Anaesthetic Gas Monitor Research Articles

Hugo-Wilhelm Knipping: a pioneer in continuous anaesthetic gas monitoring during the administration of nitrous oxide–oxygen-based anaesthesia

The fertile soil and Mediterranean climate, proximity to the Mediterranean Sea, and the interaction with the neighboring countries have had a great impact on the diversity and profusion of the Albanian cuisine. Albania has long served as a bridgehead for numerous nations and empires seeking conquest abroad. Although the country’s inhabitants claim to consume the Mediterranean diet, historically the variety of dishes that Albanians eat today have been adopted from the Byzantines, Venetians, and Turks. The Albanian cuisine had a long history developing itself through the centuries. The chapter presents typical traditional Albanian foods, with an overview of the local history, geography, agricultural landscape, culture, and eating habits, as well as the diet and health of the population.

Assessment of the respiratory exchange ratio in mechanically ventilated patients by a standard anaesthetic gas analyser

The respiratory exchange ratio (R) is the CO2 production divided with O2 consumption. R is an essential factor included in several formulas during routine blood gas analysis. Instant and individual measurement of R may be of particular interest to improve the evaluation of each single patient. A standard anaesthetic gas analyser has been recommended for measurement of R among spontaneously breathing healthy subjects, but there is no experience using this method among mechanically ventilated critically ill patients. This study validates the assessment of R by a Brüel & Kjaer gas analyser (B & K) during positive pressure ventilation of intensive care patients. The B & K sampled gas from 11 mechanically ventilated patients over a period of 5 min. The recordings of end-tidal values of O2 and CO2 based on fractions (RF) allowed for calculation of RF by the alveolar equation solved for R. The continuous recordings of corresponding values were depicted into an O2-CO2 diagram. A developed computer program calculated estimates of R as the slope of the regression lines related to the full cycle (Rfull) and the expiratory phase only (Rexp). Corrected values of the full respiratory cycle (Rfull*) were also calculated assuming changes of CO2 and O2 volumes during gas exchange. The different estimates of R were compared with simultaneous measurement of a Deltatrac indirect calorimeter (Rdelta). Ten values of RF were within the expected interval of 0.72 < R < 1.00. For the full respiratory cycles, the mean R-value was 0.94 +/- 0.07 and for the expiratory phase the mean R-value was 0.82 +/- 0.08. The O2-CO2 diagram appeared as a convexo-convex loop during each cycle. The agreement of Rexp and Rdelta (Rexp-Rdelta: 0.01 +/- 0.13) were good. This study demonstrates that gas measurements by a standard anaesthetic gas monitor can be used for determination of R, and thereby we present an alternative to R calculation made by the Deltatrac monitor.

The effect of intramuscular dexmedetomidine and medetomidine on cardiorespiratory variables during isoflurane anaesthesia in sheep

The hypoxaemic effects of intravenous alpha2-agonists in sheep are well documented. Based on preliminary trials we hypothesized that intramuscular (IM) administration of medetomidine and dexmedetomidine would lead to less severe side effects than IV administration. Nineteen healthy nonpregnant ewes of various breeds undergoing different orthopaedic procedures were studied. Pre-anaesthetic medication was 15 µg kg−1 dexmedetomidine IM [group A, n = 9] or 30 µg kg−1 medetomidine IM [group B, n = 10] 30 minutes prior to induction of anaesthesia with ketamine (2 mg kg−1) IV. Anaesthesia was maintained with isoflurane in 100% oxygen. End expired anaesthetic concentration (F eiso) and respiratory frequency (fR) were determined with a methane insensitive infrared gas analyser (Anaesthetic Gas Monitor Type 1304, Bruel & Kjaer, Naerum, Denmark). Direct mean arterial blood pressure (MAP) and a lead II ECG were monitored continuously. Arterial blood samples were taken 10 minutes after induction of anaesthesia and then at 30 minute intervals. Data were averaged over time and tested for differences between groups by independent t-tests or anova for repeated measures followed by Bonferroni corrected t-tests. The results are presented as mean ± SD. There were no significant (p < 0.05) differences in bodyweights (A: 53.2 ± 9.5 kg; B: 54.7 ± 3.8 kg), duration of anaesthesia (A: 170 ± 42 minutes; B: 144 ± 33 minutes) or surgery (A: 92 ± 32 minutes, B: 85 ± 31 minutes) between the groups. Average F eiso concentrations required to maintain a surgical plane of anaesthesia were not significantly different between groups (A: 0.82 ± 0.14%; B: 1.00 ± 0.25%). There were no differences in mean fR, mean arterial blood gas values and mean MAP between groups. Heart rates were significantly (p < 0.05) lower in group B over the course of anaesthesia. The PaO2 was more variable in group B 37.0 ± 9.7 kPa (255.45 ± 121.8 mm Hg) than in group A 34.0 ± 16.1 kPa (277.15 ± 72.4 mm Hg) with individual minimum values of 9.33 kPa and 19.2 kPa (70 mm Hg and 144 mm Hg), respectively. Effects of dexmedetomidine and medetomidine on PaO2 seem to be less severe after IM administration compared to IV application ( Kastner et al.) with less variability in dexmedetomidine, enabling stable anaesthesia during orthopaedic surgery in sheep. Acknowledgements: The authors are grateful to ORION corporation, Finland for providing medetomidine and dexmedetomidine.

LOW FLOW ANESTHESIA FOR AMBULATORY SURGERY

S10 For low flow anesthesia (LFA) techniques an initial high flow phase of 15-20 min is required, thus limiting the effectiveness in saving anesthetic vapors in short duration anesthesia. Anesthetic gas monitoring offers the opportunity to reduce the duration of the inital wash-in phase down to 1-2 min. This renders LFA practicable for brief surgical procedures. The aim of the study was to evaluate LFA for brief surgical procedures. METHODS: After IRB approval and written informed consent the anesthetic procedure shown in Figure 1 was employed in an ambulatory surgery unit. After premedication with nordiazepam, anesthesia was induced with propofol (1-2mg/kg body weight) and alfentanil (1mg) and maintained with nitrous oxide in oxygen and isoflurane or enflurane. The patient's age, surgical procedure, duration of anesthesia and post-anesthetic care unit time spent were recorded. The consumption of anesthetic vapors per patient was calculated from the overall consumption.Figure 1: Course of modified low flow anesthesia: T0: preoxygenation, intravenous induction, endotracheal intubation, controlled ventilation: T1: wash in phase - fresh gas flow at 9 L/min for 1-2 min, vaporizer setting 5Vol% isoflurane (Iso) or enflurane (Enf) until the desired endtidal anesthetic gas concentration is reached: T2: low-flow phase - fresh gas flow reduction to 1 L/min, adaptation of the vaporizer setting: T3: discontinuation of Isoflurane/N2 O, patient breathing spontaneously, O2 flow at 9 Lmin: T4: extubationRESULTS: 3185 consecutive patients were included in the study. The age of the patients ranged from 5 months to 94 years with a median of 31 years, duration of anesthesia from 15 min to 4 h with a median of 46 min. 29% of the patients were discharged from the post-anesthetic care unit within 2 h, 56% after 2-4 h and 15% after more than 4 h. On the average 24 l N2 O, 7.1 ml enflurane or 3.7 ml isoflurane (liquid) per patient were needed. CONCLUSION: LFA proved to be a useful, practicable and cost-effective anesthetic technique for brief surgical procedures in ambulatory patients. The extremely short wash-in phase as compared to previously described LFA techniques can be achieved by using anesthetic gas monitoring.

Textbook of Intravenous Anesthesia

Textbook of Intravenous Anesthesia

Pulse Oximetry as an Intravenous Flow Monitor

To the Editor: Uninterrupted continuous intravenous flow is critically important when administering remifentanil, lest our patients experience an unplanned, rapid, and potentially deleterious cessation of anesthesia. Intravenous flow interruption is possible through a variety of mechanisms, including patient movement, which cause tubing disconnection, thrombosis, external compression, etc. We have found a simple solution to part of the problem of detecting interruptions in intravenous flow. In our operating suites, two pulse oximeters are routinely available. The first utilizes a Nellcor Durasensor[R] (DS 100-A, Pleasanton, CA) reusable probe as part of the cardiovascular monitor (Eagle[R], Marquette Electronics, Milwaukee, WI). The second probe is part of an anesthetic gas monitor (Rascal II[R], Ohmeda, BOC Healthcare, Salt Lake City, UT). When the Rascal probe is used for patient monitoring, the Nellcor probe can be clamped to the intravenous drip chamber (Figure 1) to detect droplets of intravenous solution. The drip rate, wave form, and SpO2 value are displayed on the pulse oximeter. For a given clinical scenario, the wave form and SpO2 value are constant, but they differ across various clinical settings. We disable the audio signal (to avoid confusion with the patient's oxyhemoglobin saturation) and set the low rate alarm to produce an intravenous flow monitor and alarm. We have observed that the oximeter functions with adult (10 drops/mL) and pediatric (60 drops/mL) drip chambers with both crystalloid and colloid solutions.Figure 1: Pulse oximeter finger probe mounted on an intravenous drip chamber.An inherent limitation to this approach is the inability to detect tubing disconnection or catheter dislocation that is distal to the drip chamber. Additionally, overfilling, tilting, or splashing within the chamber impairs the signal. We place large, easily legible labels on the drip chamber "SpO2" display to prevent it from being mistaken with the patient's SpO2. Mark L. Wisniewski, MD Dwayne R. Westenskow, PhD Peter L. Bailey, MD Department of Anesthesiology; University of Utah Health Sciences Center; Salt Lake City, UT 84132

Comments Accepted on European Anesthetic Gas Monitor Standard

Comments Accepted on European Anesthetic Gas Monitor Standard

Messung der Atem-Alkoholkonzentration mit einem neuen elektrochemischen Sensor Modelluntersuchung zur Querempfindlichkeit gegen�ber volatilen An�sthetika und klinische Anwendung

Absorption of irrigating fluid in transurethral prostatic resection (TURP) and percutaneous nephrolitholapaxy (PNL) into veins or delayed absorption due to fluid extravasation may result in a TURP syndrome. The measurement of end-tidal breath alcohol concentration (et AC) as a monitor of absorption of irrigating fluid labelled with 2% ethanol is limited by the disturbance of infrared sensors by volatile anaesthetics and nitrous oxide (N2O) (Fig. 2). An electrochemical sensor is acceptable for this method. The aim of the present study was the evaluation of breath alcohol measurements using an electrochemical sensor device (Alcomed 3010, Envitec). The stability of the sensor in the presence of volatile anaesthetics was examined using a lung model. In a clinical investigation, the device was then applied to spontaneously breathing or mechanically ventilated patients inhaling volatile anaesthetics during endoscopic urological surgery. A two-chamber lung model filled with water for performing noninvasive measurements at the mouth of a patient has already been introduced by Brunner et al. (Fig. 1). With the addition of different amounts of ethanol to the temperature-controlled water, a constant ethanol concentration is achievable in the air above the water that is dependent on adjustments of the ventilator. Increasing concentrations of volatile anaesthetics (isoflurane, enflurane, halothane, and sevoflurane) were added to the fresh gas flow (2 l O2/3 l N2O) and etACs were measured using the manually triggered self-absorbent electrochemical sensor. First, regression equations were established between breath alcohol concentrations and increased volatile anaesthetic concentrations. Regression equations were then established between end-tidal anaesthetic gas concentrations and vaporizer adjustments in order to rule out an influence of ethanol on the anaesthetic gas monitor Ultima V (Datex). In the clinical investigation, 53 intubated and ventilated patients (33 undergoing PNL, 20 undergoing TURP) and 48 patients breathing spontaneously (32 with inhalation anaesthesia, 16 with spinal anaesthesia) were investigated. The etAC was measured with the Alcomed 3010 and compared with gas-chromatographically registered blood alcohol concentrations (BAC). The study had previously been approved by the Ethical Committee of the Medical University of Luebeck. Patients with liver disease and a history of toxic abuse were excluded. Only one value per patient (maximum BAC) was included in the statistics in order to avoid a cluster effect. The lung model experiments demonstrated that the measurement of etAC with an electrochemical sensor is free of interference by volatile anaesthetics (Table 1). The slope of the regression between the measured alcohol concentration and increased concentrations of anaesthetics did not differ significantly from baseline values. The measurement of end-tidal anaesthetic concentrations was not significantly different from vaporizer adjustments in the presence of increased alcohol concentrations (Table 2). During the clinical investigation, a regression between etAC and BAC was determined for both groups. For the group of patients breathing spontaneously, the correlation coefficient was 0.961 and the regression equation revealed etAC = 0.5677*BAC-0.1303 (Fig. 5). However, in the group of ventilated patients a biphasic course was shown that was dependent on BAC (Fig. 6). At BAC < 0.4%, a similar correlation (r = 0.856) to the spontaneously breathing group could be seen (regression equation: etAC = 0.617*BAC-0.020). Above 0.4% BAC there was no acceptable correlation (r = 0.444, regression equation: etAC = 0.202*BAC+0.104). The tested electrochemical sensor does not interfere with volatile anaesthetics and N2O as demonstrated by a lung model. There is a good correlation between etAC and BAC measurements in patients breathing spontaneously with special regard to the slope of the regression (s = 0.57).

Does monitoring end-tidal isoflurane concentration improve titration during general anesthesia?

To assess the value of end-tidal anesthetic gas monitoring with respect to intraoperative hemodynamic stability and recovery times. Randomized blinded study. Operating rooms at a university teaching hospital. 120 ASA I and II patients receiving general anesthesia maintained with isoflurane and nitrous oxide (N2O). Following a standardized induction technique, patients were assigned to either an end-tidal isoflurane monitored (n = 60) or unmonitored (n = 60) group. During each operation, the anesthesiologist attempted to maintain an adequate "depth of anesthesia" by varying the administered concentration of isoflurane with or without information from an end-tidal isoflurane monitor. Intraoperative hemodynamic stability was assessed by determining the variation from a preincisional "baseline" mean arterial pressure (MAP) value established during a 10 minute interval immediately prior to the surgical incision. Recovery times were recorded from discontinuation of isoflurane and N2O until awakening, orientation, and postanesthesia care unit discharge. Intraoperative hemodynamic stability was assessed in each patient and reported as the average error from the baseline MAP, absolute average error from the baseline MAP, coefficients of variation of heart rate (HR), systolic and diastolic MAP, and end-tidal isoflurane concentrations. Both study groups had similar intraoperative MAP and HR values, average error and coefficients of variation for the hemodynamic variables, as well as similar numbers of episodes of hypertension, hypotension, tachycardia, and bradycardia. Finally, the two groups were comparable with respect to early recovery times and postoperative side effects. This study suggests that end-tidal isoflurane monitoring does not improve the titration of isoflurane during general anesthesia.

Unbeabsichtigte Narkosegasüberdosierung bei den Naroserespiratoren Servo 900 C und D

When working with the anaesthetics vaporizers/respirators of the type Siemens Servo 900 C/D we found differences between the values adjusted at the instrument and those measured by the anaesthetic gas monitor (Sirecust 734 G). Control measurements yielded differences of inspiratory concentrations of halothane and isoflurane that were in excess by up to 80%. We found that the reason for this was the absence of reducing valves at the respirator that would reduce the static pressure of central gas supply from 5.3-5.5 bar to the values of not more than 4.0 bar that are permissible for the vaporizer. It is pointed out that the operation of respirators of this type is safe only provided the prescribed gas supply pressures are observed, if necessary with the help of the appropriate reducing valves, to ensure accurate dosage of volatile anaesthetics.

ACCURACY OF 94 ANAESTHETIC AGENT VAPORIZERS IN CLINICAL USE

Using the Brüel & Kjaer Anaesthetic Gas Monitor type 1304, we have monitored the output of 94 anaesthetic agent vaporizers (Fluotec 3:58, Enfluratec 3:24, Isotec 3:12), in seven departments of anaesthesia, at different dial settings and flow rates. The range of output, for one type of vaporizer and dial setting (flow: 6 litre min-1) was largest with the Fluotec 3 (0.85-1.55% when dial set to 1%) and smallest with the Isotec 3 (0.85-1.15% when dial set to 1%). In determining the number of vaporizers with unacceptable inaccuracy, we applied acceptance limits of +/- 15% relative on each vaporizer and each dial setting. Using a flow of oxygen 6 litre min-1 17% of Fluotec 3.8% of Isotec 3 and 71% of Enfluratec 3 vaporizers had outputs outside those limits. Even when some specific conditions (vaporizers giving output beyond the limits at any two or more dial settings; output beyond the limits in the clinically relevant range (0.5-2%)) were added, a substantial number of vaporizers did not perform within the limits. We found a significantly greater accuracy of the vaporizers after 3-monthly calibration checks (P < 0.05) compared with vaporizers undergoing service and calibration only annually. Using a questionnaire, we found that fewer than 30% of the anaesthetists using the vaporizers would accept aberrance beyond +/- 10% relative of the dial setting.

Evaluation of three transportable multigas anesthetic monitors: the Bruel & Kjaer Anesthetic Gas Monitor 1304, the Datex Capnomac Ultima, and the Nellcor N-2500.

We compared the performance of three newly developed anesthetic agent (AA) monitors: the Bruel & Kjaer Anesthetic Agent Monitor 1304 (BK 1304), the Datex Capnomac Ultima (ULTIMA), and the Nellcor N-2500 (N-2500). The following were investigated: the linearity and accuracy in measuring AAs, oxygen, carbon dioxide, and nitrous oxide; the linearity and accuracy during warm-up time; the effect of increasing respiratory rate on the accuracy; the consequences of a difference between monitored and delivered AA and of delivering a mixture of AAs; and, finally, the effect of water vapor and alcohol. For all three monitors we found that the accuracy in determining the respiratory and anesthetic gases was sufficient for clinical use (the N-2500 does not measure oxygen). Because of the calibration mixture supplied with the device, however, the ULTIMA recorded values that were 10 to 12% (relative) less than the AA that was present. The BK 1304 had greater accuracy at higher respiratory rates than did the other two monitors, probably favoring its use in pediatric anesthesia. The N-2500 will detect which agent (isoflurane, enflurane, or halothane) is being used, alone or in a mixture. With the two other monitors the user must define which agent is given. In some situations a difference between this and the one actually delivered can theoretically lead to an overdose of AA, with the ULTIMA up to a 14.9 minimal alveolar concentration (MAC) overdose. No interference from alcohol or water vapor in the expired air was found.(ABSTRACT TRUNCATED AT 250 WORDS)

SARAcap Monitoring of End - Tidal Volatile Anesthetics during Anesthesia

Thirty (19-58yr) patients received halothane, enflurane and isoflurane with Ohmeda, Cyprane and Narcomed vaporizer for maintenance of anesthesia during controlled ventilation. End-tidal fractional concentrations(FE) of the volatile anesthetic agents were measured for 40 minutes after induction. Inspired oxygen fractional concentrations during anesthesia in the three groups were slightly decreased from minimal 33.1±2.3% to maximal 49.3±1.7%. End-tidal carbon dioxide concentrations during anesthesia in the three groups were within normal lirnit ranged from minimal 24.5±3.2 mmHg to maximal 35.2±3.4 mrnHg. When vaporizer''s dial was fixed at 1% halothane, average measured FE/FI ratio were gradually increased from 5 minutes to 40 minute in the three groups. But FE/FI ratios were lower than dial setting, except after 40 minutes in the Narcomed vaporizer. When vaporizer''s dial were fixed at 1% isoflurane and enflurane, average measured FE/PI ratios in the three groups were nearly equal but lower than dial setting. These results suggest that the actual gas concentrations of used(2-3yr) vaporizers were measured slightly lower than dial setting and we need to continuously monitoring of respiratory gas and end-tidal anesthetic gases.

Anaesthetic gas monitoring and control using coated piezoelectric crystals

The monitoring and control of anaesthetic gases during a surgical procedure is of critical importance to patient welfare. This work describes the initial investigation of coatings and calibration of coated quartz piezoelectric crystals for N2O, halothane and enflurane. Once the crystals and coatings were characterised, they were incorporated into a prototype feed-back controller which allowed the required gas concentration to be present. Fluctuations outside preset alarm thresholds were indicated by means of an alarm and corrected automatically.

The influence of methane on the infrared measurement of halothane in the horse

Using two types of infrared anaesthetic analysers (Capnomac, Datex, Finland and Anaesthetic Gas Monitor [AGM] 1304, Bruel & Kjaer, Denmark) simultaneous measurements were made of halothane and methane concentrations in the expired gases from nine anaesthetised horses. Methane concentrations varied from 232 to 1770 ppm. The Capnomac gave halothane readings 0.35 to 4.5 per cent higher than those given by the other analyser. A highly significant linear relationship (r = 0.87) was found between this difference and the concentration of methane in the anaesthetic circuit. This linear relationship was confirmed by an in vitro study using methane-air mixtures containing approximately 500 to 2,500 ppm of methane and analysed in both the halothane and isoflurane measuring modes of the analysers. The AGM 1304 was totally unaffected by methane. We concluded that monitors with absorption in the upper end of the infrared spectrum are preferable for measuring the concentration of inhalation agents in low-flow anaesthetic systems.

Colon cancer cells

<h3>OBJECTIVE:</h3> Patients who experience awareness under surgery may suffer from the post-traumatic stress disorder with its long-lasting psychological damage. Furthermore, there are also media attention and legal consequences. In spite of understanding its causes, it is still occurring worldwide and there are no reports of awareness in the Saudi medical literature. This prospective study was conducted to determine the incidence of awareness when its causes are eliminated and to record patient satisfaction. <h3>METHODS:</h3> Surgical patients &gt;4 years old (ASA I-III) admitted to the Armed Forces Hospital, Wadi Al-Dawasir, Kingdom of Saudi Arabia, between October 1998 and November 2002 were included in the study. Patients were given a premedicant with an amnesic effect. Anesthetic equipment with a built-in end-tidal anesthetic gas monitor was checked preoperatively. Minimal anesthetic concentrations of vapors were delivered and monitored. Intraoperative analgesia was provided whenever appropriate. Patients were closely observed for signs of intraoperative awareness under general anesthesia. All patients were interviewed within 24 hours postoperatively on the occurrence of awareness and service satisfaction. <h3>RESULTS:</h3> There were 4368 patients admitted to the study. Their ages ranged from 14-104 years (mean 40.2 years). All patients were interviewed in the postoperative period. There was no report of awareness during surgery and patient satisfaction score was 100%. <h3>CONCLUSION:</h3> Preoperative and intraoperative anesthetic attention to patients presented for surgery, together with the use of modern anesthetic delivery units possessing facilities for monitoring anesthetic gases, and the provision of good analgesia are the most important combination in eliminating awareness during surgery.

Mass Spectrometry in Clinical Medicine: Principles and Applications

Mass spectrometry (MS) is an analytical technique for determining the structures of unknown molecules and “fingerprint” identifications of known molecules that are present in gases, liquids, and solids. MS is unsurpassed in its combination of sensitivity, specificity, and speed. Fully computerized and reliable instruments have made possible the use of this powerful tool in clinical medicine. MS has found a permanent place in clinical toxicology, indisputably confirming the results of screening assays for drugs of abuse. During the past decade, the mass spectrometer has been widely accepted for clinical anesthesia, where it provides accurate and reliable monitoring of respiratory and anesthetic gases. MS is utilized for clinical pharmacology studies of bioavailability and bioequivalence of medicinal drugs using stable isotopes. Other clinical applications include use of MS in the diagnosis of metabolic disorders. MS is used in tandem with gas and liquid chromatographs (GC/MS and LC/MS) and, more recently, with other mass spectrometers (tandem MS, or MSMS). The tandem mass spectrometers match and exceed the sensitivity of GC/MS or LC/MS but are several orders of magnitude faster. Rapid MSMS drug screening assays have been developed that appear to be directly applicable to drug testing in humans. Rapid identifications of metabolites of new drugs are now possible utilizing tandem mass spectrometers. Implementation of tandem MS in clinical medicine will undoubtedly increase should instrumentation costs decline.

Removal of halogenated anaesthetics from a closed circle system with a charcoal filter.

Halogenated anaesthetics may be removed from a closed circle system by means of a charcoal filter. With this technique dispersion to the atmosphere and a possibly destructive effect of the halogenated volatiles on the protective layer of ozone is avoided. Removal of halothane or isoflurane with a charcoal filter was studied in a closed circle system connected to an artificial lung. The concentration of anaesthetic (Ct) was recorded in relation to time by an anaesthetic gas monitor interposed between the system and the lung at ventilations of 3, 5, 7 or 9 l/min (v). Based on theoretical considerations, it was expected that Ct = Co.exp (-v/V.t), (V: volume of the system). Analysis of regression demonstrated that the results fitted well to an exponential decrease (R2 greater than 0.94) and the downslope increased with increasing rate of ventilation. However, the slopes deviated significantly from the theoretically predicted slopes, possibly because of adsorption to hoses and bags and unequal distribution of the volatiles in the system. Halothane was eliminated more slowly than isoflurane. This study demonstrates that halogenated volatiles are eliminated in an exponential way following charcoal filtration and the rate depends on the ventilation and type of volatile.

An Availability of the Anesthetic Gas Monitor for a Clinical Anesthetic Management

An Availability of the Anesthetic Gas Monitor for a Clinical Anesthetic Management

Monitoring in Anesthesia and Critical Care Medicine

Part 1 General principles: a philosophy of monitoring the senses as monitors precordial and esophageal stethoscopes monitoring and patient safety cost benefit analysis on monitoring. Part 2 Cardiovascular system: noninvasive blood pressure monitoring invasive blood pressure monitoring electrocardiographic monitoring central venous pressure monitoring the Swan-Ganz catheter - past and present pulmonary artery catheterization transesophageal data collection. Part 3 Monitoring the respiratory system: respiratory monitoring monitoring anesthetic and respiratory gases blood gas monitoring pulse oximetry. Part 4 Monitoring and the central nervous system: the electroenecephalogram evoked potential monitoring monitoring intracranial pressure. Part 5 Miscellaneous monitoring: temperature monitoring monitoring the kidney and urine miscellaneous blood measurements monitoring the anesthetic delivery system monitoring the neuromuscular junction the computer in anesthesia monitoring in unusual environments. Part 6 Monitoring and subspecialities: monitoring in neuroanesthesia monitoring in cardia anesthesia monitoring in the pediatric patient monitoring in obstetric anesthesia monitoring in the intensive care setting monitoring modalitites of the future.