Kosuke Miura

Quantitative analysis of the relationship between sedation and resting energy expenditure in postoperative patients.

ObjectiveTo analyze quantitatively the relationship between sedation and resting energy expenditure or oxygen consumption in postoperative patients. DesignA prospective, clinical study. SettingAn eight-bed intensive care unit at a university hospital. PatientsThirty-two postoperative patients undergoing either esophagectomy or surgery of malignant tumors of the head and neck who required mechanical ventilation and sedation for ≥2 days postoperatively. InterventionsNone. Measurements and Main ResultsA total of 133 metabolic measurements were performed. Ramsay sedation scale (RSS), body temperature, and the dose of midazolam were evaluated at the time of the metabolic cart study. All patients received analgesia with buprenorphine at a fixed dose of 0.625 &mgr;g·kg−1·hr−1 continuously. Midazolam was used for induction and maintenance of intravenous sedation after admission to the intensive care unit. The initial dose was 0.04 mg·kg−1·hr−1 and was adjusted to achieve a desired depth of sedation at 3, 4, or 5 on the RSS every 4 hrs. The degree of sedation was classified into three states: light sedation (RSS 2–3; n = 49), moderate sedation (RSS 4; n = 39), and heavy sedation (RSS 5–6; n = 45). ResultsWith increasing the depth of sedation, oxygen consumption index (mL·min−1·m−2), resting energy expenditure index (REEI; kcal·day−1·m−2), and REE/basal energy expenditure (BEE) decreased significantly. Oxygen consumption index (mean ± sd), REEI, and REE/BEE were 151 ± 18, 1032 ± 120, and 1.29 ± 0.17 in the light sedation, 139 ± 22, 947 ± 143, and 1.20 ± 0.16 in the moderate sedation, and 125 ± 16, 865 ± 105, and 1.13 ± 0.12 in the heavy sedation, respectively. ConclusionAn increase in the depth of sedation progressively decreases in oxygen consumption index and REEI in postoperative patients.

Effects of traditional “Juci” (contralateral acupuncture) on orofacial nociceptive behavior in the rat

Purpose“Juci”, one of the traditional acupuncture techniques, means contralateral acupuncture; i.e., implanting a needle into an acupoint to treat a given disease or disorder, but on the side of the body opposite to the diseased side. The aim of this study was: (1) to assess acupuncture effects on formalin-induced nociceptive behavior in the orofacial region in the rat, and (2) to evaluate the efficacy of Juci in the orofacial formalin test.MethodsForty-four adult male Wistar rats were used in the present study. A 1.0% formalin solution (25 µl s.c., diluted in saline) was injected into the right upper lip. The rats were randomly assigned to five groups. (1) The control group (n = 9), which received formalin injection without acupuncture pretreatment; (2) the ipsilateral Ho-ku (see note below) acupuncture group (n = 10); (3) the contralateral Ho-ku acupuncture group (n = 11); (4) the acupuncture plus naloxone group (n = 9), where intraperitoneal naloxone (1.0 mg·kg−1) was injected immediately before acupuncture pretreatment; and (5) the sham acupuncture group (n = 5). “Ho-ku” is the term used for the “Large Intestine 4” acupoint, located between the first and second metacarpal bones.ResultsThe injection of formalin produced the characteristic biphasic behavioral response. Acupuncture significantly inhibited the response in the early and late phases. Naloxone significantly reversed these effects. There were no statistically significant differences between the ipsilateral and Juci acupuncture groups. Sham acupuncture did not exert any significant effect on the formalin-induced behavior.ConclusionOur results showed that the degree of effectiveness of Juci was similar to that of the ipsilateral acupuncture technique. Therefore, the Juci technique is also useful for the treatment of orofacial pain.

Admission microalbuminuria and neurologic outcomes in intensive care unit patients with spontaneous intracerebral hemorrhage.

This study was performed to determine the prevalence and the prognostic significance of microalbuminuria in patients admitted to intensive care unit (ICU) after spontaneous intracerebral hemorrhage (ICH). From May 2004 to April 2006, we studied 59 consecutive ICH patients verified using computed tomography and admitted to our ICU within a day after stroke. General clinical, neurologic data, and Glasgow Coma Scale (GCS) were recorded at admission to ICU. Urine was collected at admission to ICU for measuring the urinary microalbumin/creatinine ratio. At hospital discharge, neurologic outcome was assessed using Glasgow Outcome Scale. Among 59 patients, 37 (63%) had unfavorable neurologic outcomes (death, persistent vegetative state, and severe disability). The prevalence rate of microalbuminuria was 85% [95% confidence interval (CI), 76-94]. The areas under the receiver operator characteristic curves showed that the urinary microalbumin/creatinine ratio [0.81 (95% CI, 0.70-0.92)] and the GCS score [0.78 (95% CI, 0.66-0.90)] at admission were significant predictors of unfavorable neurologic outcome at hospital discharge. The threshold value, sensitivity, specificity, and likelihood ratio for the urinary microalbumin/creatinine ratio were 200 mg/g, 51% (95% CI, 39-64), 96% (95% CI, 90-100), and 11.3 (95% CI, 7.9-16.0); and those for the GCS score were 11, 46% (95% CI, 36-61), 96% (95% CI, 90-100), and 10.1 (95% CI, 7.2-14.1), respectively. This study confirmed a high prevalence of microalbuminuria in ICH patients in ICU, and suggested that the urinary microalbumin/creatinine ratio >200 mg/g was comparable to the GCS score <11 at admission to the ICU with regard to its prognostic characteristics after ICH.

Pneumothorax associated with epidural anesthesia.

paramedian approach at the level of the Th7–Th8 interspace. After contacting the vertebral lamina, the angle of the needle was adjusted to identify the epidural space. The Tuohy needle was directed at an angle of 45° to cephalad, and, presumably, less than 15° toward the midline. A loss-of-resistance technique, using a salinefilled glass syringe, detected a likely space at a depth of 6 cm from the skin. A test aspiration was done with the syringe to confirm negative blood or cerebrospinal fluid, when air was aspirated unexpectedly. At that moment, the patient leaned slightly toward the resident. Although no symptom of pneumothorax, such as respiratory distress or decreased breath sounds, was observed, the needle was withdrawn. The other, experienced, anesthesiologist tried to insert the epidural needle via the left paramedian approach at the level of the Th8–Th9 interspace after adjusting the patient’s position, but without changing it to another position. The Tuohy needle was introduced 1.0 cm laterally from the midline. After contacting the lamina, “walking” on the lamina facilitated the loss-of-resistance feeling obtained at a depth of 6cm from the skin. The angle of the needle was then about 45° to cephalad, and 15° toward the midline. A test dose of 3 ml of 2% lidocaine was injected from the epidural catheter. Bilateral Th7–Th9 thermal hypesthesia was confirmed 5min later with cold test. Subsequently, general anesthesia was induced with intravenous fentanyl, 100 μg; propofol, 90 mg; and vecuronium, 9 mg. To achieve left-sided one-lung ventilation during the right bullectomy, a single-lumen endotracheal tube with a bronchial blocker was intubated. Anesthesia during one-lung ventilation was maintained with sevoflurane, 70% oxygen in nitrogen and intravenous fentanyl, and appropriate oxygenation and carbon dioxide elimination were maintained. The anesthesia and operative procedure were then uneventful. A routine postoperative chest radiograph, to verify proper pulmonary expansion, was taken about 4h after the first attempt at inserting the epidural catheter, and it

Discrepancy between SpO2 and SaO2 in a patient with severe anemia.

Anesthesia was induced and maintained using fentanyl, nitrous oxide, and sevoflurane. Vecuronium was used to provide muscle relaxation. After the induction of anesthesia, rectal temperature was 34.2°C and SpO2 was 100% (M1025B; Hewlett Packard Andover, MA, USA). Laboratory data were as follows: FiO2, 0.4; Hb, 11.3g·dl 1; pH, 7.40; PCO2, 36.7mmHg; PO2, 245.5mmHg; and SaO2, 99.8% (ABL 300; Radiometer Copenhagen, Denmark). After the dura was opened, blood pressure decreased to 40/30mmHg, and SpO2 could not be detected. There was no clear bleeding observed in the operating field. Laboratory data were as follows: FiO2, 1.0; Hb, 4.4g·dl 1; pH, 7.41; PCO2, 25.0mmHg; PO2, 555.3mmHg; and SaO2, 100%. Phenylephrine was administered, and crystalloid and colloid solutions were infused quickly until blood transfusion was prepared. SpO2 values decreased gradually to the lowest reading of 76%. When SpO2 values were low with a clear plethysmograph waveform (Figs. 1 and 2), laboratory data were as follows: FiO2, 1.0; Hb, 2.0g·dl 1; pH, 7.28; PCO2, 37.6mmHg; PO2, 584.8mmHg; and SaO2, 100%. Significant hemorrhage, causing hemoglobin to drop from 11.3 to 2.0g·dl 1, was suspected to be due to retroperitoneal hemorrhage. After surgery the patient did not regain consciousness. There was no spontaneous respiration, no corneal reflex, and no eyelash reflex. The patient died on the ninth postoperative day.