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Biomedical subjects

C Miyake

Publications and source records attributed to C Miyake.

At least 37 records · Page 2Linked to original sources

[Anesthesia for Shy-Drager syndrome; effects of elastic bandage, phenylephrine, and IPPV].

A 57-year-old man with Shy-Drager syndrome underwent plastic surgery for decubitus on the buttocks under general anesthesia. Before induction of anesthesia, an elastic bandage was applied to the legs, and its effects were examined by raising the upper body. The fall in mean blood pressure decreased from 49% to 39%, and the symptoms of cerebral hypoxia disappeared. However, the induction of anesthesia with 5 mg diazepam, 0.05 mg fentanyl, and 100 mg thiamylal reduced blood pressure abruptly from 150/88 mmHg to 95/68 mmHg. Continuous infusion of phenylephrine was then started, and blood pressure became stable at around 150/90 mmHg. In this state, IPPV did not reduce the blood pressure in the supine position, and did not intensify its fall when the upper body was raised. Anesthesia was maintained with nitrous oxide 70% in oxygen, fentanyl and pancuronium. During the surgery, ventilation was controlled, and phenylephrine was infused at the rate of 5-15 micrograms.min-1 to maintain systolic blood pressure above 100 mmHg. Phenylephrine was infused during the two postoperative days, because blood pressure fell whenever the patient's posture was changed to prevent pressure on the operative site.

Anesthesia↗

Real-time analysis of the change in arterial oxygen tension during endotracheal suction with a fiberoptic bronchoscope.

An intra-arterial Clark-type polarographic oxygen electrode was used with a fiberoptic bronchoscope for real-time analysis of the PO2 change during 1 min of suction in patients spontaneously breathing oxygen. There was a strong correlation between values obtained from the intra-arterial electrode (PiO2) and those from blood samples (PaO2), before and at the end of suction; the PiO2/PaO2 ratio was close to one. Continuous PiO2 recordings during suction without supplemental oxygen showed little change in the early period of suction, followed by a steep drop continuing even after suction. This drop in PiO2 was partially attenuated by providing oxygen with high-frequency jet ventilation and was almost completely attenuated by the use of a suction adaptor. Changes in the inspired oxygen concentration indicated the importance of keeping this variable constant during suction to prevent hypoxemia.

Adult↗

Outward transport of fluorescein from the vitreous in aphakic eyes.

By administering fluorescein intravenously to 95 patients we calculated the ratio of fluorescein concentration in the vitreous at the time of its peak level compared with the estimated unbound concentration of fluorescein in the plasma at the same time. We studied 12 normal phakic and 83 aphakic eye approximately two months, one year, and more than two years after cataract extraction. All the eyes had undergone intracapsular cataract extraction or extracapsular cataract extraction, with or without posterior capsulotomy, because of senile cataract. The calculated ratio in patients with intracapsular and extracapsular lens extraction was statistically significantly reduced at two months and one year after cataract extraction and was normalised at more than two years after the operation in comparison with normal subjects. The ratio was statistically extracapsular extraction at two months and one year after surgery. Posterior capsulotomy had no effect on the ratio. The ratio, we considered, at least partially reflects the outward transport of fluorescein from the vitreous cavity. Although the findings reflect subclinical phenomena, they are of importance when considering postoperative sequelae. The posterior lens capsule, zonule, and intact anterior vitreous face may be essential for the anterior uvea to function in the outward transport of fluorescein from the vitreous cavity.

Aged↗

Intraoperative posterior chamber lens haptic fixation in the human cadaver eye.

The authors observed the intraoperative behavior of several posterior chamber lens (PCL) loops inserted in the human cadaver eye in a manner similar to an actual operation. The procedure was viewed under an operating microscope, and was filmed by a 16-mm movie camera. In PCLs with a length of 13-mm or more, which were originally designed for ciliary sulcus fixation, the first loop (usually the inferior loop) was easily inserted into the ciliary sulcus, but the second loop (usually the superior loop) was often misinserted into the posterior capsule. Neighboring tissues sometimes were accidentally traumatized during maneuvers to correct lens decentration. In PCLs with shorter loops, which were designed for capsular bag fixation, both loops could always be placed securely in the bag. When we compared the C-loop and the J-loop, the former was found to be excellent in its flexible nature of the loop.

Aged↗

[Intraoperative dual-mode independent lung ventilation for open-chest surgery: conventional volume-set ventilation in healthy lung and high frequency jet ventilation in diseased lung].

An effort by the anesthesiologist to maintain adequate ventilation during thoracic surgery is sometimes disturbing for the operative procedures of the surgeon. Unilateral ventilation with a large tidal volume, leaving the operative site unventilated, may provide an adequate and quiet operative field, but is opposed by the problem of disturbance in pulmonary gas exchange. The application of high frequency jet ventilation has recently been introduced to solve these problems. However, the disadvantage inherent to this technique is the tendency to produce carbon dioxide retention although it provides adequate oxygenation. In the present study, using a double lumen endobronchial tube, the large-tidal volume ventilation of the non-operative site and the high frequency jet ventilation with small tidal volume of the operative site were performed simultaneously. This technique provided the satisfactory condition of operative field, i.e., "quiet lung". Also, the serial gas analysis of the arterial and mixed venous blood samples indicated the satisfactory condition of pulmonary gas exchange.

Aged↗