Takahisa Mayumi

Comparison of tympanic, esophageal and blood temperatures during mild hypothermic cardiopulmonary bypass : A study using an infrared emission detection tympanic thermometer

ObjectiveTympanic temperature can be obtained instantaneously using an infrared emission detection (IRED) thermometer. Its accuracy has been documented in a variety of clinical settings, but its performance at low body temperatures is still unknown. In this study we evaluated its performance during coronary artery revascularization surgery in which mild hypothermic cardiopulmonary bypass (CPB) was used.MethodsThirty adult patients undergoing coronary artery bypass graft surgery were enrolled in the study. Tympanic temperature obtained using IRED thermometry (Tt1) was compared with core temperatures from the esophagus (Te), and venous blood of CPB (Tv) before, during, and after CPB. We also measured tympanic temperature using a thermocouple probe (Tt2) in 16 of the 30 patients in order to study the agreement between the two methods. Values for correlation coefficients and limits of agreement were computed to assess the degree of agreement among the temperatures obtained.ResultsThe highest agreement with Tv during CPB was obtained from Tt1 (r = 0.94, 0.41 ± 1.73, limits of agreement) and from Te (0.91, 0.36 ± 2.46). Tt1 also showed good agreement with Tt2 during surgery.ConclusionsInfrared tympanic thermometry is a reliable, alternative method to measure tympanic temperature and may be useful to assess core temperature in both normothermic and mild hypothermic conditions.

End-tidal CO2 changes under constant cardiac output during cardiopulmonary resuscitation

To evaluate a) whether end-tidal CO2 values change under constant cardiac output during cardiopulmonary resuscitation (CPR), and b) what factors are responsible for the change. Design:A cohort study. Setting:University research laboratory. Subjects:Nine mongrel dogs. Interventions:Ventricular fibrillation was electrically induced. After 2 mins, open-chest cardiac massage was initiated to maintain cardiac output at 0.2 L/min (23% of baseline cardiac output) by the measurement of blood flow with an electromagnetic flow probe on the ascending aorta. The cardiac massage was kept constant until 50 mins after the induction of ventricular fibrillation. Measurements and Main Results:Before and during ventricular fibrillation, end-tidal CO2, minute volume of alveolar ventilation, and CO2 excretion were continuously monitored. Blood gases and oxygen saturation values were also measured in arterial and the mixed venous blood samples. CO2 content was calculated. After induction of ventricular fibrillation, end-tidal CO2 decreased and thereafter continued to increase until the end of the experiment. Two mechanisms may have contributed to the early reduction in end-tidal CO2. One mechanism is a further decrease in CO2 excretion compared with the reduction in alveolar ventilation and the other is an increase in alveolar deadspace (estimated from the increase in the difference between Paco2 and end-tidal CO2). The subsequent increase in end-tidal CO2 was mainly due to a change in CO2 excretion. There are two hypotheses concerning the subsequent increase in CO2 excretion: the increase in pulmonary capillary blood flow (estimated from the change in the arteriovenous C02 content gradient) and the increase in CO2 production itself. Conclusions:End-tidal CO2 changes under constant cardiac output during CPR. When end-tidal CO2 is used to estimate the effectiveness of the cardiac massage, this type of change must be recognized. (Crit Care Med 1993; 21:1572–1576)

Serum and urine inorganic fluoride levels following prolonged low-dose sevoflurane anesthesia combined with epidural block

STUDY OBJECTIVES To determine whether serum and urine inorganic fluoride levels with prolonged (more than 7 hours) low-dose (0.8 to 2.0 vol %) sevoflurane anesthesia plus epidural anesthesia were increased as compared with isoflurane anesthesia plus epidural anesthesia. To measure the urine tubular enzymes N-acetyl-beta-glucosaminidase (NAG), alpha 1-microglobulin (alpha 1-M), and beta 2-microglobulin (beta 2-M) for renal tubular injury in both groups. DESIGN Randomized, prospective study. SETTING University hospital. PATIENTS 15 ASA physical status I and II adults (7 males, 8 females) who were scheduled for prolonged laparotomy (lasting 9.5 to 10.2 hours) with general anesthesia. MEASUREMENTS AND MAIN RESULTS Epidural anesthesia was administered before induction of general anesthesia. General anesthesia was induced with thiamylal administered intravenously (IV), and the trachea was intubated following administration of vecuronium IV. It was maintained with either sevoflurane or isoflurane in nitrous oxide and oxygen. Standard monitoring was used in all patients. Serum and urine inorganic fluoride and urine tubular enzymes were measured periodically. Serum inorganic fluoride was 54 mumol/L at 4.3 minimum alveolar concentration (MAC) hours of sevoflurane; the peak level for isoflurane was 8 mumol/L at the same MAC hours. Sevoflurane also increased urine inorganic fluoride excretion to 96 mumol/hr 8 hours. NAG excretion started to increase after inhalation of either sevoflurane or isoflurane. alpha 1-M and beta 2-M excretion increased markedly postoperatively. Even though fluoride levels and tubular enzymes were high, there was no evidence of postoperative renal dysfunction. CONCLUSIONS There was no increase in urinary enzymes, which are indicators of tubular injury, specific to sevoflurane. There was no postoperative renal dysfunction, as indicated by unchanged serum creatinine and blood urea nitrogen levels.

Acetic Acid Intoxication by Rectal Administration

The enhanced toxicity of acid instilled directly into the rectum, without benefit of dilution and neutralization in the upper intestine, is evident in a case of acetic acid intoxication by accidental rectal administration of 50 mL of 9% acetic acid to a 5-year-old boy. The complications included necrosis of the colon, acute renal failure, acute liver dysfunction, disseminated intravascular coagulopathy (DIC) and sepsis.

Bleeding induced interleukin-6 decreases blood loss via activation of coagulation.

Hemorrhage is known to induce the production of inflammatory cytokines such as interleukin-6 (IL-6). IL-6 plays an intermediate role as a factor in the activation of coagulation cascade and exerts a lethal effect in sepsis. To examine the effect of endogenous IL-6 on blood loss, we performed four experiments in female ddY mice. Enzyme immunoassay using an uncontrolled hemorrhage model, i.e., 75% tail resection, revealed the production of serum IL-6 (Experiment 1). We also measured cumulative blood loss and survival rate (Experiment 2); measured blood pressure and performed thrombelastogram (TEG) (Experiment 3); and measured plasma thrombin-antithrombin III (TAT) complex levels in two groups, one pretreated with 1 mg of anti-IL-6 monoclonal antibody (mAb), and one with normal rat globulin (NRG) using the same model (Experiment 4). The mAb group showed a significantly higher blood loss than the NRG group. All mice survived for 5 days in both groups. Blood pressure did not differ between either group. The TEG results suggest that administration of anti-IL-6 mAb caused mild suppression of coagulation activation, but did not affect fibrinolysis or platelets. In the mAb group, plasma TAT complex concentrations showed a significant decrease compared with the NRG group. In conclusion, hemorrhage-induced IL-6 may contribute to hemostasis through activation of coagulation, thus reducing blood loss.

Traumatic aneurysm of the internal jugular vein causing vagal nerve palsy: a rare complication of percutaneous catheterization.

percutaneous catheterization of the internal jugular vein (IJV) has been used widely for A placement of central venous catheters (1). However, this technique has been associated occasionally with several complications including hematoma formation, pneumothorax, aortic dissection, hemothorax, and air embolization (2-5). Recently, we encountered a patient who developed traumatic aneurysm of IJV causing vagal nerve palsy after percutaneous catheterization. Surgical removal of the aneurysm was necessary for complete improvement of this palsy. Although the pseudoaneurysm of the carotid and vertebral artery after IJV catheterization has been reported (6,7), this is the first report describing aneurysm of IJV.

Does a lidocaine patch reduce the pain at venous cannulation in adults

In this study we evaluated whether a lidocaine patch reduces the pain relating to a venous cannulation in adults. The patch is consisted of the base containing 50% lidocaine on a thin polyester membrane. Its surface area is 15 cm2. Twenty-six adult patients scheduled for elective surgery (11 males and 15 females) were randomly divided into two groups according to application periods: Group A for 15 min and Group B for 30 min. Either the dorsal part of the hand or the radial side of the wrist was chosen and covered with the patch. Pain assessment was made by patients using a 0–100 point visual analog scale (VAS). In 7 patients of Group A, plasma lidocaine levels were measured 15 min after application by homogeneous enzyme immunoassay. The levels were further measured 30 and 60 min after application in 3 of those patients. The mean VAS score was 28.4±13.1 (mean ± SD) for Group A and 51.8±15.9 for Group B, and the difference was statistically significant (P<0.05). Plasma lidocaine levels were always below 0.2 μg·m−1. The results indicate that the skin was partially anesthetized by the lidocaine patch. A lidocaine patch may be useful and safely applicable for venous cannulation in adult patients.

Oral clonidine relieved postoperative pain after pheochromocytoma resection

Clonidine is a selective agonist for a2-adrenoceptors, with a ratio of 200:1 (c~2: cd). Many desirable effects in anesthesia have been studied extensively: sedation, anxiolysis, perioperative hemodynamic stability, and a reduction in the requirements for opioid and anesthetic agents [1]. We present a patient whose postoperative pain management after pheochromocytoma resection was difficult and who obtained complete pain relief by oral administration of clonidine.

Continuous Thermographic Determination of Myocardial Ischemic Area in Dogs

In an acute phase of myocardial infarction, size of the ischemic area may change depending on the collateral blood flow. Because the ischemic area of the myocardium is colder than normal surrounding tissue due to the decreased blood supply, the cold area can be identified by thermographic imaging. We have applied the thermographic identification of the cold area to an acute myocardial infarction model in dogs, and developed the system for continuous and realtime evaluation of the blood flow on an ischemic myocardium together with the hemodynamic changes.