ANESTH ANALG 2008;106(SCA Suppl):1-128

SCA49 USE OF CREATININE LEVELS FOR STAGING OF ACUTE KIDNEY INJURY IN PEDIATRIC PATIENTS UNDERGOING OPEN HEART SURGERY Székely A; Cserép Z; Sápi E; Héthársi B; Fischer K; Breuer T; Tóth R; Szenczi B; Hartyánszky I; Szatmári A Gottsegen György Hungarian Institute of Cardiology, Budapest, Budapest, Hungary

Background: Acut kidney injury (AKI) is a common clinical problem, defined by abrupt decline in renal function, with manifestations ranging from minimal elevation of serum creatinine to anuric renal failure. Changes in creatinine levels are used to identify the three stages of AKI, but the definitions require evaluation in pediatric patients undergoing open heart surgery. Methods: We have retrospectively assessed the incidence of AKI in our prospectively and consecutively collected database of 985 pediatric patients undergoing cardiopulmonary bypass between January, 2004 and December 31, 2006. 3 categories of AKI were defined by the changes of serum creatinine level (1: rise of creatinine level by >24.6 mmol/l or increase to 1,5-fold to baseline, 2: increase to 2-3-fold to baseline 3 :increase to >3-fold to baseline) and the need for dialysis. Fischer exact test, ROC analysis and MWU test were used for statistical analysis.

Results: 43 patients needed peritoneal dialysis and 205 had low output syndrome (LOS). Significant differences were found in body weight and creatinine level between the groups, but not in the urine output. Within the dialyzed group, 55.6 % did not reach the 1.5 rise in the creatinine level compared to baseline (Stage 1) on the first postoperative day and 44 % did not exceed it on the 2nd day. In the LOS group, 26.7 % had reached a creatinine rise of >50 % without need for dialysis. The increment of creatinine level > 24.6 mmol/l did not predict the dialysis on the second and third day. Within the group with LOS, 74.3 % had no change between the preoperative and postoperative creatinine level. 19 % elevation in the creatinine level compared to the preoperative level predicted the need for peritoneal dialysis with 74% specificity and 75 % sensitivity (AUC: 0,788). Conclusions: AKI categories could not be used in the early postoperative period after pediatric cardiac surgery. The need for dialysis was not predicted by the increment of creatinine level > 24.6 mmol/l contrary to the definition for adults. However, a smaller increase was associated with dialysis with highsensitivity and specificity. Further investigations are needed.

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SCA50 EFFECT OF ORAL SILDENAFIL CITRATE AND ORAL BERAPROST COMBINED TREATMENT ON INTRAOPERATIVE HEMODYNAMICS IN PATIENTS WITH PULMONARY HYPERTENSION UNDERGOING VALVULAR HEART SURGERY. Hong SW1; Lee JY1; Choi Y1; Jung SM2; Lee JH1 Yonsei University College of Medicine1, Seoul, Republic of Korea; Yonsei University College of Medicine, Seoul, Republic of Korea; Konyang University College of Medicine2, Daejeon, Republic of Korea

OBJECTIVE: Pulmonary hypertension (PH) remains a major problem during the perioperative period for surgical correction of long-standing valvular heart disease. Among pharmacological agents to reduce PH, sildenafil and beraprost are increasingly used with contradictory clinical efficacies. Sildenafil is a phosphodiesterase 5 inhibitor, whereas beraprost is the first chemically stable and orally active prostacyclin analogue. Considering that sildenafil and beraprost dilate pulmonary vessels through different mechanisms, combination therapy with both drugs may have additive or synergistic effects on pulmonary hemodynamics. We therefore evaluated the combined effects of oral sildenafil and beraprost treatment on intraoperative hemodynamics in patients with PH undergoing valvular heart surgery in a prospective, randomized, controlled and double-blind trial. METHODS: Twenty-seven patients scheduled for valvular heart surgery with mean pulmonary arterial pressure greater than 30 mm Hg were randomly allocated to either combined oral sildenafil citrate 50 mg and beraprost 40 m treatment group (n = 14) or placebo group (n = 13) 10 min before induction of anesthesia. Hemodynamic variables were measured at 15, 30 and 60 min after medication.

RESULTS: Patient characteristics and pre-induction hemodynamic variables were similar between groups. Systolic pulmonary arterial pressure, mean pulmonary arterial pressure and mean systemic arterial pressure were significantly decreased in both groups relative to values at pre-induction. In intergroup comparisons, pulmonary vascular resistance index (PVRI), mean arterial pressures and systemic vascular resistance index (SVRI) were significantly lower in the treatment group, at 15 minutes after medication. Percent changes of PVRI from the pre-induction value were significantly more pronounced in the treatment group at 15 and 60 min after medication, whereas percent changes of SVRI did not show any significant differences between the groups. In addition, PVRI was consistently lower than baseline value during study period in the treatment group but not in the control group. CONCLUSION: Combined treatment with pre-anesthetic oral sildenafil and beraprost produced significant pulmonary vasodilatory effect relative to placebo in anesthetized cardiac surgical patients with PH. These effects were relatively selective to pulmonary vasculature than systemic, implicating their potential role as a treatment modality for PH encountered in the perioperative setting in cardiac surgical patients.

Table 1. Changes in pulmonary and systemic arterial pressures and vascular resistance and % change PVRI SVRI

Group

Pre-ind

Baseline

T30

T60

control

470 ± 263

307 ± 186

256 ± 118

313 ± 97

sil + bera

420 ± 227

179 ± 98 †

237 ± 140†

240 ± 105†

control

3025 ± 817

2129 ± 584

2017 ± 383

2575 ± 610

sil + bera

2450 ± 1270

1454 ± 640 †

1722 ± 894

1630 ± 631 †

PVRI

control

-31 ± 18

-30 ± 33

-11 ± 35

(% change)

sil + bera

-49 ± 24

-37 ± 25

-39 ± 20

SVRI

control

-23 ± 16

-21 ± 16

1.25 ± 29

(% change)

sil + bera

-34 ± 14

-24 ± 21

-30 ± 17

* = p11% according to the logistic EUROSCORE were considered suitable for inclusion into the study. For echocardiographic purposes, Philips iE 33 with Real Time 3D TEE was used. All the surgeries were performed in a hybrid operation theatre, after obtaining written consent from the patients and ethical clearance from local ethical committee.The procedure was performed through a left anteriorlateral minithoracotomy in fifth intercostals space. After the introduction of a balloon catheter via puncture of the leftventricular apex, placement was confirmed through fluoroscopic and echocardiographic guidance. After valvuloplasty was done (under rapid ventricular pacing) the valve was positioned after de-airing so that the annulus bisects the stent. Confirmation of placement was through angiography and TEE guidance.As the valve needs to be firmly placed in the annulus, an oversizing technique of approximately 2-3mm was applied.

Results: As Realtime 3D is a recently introduced technological advancement in the field of TEE, we had the opportunity to perform this procedure in 15 patients in our study group. The 3D measurement of the annulus correlated well with 2D and surgical findings. 3D echo was useful for valvular assessment after valve replacement. 2D TEE was equally informative but had the disadvantage of acousting shadowing caused by the crimped steel stent of the valve and the ballon catheter. This was not so with the use of 3D echo. The placement of the catheter was assessed through AV LAX view as both the coronary ostium could be well visualized. The rotation of the trackball in 3D Live mode, with nearly simultaneous access to SAX and LAX views, made valve and catheter placement more precise, faster and accurate. We also realised that there was a significant reduction in the number of angiographic exposure post-implantation of the valve, as 3D visualisation of the aortic root was equally good. Conclusion: Although Realtime 3D has its own limitations, it is a valuable tool for quantitative and qualitative assessment of the aortic valve implantation through the transapical beating heart approach. Reference. 1.Minimal invasive transapical beating heart implantation-proof of concept. Walther et al. Eur.Journal of Crdiothoracic surgery 2007;31:9-15 2.Guidelines for the management of the patients with valvular heart disease.Executive summary. Bonow et al.Circulation 2006; 113:85-151

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SCA53 PREOPERATIVE BLOOD PRESSURE MANAGEMENT WITH SODIUM NITROPRUSSIDE OR NITROGLYCERIN IS ASSOCIATED WITH AN INCREASED RISK OF 30-DAY MORTALITY COMPARED WITH CLEVIDIPINE: RESULTS OF THE ECLIPSE TRIALS Aronson S1; Levy J2; Lumb P3; Cheung A4; Fontes M5; Avery E6; Newman M1 Duke University Med. Center1, Durham, NC, US; Emory University2, Atlanta, GA, US; University of Southern California3, Los Angeles, CA, US; University of Pennsylvania4, Philadelphia, PA, US; Cornell University5, Ithaca, NY, US; Massachusetts General Hospital6, Boston, MA, US BACKGROUND: In cardiac surgery the inability to precisely control blood pressure (BP) has been recognized as an important modifiable risk factor associated with adverse outcome. ECLIPSE is the largest randomized perioperative cardiac surgery trial so far of intravenous (IV) antihypertensives that compared clevidipine (CLV), a novel short-acting IV dihydropyridine calcium channel blocker, to sodium nitroprusside (SNP) and nitroglycerin (NTG). We evaluated 30-day mortality in a subset of patients from the ECLIPSE trials that received IV antihypertensive therapy before skin incision for BP control. METHODS: Patients undergoing cardiac surgery were randomized in an open-label (1:1) study to CLV vs SNP or CLV vs NTG. Patients who had study drug started preincision for the control of perioperative BP according to investigator discretion were included in this subset analysis. Risk factors including BP control (assessed using area under the curve [AUC] analysis capturing the magnitude and duration of BP excursions outside prespecified systolic BP range) were evaluated with multiple logistic regression analysis on the incidence of all-cause 30-day mortality.

RESULTS: A total of 282 patients were included in this analysis. The overall incidence of 30-day mortality in patients who required treatment for BP control before incision was 5% with a significant difference between groups; 3/137 (2%) of CLV patients and 11/145 (8%) of NTG/SNP patients (p< 0.03). The initiation of BP control with SNP or NTG versus CLV was associated with an increased risk of 30-day mortality. Factors that increased the risk of 30-day mortality are presented in the table below. CONCLUSION: Preincision treatment with either SNP or NTG is associated with a greater risk of mortality at 30 days compared to clevidipine. Additional studies are needed to determine the causes of this reduction in rate of mortality associated with clevidipine.

Treatment SNP/NTG vs CLV

p-value

O.R

95% CI

0.0149

7.6

1.5, 39.2

Additional procedures during surgery

0.0071

5.8

1.6, 21.2

Pre-op creatinine •1.2 mg/dL

0.0158

4.8

1.3, 17.4

Any valve or redo CABG

0.0483

3.7

1.0, 13.4

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SCA54 INTRAOPERATIVE MANAGEMENT OF CARDIAC OUTPUT AND STROKE VOLUME VARIATION MEASURED BY THE ARTERIAL PRESSURE WAVEFORM ANALYSIS DURING THE VALVE REPLACEMENT SURGERY FOR THE AORTIC STENOSIS PATIENT Ohnishi Y; Nohmi T; Yoshitani K National Cardiovascular Center, Suita, Osaka, Japan

Background: The use of pulmonary artery catheter (PAC) has been criticized because of its unclear risk-benefit ratio during the cardiac surgery. Arterial pressure waveform analysis monitor (Flo Trac / VigileoTM) is not only measured continuous cardiac output but also evaluate stroke volume variation (SVV). As patients with severe aortic stenosis hypertrophied left ventricular wall and reduced intra-ventricular volume, restrictive fluid infusion management and maintenance of systemic vascular resistance is required intraoperatively. The purpose of this study was estimated the utility of arterial pressure waveform analysis monitoring during aortic valve replacement surgery because of the severe aortic stenosis.

jugular vein, and transesophageal echocardiography (TEE) probe were inserted orally. Cardiac output with bolus thermodilution method using PAC (PACO) was measured and compared with APCO at 6 point; after induction of anesthesia, after incision of sternum, before cardiopulmonary bypass, after weaning from cardiopulmonary bypass, before closure of sternum and after closure of sternum respectively. Linear regression analysis was performed by calculation of the coefficient of correlation between PACO and APCO and mean difference (bias) and precision (SD). At the same 6 points, ventricular systolic and diastolic diameter was measured by transgastric short axis view using TEE, and compared with SVV.

Patients and Methods: After institutional approval and written informed content was obtained, 10 adult patients (male: female 5:5, mean age 71 years) who underwent aortic valve replacement because of severe aortic stenosis was included in this study. All patients were obtained radial arterial line with 20 gauge catheter and connected arterial pressure based cardiac output measurement systems and measured cardiac output (APCO) continuously. After induction of anesthesia, PAC was inserted via right internal

Result: A total of 60 paints of APCO and SVV were analyzed. Bias and precision between PACO and APCO were 0.12L/min and ±1.15L/min (r = 0.64) resulting in an overall percentage error of 39%. Left ventricular diastolic diameter were well correlated with SVV by exponential function (r = 0.59). Conclusion: Continuous monitoring of APCO and SVV was profitable and might be substituted for PAC during the aortic valve replacement surgery for severe aortic stenosis patient.

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SCA55 THE USE OF PULSECO™ FOR BIVENTRICULAR PACING OPTIMIZATION AFTER CARDIAC SURGERY Booth J; Quinn TA; Richmond M; Cabreriza S; Weinberg A; Spotnitz H Columbia University, Houston, TX, United States; Columbia University, New York, NY, United States

BACKGROUND: Temporary biventricular pacing (BiVP) can increase cardiac output (CO) in patients with left ventricular (LV) dysfunction after cardiac surgery. Optimization of LV pacing site, atrioventricular (AVD) and interventricular (VVD) pacing delay can improve BiVP efficacy and may convert nonresponders. We have selected CO as the critical optimization measure. Devices that calculate continuous CO from the arterial pressure waveform, such as PulseCO, may be useful for CO monitoring. Thus, we investigated the reliability of PulseCO in the clinical setting by comparison with aortic flow probe CO measurement during optimization of BiVP after cardiac surgery. METHODS: Seven patients in the Biventricular Pacing After Cardiac Surgery (BiPACS) trial were studied. Temporary epicardial pacing wires were sewn to the right atrium, right ventricle (RV), and two LV sites (LV1, LV2). An electromagnetic flow probe was placed around the ascending aorta. PulseCO was connected to the radial artery pressure line. BiVP was initiated using standard settings (heart rate=90 bpm, AVD=150 msec, VVD=0 msec). After weaning from cardiopulmonary bypass, AVD was varied from 90 to 270 msec in 30 msec increments. With the optimal AVD, ventricular site was varied between RV only, BiVP with LV1, and BiVP

with LV2. With the optimal LV site, VVD was varied from +80 to -80 msec in 20 msec increments. All were tested in random order for 10 seconds and repeated. Continuous CO and mean arterial pressure (MAP) were calculated by PulseCO and by integrating the recorded signals over each cardiac cycle. Values for each setting were obtained by averaging 3 consecutive cardiac cycles at end-expiration. Reliability was estimated by Fleiss method, generalized to account for replicate measures within each patient, and agreement (mean difference ± bias) was assessed by BlandAltman analysis. RESULTS: CO by PulseCO correlated well with flow probe measurements (r = 0.90, Fig. 1). There was good agreement between the two methods (-0.04±0.72 L/min, Fig. 2). However, optimal settings determined from PulseCO agreed with those from the flow probe only 62% of the time. MAP correlated poorly with both CO measurements. CONCLUSIONS: PulseCO reliably measures continuous CO in open-chest patients after cardiac surgery, but its reliability for BiVP optimization is questionable. MAP is a poor surrogate for CO in this setting, possibly due to patient instability immediately post-bypass. Further studies in the closed chest are indicated.

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SCA56 LOCATION OF THE CARADIOPULMONARY BYPASS MACHINE IN THE OPERATING ROOM: AN INITIAL SURVEY OF DIFFERENCES IN PRACTICE PATTERNS Gaitan B; Candiotti K; Martin M; Barron M University of Miami Miller School of Medicine, Miami, FL, USA

Introduction Despite more than 50 years of clinical practice, data evaluating the effectiveness and safety of cardiopulmonary bypass (CPB) remain more experience than evidence based(1). Perfusion safety includes the technical components, perfusion practices, and performance parameters including vigilance and communication(2). The type of perfusion practice does affect the rate of incidents related to CPB(3). Literature describes mostly equipment and practice accidents and further determinants of perfusion safety continue to be defined(4). The importance of human factors, including communication, and its influence on adverse outcomes is firmly established(5). The purpose of this study was to examine the current practices and beliefs of anesthesiologists, cardiothoracic surgeons, and perfusionists as they relate to the physical location of the CPB machine and whether the location might impact effective communication. Methods After obtaining Institutional Review Board approval, a 10-question survey was distributed to: anesthesiologists, cardiothoracic surgeons, and perfusionists. The survey was distributed via both open solicitation and direct email contact to members of the Society for Cardiovascular Anesthesiologists, the Society of Thoracic Surgeons, and the American Society of ExtraCorporeal Technology.

Results A total of 135 results were analyzed. Of the 135 respondents, 29.9% were cardiothoracic surgeons, 45.5% were anesthesiologists, and 24.6% were perfusionists. 72.6% of the total respondents claimed to have a strong preference as to location of the CPBM machine. 51.1% of the respondents prefer the CPBM to be located directly in front of the surgeon, specifically because communication is easier between the surgeon and the perfusionist. Individually the cardiothoracic surgeons showed the strongest preference for location of the CPBM(90%). Approximately 75% felt that the location of the machine has a significant impact on the ability to effectively communicate in the operating room. For anesthesiologists 53% indicated they had a strong preference for location and approximately 55% responded that the location has a significant impact on effective communication and patient safety. Interestingly none of the perfusionists reported a preference for the location of the CBPM, and 75% felt that its location did not impact communication or patient safety. Conversely, 56% of respondents reported the CPBM location is based on reasons other than the position of surgeon or perfusionist. Discussion Our results indicate that surgeons and anesthesiologists feel that the location of the CPBM plays a major role in optimizing communication and subsequently patient safety. There has been little research examining how to maximize the OR environment to reduce communication errors and improve outcomes. We conclude that while practitioners believed that equipment location is important for patient safety, many institutions place equipment without regard for its effect on staff interaction. 1.Bartels C et al. JTCVS 2002;124:20-27. 2.Gravlee G. Cardiopulmonary Bypass Principles and Practice. Lippincott 2008. 3.Stammers AH et al. Perfusion 2001;16:189-198. 4.Palazano DA. Perfusion 2005;20:195-203. 5.www.jointcommission.org

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SCA57 MEASUREMENT OF PULMONARY ARTERY VELOCITY (VTI) BY TRANSESOPHAGEAL PULSED WAVE DOPPLER ECHOCARDIOGRAPHY (PWD) TO ESTIMATE CARDIAC INDEX (CI). Gonzalez Luza M1; Sabbatino A2; Penna A1; Rufs J2 Universidad de Chile1, Santiago, RM, Chile; Hospital DIPRECA2, Santiago, RM, Chile; Hospital Clinico Universidad de Chile1, Santiago, RM, Chile

Background. Measurement of hemodynamic variables, especially cardiac output (CO), with transesophageal echocardiography (TEE) is complex because it is difficult to obtain quality echocardiographic visions that allow reliable measurements. Searching for an easy and constant measure that correlates with CO, we started measuring velocity time integral (VTI) in the pulmonary artery (PA), because the section area of PA is relatively constant. In our experience, measuring VTI of PA with pulsed wave Doppler is simple and requires little practice. Objective. To determine the existance of a direct relation between VTI and CO. Design: Prospective study. Methods. Twenty patients with surgical indication of cardiac pathology (4 women and 16 men, mean age 58.6 years) undergoing valve replacement surgery (11 p) and coronary artery surgery (9 p), all on sinus rhythm, under cardiopulmonary bypass (CPB) were monitored with pulmonary artery catheter and TEE. The data recorded included demographic variables, diagnostic, body surface area (BSA), ejection fraction (EF) and easiness on the acquisition of the image of the PA trunk at upper esophagic level, between 0 and 20° through TEE (fig. 1). After anesthetic induction, CO and CI measurements were made with the thermodilution technique (TD) and VTI in PA was measured by TEE (2 measurements) during three different stages of the surgery: before CPB (before skin incision), after CPB; 15 min. after the removal of CPB and after sternotomy closure. The measurement of VTI on the PA was made by two independent CO measurement-blinded operators. Pearsons correlation factor between CO and VTI was used for the statistical analysis of each measurement.

Results. BSA average of 1.82m2 with an EF of 40.8%. The acquisition of the echocardiographic AP image was classified as easy on 16 patients and of moderate difficulty on four. A total of 114 CI and VTI measurements were carried out. For the purpose of calculations only the average values were considered. A Pearson correlation factor of 0.74 (p