16 CARDIOPULMONARY BYPASS MANAGEMENTA.31 A.32COMPARATIVE ASSESSMENT OF THE PERI OPERATIVE CHANGES IN RECEPTORS FORBIOCOMPA TIBILITY OF 4 TYPES OF TUBING FOR ICAM-1/CD54 & IMMUNGLOBULIN G ON MONOCYTESCARDIOPULMONARY BYPASS BY EXTRACORPOREAL CIRCULATION (ECC)F.Briquet, M.F Hannand, C.Isetta Hiesmayr M, Spittler A, LaBnigg A, Berger R, Boltz G, Roth EDOW CORNING Dept. of Cardiothoracic and Vascular Anaesthesia andSophia Antipolis 06904 FRANCE Intensive Care and Dept. of Surgical Research, University of Vienna, AustriaINTRODUCTION: The contact of blood with the wall oftubing for extracorporeal circulation (ECC), gives rise to many INTRODUCTION: Circulating monocytes partiCipate in theinteractions at the interface of the material and its unspecific as well as specific immunologic functions.bioenvironment. This activation involves different plasmatic Monocytes interact with activated endothelial cells 1 and partiCipate in the inflammatory response to injury. After cardiacsystems and may even provoke a generalized inflammatory surgery with use of a heart-lung machine (HLM) a postreaction syndrome during cardiopulmonary bypass (CPB). A perfusion syndrome is common 2• The aim of this study is tocomparative assessment has been initiated with 4 types of tubing evaluate the changes in monocytes phenotype due to EGC andused in CPB applications. The methodology consisted of in vitro surgery. Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012static-dynamic and in vivo tests to determine if these productscould lead to clinical differences. This paper addresses the first METHODS: After approval of the ethical committee and informed consent 17 patients were included: ECC (8) hadin vitro part of this global study. Parameters tested are cardiac surgery with HLM while THOR (9) had cardiac orbiomarkers of the coagulation-fibrinolytic cascades, the thoracic surgery. The anaesthetic technique included complement system and leukocyte activation. etomidate, midazolam, pancuronium and fentanyl, and METHOD: Tubing materials were represented by 2 cross- ventilation with oxygen in air. The HLM was primed with linked silicones using a platinum catalyst (RX Pump- Ringers Lactate, mannitol 20 g and aprotinin 500,000 IE. The DowComing) or a peroxide initiator (Raumedic ECC-Rehau), a Monocyte receptors for IgG (Fey RIICD64, Fey RII/CD32, Fey polyvinyl-chloride (PVC) (Medituub-Draka Plastics) and a Rill! CD16), IGAM-1/CD54 and GD14 were determined in whole blood by FACS analysiS. The 4 timepoints were before heparin-coated PVC (Bentley Bypass 70-Baxter). anaesthesia (awake), before skin incision (anaesthesia), at the The same production batch was used throughout the study for end of operation (operation) and on the morning after surgery each of the materials. Static tests were performed according to (post OP + 1d). Statistical analYSis was done by repeated ISO 10993-4 and by direct material contact or by filling a measurement analysis of variance (Systat 5.0). Data are given defined length of tubing with one or several fresh samples of as mean ±SD. human blood. Dynamic tests were performed simultaneously RESULTS: There was no difference in age, weight, height, sex with heparinized fresh human blood circulating by a set of and ASA score between groups. The duration of the operation rotative pumps. A CPH circuit was recreated to reproduce the was 301 ±110 (EGG) and 175 ±42 (THOR). The dose of clinical conditions and the tests made with two different bloods. midazolam and fentanyl were similar as was the postoperative RESUL TS: In static conditions, no significant differences were dose of opioids. There was no change in CD16. There was no found by testing the cytotoxicity, haemolysis and the CH50, difference in the time course of CD64 (Fig.1 a) between groups, C3a and C5a. Leukocyte adhesion evaluated by light but CD64 fell with anaesthesia (p<0.001) and increased after microscopy, showed a significantly lower count for both silicone surgery (p<0.001). CD32 and CD54 (Fig.1b) fall both (p<O.01) due to the HLM. tubings at 5 min. The same cell adhesion at 15 min remained constantly low with the silicone platinum whereas it increased I,~ _THORAX with the silicone peroxide and disappeared for both PVc. In LL ~ECC ~ dynamic conditions, fibrinogen adhesion tested by chronometry, was lower with both silicones at 60 min, but equivalent values were found after 120 min for all materials. Complement activation, with the CH50 value assessed by using the technique i i • • of Mayer, was lower for the silicones at any sampling time and awake operation awake operation aruesthesia post OP+1d aruesthesla post OP+ld contrary to both PVC. DISCUSSION: Results obtained by in vitro static as well DISCUSSION: The use of a HLM induces a depreSSion in the dynamic conditions showed that both silicone tubings had less immunglobin receptor CD32 and the receptor for ICAM1 that effect on some parameters linked to the coagulation equilibrium may be related to the inflammatory syndrome after cardiac surgery. and the complement system which are acting in the CPB syndrome. REFERENCES: 1 Wang J, Beekhuizen H, van Furth R. REFERENCES Surface mOlecules involved in the adherence of recombinant l.Kirklin JK Westaby S, Blackstone EH, et al. Complement and the interferon-gamma (rIFN-gamma)-stimulated human monocytes damaging effects of cardiopulmonary bypass. J Thorac Cardiovasc Surg to vascular endothelial cells. Clin Exp Immunol 1994; 95: 263- 1983; 86: 845-857 269. 2.Kirklin JK, George IF, Holman W. The inflammatory response to 2 Boldt J, Osmer C, Linke L et al. Circulating adhesion cardiopulmonary bypass .. In: Gravlee GP, Davis RF, eds. Cardiopulmonary molecules in pediatric cardiac surgery. Anesth Analg 1995; 80: Bypass: Principles and Practice. Baltimore: Williams Wilkins, 1993; 233- 1129-1135. 248.
CARDIOPULMONARY BYPASS MANAGEMENT 17A.33 A.34BLOOD LACTATE DURING CARDIOPULMONARY STANDARD PUMP FLOW RATE AND SVO, ABOVE 60% DOBYPASS WITH A LACTATED PRIMING SOLUTION. NOT IMPLY ADEQUATE OXYGEN DELIVERY DURING CPODavid Hett. Sally Pilkington, Ellen Janke, Stuart Sheppard, DavidSmith. F Ryckwaert, P Colson, G Brunat, P WintrebertWessex Cardiothoracic Unit, Southampton General Hospital, Service d Anesthesie Reanimation R Montpellier, France.Southampton, United Kingdom.Introduction. Diabetic patients have a low pyruvate Introduction: Mixed venous oxygen saturation (SV02) is generallydehydrogenase activity with reduced metabolism of lactate in accepted as an indicator of adequacy of systemic oxygen delivery;extra-hepatic tissues [I]. Hartmanns solution (Ringers-Lactate However, cardiopulmonary bypass (CPB) may alter this relationship)solution) is not recommended for diabetic patients . Lactate production commonly found in patients undergoing CPB, is a marker of this alteration. The aim of this study was to determineMethods. We studied 100 adult patients (40 non-insulin the causes of this alteration during hypothermic CPRdependent diabetics, 20 insulin dependent diabetics and 40 non- Methods: In routine coronary artery bypass graft surgery (CABG) at Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012diabetics) having elective cardiac surgery. Patients in each our institution, CPB is initiated while completing the proximalgroup were randomly allocated to receive either Hartmanns anastomosis with a side-clamped aorta. Cooling is initiated at thesolution 21 plus heparin 6000 iu (H) or Ringers solution 21 plus end of this period, then the aorta is cross-clamped and the heart isheparin 6000 iu (R) as prime. The same solution was used if arrested by infusion of hypothermic hyperkalaemic cardioplegia, andany additional fluids given during bypass, and blood glucose the distal anastomoses are sutured in place. As the grafting process approaches 75% completion, core temperature is gradually increasedwas controlled with an insulin infusion. Blood was taken for to 37°C. SV02 during CPB is held above 60%. Pump flow rate (PF) isbaseline glucose and whole blood lactate estimations at maintained above 2.41 min,1 m-2 during non hypothermic CPE. Timeinduction of anaesthesia and at aortic cannulation. Further between the onset of CPB and the end of cooling ("time to n ") wasmeasurements of lactate were made every 15 minutes during noted. Arterial and venous blood gases, oxygen extraction (02-Extr),bypass, and glucose was measured hourly. Lactate and glucose ~C02 (defined as PvC02-PaC02 mmHg), lactate level and corewere measured again at skin closure. Results were analyzed by temperature were studied during CPB and at arrival in ICU in 20Students t-test. patients undergoing CABG, The variables were measured after induction of anaesthesia (TO), after cooling to 27°C (Tl), after aorticResults. The lactate concentrations are in the table below cross declamping (T2), after rewarming to 37°C (T3) and 1 hour(normal value in our laboratory <2.0 mmon The glucose after arrival in ICU (T4). Data are expressed as mean ± SO; linearconcentrations did not differ significantly between the groups. regression analysis, ANOVA and StudentS t-test for repeated measures were used when appropriate. Cannulation 30 min CPB Skin closure Results: Lactate level increased significantly (p<O.OS) at n, Normal R 0.9(0.6-2.3) 1.0 (0.8-2.S) 1.4 (0.6-3.3) remained stable at T2 and T3, and decreased significantly (p<O.OS) Normal H 1.3 (0.6-3 9) 1.9 (1.1-3.1) 1.6 (0.8-2.S) at T4 (Figure 1). Lactate level at Tl was correlated with "time to Tl" NIDDM R 1.4 (0.8-2.2) 1.3 (0.8-2.l) 1.6 (0.7-3.6) (r= 0.47, p=0.035) Lactate level at T4 was correlated with PF during NIDDM H 1.6 (0.3-3.l) 2.5 (1.0-S.1)* 2.3 (0.8-6.1)* rewarming (r=0,72, p=0,006), During the hypothermic period, O2- Extr and ~C02 decreased significantly (p<O.OS) «10% and <3.5 IDDM R 1.0 (0.7-1.6) 1.1 (0.8-1.6) 1.9 (0.9-3.2)* respectively) and increased (p<0.05) during rewarming. IDDM H 1.3 (0.6-2.9) 2.2 (1.6-3.0)* 2.1 (1.1-3.9)* Figure 1 : Lactate level during CPOMean (range) whole blood lactate in mmoll- 1. 4 ~~----~----~-----L----~--rIDDM = insulin dependent, NIDDM = non insulin dependent. mmol.l-l*p < 0.05 compared to cannulation baseline 3,5 *p<o.os 3Discussion. Although mean values were not excessive, somediabetics had high lactate concentrations after bypass. Half the 2,5cardiac centres in Britain use a lactated prime  but our results 2suggest that a lactate-free prime is preferable for diabetics. 1,5References.I. Mukherjee C, Jungas RL. Activation of pyruvate TO T1 T2 T3 T4 dehydrogenase in adipose tissue by insulin. Evidence for an effect of insulin on pyruvate dehydrogenase phosphate. Conclusion: Meaningful changes in regional oxygen kinetics occur Biochemical Journal 1975; 148: 229. during CPE. These effects, possibly related to increased production2. Alberti KGMM, Thomas DJB. The management of diabetes of endogenous vasoconstrictors, are lightened by lowering core temperature. However, during non hypothermic CPB, SV02 and during surgery. British Journal of Anaesthesia 1979; 51: pump flow of more than 60% and 2.41 min-) m-2 respectively, do not 693-710. imply adequate systemic o":ygen delivery.3. Hett DA, Smith DC. A survey of priming solutions used for Reference: 1.- McDaniel LB, et al. Mixed venous oxygen saturation cardiopulmonary bypass. Perfusion 1994; 9: 19-22. during cardiopulmonary bypass poorly predicts regional venous saturation. Anesth Analg 1995: 80: 466-72.
18 CARDIOPULMONARY BYPASS MANAGEMENTA.35 A.36CEREBRAL BLOOD FLOW RESPONSE TO CHANGES IN SPLANCHNIC BLOOD FLOW DURING CO 2 AT HYPOTHERMIA AND NORMOTHERMIA. A CARDIOPULMONARY BYPASS ASSESSED BY CONTROLLED, RANDOMIZED CROSS-OVER STUDY INDICATOR DILUTION TECHNIQUE. Weyland A, Grune F, Stephan H, von der Veldt J, Kazmaier S, Sonntag H Gardeback M*, Settergren G*, Wahren J**, Ekberg K**, Barr G*, Zentrum Anaesthesiologie, Rettungs- und Intensivmedizin Department 0/ Cardiothoracic Anaesthetics and Intensive Care*, Georg-August-Universitat Gottingen, Germany and Section o/Clinical Physiology**, Karolinska Hospital, SwedenIntroduction: The understanding and application of optimal acid-base management during hypothermic cardiopulmonary bypass Hepatic and gastrointestinal dysfunction following cardiopulmonary(CPB) IS still a subject of controversy. Brain hyperperfusion has been bypass (CPB) is an infrequent but serious complication, probablyconsidered as a consequence of pH-stat management. Beside the related to low splanchnic blood flow (SBF) in the peri operativecerebral response to changes in arterial PC02 (paCOz), other factors period. The incidence of clinically overt gastrointestinal diseasehave been suggested as additional reasons for this phenomenon (I). following heart surgery may be as low as 0.6 %, but the incidence isWe investigated the cerebral haemodynamic consequences of Ct-stat probably underestimated in most retrospective studies I There areversus pH-stat management and compared these effects with the few studies of SBF during CPB and only one clinical study isrespective flow response to variations in PaC02 during normothermia published2 The present ongoing study examines SBF using the Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012in a prospective cross-over study. indicator dilution technique and constant rate infusion ofMethod: With ethical committee approval and written informed indocyanine green (ICG), compared with echo-Doppler estimationsconsent, we investigated 20 patients undergoing coronary artery of hepatic blood flow. In the following, only the ICG results arebypass surgery. First, measurements were performed during reported.spontaneous circulation and normothermia at two different PaC0 2 Methods: Ten adult patients were studied, 7 coronary bypasslevels in a random sequence (control period). During hypothermic grafting (CABG), I aortic valve replacement (AVR) and 2 combinedCPB (30 D C), measurements were repeated under Ct-stat and pH-stat procedures. Mean age was 64 years (range 40-75). CPB time 86management, respectively. Each patient served as his own control. minutes (58-129) and aortic cross-clamp time 52 minutes (29-98).PaCOz was measured at 37 D C. Measurements of global cerebral blood Following anaesthetic induction the hepatic vein and the pulmonaryflow (eBF) were performed with the Kety-Schmidt technique using artery were catheterized. Cardiac output (CO) was measured by70% argon as a tracer. Calculations of cerebral perfusion pressure thermodilution. ICG was infused at a constant rate of 0.6 mg.min· 1(CPP) and cerebral vascular resistance (CVR) were based on jugular during the study period. After 50 min of ICG infusion arterial andbulb pressure. Cerebral metabolic rate for lactate (CMR,,,t) was hepatic vein blood samples were drawn every 5th min: I, beforecalculated according to the Fick principle. To assess the effects of surgery (3 paired samples) n, during surgery before CPB (2 hypothermic CPB and PaC02 , two-way analysis of variance samples) and Ill, during hypothermic CPB (33°C)(3 samples). (MANOVA) was performed using a repeated measures design. Oxygenation and ICG concentration were measured. SplanchnicResults: oxygen uptake (V02sp) and systemic oxygen uptake (V02), SBF Hypocapnia Hypercapnia a.-stat pH·stat and CO were calculated. Gastric mucosal pH (PHJ was measuredPaCOz*"- N 33.3±2.9 47.5±5.4 37.2±2.6 50.5±2.8 [mmHg] with a gastric tonometer. Statistical analysis was performed using t-Hct 38.1±3.0 38.1±3.0 24.6±2.5 24.9±2.5 [%]T 35.3±0.3 35.3±0.3 30.2±0.5 30 1±0.5 [C] test and Wilcoxon rank sum test "CBF"# 3h5 55±13 38±lO 63±21 [ml-min-1·lOOg"lj Results: Mean values and standard error of the mean were:CtviR 1act" ·1.8±2.2 ·0.8±1.5 ·1.7±3.1 0.0±2.5 [fUIlol.min·.IOOg"]CPP 70±12 66±1I 76±16 69±18 [mmHg] Anaesthesia Surgery CPB 1CVR 2.3tO.6 1.2±0.3 2.2±0.8 1.2±0.5 [mmHg·mr min·IOOg] SBF (mLmin·1) 765 ± 44 911 ± 88 789 ± 91* sigruficant influence of PaCOl level. • significant influence of hypothennic CPB SBF in %ofCO 24 ± 0.8 24 ± 2.2 19 ± 1.6(MANOV A, p<O.05). Values are mean ± SD. CO (L min· l ) 3.4 ± 0.2 3.9 ± 0.4 4.1 ±O.Z**The periods of different PaC02 levels were comparable with respect V02sp (mL min") 52 ±7.8 63 ± 9.3 28 ± 2.6"to haematocrit (Hct) and nasopharyngeal temperature (Tnp) At both V02 (mL min· l ) 150 ± 16.8 119± 11.8levels of PaC02, mean CBF during hypothermic CPB was slightly pHi 7.32 ± 0.03 7.35 ± 0.02 7.33 ± o.ozhigher than during the control period. This small increase, however, (*=p<O.05, ·*=p<O.OI, different from 1st measurement)could be explained by the slight difference in PaC0 2 levels betweenthe control and the CPB period: CBF values during hypothermic CPB The ICG concentrations before and after the extracorporeal circuitdid not show any difference when compared to CO2-adjusted values were identical and hence there was no extracorporeal dyeduring the control period (38 vs. 36 and 63 vs. 62 ml.min··IOOg·l, elimination. The required steady state of arterial ICG concentrationrespectively). Similarly, cerebrovascular CO2 reactivity of CBF did was established.not differ between the two periods of measurement (4.1 vs. Conclusion: CPB did not cause a reduction in SBF. Splanchnic4.5%/mmHg change in PaC0 2 ). blood flow following anaesthetic was only approx. 50% of the flowDiscussion: This study demonstrates that under moderate in awake subjects3 . V02sp was normal following anaesthetichypothermia cerebral haemodynamic differences between Ct-stat and induction but reduced during CPB.pH-stat management can completely be explained by respective References:differences in non temperature-corrected PaC02 . Increased CBF I Ohri S, Bowles C. Gastrointestinal complications ofduring pH-stat acid-base management thus only reflects normal cardiopulmonary bypass. In Yacoub M, ed. Annual of Cardiaccerebral vasoreactivity to CO2 . The agreement in CBF and in CMRaoi Surgery. London: 1995; 74-86.between the control and the CPB period suggests that the 35% 2 Hampton WW, Townsend MC, Schirmer WJ, et al: Effectivereduction in Hct was counterbalanced by hypothermia-induced hepatic blood flow during cardiopulmonary bypass. Arch Surg 1989;reduction in cerebral oxygen demand. 124:458-459. 3References: Bmndin T, Wahren J Effects of Lv. amino acids on human I. Henriksen L. Brain luxury perfusion during cardiopulmonary bypass in splanchnic and whole body oxygen consumption, blood flow and bloodhumans J Cereb Blood Flow Metab 1986; 6:366-378 temperature. Am J Physiol 1994; 266 (3 Pt I): E396-E402.
CARDIOPULMONARY BYPASS MANAGEMENT 19A.37 A.38ASSESSMENT OF RIGHT AND LEFT HEART VOLUME INDICES THE HEMOPUMP AS LEFT VENTRICULAR ASSIST IN PATIENTS UNDERGOING CORONARY ARTERY BYPASS DEVICE IN POSTCARDIOTOMY HEART FAILURE. SURGERY W BUHRE, *B SCHORN, S KAzMAIER, A WEYLAND, *S GIAm;ARls, Meyns B, Sergeant P, Demeyere R, Vandommele J, Lauwers p. Ferdtnande p. Verwaest C, Daenen Wand Flameng W A HOEFT AND H SONNTAG Gasthuisberg University Hospital Zentrum Anaesthesiologie, Rettungs- und Intensivmedizin, *Klinik jur Leuven, Belgium Herzchirurgie der Universitat Gottingen, G6ttingen, Germany Introduction: Postcardiotomy heart failure is the most·Introduction: The value of central venous and pulmonary serious complication in cardiac surgery. Even with the usecapillary wedge pressure (CVP, PCWP) as indices for cardiac of assist devices survival does not exceed 25%.(1) Thepreload has been questioned during the past years, particularly Hemopump is a miniature rotary blood pump forin patients undergomg cardiac surgery]. Thus, more direct intraventricular use. We have used this device since 1989measurements of intravascular volume status have gained as a left ventricular assist device in postcardiotomy heartincreasing interest. The double indicator-dilution-techni~ue failure.enables bedside assessment of intravascular volume status 2 Patients: In this 6-year period 9585 patients underwentDiscrimination of sub compartments like right ventricular end- cardiac surgery in our hospital. 2.2% were assisted with Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012diastolic (RVEDVi) and left heart volume (LHVi) is available. intra-aortic balloon pumping and 0.6% (57 patients) wereThe objective of this study was to compare the perioperative assisted with a more powerful assist device fortime course of CVP and PCWP and cardiac volume indices, postcardiotomy heart failure. Patients were considered toestimated by indicator dilution, in patients undergoing CABO- have a low cardiac output due to left ventricular failure ifsurgery. the cardiac index was less than 2 I min" m,2 or systolicMethods: After ethical committee approval and written arterial pressure was less than 90 mmHg with left atrialinformed consent, ten patients were investigated. Cardiac pressure greater than 20 mHg, despite maximaloutput (CI) was determined by thermodilution. CVP as well as pharmacological support and the intra-aortic balloon pump.PCWP were determined by standard technique. Additionally, a In 39 cases we used the Hemopump as left ventricularfibreoptic-thermistor catheter was placed in the aorta]. Ice- assist device with the intention to salvage the heart. Meancooled indocyanine green dye was injected into the right atrium age was 64.8 (t7) years; 51% needed cardio-pulmonaryand resulting thermo-dye curves were detected in the pulmonary rescucitation prior to the Hemopump insertion; 41% wereartery and aorta. RVEDVi was calculated from the expOilential anuric and all of these patients were excluded fordecay time of the pulmonary artery thermodilution curve transplantation because of age or underlying diseases 3according to Newman LHVi was calculated from the (diabetes, COPD, vascular disease, hypertension).difference of central blood volume (CBV) and pulmonary blood Methods: In a first period, until 31-12-1992, the 21Fvolume (PBV)1.2 Measurements were performed before cannula for introduction through the femoral artery was(control) and I, 6 and 24 hours after surgery. Statistical used in 13 patients. From 1-1-1993 we used the 31 Fanalysis was done by one-way analysis of variance using a transthoracic cannula in 26 patients.repeated measures design. Results: Immediate haemodynamic improvement wasResults: Postoperatively, CVP significantly increased, whereas obvious (Table shows mean.:!:SD; paired Students t-test forR VED Vi showed a smaller insignificant increase [Tab. I]. significance)Similarly, PCWP was increased during the postoperative timecourse. In contrast, LHVi decreased. CI was increased in all pre-assist assisted p-valuepatients I, 6 and 24h after surgery, whereas stroke volume LAP (mmHg) 20±4.8 10±3.3 <0.0001index (SVI) significantly decreased Ih after surgery. mean ASP (mmHg) 53±11 72±10 <0.0001 LHVi RVEDVi CI SVI CVP PCWP Cardiac index 1.7±0.7 3.3±0.7 <0.0001 [ml m") [ml m") [I m") [ml m") [mmHg) [mmHg) (I min" m,2) control 272±59 99±16 2.2±O.7 34±9 6±5 9±4 lactate (mmolll) 6.4±4.7 3.1±1.4 =0.0002 Ih 202±44* I09±28 3.2±l.O* 28±6* 11±2* 13±3 6h 210±59 I 24±26 3.8±l.O* 35±11 12±2* 12±2 24h 215±54 118±18 3.2±1.l* 32±9 9±4* lId 56.4% of these patients were weaned and 28.2% wereTable 1: * significant vs. control (p<O.05) discharged home. Deaths occurred in two clusters: oneDiscussion In our patients, RVEDVi, CVP, PCWP and CI early phase within 24 hours of commencement of theincreased, whereas LHVi and SVI decreased. The rise in filling Hemopump, and one later phase, after one week. Causespressure may be due to changes in myocardial compliance, of death in the first group were right ventricular heartsince the increase in CI can be explained by an increase in heart failure and severe low cardiac output. Immediaterate and catecholamine support after CPB Our results suggest, haemodynamic improvement was worse in these patients.that after CABO-surgery, cardiac filling pressures are of All patients with a cardiac index < 2.5 I min" m,2 , despitelimited value as a guide for postoperative volume therapy. the Hemopump support, died rapidly. Fatalities in theReferences: second, late group, were caused by the consequences of1. Hoeft A etal. Bedside assessment of intravascular volume status in multiple organ failure. Device related problems were farpatients undergoing coronary bypass surgery. Anesthesiology 1994; 81: 76- more frequent with the femoral cannula (53%) then with the86 transthoracic cannula (3%).2. Hachenberg T et al. Thoracic intravascular and extravascular t1uid Discussion: The Hemopump is an effective assist devicevolumes in cardiac surgical patients. Anesthesiology 1993; 79: 976-984 and became our first choice in left ventricular failure. The3. Newman EV at al. The dye dilution method lor describing the central transthoracic cannula is reliable and easy to use. A cardiaccirculation: An analysis of factors shaping the time concentrations curves index < 2.5 I min" m,2 in the assisted situation carries aCirculation 1951;4: 735-746 bad prognosis. References: 1. Pae WE Jr, Miller CA, Matthews Y, Pierce WS. Ventricular assist devices for postcardiotomy cardiogenic shock. A combined registry experience. J Thorac Cardiovasc Surg 1992; 104: 541-553.
20 CARDIOPULMONARY BYPASS MANAGEMENTA.39 A.40 EFFECT OF 8-BLOCKERS VERSUS CALCIUM CHANNEL CONTINUOUS TEMPERATURE and 0 2 SATURATION BLOCKERS IN MYOCARDIAL REVASCULARIZATION MONITORING of JUGULAR BLOOD during DHCA WITHOUT CARDIO-PULMONARY BYPASS IN PIGS PROCEDURES for AORTIC SURGERYRajek A Podesser R Kupilik N, Hiesmayr M, Moritz A, Haider R. Paino, F. Milazzo, B. Amari, M. VisigalJi, M Ferrante, M. Mer[i. Department of Cardiothoracic Anaesthesia and Intensive CareW, Ospeda[e Niguarda Ca Granda - Mi[ano ([ta[y)Dept of Anaesthesiology and Intensive Medicine,Dept of Cardiothoracic Surgery, University of Vienna, Austria There is no consensus concerning adequate monitoring to predict brain protection during deep hypothermic circulatory arrest (DHCA).Introduction: To develop the surgical technique for internal We studied the effects of cardiopulmonary bypass (CPS) with DHCAmammary artery grafting (lMA) on a beating heart, we combined on temperature (Tjv) and oxygen saturation (Sjv02) of jugular blood.a reduction in heart rate with intraoperative myocardial Methods: After Ethical Committee approval and patients informed consent, 11 patients (pts), (10 M, 1 F) aged 53±11 years, withoutprotection. Therefore we compared intravenous administration of evident neurological damage, scheduled for aortic surgery, werethe ~-blocker esmolol (es) and the Ca-channel blocker verapamiI anaesthetized with isoflurane and fentanyl. Temperatures were(ver) during the ischaemic period. obtained by rectal (Tr), nasopharyngeal (Tnp) probes and by aMethods: After approval of the animal care committee, IMA percutaneous thermic probe (Thermod Probe 2.5F, Edwards Lab.)grafting was done without CPB in 10 pigs (mean weight 21 kg). advanced into the right jugular bulb (Tjv) together with a fibreoptic Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012Anaesthesia was induced and maintained with pancuronium, catheter (Opticath Catheter U 425C 4F, Abbott Lab.). All parametersfentanyl, oxygen and nitrous oxide (50%). Cardiac output (CO), were recorded every minute (min). CPS was performed with a roller pump and hollow fibre oxygenator. Cooling and rewarming wereheart rate (HR), mean arterial pressure (MAP) and mixed venous managed according to Tnp (15°C for DHCA and 3rC for completeoxygen saturation (SV02) were measured and stroke volume (SV) rewarming) with alpha-stat acid base management. Data (mean±SD)was calculated. Left ventricular function and wall motion were analyzed by linear regression with p < 0.05 being significant.abnormalities were investigated by echocardiography before Results: The table shows values of SjV02. Tr, Tjv and Tnp. pericardiotomy (baseline, TO), after drug administration (TI), at Cooling: Cooling time was 59±20 min. Tjv and Tnp were not different the end of ischaemia (T2), (by local clamping of the left anterior at any time, while Tr showed a foreseeable delay. Sjv02 increased descending artery, LAD) and 5 (T3), 15 (T4), 30 (T5), 90 (T6), until the end of cooling but did not always reach full saturation minutes after the end of ischaemia. Five pigs received esmolol (86.3±13%). SjV02 did not show any correlation with Tjv, Tnp, Tr, pump flow (CI) and rate of cooling at any time. Mean values of (es-group) and the other 5 pigs received verapamil (ver-group) PaC02, Pa02, mean AP (mmHg), pH, CI (I min· m~2) were 36.2±5, intravenously during the ischaemic period. Drug dose was 347±75, 41±13, 7.41±0.05, 2.18±0.5 respectively increased until heart rate was below 80 beats/min. DHCA: DHCA time was 33.4±17 min. Tjv, Tnp, Tr were stable. SjV02 Results: There were no differences in pre-ischaemic slightly decreased at mean rate of O.17%/min. haemodynamics, echocardiography and in ischaemic clamping Rewarming: Rewarming time was 85.8±26 min. Restarting CPS was time of the LAD in both groups. At T2 (end of ischaemia) CO, associated with immediate Tjv increase (2°C). Tr change showed a SV02 and SV were lower in the es-group «0.05). At TI, T2, T3 forseeable delay during the cooling phase. Restarting CPS was also associated with transient Sjv02 drop (Sjv02=24-87%). Sjv02 drop and T4 there was an increase in wall motion abnormalities and a was significantly correlated with DHCA time (y=0.75 x, r=0.936, decrease in left ventricular function in both groups. In the ver- p<O. 001). SjV02 under 50% was observed 19 times in pt 1 and 36 group one pig died because of ventricular fibrillation during times in pt 9. Sjv02 did not show any correlation with Tjv, Tnp, Tr, CI ischaemia and in one pig ventricular fibrillation occurred 2 or rewarming rate at any time. Mean values of PaC02, Pa0 2, mean minutes after the end of ischaemia (2/5, 40% incidence of AP (mmHg), pH, CI (I min" m·2) were 30.1±3.8, 293±100, 49.4±24, ventricular fibrillation, p<O.OI). Coronary angiography showed 7.47±0.07, 2.4±0.3 respectively. all anastomoses to be open. Data are presented as mean ± SEM Outcome: 9 pts showed no clinical evidence of neurological dysfunction. 1 pt died while in the operating room, due to heart and *p<O.05. Analysis was done by StudentS t-test. failure after CPS. 1 pt who showed the lowest Sjv02 (24%) at start of TO T1 T2 T3 T4 T5 T6 rewarming and several episodes of Sjv02 desaturation, suffered ImmHa ... MAP as 109,111:10 116,8t11 85,6±10, 66,4±7,4 81,111:12,1 100,111:8,.2 96,4:t13,~ 105:t82 57:t7,7 55,~,3 66,3:t15,E 75,5:t14,E 85,2:t18] 75,5:tl0, transient postop. coma. Discussion: a) During DHCA procedures Tnp reflects the IImIn ... CO as 3,QlO,3 3,4:tO," 2,1:tD,07 l,&:tO,l· 1,7:tO,2 2.2:tO,13 2:tO,2 3:tO,5 3,1:tO,4 2,&:tO," 2,7:tO,6 2,4:tD,5 3,2:tO,7 2,9:tO,3 temperature of blood from the brain as measured by Tjv. b) Tnp 15°C is associated with a variable Sjv02, not always nearing 100%. c) min - Hr as 106,111:13 108,2i9.i SV02 as 84,111:5,7 110 ..r 65,5:t3,6 ao,4:t5,7 78,2:t4,6 79,4:t6,l 84,7:1:9,1 95,111:13 121,2:t18, 90.2:1:9,8 91,2±12 89:t12 105:t15,4 l06,6:t20 96,5:t10,7 46,4:t3,4 27,111:5,6 32,3:t6,8 38,7:t5,8 51,111:5,7 60,4:t5,2 6O:t7,3 SO,5:t4,O 55,3:t4,9 55:t9 542±7,3 53±7,8 Slight Sjv0 2 decrease during DHCA implies stagnant blood. d) Restarting CPS moves this stagnant blood: the observed transient low Sjv02 and its significant. correlation with DHCA time suggest persistent brain 02 consumption despite deep hypothermia. It remains to be clarified whether this phenomenon relates to different Discussion: We found that an infusion of esmolol provides stable clinical outcomes and whether reaching 100% Sjv02 before DHCA has a protective effects2 . MAP values while the other measured haemodynamic parameters SjvO,(%) Tjv(OC} Tnp (0G) Tr("QL were significantly reduced compared to the ver-group. Start!n>! CPB 70.3+16.2 34.4+1.7 34.8+1.5 35.4t1.5 Echocardiography did not show any differences between the two Durin!Lcooling 78.9+17.1 groups. However, there was no case of ventricular fibrillation in End cooling 86.3+13.3 15.8±1.4 15.4±1.6 19.9±3.6 the es-group indicating superior antiarrhythmic protection. Startill!lDHCA 87.8t9.5 15.3±1.4 15.4±1.4 19.6:1:3,6 References: During DHCA 87.7:1:8.9 16.1:1:1.3 15.6:1:1.3 19.7:1:2.8 1. Pfister AI. et al. Coronary artery bypass without cardio- EndDHCA 85.6±8,O 16.3:1:1.3 16.2:1:1.5 20.2:1:3.3 Startingrewarm. 62.6±21.5 18.3t2.3 17.0±2.4 20.0±3.0 pulmonary bypass. Ann Thorac Surg 1992; 54: J085-1092. During rewarm. 73.3±14.4 2. Benetti Fl. Direct myocardial revascularization without End rewarm. 66.6±16.8 37.5±1.7 36.8±1.8 33.3±3.4 extracorporeal circulation. Experience in 700 patients. Chest 1991; 100: 312-316. References: 1 Steven JM, Nicolson SC. Pro: Monitoring of nasopharyngeal and rectal temperatures is an adequate guide of brain cooling before deep hypothermic circulatory arrest. J Cardioth Vasc Anesth 1994; 8: 360-362. 2. Kern FH et al. Temperature monitoring during CPB. in infants: Does it predict efficient brain cooling? Ann Thorac Surg 1992; 54: 749-54.
CARDIOPCLMO~ARY BYPASS MA:AGEME~T 21A.41 A.42A COMPARISON OF CORE TEMPERATURE WITH CONVECTIVE WARMING OVERCOMES EFFECTSTHERMAL ENERGY BALANCE IN PREDICTING OF COOLING AFTER CARDIOPULMONARY BYPASSADEQUACY OF REWARMING }ROMHYPOTHERMIC CARDIOPULMONARY BYPASS Knowles PRo Moshal DC, Djaiani GN, Gopinath S. Duthie DJRCD Deakin, AC Sewell, F Clewlowt, JMT Pierce,Departments of Anaesthetics, and Medical Enginccnngt, Papworth Hospital, Cambridge, CB3 8RE, UXSouthampton General Hospital, Southampton, England, Introduction: During cardiac surgery with hypothcnnicIntroduction: Hypothennic cardiopulmonary bypass (CPB) IS cardiopulmonary bypass (CPB), strategies to rewann patientsinvariably associated with a significant period of post-opClauve may be invalidated by heat loss from the chest and body afterhypothennia despite achieving nonnal or above nonnal core weaning from CPB, Convective wanning after surgery in thetemperatures on tennination of bypass, Thennal energy b:llance intensive care unit (ICU) may reverse these effects,on tennination of CPB may provide a better indicator of theadequacy ofrewanning, Methods: Heat transferred between body and CBP pump wasMethods: We prospectively studied the thennal energy balance measured III 23 patients undergoing myocardialand core temperature of cardiac surgical patients at the end of Downloaded from http://bja.oxfordjournals.org/ at McGill University Libraries on March 8, 2012 revascularization [I], In ICU, patients were randomlycardiopulmonary bypass and compared them in relation (0 the allocated to be nursed with sheets and cotton blanketspostoperative temperature profile, Using a thennal energy (Control) or convective Warming (WannTouch CareQuilt,balance (TEB) meter l, temperature of arterial and venOU5 blood Mallinckrodt, Northampton), Core temperatures werein the bypass circuit was recorded every minute together Wtthpump flow, to allow continuous calculation of thennal energy measured with thennocouples applied to tympanic membraneflux during CPS. Themlal energy balance on tennInatLon of and nasopharynx and logged to computer every minuteCPB was recorded prospectIvely in 53 sequential patients Linear regression analysis and the Mann-Whitney U test wereundergoing cardiac surgery for coronary artery bypass gJ aftmg used to assess statistical significance, which was acceptedand/or valve replacement Tympanic temperature was used as when P<O,05.an accurate measure of core temperature Results wereanalyzed using linear regression with statistical slgmficance Results: On CPB, during cooling 608 (247 (SD» kJ weretaken as PsO,05, removed from the body and 850 (259) kJ replaced dunngResults: Core temperature on tennination of CPB did not wanning, Core temperatures were 37,2 (0.7)OC comIng off CPBcorrelate with the degree of post-operative hypothem1ia as and 34,6 (0,5)OC on admission to ICU, 58 (10) minutes later. Injudged by time to rewann to 37,0°C (r=0,002, P=O 651) and all patients, core temperatures fell no further after admission tocorrelated poorly with the coldest post-operative tempcIature ICU, The time to regain core temperature of 37°C was shorter(r2=0,244, P=O,OII) Thennal energy balance provided a better (P=0,042) in the Wanning group, 160 (52) minutes (n=ll) than indicator of the adequacy of rewanning than core tempelature, the Control group, 233 (103) minutes (n=12), The- time to coreas judged by time to rewarm to 37,0°C (r2=0, 150, P=O,OLl) and 37°C was related directly to the lowest core temperature (oncoldest post-operative temperature (r2=0,333, P=O,OOOI), admission to ICU) recorded in the Control group (P=0,007) but Discussion Thennal energy balance provides a better Indicator not the Wanning group, Time to extubation in ICU was relatedof the adequacy of rewanning from hypothennic CPB than core directly to the time from weaning from CPB to admission totemperature measurements, Estin1ation of adequate rewarming ICU in the Control group (P=0,016), but not the Wanning from hypothennic CPB using thennal energy balance may be of group, use;: in minimizing the degree of post-operative hypothennia ~ )8 Discussion: Convective warming after hypothennlc CPB !! shortens the tin1e taken for core temperature to return [0 37°C :I ~ n It removes the influence of heat lost from the body after weaning l!. E from CPB, on time to return to core 37°C, and time to = 36 extubation, Heat transfer from and to the body during CPB .~ i! could not be related to core temperature changes ill ICU, nor l!. JS ~ time to extubation. Strategies to prevent heat loss after weaning i i 34 3~ . ~ from CPB deserve further study, Reference: " 0 SOD 1000 En~rgy balanc~ I~ kJ zDbo I, Sansome AJ, Apparatus for the real-tin1e caJculauDn ofReference: l. Sansome AJ. Apparatus for the real-time calculation of thennal energy flux during cardiopulmonary bypass. Br J Hospthermal energy flux during cardiopulmonary bypass, British Journal Med 1989: 42 494,of Hospital Medicine 1989; 42: 494, 2, Sessler 01, Rubinstein EH, Eger EL Core temperature2, Davis FM, Barnes PK, Bailey JS, Aural thermometry during changes during N20 fentanyl and halothane 0, anesthesia.profound hypothermia, Anesthesia and Intensive Care 1981; 9 124- Anesthesiology 1987; 67: 37-139.128,