Pupil reactivity can be used to evaluate central nervous system function and can be measured using a quantitative pupillometer. However, whether anesthetic agents affect the accuracy of the technique remains unclear. We examined the effects of anesthetic agents on pupillary reactivity. Thirty-five patients scheduled for breast or thyroid surgery were enrolled in the study. Patients were divided into four groups based on the technique used to maintain anesthesia: a sevoflurane-remifentanil (SEV/REM) group, a sevoflurane (SEV) group, a desflurane-remifentanil (DES/REM) group, and a propofol-remifentanil (PRO/REM) group. We measured maximum resting pupil size (MAX), reduction pupil size ratio (%CH), latency duration (LAT) and neurological pupil index (NPi). A marked reduction in MAX and %CH compared with baseline was observed in all groups, but LAT was unchanged during surgery. NPi reduced within the first hour of surgery in the SEV/REM, SEV, and DES/REM groups, but was not significantly different in the PRO/REM group. Compared with the PRO/REM group, mean %CH and NPi in patients anesthetized with SEV/REM, SEV or DES/REM were markedly lower at 1 h after surgery had commenced. There was no correlation between NPi and bispectral index. Fentanyl given alone decreased pupil size and %CH in light reflex, but did not change the NPi. NPi was decreased by inhalational anesthesia not but intravenous anesthesia. The difference in pupil reactivity between inhalational anesthetic and propofol may indicate differences in the alteration of midbrain reflexs in patients under inhalational or intravenous anesthesia.
Pulmonary artery temperature measurement is recommended to estimate brain temperature during deep hypothermic cardiopulmonary bypass, even if it is conducted with the sternum opened; however, caution needs to be exercised in interpreting its measurements during periods of the cardioplegic solution infusion.
1 An unsaturated fatty acid, leukotriene C 4 (LTC 4 ), has a potent contractile eect on human airway smooth muscle, and has been implicated in the pathogenesis of human asthma. Using frontsurface¯uorometry with fura-PE3, the eect of LTC 4 on the intracellular Ca 2+ concentration ([Ca 2+ ] i ) and tension were investigated in porcine tracheal smooth muscle strips. 2 The application of LTC 4 induced little or no contraction despite a small and transient increase in [Ca 2+ ] i . In the presence of LTC 4 , however, the contractions evoked by high K + depolarization or a low concentration of carbachol (CCh) were markedly enhanced without inducing any changes in the [Ca 2+ ] i levels, thus indicating that LTC 4 increases the Ca 2+ responsiveness of the contractile apparatus. This LTC 4 -induced increase in Ca 2+ responsiveness could partly be reproduced in the permeabilized preparation of tracheal smooth muscle strips. 3 The LTC 4 -induced enhancement of contraction was accompanied by an increase in myosin light chain (MLC) phosphorylation and was blocked by a rho kinase inhibitor (Y-27632), but not by either a PKC inhibitor (calphostin C) or a tyrosine kinase inhibitor (genistein). 4 These results indicated that, in porcine tracheal smooth muscle, LTC 4 enhances the contraction by increasing the Ca 2+ responsiveness of the contractile apparatus in a MLC phosphorylation dependent manner, possibly through the activation of the rho-rho kinase pathway.
Sugammadex can rapidly reverse NMB after continuous infusion of rocuronium in patients with liver dysfunction undergoing hepatic surgery. Sugammadex was found to be safe and well tolerated. However, further studies of sugammadex under similar conditions should be conducted involving a large number of patients with liver dysfunction undergoing hepatic surgery.
Introduction: To examine whether sex and polymorphisms of cytochrome P450 (CYP) 2B6 and UDPglucuronosyltransferase (UGT) 1A9 affect the difference between predicted and measured plasma propofol concentration during continuous infusion by target-controlled infusion.Results: Blood samples of 69 patients (48 men and 21 women) were obtained at 4 h after initial propofol infusion. Percentage performance error (PE) was calculated to assess the difference between measured and predicted propofol concentration. Regression coefficients (β) and 95% confidence intervals (CI) of sex and the polymorphisms of CYP2B6 and UGT1A9 for PE were, separately and mutually, estimated with linear regression. Covariates included age and body mass index in the minimal adjusted model, and additionally included clinical factors (mean blood pressure, heart rate, volume of intravenous fluid, surgical site, surgical position, and pneumoperitoneum) in the full adjusted model. PE was higher in men than in women (28.7% versus 10.5%, p = 0.015). Female sex was inversely associated with PE: the minimal adjusted β = − 8.84 (95% CI, − 16.26 to − 1.43); however, the fully adjusted β with clinical factors became not significant. The average of PE did not differ between polymorphisms of CYP2B6 and UGT1A9, and β of CYP2B6 516G>T polymorphisms mutually adjusted with female sex was not significant. Mean blood pressure, heart rate, and volume of intravenous fluid were independently associated with PE in the full adjusted model. Conclusions: Under 4 h anesthesia with propofol target-controlled infusion in our population, sex differences appeared to exist in the propofol concentration, which might be largely mediated by clinical factors, such as hemodynamic status.
In small mesenteric arteries, etomidate influences the contractile response to norepinephrine or membrane depolarization through endothelium-dependent enhancing and endothelium-independent inhibitory actions. The enhancement is at least in part independent of nitric oxide, endothelium-derived hyperpolarizing factor, cyclooxygenase products, lipoxygenase products, angiotensin II, serotonin, or endothelin-1, but may involve some signaling pathway that is impaired by aging. The endothelium-independent inhibition is due to decreases in both the [Ca(2+)]i and myofilament Ca(2+) sensitivity in vascular smooth muscle cells. The decrease in [Ca(2+)]i would be due mainly to inhibition of voltage-gated Ca(2+) influx. The observed inability of lower concentrations (1-3 microM) of etomidate to cause significant vasodilation is consistent with minimal changes in hemodynamics during induction of anesthesia with etomidate in young subjects, whereas the observed vasodilator action of higher concentrations of etomidate might underlie systemic hypotension caused by higher doses of etomidate in the clinical setting.
Background Forced air warming systems are used to maintain body temperature during surgery. Benefits of forced air warming have been established, but the possibility that it may disturb the operating room environment and contribute to surgical site contamination is debated. The direction and speed of forced air warming airflow and the influence of laminar airflow in the operating room have not been reported. Methods In one institutional operating room, we examined changes in airflow speed and direction from a lower-body forced air warming device with sterile drapes mimicking abdominal surgery or total knee arthroplasty, and effects of laminar airflow, using a three-dimensional ultrasonic anemometer. Airflow from forced air warming and effects of laminar airflow were visualized using special smoke and laser light. Results Forced air warming caused upward airflow (39 cm/s) in the patient head area and a unidirectional convection flow (9 to 14 cm/s) along the ceiling from head to foot. No convection flows were observed around the sides of the operating table. Downward laminar airflow of approximately 40 cm/s counteracted the upward airflow caused by forced air warming and formed downward airflow at 36 to 45 cm/s. Downward airflows (34 to 56 cm/s) flowing diagonally away from the operating table were detected at operating table height in both sides. Conclusions Airflow caused by forced air warming is well counteracted by downward laminar airflow from the ceiling. Thus it would be less likely to cause surgical field contamination in the presence of sufficient laminar airflow.
Purpose. Surgical lights in the operating rooms are typically installed in a single axis in the center of the room or in two axes on both sides of the operating table. In the single-axis installation, the air-conditioning outlet cannot be placed in the center of the ceiling, which may affect the air current. Therefore, we measured the air current and cleanliness in two equivalent operating rooms using a vertical laminar airflow system equipped with either single-axis or double-axis surgical lights. Methods. Air current was measured using a three-dimensional ultrasonic anemometer. Cleanliness was evaluated by measuring the amount of dust before and after air-conditioner activation. To visualize the air current, smoke was illuminated on a sheet of laser light while the air-conditioning was stopped, and changes after air-conditioning activation were observed. Results. In the single-axis room, an oblique fast air current flowing from the surrounding air outlet toward the center was observed, and the flow velocity fluctuated greatly. In the double-axis room, uniform downward laminar airflow was observed. The amount of dust at the center decreased significantly faster in the double-axis room; thus, the cleanliness at the center was higher in the double-axis room. Persistent stagnation of smoke was observed below the single-axis lighting, whereas smoke below the double-axis lighting was immediately dispersed and the air cleared even when surgical lights were in the position for surgery. Conclusion. Uniform vertical laminar airflow was formed and high cleanliness was achieved in the center of the room when the surgical lights were arranged in two axes.
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