Continuous Blood Gas Monitoring Research Articles

Does Hypercarbia Develop Faster During Laparoscopic Herniorrhaphy than During Laparoscopic Cholecystectomy? Assessment with Continuous Blood Gas Monitoring

Does Hypercarbia Develop Faster During Laparoscopic Herniorrhaphy than During Laparoscopic Cholecystectomy? Assessment with Continuous Blood Gas Monitoring

Continuous arterial blood gas monitoring: a technology in transition

Continuous arterial blood gas monitoring: a technology in transition

Continuous intra-arterial blood gas monitoring

ObjectiveTo review the technology, clinical trials and current status of continuous blood gas monitoring in intensive careDesignThe review describes the history, technology, various clinical trials on continuous blood gas monitoring and discusses the various factors which might affect their performance characteristics and outlines their potential role in intensive care and during anaesthesia.ConclusionsOver the past 10 years a number of continuous intra-arterial blood gas monitoring systems have been developed. The performance characteristics of these systems are comparable. Their levels of accuracy as measured in bench tonometry are not consistently achieved in clinical trials. The potential usefulness of these monitors in various clinical situations has been described in case studies. Controlled studies demonstrating an improvement in outcome with the use of these monitors have not been published.

Continuous intra-arterial blood gas monitoring.

To review the technology, clinical trials and current status of continuous blood gas monitoring in intensive care. The review describes the history, technology, various clinical trials on continuous blood gas monitoring and discusses the various factors which might affect their performance characteristics and outlines their potential role in intensive care and during anaesthesia. Over the past 10 years a number of continuous intra-arterial blood gas monitoring systems have been developed. The performance characteristics of these systems are comparable. Their levels of accuracy as measured in bench tonometry are not consistently achieved in clinical trials. The potential usefulness of these monitors in various clinical situations has been described in case studies. Controlled studies demonstrating an improvement in outcome with the use of these monitors have not been published.

Continuous Fiberoptic Arterial and Venous Blood Gas Monitoring in Hemorrhagic Shock

To compare the performance of continuous fiberoptic blood gas monitoring with standard, intermittent blood gas sampling in the measurement of arterial and central venous blood gases during marked hemodynamic changes. Prospective, consecutive, enrollment, experimental study. Research laboratory at a university medical center. Seven anesthetized, mechanically ventilated pigs. Severe shock was induced by hemorrhage in pigs monitored by a pulmonary artery catheter, an arterial line, and two fiberoptic blood gas sensors: one intra-arterial, and the other inserted into the superior vena cava via right internal jugular vein cutdown. Fiberoptic blood gas monitor measurements were compared with standard intermittent blood gas sampling. A total of 184 blood gas samples were compared in seven animals at baseline, during shock, and after resuscitation. The baseline mean (+/- 1 SD) cardiac output decreased from 4.0 +/- 0.9 to 1.2 +/- 0.6 L/min during shock and returned to baseline after retransfusion (3.9 +/- 1.3 L/min). The comparison of continuous fiberoptic blood gas monitoring with intermittent blood gas sampling showed a bias+/-precision of 0.035 +/- 0.047 for arterial pH, 0.021 +/- 0.031 for central venous pH, -4.09 +/- 2.96 mm Hg (-0.55 +/- 0.39 kPa) for arterial Pco2, -3.67 +/- 2.44 mm Hg (-0.49 +/- 0.3 3 kPa) for central venous Pco2, -5.79 +/- 9.64 mm Hg (-0.77 +/- 1.29 kPa) for arterial Po2, and -7.85 +/- 8.52 mm Hg (-1.05 +/- 1.14 kPa) for central venous Po2. Continuous fiberoptic blood gas monitoring agrees closely with standard intermittent blood gas sampling during severe hemodynamic shifts and has a comparable accuracy for both arterial and venous blood gas measurements. Changes in venous Pco2 have recently been shown to correlate with changes in global tissue perfusion (eg, changes in cardiac output). Such data, available immediately via continuous venous blood gas monitoring, may be useful for monitoring shock and the response to resuscitation.

Continuous Intra-arterial Blood Gas Monitoring in Patients Undergoing Suprarenal Aortic Surgery

The authors used an on-line, real-time, continuous blood gas monitor in 5 patients undergoing elective suprarenal aortic reconstruction. They retrospectively analyzed data to evaluate its utility in acid-base management and in detection of dynamic changes in oxygenation. Seven sets of data were analyzed since 1 patient underwent two additional periods of aortic crossclamping. A similar group of 7 patients undergoing elective suprarenal aortic surgery without continuous blood gas monitoring was analyzed and served as a control group. There was a highly significant mean decrease in partial pressure of oxygen (P02) of 158 mm Hg (P = 0.0060) with unclamping. In 1 patient the P02 dropped from 218 to 63 mm Hg within sixty seconds of unclamping, and this required immediate reinstitution of two-lung ventilation. Continuous availability of pH permitted accurate therapy with bicarbonate infusion during clamping. As a result there was no significant change in pH between preclamp and immediately after unclamping (P = 0.97). In the control group the pH decreased from a mean of 7.38 to a mean of 7.24 (P = 0.0005) between preclamp and after unclamping. In summary, dynamic changes in oxygenation and pH are observed during suprarenal aortic surgery. Continuous blood gas monitoring provided data resulting in improved management of acid-base status and early detection of significant decreases in oxygenation.

Does Hypercarbia Develop Faster During Laparoscopic Herniorrhaphy Than During Laparoscopic Cholecystectomy? Assessment with Continuous Blood Gas Monitoring

The use of CO2 to create and maintain a pneumoperitoneum during laparoscopic surgery may lead to hypercarbia and acidosis.CO2 is also insufflated into the preperitoneal space to create and maintain a pneumopreperitoneum for laparoscopic herniorrhaphy. This study examined the influence of CO2 pneumopreperitoneum on the development of hypercarbia and acidosis assessed with continuous intraarterial blood gas monitoring. Changes in blood gas values were measured with both continuous intraarterial and intermittent blood gas monitoring. Over a 4-mo period, blood gas values of 14 patients undergoing laparoscopic herniorrhaphy (pneumopreperitoneum) were compared with those of 13 patients undergoing laparoscopic cholecystectomy (pneumoperitoneum) in a tertiary referral center. Additionally, heart rate and blood pressure were measured during stable ventilation at constant insufflation pressure. Pneumopreperitoneum resulted in a significantly faster development of hypercarbia (P = 0.023) and acidosis (P = 0.027) than pneumoperitoneum. These results were not explained when corrected for changes in hemodynamic and ventilatory variables using analysis of covariance. We conclude that the more rapid development of hypercarbia and acidosis during pneumopreperitoneum can be explained by increased CO2 absorption through an increasing gas exchange area during the procedure and through a larger wound bed. (Anesth Analg 1995;81:1243-9)

Continuous intra-arterial blood gas monitoring during cardiopulmonary resuscitation

Continuous intra-arterial blood gas monitoring is becoming more common in Intensive Care practice. Several trials have been undertaken to evaluate their performance in critically ill patients and varying degrees of accuracy have been reported [l-S]. No published trial to date has addressed the question of their utility in clinical practice, though there are anecdotal reports of their usefulness in various clinical situations. We report a case of a patient with a continuous intra-arterial sensor, who suffered a cardiac arrest and required cardiopulmonary resuscitation (CPR). Continuous blood gas monitoring during CPR has been reported before [6-81 using transcutaneous and transconjunctival oxygen electrodes and was shown to be useful in guiding therapy; continuous Pco2 monitoring was used in one study. To our knowledge, continuous pH monitoring during CPR has not been reported before. The Paratrend 7 (Biomedical Sensors, UK) is a multiparameter intravascular sensor for on-line, continuous measurements of pH, Pco2, PO* and temperature. It comprises an electrochemical oxygen sensor [9], optode-based Pco2 and pH sensors [lo] and a thermocouple for the determination of temperature. Preliminary evaluation of its use in Intensive Care patients and during anaesthesia has shown an acceptable level of accuracy over a wide range of pH, Pc02 and Pot measurements [ll-131.

Continuous Intra-Arterial Blood Gas Monitoring

To review the technology and the role of continuous intra-arterial blood gas monitoring in critical illness.Articles and published peer review abstracts on continuous intra-arterial blood gas monitoring.The history of intermittent and continuous blood gas analysis and the development of technology of continuous blood gas monitoring are reviewed. A summary of the various clinical trials on the evaluation of continuous blood gas monitoring systems, and the various factors which might affect the performance characteristics in the clinical setting is also presented. The potential role and future applications of this technology in critical illness are described.Over the last 10 years, a number of continuous intra-arterial blood gas monitoring systems have been developed. Only a few have reached commercial availability. While the performance characteristics of these systems are comparable, the levels of accuracy of these systems obtained in vitro are not consistently obtained in clinical trials. Arterial blood flow, wrist movement, wall effect and variability of blood gas analysers are some of the factors which determine the accuracy and reproducibility of these systems. Evidence to support the clinical usefulness of these monitors exists only in the form of case studies. Controlled studies demonstrating an improvement in outcome with the use of these monitors are lacking.

Electrochemical Sensors for the Continuous Monitoring of Blood Gases and Electrolytes

Electrochemical Sensors for the Continuous Monitoring of Blood Gases and Electrolytes

Comparison of Continuous Blood Gas Monitoring and End-tidal Carbon Dioxide Tension after Carbon Dioxide Injection

Comparison of Continuous Blood Gas Monitoring and End-tidal Carbon Dioxide Tension after Carbon Dioxide Injection

Design of intravascular fiber optic blood gas sensors

Arterial blood gas analysis is one of the most frequently requested tests performed on critically ill patients in both the operating room and intensive care unit. Fiber optic sensors are advantageous in that they require no electrical connection to the patient (except to measure temperature) and are low cost and disposable. The author details the design requirements of fiber optic sensors for continuous monitoring of blood gases and pH, and describes some of the design approaches used to meet these requirements. Attention is also focused on the challenges of using these sensors in human clinical applications.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Continuous intravascular blood gas monitoring

The benefit of a continuous intra-arterial blood gas monitor is apparent to any physician who has ever waited for the return of blood gas values at the bedside of a critically ill patient. The potential for rapid detection and prompt treatment of blood gas changes, coupled with immediate evaluation of the effectiveness of a therapeutic intervention, appears great. Whereas these systems may offer a tremendous advance in the physician's ability to track and treat alterations in cardiopulmonary physiology, no large-scale in vivo human trials have yet been reported. The only data available on accuracy, bias, precision, drift, and complication rate are from relatively small trials. Hopefully, when large-scale trials are completed, these systems will live up to their tremendous potential.

Comparison of Blood Gas and Electrolyte Test Results From the Gem-Stat and CDI-300 Versus a Conventional Laboratory Analyzer

Continuous blood gas monitoring devices have been an aid to the perfusionist since the introduction of the oxygen saturation meters of the early 1980s. Since that time, the perfusionist has had to decide between continuous versus intermittent sampling, and on-line (an analyzer that can automatically sample either at prescribed intervals and/or on demand) versus in-line devices (monitors that continuously sample and display results). This report compares the continuous, inline CDI-300 blood gas monitor and the Mallinckrodt Gem-Stat blood gas analyzer using intermittent sampling with the Coming 278 blood gas analyzer and 2500 Co-Oximeter. Thirty samples were taken, one per 30 patients, for comparison. Five samples were disqualified from the study. When comparing the remaining 25, the Gem-Stat results to the Coming 278 blood gas analyzer results, all measured values (arterial pH, pCO2, pO2, venous pO2, Na, K and Hct) correlated &gt;0.5000 with a p value of &lt;0.001. The exception was the ionized calcium value which had a correlation of0.2473 with a p value of &lt;0.232. When comparing the CDI-300 results to the Coming 278 blood gas machine results, all measured values (pH, pO2, pCO2 and venous pO2) correlated &gt;0.5000 with a p value of &lt;0.003 or better. When comparing the Gem-Stat results to the CDI results, all measured values (pH, pCO2, pO2 and venous pO2) correlated &gt;0.5000 with a p value of &lt;0.002 or better.

Continuous blood gas monitoring in haemodialysis using an electrode inserted in the extracorporeal dialysis circulation.

The aim of this study was to evaluate the usefulness of continuous gas monitoring during haemodialysis using an oxygen- and carbon dioxide-sensitive electrode inserted in the 'arterial' line from the arteriovenous fistula. We investigated 15 patients with chronic renal failure, treated with regular bicarbonate haemodialysis. The PO2 and PCO2 were measured by the new method and compared to conventional blood gas analysis of the 'arterial' blood from the dialysis circulation. We found the in situ gas sensors were stable and there was no systematic difference between gas tensions measured by in situ and conventional blood gas measurements. The standard deviations of the difference between paired measurements for PO2 and PCO2 were 1.3 and 0.4 kPa, respectively. Therefore, the method can be used to detect major changes in blood gas tensions during haemodialysis.

Continuous Monitoring of Arterial Blood Gases

Continuous Monitoring of Arterial Blood Gases

Standards of Care in Perfusion: Should Not Continuous In-line Blood Gas Monitoring Be One?

Standards of Care in Perfusion: Should Not Continuous In-line Blood Gas Monitoring Be One?

Con: continuous blood gas monitoring should not be a standard during cardiopulmonary bypass

Con: continuous blood gas monitoring should not be a standard during cardiopulmonary bypass

Continuous Blood Gas Monitoring Using the CDI System 300

The virtues and benefits of continuous on-line, realtime blood gas monitoring cannot be successfully denied, or its need be dismissed, on the basis of unavailable technology. Not electing to monitor blood gases continuously is parallel in thought to not continuously monitoring arterial blood pressures or the electrocardiogram. Given the ever changing pH, and the fluctuation of the pCO2 and pO2, we are never really sure of the trending that occurs during periods of low flow, temperature, and the myriad of other factors which affect acid/base balance. In order to be fully informed as to the total status of the patient, it is of the utmost importance to recognize continuous blood gas monitoring as an adjunct to cardiopulmonary bypass and not just a luxury option. The CDI System 300 continuously monitors arterial and venous pH, pCO, pO2 and calculates HC03/B.E., and SvO2 while storing the hematocrit. With virtually effortless calibration and insignificant set-up time, the perfusionist can create a wide margin of safety for himself and quality perfusion of the patient, as well as providing the minimum standard care.

Continuous blood gas monitoring with an intraarterial optode during one-lung anesthesia

ECAUSE OF THE possibility of hypoxemia and hypoventilation during one-lung anesthesia, an accurate method of continuously monitoring both oxygenation and ventilation would be useful. Arterial blood gas (ABG) sampling is intermittent, expensive, and may result in delays in recognizing hypoxia, hypercarbia, and acidosis. Transcutaneous oxygen tension measurement and pulse oximetry have been recommended during one-lung ventilation (OLV), but both techniques have limitations and neither monitors ventilation.‘” The fiberoptic intraarterial optode makes use of the phenomenon of fluorescence quenching to determine blood gases and pH? The three-component optode (Cardiovascular Devices, Inc, Irvine, CA) is easily inserted through an 18-gauge radial artery catheter and allows continuous arterial pressure monitoring as well as access for blood sampling. The optode technology has also been applied to continuous blood gas monitoring in the extracorporeal circuit during cardiac surgery.6Z7 A case of OLV using continuous intraarterial optode measurement of pHa, PaOZ, and PaCO, is reported.