Transesophageal Doppler Monitoring Research Articles

Techniki impedancyjne w praktyce lekarskiej

Hemodynamics monitoring provides important information about the performance of the heart, including preload, afterload, contractility, and pump efficiency. The most popular techniques used to be based on invasive methods, such as the Fick’s formula, thermodilution, and invasive intravascular pressure monitoring, and noninvasive ultrasound-based methods such as echocardiography, transesophageal Doppler monitoring of stroke volume, and peripheral arterial tonometry. Impedance methods combined with opportunities provided by telemedicine could bring new quality to the medical practice.

Meta-analysis of goal-directed fluid therapy using transoesophageal Doppler monitoring in patients undergoing elective colorectal surgery

Background Intraoperative goal-directed fluid therapy (GDFT) is recommended in most perioperative guidelines for intraoperative fluid management in patients undergoing elective colorectal surgery. However, the evidence in elective colorectal surgery alone is not well established. The aim of this meta-analysis was to compare the effects of GDFT with those of conventional fluid therapy on outcomes after elective colorectal surgery. Methods A meta-analysis of RCTs examining the role of transoesophageal Doppler-guided GDFT with conventional fluid therapy in adult patients undergoing elective colorectal surgery was performed in accordance with PRISMA methodology. The primary outcome measure was overall morbidity, and secondary outcome measures were length of hospital stay, time to return of gastrointestinal function, 30-day mortality, acute kidney injury, and surgical-site infection and anastomotic leak rates. Results A total of 11 studies were included with a total of 1113 patients (556 GDFT, 557 conventional fluid therapy). There was no significant difference in any clinical outcome measure studied between GDFT and conventional fluid therapy, including overall morbidity (risk ratio (RR) 0·90, 95 per cent c.i. 0·75 to 1·08, P = 0·27; I 2 = 47 per cent; 991 patients), 30-day mortality (RR 0·67, 0·23 to 1·92, P = 0·45; I 2 = 0 per cent; 1039 patients) and length of hospital stay (mean difference 0·01 (95 per cent c.i. -0·92 to 0·94) days, P = 0·98; I 2 = 34 per cent; 1049 patients). Conclusion This meta-analysis does not support the perceived benefits of GDFT guided by transoesophageal Doppler monitoring in the setting of elective colorectal surgery.

Early High Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure

AbstractBackground: High frequency oscillatory ventilation (HFOV) has been a staple in the management of children with acute respiratory failure (ARF). HFOV is a mode of mechanical ventilation that recruits diseased lung and improves oxygen-ation through the use of high mean airway pressures with tidal volumes less than anatomic dead space. Although HFOV is commonly used in children, efficacy data are limited and predate the era of low tidal volume (Vt) conventional mechan-ical ventilation (CMV).Aim of the Study: It was to compare the impact of early high frequency oscillatory ventilation (within 24-48 hours of endotracheal intubation) to conventional mechanical ventilation and/or late high frequency oscillatory ventilation in children with acute respiratory failure.Patients and Methods: The study was carried out on thirty patients with acute respiratory failure (ARF) who attended to the pediatric intensive care unit, Pediatric Department, Tanta University Hospital. All studied children were subjected to detailed history taking, complete physical examination, mon-itoring of SV, SVI, CO, CI, SVR, SVRI through trans-esophageal doppler monitoring and oxygenation index.Results: There was significant decrease of O2Sat of Early HFOV group compared with P-CMV and Late HFOV. there was significant increase of O2Sat in Early HFOV in 2nd and 3rd days compared with 1st day There was significant decrease of oxygenation index in late HFOV and P-CMV groups compared with Early HFOV group. It is one of most important prognostic factors for detection timing of HFOV according to ROC curve.Conclusion: As hypoxia worsened, patient percentage with Early HFOV increased Oxygenation index was significant as a predictor and prognostic factor for early HFOV success.

Efficacy of corrected left ventricular ejection time and stroke volume in guiding volume therapy during single lung transplantation: transesophageal Doppler monitoring

Objective To evaluate the efficacy of corrected left ventricular ejection time (LVETc) and stroke volume (SV) monitored by transesophageal Doppler in guiding volume therapy during single lung transplantation. Methods Twenty-six American Society of Anesthesiologists physical status Ⅲ or Ⅳ patients, aged 32-55 yr, with body mass index of 18.0-24.6 kg/m2, scheduled for elective single lung transplantation, were divided into 2 groups (n=13 each) using a random number table: control group (group C) and LVETc plus SV group (group LS). After implanting double lumen endobronchial tube, a transesophageal probe was inserted to monitor LVETc and SV in group LS, and Swan-Ganz catheter was inserted via the right internal jugular vein puncture to monitor CVP in group C. Fluid infusion was given according to CVP, and CVP was maintained at 6-12 cmH2O in group C. In group LS, fluid infusion was given according to LVETc and SV, LVETc was maintained at 0.35-0.40 s, and the fluctuation of SV was less than 10% of the baseline before fluid replacement.At 5 min before one-lung ventilation, 30 min of one-lung ventilation, 30 min of pulmonary artery occlusion and 30 min of pulmonary artery unclamping and at the end of operation, blood samples were collected from the radial artery for blood gas analysis, blood lactate levels were recorded, and oxygenation index was calculated.The liquid intake and output volume was recorded before pulmonary artery occlusion (from the end of one-lung ventilation until the time point before pulmonary artery occlusion), during pulmonary artery occlusion and during pulmonary artery unclamping (from removal of atrial clamp until the end of operation). The consumption of intraoperative furosemide and metaraminol was recorded.The development of pharyngeal mucosal membrane injury, esophageal perforation, hemorrhage or local hematoma was recorded after operation. Results Compared with group C, the oxygenation index was significantly increased and blood lactate concentrations were decreased at 30 min of pulmonary artery occlusion, 30 min of pulmonary artery unclamping and at the end of operation, the amount of crystalloid and colloid solution infused was increased before and during pulmonary artery occlusion and reduced during pulmonary artery unclamping, the urine output was increased in each period, and the consumption of intraoperative metaraminol was reduced in group LS (P<0.05). No postoperative esophageal perforation, bleeding or local hematoma was found in two groups, and only one patient had pharyngeal mucous membrane injury after operation in group LS. Conclusion LVETc and SV monitored by transesophageal Doppler can not only keep circulation capacity and tissue perfusion effective, but also maintain hemodynamics relatively stable during operation for patients undergoing single lung transplantation. Key words: Lung transplantation; Ventricular function, left; Stroke volume; Fluid therapy; Transesophageal, Doppler

Pulse-induced Continuous Cardiac Output Monitor versus Trans-esophageal Doppler Monitor for Optimization of Fluid Management in Patients Undergoing Major Abdominal Surgery. A Comparative Study

Pulse-induced Continuous Cardiac Output Monitor versus Trans-esophageal Doppler Monitor for Optimization of Fluid Management in Patients Undergoing Major Abdominal Surgery. A Comparative Study

Effect of Target-Controlled Infusion of Propofol-Fentanyl versus Desflurane in Cirrhotic Patients Undergoing Major Hepatic Resection with Transoesophageal Doppler Monitoring A Randomized Control Study

Background and aim: The choice of anaesthetic agents is important for cirrhotics undergoing liver resection. Aim is to compare Target Controlled Infusion (TCI) Propofol-Fentanyl versus Desflurane (Des) on recovery, hemodynamics monitored with Transoesophageal Doppler (TED), the effect on hepatocellular, kidney functions and economics. Patients and methods: Prospective randomized controlled study, 50 patients (Child A) divided equally. In (Des) group induction with fentanyl (1microgram/kg), propofol (2 mg/kg) and rocuronium (1 mg/kg) and maintenance with Desflurane. In (TCI) group the Propofol blood target concentration (Ct) for induction was set at 4 μg/min and Fentanyl infusion was set at 3 μg/kg for 30 seconds , 2 μg/kg/h for 30 min, 1.5 μg/kg/h from 31-150 min, and 1 μg/kg/h until 30 min before end. Both propofol and fentanyl maintained with Navigator pharmacokinetic software and Entropy guidance. TED, urinary micro albuminurea (microalb), blood Glutathione-S-transferase (GST) were monitored. Results: Extubation time prolonged with TCI vs. Des (15.2 ± 2.6 vs. 9.7 ± 1.5 min respectively, (P 0.05), (Microalb. 17.7 ± 2.5 vs. 18.64 ± 1.19, (μgm/ml) respectively, P>0.05). Des more economic than TCI (33.5 ± 8.2 vs. 69.1 ± 8.1 US Dollars), (P< 0.05) respectively during same surgical time and with comparable hemoglobin concentrations. Conclusion: Recovery was enhanced better with Desflurane. TED monitoring demonstrated a significant preservation of SVR and MABP post-resection with Des vs. TCI. Neither was superior to the other with respect to liver and kidney functions. Further studies on a larger scale are recommended.

Transesophageal Doppler monitoring for fluid therapy in patients undergoing major abdominal surgery

Objective To investigate the significance of transesophageal Doppler monitoring for fluid therapy in patients undergoing major abdominal surgery.Methods Ninety-six patients undergoing major abdominal surgery were randomly assigned into transesophageal Doppler monitoring group (ODM group,n =49) and control group (C group,n =47).Fluid volume,urine volume,mean arterial pressure and heart rate,lactic acid and B-type natriuretic peptide at ICU admission and complications 7 days after surgery were compared between two groups.Results Fluid volume [(5651.5 ± 561.8) ml vs.(5423.8 ±542.3) ml,P ＜0.05],urine volume [(376.5 ±99.6) ml vs.(228.9 ±68.2) ml,P ＜0.01] in ODM group significantly increased as compared with control group.At the end of operation,mean arterial pressure [(80.3 ± 8.2) mum Hg (1 mm Hg =0.133 kPa) vs.(70.0 ± 5.1) mm Hg,P ＜ 0.01] was higher in ODM group than that in control group,but no significant difference was found in heart rate between groups (P ＞ 0.05).Lactic acid [(1.9 ± 0.3) mmol/L vs.(3.8 ± 1.1) mmol/L,P ＜ 0.01] at ICU admission was markedly lower in ODM group than that in control group,but BNP showed no significant difference between groups.At 7th day after surgery,incidence of complications was lower in ODM group than that in control group.Conclusion Fluid therapy was guided with ODM,which could improve tissue oxygenation and low complication after surgery. Key words: Transesophageal doppler monitoring; Major abdominal surgery; Fluid therapy; Stroke volume

Transoesophageal Doppler compared to central venous pressure for perioperative hemodynamic monitoring and fluid guidance in liver resection

Purpose:Major hepatic resections may result in hemodynamic changes. Aim is to study transesophageal Doppler (TED) monitoring and fluid management in comparison to central venous pressure (CVP) monitoring. A follow-up comparative hospital based study.Methods:59 consecutive cirrhotic patients (CHILD A) undergoing major hepatotomy. CVP monitoring only (CVP group), (n=30) and TED (Doppler group), (n=29) with CVP transduced but not available on the monitor. Exclusion criteria include contra-indication for Doppler probe insertion or bleeding tendency. An attempt to reduce CVP during the resection in both groups with colloid restriction, but crystalloids infusion of 6 ml/kg/h was allowed to replace insensible loss. Post-resection colloids infusion were CVP guided in CVP group (5-10 mmHg) and corrected flow time (FTc) aortic guided in Doppler group (>0.4 s) blood products given according to the laboratory data.Results:Using the FTc to guide Hydroxyethyl starch 130/0.4 significantly decreased intake in TED versus CVP (1.03 [0.49] versus 1.74 [0.41] Liter; P<0.05). Nausea, vomiting, and chest infection were less in TED with a shorter hospital stay (P<0.05). No correlation between FTc and CVP (r=0.24, P > 0.05). Cardiac index and stroke volume of TED increased post-resection compared to baseline, 3.0 (0.9) versus 3.6 (0.9) L/min/m2, P<0.05; 67.1 (14.5) versus 76 (13.2) ml, P<0.05, respectively, associated with a decrease in systemic vascular resistance (SVR) 1142.7 (511) versus 835.4 (190.9) dynes.s/cm5, P<0.05. No significant difference in arterial pressure and CVP between groups at any stage. CVP during resection in TED 6.4 (3.06) mmHg versus 6.1 (1.4) in CVP group, P=0.6. TED placement consumed less time than CVP (7.3 [1.5] min versus 13.2 [2.9], P<0.05).Conclusion:TED in comparison to the CVP monitoring was able to reduced colloids administration post-resection, lower morbidity and shorten hospital stay. TED consumed less time to insert and was also able to present significant hemodynamic changes. Advanced surgical techniques of resection play a key role in reducing blood loss despite CVP more than 5 cm H2O. TED fluid management protocols during resection need to be developed.

Transesophageal Doppler devices: A technical review

Monitoring of aortic blood flow, conducting large portions of the cardiac output (CO), allows conclusions on the global hemodynamic status of patients. For this purpose, transesophageal Doppler (TED) devices have been developed, which interrogate the descending aorta and calculate aortic blood flow velocity using the Doppler principle. The recorded velocity-time curve can be used to estimate CO as well other advanced hemodynamic parameters such as preload, afterload and myocardial contractility. Clinical studies in perioperative patients have demonstrated a reduced postoperative morbidity and shorter length of hospital stay when TED is used to guide fluid management. However, several assumptions are needed to translate the measured Doppler frequency shift to hemo- dynamic variables and discrepancies between the assumed and the actual condition may introduce a considerable risk for erroneous calculations. A correct interpretation of the displayed parameters requires profound knowledge on the technical basis of this method as well as its technical limitations. Our review focuses on these technical aspects which the clinician should be familiar with to allow proper use of TED monitoring devices.

The hemodynamic effects of a reversed Trendelenburg in elderly patients with increased cardiac risk during laparoscopic cholecystectomy.

We studied the hemodynamic changes induced by pneumoperitoneum and a reversed Trendelenburg in elderly patients with increased cardiac risk (ASA class III; n = 30; age 70.8 +/- 4.9 years, mean +/- SD) and compared the results with elderly patients at normal risk (ASA class II; n = 30; age 69.2 +/- 4.1 years) during laparoscopic cholecystectomy. The transesophageal Doppler monitor was performed after induction of general anesthesia (pre-incision), after onset of pneumoperitoneum (insufflation), after head-up (20degrees) and a left lateral tilt (15degrees) (reversed Trendelenburg) and after deflation and horizontal position (desufflation). Mean arterial pressure (MAP), heart rate, cardiac index (CI) and systemic vascular resistance (SVR) were measured, respectively. Induction of pneumoperitoneum and head-up tilt in patients with cardiac risk resulted significantly in a decrease in CI and an increase in SVR compared with patients with normal risk (P < 0.05), and that remained until deflation, but no interval changes in MAP and heart rate. The CI, MAP and heart rate decreased and SVR increased significantly in patients with cardiac risk compared with patients with normal risk before incision (P < 0.05). No complications occurred. The results indicate that pneumoperitoneum and a reversed Trendelenburg are associated with significant but relatively benign hemodynamic changes. Anesthesia for laparoscopic cholecystectomy in elderly patients with increased cardiac risk should be performed with an adequate hemodynamic monitoring.

Transoesophageal Doppler Monitoring For Fluid And Hemodynamic Treatment During Lung Surgery

Patients undergoing lung resection are vulnerable to fluid overhydration. Recently, goal-directed fluid therapy using transoesophageal Doppler monitoring (TDM) has been shown to improve postoperative clinical outcome. The aim of this study was to assess the feasibility of TDM during open-chest procedures for guiding fluid and hemodynamic treatment. We performed an observational prospective study including 127 high-risk patients undergoing lung cancer resection. A restrictive fluid strategy was targeted to achieve a stroke volume index (SVI) > or = 30 ml/min/m(2). Besides standard hemodynamic measurements, stroke volume index (SVI), corrected flow time (FTc), maximal acceleration (MA) and velocity (PV) were recorded during two-lung ventilation (TLV) and one-lung ventilation (OLV). Doppler flow tracings could not be obtained in 4 patients during TLV (3.1%) and in 6 patients during OLV (4.9%). Preoperatively, 96 pts had SVI > or = 30 ml/min/m(2) (N-SVI group) whereas 21 patients had SVI < 30 ml/min/m(2) (L-SVI group) associated with lower FTc values. After OLV, SVI transiently decreased (-17 +/- 9%; P < 0.05) in the N-SVI group whereas in the L-SVI group, SVI increased steadily until the end of surgery (+40 +/- 12%). Other flow-related parameters as well as heart rate and mean arterial pressure remained unchanged. Surgical and medical characteristics did not differ between the two groups, except that larger volumes of colloids were administered intraoperatively in the L-SVI group (+2.2 +/- 0.6 ml/min/h compared with N-SVI group, P < 0.05). In thoracic surgical patients, TDM can be used to detect and correct low flow conditions and to guide hemodynamic support during the intraoperative period.

The Transesophageal Doppler and Hemodynamic Effects of Epidural Anesthesia in Infants Anesthetized with Sevoflurane and Sufentanil

It is thought that pediatric epidural anesthesia (EA) provides hemodynamic stability in children. However, when compared with information relating to adults, little is known about the hemodynamic effects of epidural EA on cardiac output (CO) in infants. Using transesophageal Doppler to monitor CO, we prospectively studied 14 infants <10 kg who were scheduled for abdominal surgery. During sevoflurane general anesthesia, CO transesophageal Doppler monitoring was performed before and after lumbar EA with 0.75 mL/kg of 0.25% bupivacaine and 1:200,000 adrenaline. CO, arterial blood pressure, and heart rate were measured before and 5, 15, and 20 min after performance of EA. In patients anesthetized with sevoflurane and sufentanil, EA resulted in an increase in stroke volume by 29% (P < 0.0001) and a decrease in heart rate by 13% (P < 0.0001). EA also induced a significant decrease in systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance by 11%, 18%, 15%, and 25%, respectively. Conversely, CO remained unchanged. The increase in stroke volume observed is probably explained by optimization of afterload because of the sympathetic blockade induced by EA. These results confirm that EA provides hemodynamic stability in infants weighing <10 kg and supports the use of EA in this pediatric population.

Hémorragie méningée et défaillance myocardique : intérêt du monitorage hémodynamique par doppler œsophagien

Spontaneous subarachnoidal haemorrhage can be associated with neurogenic pulmonary oedema and cardiogenic shock. The presentation is an ischemic myocardial dysfunction associated with normal coronary arteries. Hypoxaemia associated with arterial hypotension on patients with brain injury can worsen neurological outcome. The administration of norepinephrine associated with fluid expansion could be deleterious on cardiac function. We report the case of a patient with acute pulmonary oedema associated with post-aneurysmal subarachnoid haemorrhage managed with transoesophageal Doppler monitoring.

Hemodynamic Measurements After Cardiac Surgery: Transesophageal Doppler Versus Pulmonary Artery Catheter

The purpose of this study was to compare hemodynamic data derived from the transesophageal Doppler monitor (Medicina TECO, Berkshire, United Kingdom) against those obtained from a pulmonary artery catheter after coronary artery bypass grafting (CABG). Prospective, nonrandomized, clinical study. Single, tertiary referral center. Thirty-five adult patients. Cardiac output and hemodynamic variables were measured and compared at 4 predefined time points in patients undergoing elective off-pump CABG surgery from January 2003 through June 2003. A total of 140 pairs for cardiac output (CO) data were obtained. Transesophageal cardiac output (TECO) values ranged from 1.9 to 8.7 L/min. Thermodilution cardiac output (TDCO) values ranged from 2.7 to 7.6 L/min. Matched measurements were made with each patient at intervals of 30 minutes. Bland-Altman analysis revealed a mean bias of 1.18 +/- 1.36 L/min, with a correlation (r) of 0.593 (p < 0.000) between TECO and TDCO. Similarly poor correlation was observed among cardiac index (r = 0.523), stroke volume (r = 0.615), systemic vascular resistance (r = 0.595), left ventricular stroke work index (r = 0.594), and right ventricular stroke work index (r = 0.590) measured by an esophageal Doppler monitor against a pulmonary artery catheter. A transesophageal Doppler device (Medicina TECO) cannot be relied on as a sole method for monitoring cardiac output and derived hemodynamic variables in patients after CABG surgery.

The Effects of Spread of Block and Adrenaline on Cardiac Output After Epidural Anesthesia in Young Children: A Randomized, Double-Blind, Prospective Study

Epidural anesthesia is considered to be without significant hemodynamic consequence in young children. However, conversely to adults, few studies have investigated cardiac output. Using transesophageal Doppler monitoring of cardiac output, we prospectively investigated hemodynamic alterations in 48 children (median age, 22.5 mo) receiving sevoflurane general anesthesia combined with caudal or thoracolumbar epidural anesthesia. They were randomly assigned to receive 0.8 mL/kg of plain local anesthetic mixture (lidocaine 1% + bupivacaine 0.25% (50/50) + 1 microg/mL of fentanyl) or 1 mL/kg of the same mixture with 5 microg/mL of adrenaline. No significant hemodynamic alteration was elicited in caudal and thoracolumbar groups receiving the plain mixture except a moderate decrease in heart rate. Conversely, a mixture with adrenaline added provoked a significant decrease in mean arterial blood pressure by 14% and 17%, in systemic vascular resistance by 24% and 40%, and an increase in cardiac output by 20% and 34% in caudal and thoracolumbar groups, respectively. The adrenaline effect was greater by the thoracolumbar than the caudal approach. In young children, epidural anesthesia induces an increase in cardiac output only when adrenaline is added to local anesthetics, probably through its systemic absorption from the epidural space. Epidural anesthesia may induce significant hemodynamic changes, well documented in adults. Using noninvasive hemodynamic monitoring in children, we reported an increase in cardiac output and a decrease in arterial blood pressure only when epinephrine was added to epidurally-injected local anesthetics.

Procedures and Monitoring for the Critically Ill

Procedures and Monitoring for the Critically Ill is a multi-authored manual, detailing 29 procedures and monitoring techniques used in intensive care. This is an expedient, introductory critical care reference, particularly for physicians in training. The topics are pragmatic, describing common procedural topics for intensive care. Typically, each area has an effective description of the methods and illustrations of the techniques. A bibliography of key references accompanies each chapter. Succinct descriptions of step by step methods as well as the required supplies are included for 1) hemodynamic monitoring (e.g., central venous pressure, pulmonary artery catheterization, arterial catheterization); 2) neurologic monitoring (e.g., intra-cranial pressure monitoring, jugular bulb oximetry); 3) trauma related areas (e.g., spinal immobilization, intra-abdominal pressure monitoring, abdominal paracentesis; 4) emergency airway support (e.g., endotracheal intubation, cricothryrotomy, bronchoscopy, and tracheostomy); as well as 5) other areas including transesophageal Doppler monitoring, epidural analgesia, renal support, and inferior vena cava filter placement. For greater detail in ICU monitoring procedures, interested readers are recommended to more encyclopedic texts, such as Principles and Practices of Intensive Care Medicine, edited by M.Tobin. In summary, this text is a useful reference during the preliminary years of training for critical care or rapid review of methodologies of ICU procedures and monitoring techniques.

Cardiac output determination during experimental hemorrhage and resuscitation using a transesophageal Doppler monitor

Transesophageal Doppler (TED) has been considered a noninvasive and accurate alternative to pulmonary artery catheter for volume replacement and cardiac output measurement in patients undergoing major surgeries.

Comparison of Transesophageal Doppler Monitor vs. Pulmonary Artery Catheter in the Hemodynamic Indices of Major Burn Patients Undergoing an Extensive Escharectomy

Background: In major burn patients, many invasive monitors including a pulmonary artery catheter (PAC) are often required to assess hemodynamic status. An esophageal Doppler monitor (EDM), as a noninvasive method of measuring hemodynamic parameters, may be a substitute for a PAC in this clinical circumstance. This study was conducted to evaluate the validity of Doppler derived hemodynamic indices in comparison to that of a PAC. Methods: A total of 20 critically ill, severe burn patients, scheduled for an elective escharectomy and application of artificial dermis, were enrolled for the placement of a PAC and EDM. Simultaneous data was collected in regular intervals and the various parameters were compared between the two methods. Results: A total of 158 pairs of data in 20 patients were gathered. Among all the parameters, cardiac output (CO) and stroke volume (SV) showed consistently 20% less in EDM. Correlation coefficients of heart rate (HR), CO, SV and systemic vascular resistance (SVR) were 0.97, 0.54, 0.62, and 0.68 respectively. Corrected flow time (FTc) had poor correlations with central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP). In the mean time, significant, but very weak correlations with FTc vs. CO and SV were demonstrated. Conclusions: EDM may be a substitute for a thermodilution (TD) PAC technique, it can be used with usefulness for hemodynamic and preload assessment in major burn patients.

Argon Pneumoperitoneum Is More Dangerous than CO2 Pneumoperitoneum During Venous Gas Embolism

We investigated the possibility of using argon, an inert gas, as a replacement for carbon dioxide (CO2).The tolerance of argon pneumoperitoneum was compared with that of CO2 pneumoperitoneum. Twenty pigs were anesthetized with enflurane 1.5%. Argon (n = 11) or CO2 (n = 9) pneumoperitoneum was created at 15 mm Hg over 20 min, and serial intravenous injections of each gas (ranging from 0.1 to 20 mL/kg) were made. Cardiorespiratory variables were measured. Transesophageal Doppler and capnographic monitoring were assessed in the detection of embolism. During argon pneumoperitoneum, there was no significant change from baseline in arterial pressure and pulmonary excretion of CO2, mean systemic arterial pressure (MAP), mean pulmonary artery pressure (PAP), or systemic and pulmonary vascular resistances, whereas CO2 pneumoperitoneum significantly increased these values (P < 0.05). During the embolic trial and from gas volumes of 2 and 0.2 mL/kg, the decrease in MAP and the increase in PAP were significantly higher with argon than with CO2 (P < 0.05). In contrast to CO2, argon pneumoperitoneum was not associated with significant changes in cardiorespiratory functions. However, argon embolism seems to be more deleterious than CO2 embolism. The possibility of using argon pneumoperitoneum during laparoscopy remains uncertain. Implications: Laparoscopic surgery requires insufflation of gas into the peritoneal cavity. We compared the hemodynamic effects of argon, an inert gas, and carbon dioxide in a pig model of laparoscopic surgery. We conclude that argon carries a high risk factor in the case of an accidental gas embolism. (Anesth Analg 1997;85:1367-71)

Argon Pneumoperitoneum Is More Dangerous than CO2 Pneumoperitoneum During Venous Gas Embolism

We investigated the possibility of using argon, an inert gas, as a replacement for carbon dioxide (CO2). The tolerance of argon pneumoperitoneum was compared with that of CO2 pneumoperitoneum. Twenty pigs were anesthetized with enflurane 1.5%. Argon (n = 11) or CO2 (n = 9) pneumoperitoneum was created at 15 mm Hg over 20 min, and serial intravenous injections of each gas (ranging from 0.1 to 20 mL/kg) were made. Cardiorespiratory variables were measured. Transesophageal Doppler and capnographic monitoring were assessed in the detection of embolism. During argon pneumoperitoneum, there was no significant change from baseline in arterial pressure and pulmonary excretion of CO2, mean systemic arterial pressure (MAP), mean pulmonary artery pressure (PAP), or systemic and pulmonary vascular resistances, whereas CO2 pneumoperitoneum significantly increased these values (P < 0.05). During the embolic trial and from gas volumes of 2 and 0.2 mL/kg, the decrease in MAP and the increase in PAP were significantly higher with argon than with CO2 (P < 0.05). In contrast to CO2, argon pneumoperitoneum was not associated with significant changes in cardiorespiratory functions. However, argon embolism seems to be more deleterious than CO2 embolism. The possibility of using argon pneumoperitoneum during laparoscopy remains uncertain. Laparoscopic surgery requires insufflation of gas into the peritoneal cavity. We compared the hemodynamic effects of argon, an inert gas, and carbon dioxide in a pig model of laparoscopic surgery. We conclude that argon carries a high risk factor in the case of an accidental gas embolism.