for the 10 board-certified radiologists (P = .190) and 0.768 +/- 0.078 and 0.901 +/- 0.036, respectively, for the nine radiology residents (P = .009). CONCLUSION: Use of the CAD system significantly (P = .009) improved the diagnostic performance of radiology residents for assessment of the malignancy of pulmonary nodules; however, it did not improve that of board-certified radiologists.

Adenocarcinoma↗
PubMed2006

[Insertion of a laryngeal mask airway before removal of a nasotracheal tube in a patient after anterior spine surgery].

A 19-year-old man with cervical spondylosis (C4-C6) was scheduled for an anterior spine surgery. Anesthesia was induced with propofol and fentanyl, and nasotracheal intubation was performed without difficulty after vecuronium administration. Anesthesia was maintained with sevoflurane and nitrous oxide in oxygen supplemented with fentanyl. No complications were observed during the operation. After surgery, the patient's head and neck were stabilized by a halo-vest, and we attempted to minimize stress responses associated with tracheal extubation. While the patient was still deeply anesthetized, and the nasotracheal tube was in place, a laryngeal mask airway (LMA) was placed without difficulty. After confirming correct position of the LMA, the nasotracheal tube was removed without body movement or coughing. Removal of the LMA was safely performed after recovery of the patient's respiration and consciousness. We believe that the laryngeal mask airway is useful during emergence from anesthesia in the patient whose trachea is intubated nasally.

Adult↗
PubMed2006

[Bronchial blocking with a balloon wedge pressure Catheter in a small infant].

The need for one-lung ventilation has been increasing even in pediatric patients. However, the trachea is so narrow in pediatric patients that ordinary double-lumen tubes can not be used and there have been many reports on devices or measures to block one lung. We report our experience with a female infant weighing 2 kg who had severe chronic lung disease under mechanical ventilation, and underwent left lung lower lobectomy with one-lung ventilation technique. We chose a balloon wedge pressure catheter to block the left main bronchus, because it has a central lumen through which a guide wire can be passed and sucking is available. The infant was in need of continuous ventilation and the catheter was too soft to be inserted directly. We first inserted an 18G catheter of a needle-catheter assemble outside the tracheal tube through which a guide wire was inserted into the left main bronchus with the aid of direct vision of a 2-mm fiberoptic bronchoscope through the tracheal tube, and then inserted the balloon wedge pressure catheter placing it in an appropriate position. One-lung ventilation was successfully achieved and the operative and postoperative course was uneventful.

Catheterization↗
PubMed2005

Successful management of cesarean section in a patient with Romano-Ward syndrome using landiolol, a selective and short-acting beta1 receptor antagonist.

Romano-Ward (R-W) syndrome is an autosomal dominant hereditary disorder and is characterized by a prolonged QT interval on the electrocardiogram (ECG), syncope, and sudden death. We report here a case of cesarian section in a patient with R-W syndrome whose QT prolongation was successfully managed with landiolol, a selective beta1 receptor blocker. A 25-year-old woman with R-W syndrome was scheduled for cesarean section. In the operating room, the patient's ECG showed tachycardia (102 beats x min(-1)) and marked QT prolongation (QTc = 0.56 s). After spinal anesthesia, the patient's heart rate (HR) increased to 130 beats/min accompanied by a slight decrease in arterial blood pressure to 97/57 mmHg and the QTc was prolonged to 0.57 s. Landiolol was continuously infused at a rate of 0.04 mg.kg(-1) x min(-1) and the HR gradually decreased to 80-90 beats x min(-1) accompanied by the normalization of QTc to 0.48 s. We thought that the use of landiolol was more rational and was preferable to a nonselective beta receptor blocker for a term-pregnant woman because blockade of the beta2 receptor might cause uterine contraction. After the use of landiolol, intraoperative and postoperative courses in both the patient and the baby were uneventful.

Adrenergic beta-Antagonists↗
PubMed2005

[Anesthesia for cesarean section in a patient with cor triatriatum].

Cor triatriatum is a rare congenital cardiac anomaly, in which left ventricular filling is impeded by obstructive membrane in the left atrium. We administered spinal anesthesia for cesarean section in a patient with cor triatriatum (type III A1) with congestive heart failure. We optimized hemodynamics with the aid of pulmonary artery cathter. In general, cor triatriatum involves similar hemodynamic profiles to mitral stenosis and thus tachycardia should be avoided during anesthesia. However, in our patient, increasing the heart rate to 80-90 beats x min(-1) was beneficial in maintaining adequate systemic blood pressure and cardiac output. Spinal anesthesia could be a method of choice for cesarean section in a patient with cor triatriatum when adequate hemodynamic monitoring is available.

Adult↗
PubMed2005

[Anesthetic management of an 18-trisomy neonate with high frequency ventilation].

Neonates with 18-trisomy syndrome have various anomalies including cardiac and facial anomalies. Active treatments for them have not been recommended due to a low survival over one year which is less than 10%. However, the survival over one year in our institute between 1985 and 2003 is higher at 22%, and we had a patient with survival of over 5 years. We report a case of anesthetic management in a male 18-trisomy neonate who received a radical repair of umbilical hernia immediately after his birth. Tracheal intubation was difficult due to small airway and facial anomalies; cleft clip, cleft palate, and macrognathia. Conventional ventilation was ineffective for elimination of carbon dioxide and oxygenation due to pulmonary hypoplasia and intra- and extra-cardiac shunts. A high frequency ventilation improved elimination of carbon dioxide and oxygenation.

Abnormalities, Multiple↗
PubMed2005

[Brain protection with mild hypothermia during carotid artery clamping].

A 71-year-old man was scheduled for removal of a Kirchner wire malpositioned in the mediastinum, which had been placed for fixing the fractured right clavicle five months before. Anesthesia was induced and maintained with propofol, fentanyl and vecuronium. The wire was found to be penetrating the brachiocephalic artery after sternotomy. An emergency angiography performed in the operating room showed that Willis arterial circle was sufficiently developed for clamping the brachiocephalic artery. The wire was removed under clamping the brachiocephalic artery for 9 minutes, but massive bleeding from the left common carotid artery continued, then the left common carotid artery was clamped and injured region was resected and reconstructed for 68 minutes. The body temperature was reduced to 32.5-33 degree with a cooling water mattress for brain protection and prostaglandin E1 was infused for vasodilation during hypothermia. Monitoring with somatosensory evoked potential was added during anesthesia. The surgery was performed uneventfully and the patient showed no neurological sequelae postoperatively.

Aged↗
PubMed2004

Pulmonary nodules at chest CT: effect of computer-aided diagnosis on radiologists' detection performance.

PURPOSE: To evaluate the effect of computer-aided diagnosis (CAD) on radiologists' detection of pulmonary nodules. MATERIALS AND METHODS: Fifty chest computed tomographic (CT) examination cases were used. The mean nodule size was 0.81 cm +/- 0.60 (SD) (range, 0.3-2.9 cm). Alternative free-response receiver operating characteristic (ROC) analysis with a continuous rating scale was used to compare the observers' performance in detecting nodules with and without use of CAD. Five board-certified radiologists and five radiology residents participated in an observer performance study. First they were asked to rate the probability of nodule presence without using CAD; then they were asked to rate the probability of nodule presence by using CAD. RESULTS: For all radiologists, the mean areas under the best-fit alternative free-response ROC curves (Az) without and with CAD were 0.64 +/- 0.08 and 0.67 +/- 0.09, respectively, indicating a significant difference (P <.01). For the five board-certified radiologists, the mean Az values without and with CAD were 0.63 +/- 0.08 and 0.66 +/- 0.09, respectively, indicating a significant difference (P <.01). For the five resident radiologists, the mean Az values without and with CAD were 0.66 +/- 0.04 and 0.68 +/- 0.04, respectively, indicating a significant difference (P =.02). At observer performance analyses, there were no significant differences in Az values obtained either without (P =.61) or with (P =.88) CAD between the board-certified radiologists and the residents. For all radiologists, in the detection of pulmonary nodules 1.0 cm in diameter or smaller, the mean Az values without and with CAD were 0.60 +/- 0.11 and 0.64 +/- 0.11, respectively, indicating a significant difference (P <.01). CONCLUSION: Use of the CAD system improved the board-certified radiologists' and residents' detection of pulmonary nodules at chest CT.

Adult↗
PubMed2004

[Propofol anesthesia for fetal sedation].

We were requested to reduce neonatal respiratory effort at delivery in anesthetic management for Cesarean section. A 26-year-old pregnant woman was suspected through abdominal ultrasound examination and amniotic fluid test, of her baby having immature lungs associated with remarkable pleural effusion. Lungs could be damaged by respiratory effort after delivery, and respiratory management immediately after delivery was planned. Anesthesia was induced with propofol and fentanyl 300 micrograms. Propofol was administered with a target controlled infusion setting with the target blood concentration of 10 micrograms.ml-1. Fetal electrocardiogram was monitored for detecting fetal sedation. The concentrations of propofol at delivery were 10.7 and 4.1 micrograms.ml-1 in maternal arterial and umbilical venous blood, respectively, and the baby was apneic. Respiration of the baby was managed with a high frequency jet ventilation mode, and 160 ml of pleural effusion was aspirated immediately after the delivery. The baby was discharged from the hospital 5 weeks afterward.

Adult↗
PubMed2004

[Airway obstruction during one-lung ventilation using a bronchial blocker and a tracheostomy tube].

We describe our experience with a 60-year-old man who had severe airway obstruction during one-lung ventilation with the tracheostomy tube using a bronchial blocker. The blocker, deriving from Univent tube, was passed through the tracheostomy tube and placed in the right main bronchus. We checked that the blocker was in appropriate place with a bronchofiberscope and obtained good one-lung ventilation with the patient in the left lateral position. However, just after the start of operation, when the skin was incised, sever hypoxia and resultant bradycardia and hypotension occurred, probably because of not only malposition of blocker but also atelectasis in the upper lobe of the dependent lung by secretion.

Airway Obstruction↗
PubMed2003

[Difficult tracheal intubation in a patient suspected of malignant hyperthermia].

We report anesthetic management of a patient suspected of malignant hyperthermia with difficult tracheal intubation. A 64-year-old man was scheduled for a fixation of humerus bone fractures in prone position. He had a history of difficult tracheal intubation due to masseter spasm, and his niece was suspected to be malignant hyperthermia. Anesthesia was induced with propofol using a target controlled infusion. No muscle relaxant was given and spontaneous breathing was maintained. Trials for tracheal intubation failed whenever using a standard laryngoscope, a bronchofiberscope, a laryngeal mask airway or an intubating laryngeal mask airway. Resecting the epiglottic elevating bar of an intubating laryngeal mask airway enabled fiberoptic tracheal intubation. No symptom suggesting malignant hyperthermia developed.

Anesthesia↗
PubMed2003

[Anesthesia for laparoscopic cryptorchidpexy in a patient with congenital myopathy].

A relatively high incidence of malignant hyperthermia (MH) and an unpredicted (usually increased) sensitivity to muscle relaxants are reported in patients with congenital myopathies (CM). We present a case of anesthetic management of a patient with a clinical diagnosis of CM. An 18-month-old, 11.3-kg, male patient, who had received a diagnosis of CM, was scheduled for the laparoscopic cryptorchidpexy. Anesthesia was induced with propofol and fentanyl, and the trachea was intubated without muscle relaxants. An epidural catheter was inserted via the sacral hiatus, the tip of which was located at the second lumbar level for a purpose of obtaining not only pain relief but also muscle relaxation. Anesthesia was maintained with propofol, nitrous oxide and fentanyl, combined with epidural anesthesia. The anesthetic course was uneventful with enough pain relief and good muscle relaxation.

Anesthesia, Epidural↗
PubMed2003

[Comparison of analgesic effects of intravenous flurbprofen and suppository indomethacin after laparoscopic cholecystectomy].

BACKGROUND: Epidural analgesia may not be necessary after laparoscopic cholecystectomy, but analgesics, such as non-steroidal anti-inflammatory drugs, may often be required postoperatively. There have been only a few studies comparing different NSAIDs in this situation. METHODS: After laparoscopic cholecystectomy under general anesthesia using intravenous propofol, nitrous oxide and fentanyl 3 micrograms.kg-1, 40 patients were randomly allocated to receive either intravenous flurbprofen 50 mg or suppository indomethacin 50 mg. Visual analogue scales of postoperative pain at 0, 10, 20, 30 and 60 min after surgery (at rest and at coughing), use of rescue analgesics, and the presence or absence of complications were recorded. RESULTS: Pain score at rest was markedly reduced (> 15% reduction from the baseline value) in 13 of 20 patients after injection of flurbiprofen and in five patients after indomethacin during the initial 60 min after surgery (P < 0.05), whereas there was no significant difference between the two groups for the pain score during coughing. There was no difference in the need of rescue analgesics within the initial 60 min, but the flurbiprofen group required significantly more rescue analgesics than the indomethacin group during 1-24 h after surgery (P < 0.005). The incidence of complications was low in both groups. CONCLUSIONS: Compared with suppository indomethacin, intravenous flurbiprofen is more effective in acute postoperative pain but the duration of its analgesic effect is shorter.

Acute Disease↗
PubMed2002

Anticonvulsant effects of sevoflurane on amygdaloid kindling and bicuculline-induced seizures in cats: comparison with isoflurane and halothane.

PURPOSE: We compared the anticonvulsant effects of sevoflurane with those of isoflurane and halothane in amygdaloid kindling and bicuculline-induced seizures in cats. METHODS: In a crossover design, the effects of 70% nitrous oxide, and 0.3, 0.6, and 1.5 minimum alveolar concentration (MAC) of volatile anesthetics were studied in five cats in which the amygdala was electrically stimulated at the current used for establishing the kindled state. The effects of 0.6 and 1.5 MAC of volatile anesthetics were studied in another five cats, in which 0.2 mg.kg(-1) of bicuculline was administered i.v.. RESULTS: In the amygdaloid kindling model, all four anesthetics decreased the duration of after-discharge (AD), the rise of multiunit activity in midbrain reticular formation (R-MUA), and the behavior scores compared with findings without anesthetics. Halothane, at 1.5 MAC, significantly decreased the number of cats showing AD ( P < 0.05). In the bicuculline-induced seizure model, all five cats showed repetitive spikes during 1.5 MAC of sevoflurane, whereas only two and three cats, respectively, showed the repetitive spikes during 1.5 MAC of isoflurane and halothane. All three volatile anesthetics decreased the rise of R-MUA, the duration of the repetitive spikes, and the behavior scores. The suppression of the rise in R-MUA and the behavior scores with 1.5 MAC of sevoflurane was significantly less than that with 1.5 MAC of isoflurane. CONCLUSION: The anticonvulsant effects of sevoflurane were less potent than those of halothane in the amygdaloid kindling model and less potent than those of isoflurane in the bicuculline-induced seizure model.

Journal Article↗
PubMed2002

[Anesthesia for a severe ankylosing spondylitis patient whose posture had been restricted to only sitting for over 20 years].

A 42-year-old woman with an Arnold-Chiari abnormality was scheduled for cervical spine surgery. She had severe ankylosing spondylitis, and all her joints from ankles to occipitocervical joint were fixed except hip joints, which had been replaced with artificial joints 20 years before. She could bend her upper body only in a range from -20 to 70 degree from the sitting position. Her posture had been restricted to only sitting for over 20 years, and she complained vertigo when positioned in supine position. The trachea was intubated with an aid of bronchofiberscopy under sedation in sitting position, and then anesthesia was induced with propofol and fentanyl. When she was turned to prone position, nasal bleeding was noticed and the surgery was performed in a modified sitting position. The intra- and post-operative course was uneventful. The present case indicates that long-term restriction only to sitting position modulates circulatory control in response to changing postures, and that preoperative evaluation for appropriate posture for surgery is mandatory.

Adult↗