Morimasa Yamada

Continuous Urine Oxygen Tension Monitoring in Patients Undergoing Cardiac Surgery

OBJECTIVES To evaluate the effect of cardiopulmonary bypass (CPB) on urine oxygen tension (PuO2) and to determine whether perioperative PuO2 can predict postoperative renal dysfunction in patients undergoing cardiac surgery. DESIGN Prospective clinical study. SETTING A university research laboratory, a university-affiliated hospital. PARTICIPANTS Ninety-eight consecutive adult patients undergoing coronary artery bypass surgery or valvular surgery. INTERVENTIONS PuO2 was continuously measured by inserting a polarographic electrode into the urinary tube connected to a Foley catheter. MEASUREMENTS AND MAIN RESULTS PuO2 was constant before CPB and then progressively decreased after the start of CPB. It partially recovered at weaning from CPB but did not completely return to its original level until the end of surgery. Postoperative serum creatinine concentrations were significantly higher in patients whose PuO2 decreased after CPB, as compared with those whose PuO2 was constant or increased. The amplitude and the rate of recovery in PuO2 after CPB were significantly associated with peak values of postoperative serum creatinine concentrations. CONCLUSIONS These results suggest the possibility of PuO2 detecting an early stage of renal dysfunction in cardiac surgery, although further studies will be required to substantiate it.

Latent development of cardiac tamponade heralded by a progressive fall in hepatic venous hemoglobin oxygen saturation

Sir: Hepatic venous hemoglobin oxygen saturation (ShvO2) provides information concerning hepatic oxygen balance, and we routinely monitor it during and after hepatic resection [1]. A 67-year-old male, height 170 cm, weight 56 kg, was scheduled for right lobectomy of the liver for hepatocellular carcinoma and potential invasion into the inferior vena cava. Following induction of anesthesia, fiberoptic pulmonary artery catheters (Opticath model P 7110-EH, Oximetrix, USA) were inserted via the right internal jugular vein into the left hepatic vein and the pulmonary artery to measure ShvOz and mixed venous oxygen saturation (SvO~), respectively. Accurate placement of the catheter was guided by fluoroscopy. The readings of ShvOz and SvO 2 were calibrated by oxygen saturation values measured with a Co-oximeter (OSM-3, Radiometer, Denmark). Hepatic resection led to the detection of tumor invasion into the pericardium. Median sternotomy was performed and the extended tumor was excised. After surgery, the patient entered the intensive care unit with an endotracheal tube

Appropriate Tongue Blade Length of the Dingman Mouth Gag for Japanese Pediatric Patients With Cleft Palate and Mandibular Micrognathia

Objective Our objective is to determine appropriate specifications for smaller tongue blade for Japanese pediatric patients with cleft palate (CP) and mandibular micrognathia. Patients We investigated 59 patients who underwent palatoplasty. Patients were divided into two groups: the micrognathia (MG) group consisted of 11 patients and the normognathia (NG) group consisted of 48 patients. Interventions The following five items were investigated retrospectively: (1) gender, (2) cleft type, (3) age at the time of surgery, (4) weight at the time of surgery, and (5) distance from the tongue blade base to the posterior pharyngeal wall (Dis). Result There was a significant difference (P < .01) in age at the time of surgery and in Dis between groups, but not in weight. The minimum values were 55 mm for the MG group. As for correlations between age and weight at the time of surgery, the P values for the MG and NG groups were .993 and .052, respectively. As for correlations between weight at the time of surgery and Dis, the P values for the MG and NG groups were .987 and .099, respectively. Conclusions It was difficult to predict Dis on the basis of the patients age and weight measured preoperatively. The minimum Dis was 55 mm, equal to the length from the base to the tip of the Dingman Mouth Gag tongue blade currently in use, suggesting that a tongue blade of approximately 50 mm in length, shorter than the current minimum specifications, may be appropriate.

The use of obtuse needles in aspirating drugs from ampules in the practice of anesthesia

To the editor: Risks of needlest ick injuries and needle stickt ransmit ted diseases in the practice of anesthesia have been reported [1,2]. Many needleless or protected-needle devices have been developed to reduce the risk of infections [3,4]. However, there has been little debate over unnecessary use of acute needles in aspirating drugs from ampules. We use acute needles for t ranscutaneous access including venipuncture or arterial catheterization during the anesthetic induct ion period. Afterwards, drugs are administered and arterial blood samples are taken, usually through the stopcocks. At the moment there are few occasions when we have to use acute needles during anesthetic management . However, we are forced to use acute needles even in aspirating drug from ampules, because obtuse needles for that purpose are not yet available. Consequent ly we are liable to prick our fingers instead of aspirating the drug. To make matters worse, such a form of injury often occurs when haste is required in preparing the drug to help our patient. To reduce this type of unpleasant risk, we have developed the sterilized obtuse needle (Fig. 1). Al though the idea is very simple, it promises a lot of benefit to us and our occupational envi ronment . We recommend to anesthesiologists extensive use of this obtuse needle. It could cost much less than acute needles if large-scale product ion was under taken by manufacturers. Fig. 1. A n obtuse needle (21 gauge and 3.0cm length) and its cap

A device for tracheal tube during CO2 Laser irradiation in laryngomicrosurgery

We devised that the segment of commercially available defensor II tube coming in contact with the vocal cord was concaved. We used this new tube during CO2 laser irradiation in laryngomicrosurgery. We corned to the conclusion that it was much more superior to the conventional tube in safety and resistance of the material to CO2 laser irradiation and in increase of the operation field.