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Biomedical subjects

K Shingu

Publications and source records attributed to K Shingu.

At least 55 records · Page 3Linked to original sources
PubMed2001

Leakage of fluid around high-volume, low-pressure cuffs apparatus A comparison of four tracheal tubes.

We studied the ability of high-volume, low-pressure tracheal tube cuffs (Portex Soft Seal, Portex Profile, Mallinckrodt Lo-Contour and Mallinckrodt Hi-Lo tubes) to prevent leakage of fluid into the airway, in a model trachea and lung. Five tubes (7.0 and 8.0 mm internal diameter) of each type were used. Each tube was inserted into the model trachea and the cuff inflated until the intracuff pressure reached either 20, 30 or 40 cm H2O. The model lung was ventilated with a tidal volume of 700 ml and respiratory rate of 14 breath.min-1 at a compliance of 20 cm H2O. Ten millilitres of 0.01% methylene blue solution were infused over the cuff and the volume of fluid leaking past the cuff over 5 min was measured. The leak volume for the Soft Seal tube was less than that for the Profile or Lo-Contour tubes at all intracuff pressures (all p<0.05). Compared with the Hi-Lo tube, the volume leaking past the cuff for the Soft Seal tube was greater at an intracuff pressure of 20 cm H2O (p<0.05), whereas there was no significant difference between these two tubes at an intracuff pressure of 30 or 40 cm H2O. We conclude that the cuff of the Portex Soft Seal tube prevented leakage of fluid significantly more than that of the Portex Profile or Mallinckrodt Lo-Contour tubes, and to a similar degree to that of the Mallinckrodt Hi-Lo tube.

Equipment Design↗
PubMed2001

Evaluation of the disposable Vital View laryngoscope apparatus.

The Vital View laryngoscope (Vital Signs, NJ, USA) consists of a plastic disposable blade containing a fibrelight and a non-disposable handle; there is therefore no need to sterilise the blade and no concern about disintegration of the fibrelight. In a random cross-over design, we compared the Vital View laryngoscope with a conventional metal fibrelight laryngoscope (Welch Allyn, NY, USA) in 100 patients. The Vital View laryngoscope produced a brighter field than the metal laryngoscope (p < 0.001), whereas there was no significant difference in the view of the glottis or the success rate of tracheal intubation. In no patient did any problem occur, such as damage to the laryngoscope blade or loss of light during laryngoscopy. In another 10 patients, prevention of light emission from the side of the laryngoscope blade reduced the brightness (p < 0. 01). This indicated that the brightness of the Vital View laryngoscope is produced by light emission not only from the tip of the blade but also from the side of the blade. Therefore, the disposable Vital View laryngoscope can be used as effectively as a conventional non-disposable laryngoscope.

Adolescent↗
PubMed2001

The rate of tumour growth does not distinguish between malignant and benign thyroid nodules.

OBJECTIVE: To clarify whether or not the rate of tumour growth is a useful measure for distinguishing papillary thyroid cancer from benign nodules. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. SUBJECTS: Fourteen patients with 27 nodules (<20 mm) followed up for 20 months or more. INTERVENTIONS: High resolution ultrasonography (US). MAIN OUTCOME MEASURE: Growth rate. RESULTS: There were 15 papillary thyroid cancers and 12 benign nodules. The median tumour diameters at the first and the last US examination were 9.0 mm (range 6-19) and 9.0 mm (range 5-21) in papillary thyroid cancers followed up for 37 months (range 21-85), and 11.5 mm (range 4-19) and 11.5 mm (range 5-23) in benign nodules followed up for 38 months (range 20-84), respectively. CONCLUSION: The rate of growth of thyroid nodules as documented by ultrasound did not prove to be useful in distinguishing between malignancy and benign disease of small thyroid nodules (<20 mm).

Adult↗
PubMed2001

Xenon inhibits but N(2)O enhances ketamine-induced c-Fos expression in the rat posterior cingulate and retrosplenial cortices.

Both nitrous oxide (N(2)O) and xenon are N:-methyl-D-aspartate receptor antagonists that have psychotomimetic effects and cause neuronal injuries in the posterior cingulate and retrosplenial cortices. We investigated the effect of xenon, xenon with ketamine, N(2)O, and N(2)O with ketamine on c-Fos expression in the rat posterior cingulate and retrosplenial cortices, a marker of psychotomimetic effects. Brain sections were prepared, and c-Fos expression was detected with immunohistochemical methods. A loss of microtubule-associated protein 2, a marker of neuronal injury, was also investigated. The number of Fos-like immunoreactivity positive cells by ketamine IV at a dose of 5 mg/kg under 70% N(2)O (128 +/- 12 cells per 0.5 mm(2)) was significantly more than those under 30% (15 +/- 2 cells per 0.5 mm(2)) and 70% xenon (2 +/- 1 cells per 0.5 mm(2)). Despite differences in c-fos immunoreactivity, there was no loss of microtubule-associated protein 2 immunoreactivity in any group examined. Xenon may suppress the adverse neuronal effects of ketamine, and combined use of xenon and ketamine seems to be safe in respect to neuronal adverse effects.

Animals↗
PubMed2001

Propofol depressed neutrophil hydrogen peroxide production more than midazolam, whereas adhesion molecule expression was minimally affected by both anesthetics in rats with abdominal sepsis.

The treatment of sepsis may require mechanical ventilation of the lungs and sedation. Because neutrophils are the most important effector cells for protecting against sepsis, and propofol and midazolam are the most widely used anesthetics for sedation, we studied the effects of these two anesthetics on the neutrophil function during sepsis. Sepsis was induced in rats by cecal ligation and puncture. At either 4 h or 24 h after cecal ligation and puncture, blood and peritoneal neutrophils were obtained, incubated with the test anesthetics, and the hydrogen peroxide (H(2)O(2)) production and CD11b/c expression were determined by flow cytometry. In both early (at 4 h) and late (at 24 h) sepsis, propofol and midazolam depressed H(2)O(2) production by blood and peritoneal neutrophils at clinical concentrations. Propofol caused more depression than midazolam (P < 0.005). In both early and late sepsis, the effect of the anesthetics on the up-regulation of the stimulation-induced CD11b/c expression on blood neutrophils was minimal at clinical concentrations. If these results ultimately become clinically relevant, midazolam may be preferable to propofol for sedation during sepsis.

Anesthetics, Intravenous↗
PubMed2001

[A case of diaphragmatic paralysis in a patient with diabetes mellitus after surgery in prolonged prone position].

A 56-year-old woman with diabetes mellitus was scheduled for bilateral kidney lithotomy. She was in the prone position for about seven hours during operation. At the end of operation, arterial blood gas analysis showed PaO2 64 mmHg and PaCO2 44 mmHg under 100% oxygen inhalation through a face mask, and the chest x-rays showed elevation of the right diaphragm. Her trachea was intubated again. The right diaphragm returned to the preoperative level by positive pressure ventilation on supine position. Hypoxemia disappeared when the patient was placed in the sitting position, and the trachea was extubated. The right diaphragm returned to the normal level on the 1st postoperative day, but hypoxia continued until the 6th postoperative day with the patient on supine position. We speculate that the diaphragmatic paralysis was caused by over-extension of the neck for a prolonged period, and that the patient might have been susceptible to nerve injury due to underlying diabetes mellitus.

Diabetes Complications↗
PubMed2001

[A case of atropine-resistant bradycardia in a patient on long-term lithium medication].

A 44-year-old woman was scheduled for laparoscopic cholecystectomy and partial thyroidectomy. She had received lithium, 400-1200 mg daily, and other antidepressants for 10 years for her depressive disorder. Preoperative examination revealed a swelling of the right thyroid associated with hypothyroidism. Her heart rate was in the range of 45-70 min-1 preoperatively. After induction of anesthesia with propofol 50 mg, and fentanyl 100 micrograms, heart rate decreased to 36 min-1 and remained low after tracheal intubation. Atropine sulfate 1.1 mg in divided doses, and ephedrine 4 mg i.v. did not change the heart rate. However, a bolus of isoproterenol 0.02 mg i.v. increased the heart rate to 95 min-1. We suspect that atropine-resistant bradycardia was due to sinus node dysfunction produced by interaction of chronic lithium treatment, fentanyl and propofol. Therefore, an intractable sinus node dysfunction may occur in a patient in whom lithium is given chronically, particularly in whom hypothyroidism is associated. In such a patient, a beta-adrenergic stimulant may be effective in treating bradycardia.

Adult↗
PubMed2000

The effect of ketamine isomers on both mice behavioral responses and c-Fos expression in the posterior cingulate and retrosplenial cortices.

Ketamine, a non-competitive NMDA receptor antagonist, is a racemic mixture. S(+) ketamine is presumed to be more potent as an anesthetic than R(-) ketamine, and causes less postanesthetic stimulation of locomotor activity than R(-) ketamine in animals at equihypnotic doses. In the present study, we investigated the effect of S(+), R(-), and racemic ketamines on mice behavioral responses and c-Fos expression in the posterior cingulate and retrosplenial cortices (PC/RS), which are suggested to be the brain regions responsible for NMDA-receptor-antagonist-induced psychotomimetic activity. Ataxia and head weaving and c-Fos expression in the PC/RS were significantly more induced by both S(+) and racemic ketamines than by R(-) ketamine at the same dose. S(+) ketamine induced significantly more potent ataxia than racemic ketamine at the same dose. Ketamine-induced c-Fos expression in the PC/RS correlated well with the intensity of behavioral responses. These results imply that R(-) ketamine is weaker than both S(+) and racemic ketamines in a psychotomimetic effect. Also, S(+) ketamine is more potent than racemic ketamine in a psychotomimetic effect and possibly in an anesthetic effect. They also indicate that PC/RS is at least one of the specific brain regions responsible for ketamine-induced behavioral responses in animals and a psychotomimetic activity in humans.

Animals↗
PubMed2000

Intubating laryngeal mask for fibreoptic intubation--particularly useful during neck stabilization.

PURPOSE: To assess the ease of fibrescope-assisted tracheal intubation while the patient's head and neck were placed in the neutral or the manual in-line position, and to determine if the intubating laryngeal mask facilitated fibreoptic intubation in these positions. METHODS: In 84 patients, the patient's head and neck were placed in the neutral position (pillow placed under occiput), and in another 40 patients the head and neck were stabilized by the manual in-line method (no pillows under occiput). In both groups, after induction of anesthesia with 2.0-2.5 mgxkg(-1) propofol, 50-100 microg fentanyl and 1.0 mgxkg(-1) vecuronium, patients were allocated randomly into two groups: in Group C tracheal intubation was attempted using only a fibrescope, whereas in Group L fibreoptic intubation through the intubating laryngeal mask was attempted. RESULTS: In group C the success rate of fibreoptic tracheal intubation within two minutes was higher in the neutral position (31 of 42 patients (73%)) than in the manual in-line position (8 of 20 patients (40%)). In contrast, in group L the success rate was similar between the two positions. Tracheal intubation was easier in group L than in group C (P < 0.01 or 0.001) and the time for intubation was shorter in group L than in group C in both head and neck positions. CONCLUSIONS: Fibreoptic tracheal intubation was more difficult in the manual in-line position than in the neutral position. The intubating laryngeal mask facilitated fibreoptic intubation in both positions.

Anesthesia, Inhalation↗
PubMed2000

Failed tracheal intubation using a laryngoscope and intubating laryngeal mask.

PURPOSE: To report unexpected failed tracheal intubation using a laryngoscope and an intubating laryngeal mask, and difficult ventilation via a facemask, laryngeal mask and intubating laryngeal mask, in a patient with an unrecognized lingual tonsillar hypertrophy. CLINICAL FEATURES: A 63-yr-old woman, who had undergone clipping of an aneurysm seven weeks previously, was scheduled for ventriculo-peritoneal shunt. At the previous surgery, there had been no difficulty in ventilation or in tracheal intubation. Her trachea remained intubated nasally for 11 days after surgery. Preoperatively, her consciousness was impaired. There were no restrictions in head and neck movements or mouth opening. The thyromental distance was 7 cm. After induction of anesthesia, manual ventilation via a facemask with a Guedel airway was suboptimal and the chest expanded insufficiently. At laryngoscopy using a Macintosh or McCoy device, only the tip of the epiglottis, but not the glottis, could be seen, and tracheal intubation failed. There was a partial obstruction during manual ventilation through either the intubating laryngeal mask or conventional laryngeal mask; intubation through each device failed. Digital examination of the pharynx, after removal of the laryngeal mask, indicated a mass occupying the vallecula. Lingual tonsillar hypertrophy (1 x 1 x 2 cm) was found to be the cause of the failure. Awake fibrescope-aided tracheal intubation was accomplished. CONCLUSIONS: Unexpected lingual tonsillar hypertrophy can cause both ventilation and tracheal intubation difficult, and neither the laryngeal mask nor intubating laryngeal mask may be helpful in the circumstances.

Anesthesia, Inhalation↗
PubMed2000

The likely transformation of papillary thyroid carcinoma into anaplastic carcinoma during postoperative radioactive iodine-131 therapy: report of a case.

We report herein a case of papillary carcinoma which appeared to transform into anaplastic carcinoma during postoperative radioactive iodine-131 (131I) therapy. A 67-year-old man who was diagnosed as having papillary thyroid carcinoma with bilateral neck lymph node involvement and multiple lung metastases underwent total thyroidectomy prior to 131I therapy. Immediately after a second course of 131I therapy, the patient complained of right neck pain and swelling, and a biopsy of the swollen neck lymph node was taken. Histologic examination of this biopsy specimen revealed anaplastic carcinoma. With p53 immunohistochemical staining, both the primary tumor and the biopsy specimen were positive. We speculate that first, some DNA damage in tumor cells was induced by the initial 131I therapy, but neither DNA repair nor cell apoptosis occurred because the p53 gene was already mutated; then further DNA damage was induced by the second 131I therapy, leading to anaplastic transformation.

Aged↗
PubMed2000

Solitary brain metastasis from papillary thyroid carcinoma in a patient with depression: report of a case.

Papillary carcinoma of the thyroid is a common thyroid malignancy with a relatively good prognosis. However, distant metastases may develop and become threatening, particularly to older patients, in a more aggressive manner. We report herein the clinical, radiological, and pathological findings of a patient with papillary thyroid carcinoma who had a solitary cerebral metastasis. The patient had been suffering from depression and had already undergone a hemithyroidectomy for primary thyroid carcinoma, and was known to have metastatic thyroid carcinoma of the lungs and bone. After the removal of the remnant thyroid gland prior to radioiodine (131I) therapy, he developed additional problems related to depression. Electroencephalography played an important role in identifying suspected brain metastasis and computed tomography demonstrated a space-occupying lesion in the left cerebral hemisphere. Consequently, an early removal of intracranial mass could be performed without any further life-threatening complications. Moreover, after removal of the brain mass the patient's depression improved immediately without the use of any antidepressants. This case report indicates the possibility that a patient's depression might be associated with brain metastasis from papillary thyroid carcinoma, and also suggests that an early diagnosis with the appropriate surgical management of a brain metastasis followed by radioiodine therapy could be valuable for achieving a prolonged disease-free period.

Bone Neoplasms↗