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Biomedical subjects

K Shingu

Publications and source records attributed to K Shingu.

At least 37 records · Page 2Linked 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

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↗
PubMed2002

Analgesia for pelvic and perineal cancer pain by intrathecal steroid injection.

BACKGROUND: Corticosteroids are used systemically in patients with advanced cancer to alleviate pain. Intrathecal administration of steroids is rarely performed but analgesic effects of intrathecal steroids have been reported in animal studies. We administered betamethasone intrathecally in three cancer patients with uncontrollable pain. CASE REPORT: Intrathecal injection of betamethasone (1-4 mg) with saline (total volume = 2 mL) was performed in three patients with advanced pelvic or perineal cancer, in whom pain could not be controlled in spite of various analgesic therapies. After obtaining the patient's informed consent for the procedure, betamethasone was administered intrathecally through the L4/5 intervertebral space. Intrathecal betamethasone produced rapid analgesia within 10 min and subsequent long-lasting analgesia for 5 days or more. Sleep, appetite and activity improved. No adverse effects were observed in any of the patients. CONCLUSIONS: Intrathecal injection of betamethasone may be a useful approach in some patients with intractable cancer pain.

Adult↗
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↗
PubMed2001

Caudoputamen is damaged by hypocapnia during mechanical ventilation in a rat model of chronic cerebral hypoperfusion.

BACKGROUND AND PURPOSE: Postoperative brain dysfunction, such as delirium, is a common complication of anesthesia and is sometimes prolonged, especially in patients with cerebrovascular disease. In the present study we investigated the effect of hypocapnia during anesthesia on neuronal damage using a rat model of chronic cerebral hypoperfusion. METHODS: Chronic cerebral hypoperfusion was induced by clipping the bilateral common carotid arteries in male Wistar rats. Fourteen days after the operation, these animals were mechanically ventilated for 2 hours and then kept in suitable conditions for an additional 14 days. Twenty-four rats were assigned to 4 groups: those with chronic cerebral hypoperfusion with either hypocapnia or normocapnia during anesthesia, and those given sham operation with either hypocapnia or normocapnia. White matter lesions in the brain sections were evaluated with Klüver-Barrera staining. Proliferation of glial cells was estimated with the use of immunohistochemistry of glial fibrillary acidic protein, a marker for astroglia, and CD11b, a marker for microglia. Computer-assisted morphometry was applied to the immunohistochemical results of microtubule-associated protein 2 to evaluate the loss of neurons. RESULTS: The histological damage was localized almost exclusively in the white matter in the rats subjected to chronic cerebral hypoperfusion but without hypocapnia. Neuronal damage and astroglial proliferation occurred with aggravated white matter lesions in the caudoputamen in the rats with chronic cerebral hypoperfusion and hypocapnia. No lesions were observed in sham-operated rats with either hypocapnia or normocapnia. CONCLUSIONS: These results indicate that hypocapnia during anesthesia causes tissue damage in the caudoputamen, which may be responsible for long-lasting postoperative delirium in patients with stroke and/or dementia.

Anesthesia↗
PubMed2001

Case report: a normal capnogram despite esophageal intubation.

PURPOSE: To report a case of accidental esophageal intubation which could not be detected by capnography. CLINICAL FEATURES: A 43-yr-old man with osteogenic sarcoma of the mandible underwent mandibulectomy, radical neck dissection, reconstruction of the mandible and radiation therapy. He was scheduled for revision surgery to the mandible. He had a limited mouth opening and neck movement after operation and radiation. After the cuffed oropharyngeal airway (COPA) was inserted, anesthesia was induced with sevoflurane, and fibreoptic nasotracheal intubation attempted, but it was impossible to insert the fibrescope into the trachea because of a deformed larynx. While equipment for tracheostomy was prepared, one last attempt was made to insert the tube blindly into the trachea. The capnograph showed apparently normal carbon dioxide waveforms, and the reservoir bag inflated and deflated regularly. However, immediately after inflation of the cuff of the tracheal tube the reservoir bag movement stopped and CO(2) waveforms disappeared. Fibreoptic bronchoscopy showed that the tube was in fact in the esophagus. It was then noticed that the patient was still breathing spontaneously through the cuffed airway. The patient was awakened and tracheostomy performed. It was considered that egress of the expired gas was partially prevented by the cuffed airway, pooled in the oral cavity, aspirated down the esophagus during inspiration (likely to be due to negative intrathoracic pressure) and pushed out through the tube during expiration; inflation of the cuff prevented the gas entering the esophagus. CONCLUSION: Under such exceptional circumstances, apparently normal carbon dioxide waveforms were observed despite esophageal intubation in a spontaneously breathing patient.

Adult↗
PubMed2001

Effects of propofol and thiopental on the central nervous system during nociceptive stimulation in cats.

PURPOSE: Nociceptive stimulation may increase central nervous system (CNS) activity during anesthesia. However, it is not known whether propofol and thiopental have a similar inhibitory effect on the CNS during nociceptive stimulation. Therefore, we compared the antinociceptive effects of propofol and thiopental in cats. METHODS: In 12 cats, anesthesia was induced with 4% halothane in oxygen and maintained with 0.5% halothane in oxygen. The cortical electroencephalogram (EEG) and the electrical activity from the midbrain reticular neurons (R-MUA) were measured before and after sciatic nerve stimulation. The cats were then allocated to receive cumulative doses of either propofol (n = 6) or thiopental (n = 6) i.v. at 5-min intervals. Two minutes after each dose, the cortical EEG and the R-MUA were compared before and after sciatic nerve stimulation. RESULTS: Propofol and thiopental depressed the basal R-MUA to a similar degree at each dose. Sciatic nerve stimulation increased the R-MUA, and there were no differences in the maximum R-MUA values between propofol and thiopental. The cortical EEGs after each dose of anesthetic without stimulation showed similar patterns, and the patterns of change with stimulation were also similar for these two anesthetics. CONCLUSION: Propofol and thiopental have similar antinociceptive effects in cats.

Journal Article↗
PubMed2001

Tracheal intubation through the intubating laryngeal mask in patients with unstable necks.

BACKGROUND: In patients with unstable necks, the neck should be stabilized during induction of anaesthesia, but this may make tracheal intubation difficult. Awake intubation may produce straining, which could be detrimental to the unstable neck. METHODS: We studied 20 patients with unstable necks to examine the efficacy of insertion of the intubating laryngeal mask under conscious sedation (to minimize the possibility of losing a patent airway and to facilitate fibrescope-aided intubation) followed by tracheal intubation through the laryngeal mask after induction of anaesthesia (to reduce stress response to intubation). After the patient had been sedated with midazolam (up to 5 mg) and fentanyl (up to 100 microg), the intubating laryngeal mask was inserted. General anaesthesia was then induced with sevoflurane and tracheal intubation attempted. RESULTS: In all patients, tracheal intubation through the laryngeal mask succeeded without airway obstruction. Neither insertion of the mask under conscious sedation nor tracheal intubation after induction of anaesthesia caused straining, and only two patients moved upper extremities at intubation. Insertion of the laryngeal mask did not significantly alter blood pressure or heart rate. Tracheal intubation significantly increased blood pressure and heart rate, but the increase was considered to be small. CONCLUSIONS: In the patient with an unstable neck with a low risk of pulmonary aspiration, insertion of the intubating laryngeal mask while the patient is sedated may minimize difficulty in obtaining a patent airway before tracheal intubation and may facilitate a fibrescope-aided tracheal intubation; subsequent induction of anaesthesia before tracheal intubation may minimize stress response to intubation.

Adult↗