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    • Maintenance of anaesthesia during cardiopulmonary bypass inpatients undergoing cardiac surgery – A National surveyV.D. Umashankar, K. Wilkinson and D.C. SmithDept of Anaesthesia, Southampton General Hospital, UKThere is little information on appropriate doses of anaesthetic drugsfor maintenance of anaesthesia during cardiopulmonary bypass.Approximately 25% less isoflurane is required at the end of bypassthan at the start [1]. The aim of this survey is to identify the currentUK practice for maintenance of anaesthesia during cardiopulmonarybypass.MethodsWe sent a questionnaire to the 373 consultant members of ACTApracticing cardiac anaesthesia in the United Kingdom in 2005.Information was requested about the agent used to maintainanaesthesia during CPB, the dose used and whether any other adjunctswere used along with these agents. We had 248 replies (66.5%).ResultsPropofol is used as the primary anaesthetic by 108 respondents (44%),while isoflurane is used by 85 (34%). There were 49 respondents whouse either propofol or isoflurane depending on various factors, and 6who use other anaesthetic agents.PropofolOf the 157 consultants who use propofol, 57 (36%) begin the infusionat induction of anaesthesia, 61 (39%) after transferring the patient intothe operating room and 39 (25%) at the start of bypass. A variety ofdosing schemes are used (Table 1).Table 1. Propofol infusion schemes used by respondentsSimple infusion Target-controlled infusionRate Responses Target Responses2-3 mg/kg/hr 37 1.5 – 2.0 mcg/ml 173-4 mg/kg/hr 45 2.0 – 3.0 mcg/ml 114-5 mg/kg/hr 24 3.0 – 5.0 mcg/ml 7>5 mg/kg/hr 11IsofluraneOf those consultants who use isoflurane, 59 (44%) respondents set afixed concentration of 1% on the vaporizer. The majority adjust thevaporiser setting within a defined range according to clinical criteria,with 27 (20%) respondents using 0.5-1.0% and 40 (30%) respondentsusing 1.0-2.0%. Four respondents based the vaporiser setting on theoxygenator exhaust gas concentration and another four on BISmonitoring. The exhaust gas from the oxygenator is scavenged by 83respondents, though only 31 measure the exhaust gas concentration ofisoflurane.DiscussionIn this UK population of consultant anaesthetists there is roughlyequal use of propofol and isoflurane to maintain anaesthesia duringbypass. The concentration of isoflurane used in the majority of casesis much greater than the 0.3-0.4% that maintains a BIS value of 55during bypass [1].Reference1. Lundell JC, Scuderi PE, Butterworth JF. Less isoflurane is required after than before cardiopulmonary bypass to maintain a constant
    • bispectral index value. J Cardiothorac Vasc Anesth 2001;15:551-4
    • Siting of epicardial pacing leads after cardiac surgery – safetyissuesC. Dornan, L. Mitchell and A. Lal1. Cardiac Services, Golden Jubilee National Hospital, UK2. Clinical Educator, ICU, G.J.N.H., UK3. Department of Peri-operative Medicine, G.J.N.H., UKAfter identifying 4 incidents of ‘R-on-T’ phenomena inducingtachyarrhythmias an audit measuring intrinsic R wave amplitudeswas instituted.MethodsThe ECG amplitude & slew rate were measured in epicardial pacingwires attached to the right ventricle. 56 patients had double epicardialpacing leads attached to the anterior wall (AW) of the right ventricle,29 patients had epicardial pacing leads attached to the AW anddiaphragmatic wall (DW) of the RV simultaneously and 15 patientshad a single epicardial lead attached to the AW of the RV dependingon surgeon’s choice.Results slew rate R <2mV R <4 mV R >4 mV <0.5 n (%) (%) (%) V/sec2leadsAW 56 6 (11) 26 (46) 30 (54) 15 (27)AW&DW 29 0 0 29 (100) 01 leadAW 15 0 8 (53) 7 (47) 6 (40)46.4% of the patients with both leads attached to the AW of the RVwere at risk of under sensing and VT/VF arrest from an ‘R-on-T’phenomenon. ALL patients with epicardial leads attached to the AWand the DW of the RV would sense appropriately and therefore wereNOT at risk.DiscussionNASPE & BPEG recommend that an intrinsic R wave shouldmeasure >4mV. The default lower setting on the pacing box is 2 mV.From this study it would appear that both wires on the AW of the RVis not suitable for temporary cardiac pacing due to the high risk ofunder sensing and that the optimal sites would be to attach two leadsto the AW & DW of the RV simultaneously to ensure adequateintrinsic R wave amplitudes.References1. Hurle A, Gomez-Plana J, Llamas P. Pacing & ClinicalElectrophysiology 2002; 25(7):1049-52.2. Cardiac Pacing and Defibrillation: A Clinical Approach, Chapter5 Hayes D L, Lloyd M A, Friedman P A. Futura Publishing, NY159-2003. Cardiac Pacing and ICD’s 3rd Edition, Chapter 5,Ellenbogen K A, Wood M. Blackwell Science,Inc. Massachusetts216-284
    • An Audit of Hydration Status in Cardiac Surgical PatientsR. Chapman,1 A. MacFie,1 M. Higgins,2 R. Spooner3 and D.O’Reilly21 Dept of Anaesthesia, Western Infirmary, Glasgow, UK2 Dept of Anaesthesia, Glasgow Royal Infirmary, Glasgow, UK3 Dept of Biochemistry, Western Infirmary, Glasgow, UK4 Dept of Biochemistry, Glasgow Royal Infirmary, Glasgow, UKAcute renal failure following cardiac surgery is a well recognized andserious complication. Patients who develop acute renal failure haveincreased mortality rates and resource utilization [1]. Recent studiessuggest that treatment of even mild degrees of preoperative renaldysfunction may lead to benefits in terms of survival [2]. Anecdotalreports from our cardiac audit group suggested that some patientspresenting for urgent operations may have been clinically dehydrated.We therefore attempted to audit preoperative hydration status incardiac surgical patients.MethodsUrine osmolality was used to measure hydration status. The audit wascarried out in collaboration with our Biochemistry department.Following placement of a urinary catheter in the anaesthetic room asample was sent for measurement of urine osmolality.ResultsA total of 104 patients were included in the audit at two hospital sites.89 of the patients were for elective surgery and 15 presented forurgent procedures. The mean urine osmolality was 642mOsmol/kg(range 206-1285). 18.3% (n=19) of the patients had an osmolalityabove 900mOsmol/kg.DiscussionThis audit suggests that most of the patients are concentrating theirurine in response to preoperative fasting. The subgroup with highurine osmolalities (>900mOsmol/kg) may represent a group who arerelatively dehydrated. Further studies are required to confirm thesefindings and to assess if treating this prerenal element preoperativelyconfers protection against the development of postoperative renaldysfunction.References1. Mehta RL. Acute renal failure and cardiac surgery: Marching inplace or moving ahead. Journal of the American Society ofNephrology 2005; 16: 12-14.2. Thakar CV, Worley S, Arrigain S, Yared JP, Paganini EP.Influence of renal dysfunction on mortality after cardiac surgery:Modifying effect of preoperative renal function. Kidney International2005; 67: 1112-1119.
    • Long Term Remifentanil Sedation in Cardiothoracic IntensiveCare – Is it beneficial?K. Valchanov and A. Vuylsteke.Department of Anaesthesia, Papworth Hospital, UKRemifentanil has recently gained popularity as a sedative in intensivecare units (ICU) due to its ultra-short action, favourablepharmacokinetics in patients with renal failure [1], and potentlaryngeal reflex and respiratory centre suppression [2]. However,recent reports have highlighted that the withdrawal symptoms anddelirium seen with all opioids may develop rapidly in patientsreceiving remifentanil [3]. To evaluate the incidence of withdrawalsymptoms and explore the risk/benefit ratio of using remifentanil in acardiothoracic ICU, we conducted a retrospective audit of the use ofremifentanil.MethodsA retrospective audit of patient’s notes in a cardiothoracic ICU for theperiod between October 2002 and August 2003 was conducted.Patients having received remifentanil were identified from pharmacyrecords. Data related to withdrawal symptoms were obtained from thenursing, medical and physiotherapy charts.ResultsThirty-six patients were identified as having received remifentanil;with remifentanil discontinued before death in 25 patients. Confusionand agitation after discontinuing remifentanil infusion were verycommon. Medical therapy to control agitation and aggressivebehaviour was needed in 66% of patients treated for longer than 2days, compared to 40% of patients treated for up to 2 days. Therapyused included morphine, benzodiazepines, haloperidol, or clonidineinfusion. The mortality rate of patients having received remifentanilfor less than 2 days was 35%, whereas it was 54% for those havingreceived remifentanil for longer than 2 days.DiscussionThe use of remifentanil as a sedative in a cardiothoracic ICU forlonger than two days is associated with withdrawal symptoms anddelirium. These necessitate the use of further psychotropic medicationand thus abolished the rapid arousal advantage of the drug.References1. Pitsiu M, Wilmer A, Bodenham A, Breen D. Pharmacokinetics ofremifentanil and its major metabolite, remifentanil acid, in ICUpatients with renal impairment. BJA 2004; 92:493-5042. Dahaba AA, Grabner T, Rehak PH Werner F, Metzler H.Remifentanil versus Morphine Analgesia and Sedation forMechanically Ventilated Critically Ill Patients: A Randomized DoubleBlind Study. Anesthesiology 2004; 101:640-6463. Delvaux B, Ryckwaert Y, Van Boven M, De Kock M, Capdevila X.Remifentanil in the Intensive Care Unit: Tolerance and AcuteWithdrawal Syndrome after Prolonged Sedation. Anesthesiology2005; 102:1281-128
    • Retrospective analysis of the outcome of post-operative cardiacpatients having surgical tracheostomyI. Ahmad,1 E. Hill11 Nuffield Department of Anaesthetics, John Radcliffe Hospital,Oxford, UKPatients undergoing surgical tracheostomy after open heart surgery area high risk group for post-operative complications. We aim to identifythe outcome of this group of patients in our cardiac department.MethodsPatients having cardiac surgery from January 2003 to June 2005 werereviewed. We performed a retrospective analysis of those whounderwent surgical tracheostomy and aimed to characterise theoutcome of this cohort of patients. The primary outcome measurementwas mortality, secondary outcome measurements were number ofdays spent on ITU, sedation and on a ventilator, total number of daysspent in hospital and complications of tracheostomy.Results55 surgical tracheostomies were performed during this period.Complete data was available in 50 patients. Overall mortality was40%. Median number of days spent on ITU was 26 (range 9-180),median days of mechanical ventilation was 20 (range 2-68) andmedian days spent on sedation was 10 (range 3-47). Mean number ofdays spent in hospital was 57 (range 5-180) and 22% of patients hadtracheostomy complications.90% of the patients had failed one or more tracheal extubation prior totracheostomy and the average number of days to tracheostomy was 12(range 4-34 days).DiscussionPost-operative cardiac patients having had surgical tracheostomy are avery ill subset of patients [1]. In our study 30 day mortality was 12%and overall mortality was 40%. Commonest complications weredisplaced tube (8%) and stomal infection (8%), none of thecomplications were fatal and all of the survivors were successfullydecannulated. Our complication rate is lower than other published datafor percutaneous and surgical tracheostomies [1], which supports ourunit’s philosophy for performing only surgical tracheostomies.90% of our patients failed tracheal extubation before tracheostomy,this is associated with increased mortality, increased length ofmechanical ventilation, ITU and hospital stay and an increased needfor tracheostomy. Tracheal extubation failure rate after open heartsurgery has been shown to be 4-7%, but is higher in patients with co-morbidity. Accurate timing of successful tracheal extubation isnotoriously difficult, but vitally important in the cardiac surgicalpopulation, as failed tracheal extubation results in increasing co-morbidity due to potential complications of tracheostomy and effectsoverall outcome.References1 LoCicero J, McCann B, Massad M, Joob A. Prolonged ventilator
    • Respiratory Quotient during Hypothermic Cardiopulmonary BypassB. A. Ozdemir1, H. Patel1 and G. Lockwood21 Imperial School of Medicine, UK2 Department of Anaesthesia, Hammersmith Hospital, UKThe respiratory quotient (RQ), defined as the ratio of carbon dioxideproduction (VCO2) to oxygen consumption (VO2), is an indicator ofsubstrate metabolism in aerobic organisms. Little is known about changesin metabolism during cardiopulmonary bypass (CPB). One previous studyhas measured the temperature dependence of RQ during CPB using arterialand venous blood gas measurements: no correlation between RQ and coretemperature was found [1].MethodsWe used two different methods to calculate VCO2 and VO2. The firstmeasured VCO2 and VO2 directly from the gas passing through theoxygenator (gas method). The second used differences in the gas content ofarterial and venous blood calculated from blood gas measurements (bloodmethod). 28 paired samples from 11 male and 3 female adult patientsundergoing coronary artery bypass grafting under CPB were included in theanalysis. Measurements were made during hypothermic CPB and systemicnormothermia at the end of CPB.ResultsSampling temperatures ranged from 31.9 °C to 37.5 °C. RQ(mean±standard deviation) was 0.69±0.15 by the gas method with 96% ofmeasurements falling in the range 0.5-1.2 and it correlated withtemperature (r=0.42, P<0.05: Figure 1). Using the blood method RQ was1.00±0.50 and 65% of measurements fell in the range 0.5-1.2; it did notcorrelate with temperature. 1 0.9 0.8 0.7 0.6 Respiratory Quotient 0.5 0.4 31 32 33 34 35 36 37 38 Temperature ( 0 C)Figure 1. Line of best fit for correlation of respiratory quotient withtemperature.DiscussionThe gas method may be a better approach for assessing RQ because it gavefew physiologically implausible results. There are significant temperaturedependent changes in RQ during CPB.Reference1. Boschettii F, Pennati G, Montevecchi FM. Factors affecting the respiratory ratio during cardiopulmonary by-pass. Int J Artif Organs 1998; 21: 802-8.Additional specialist training for CICU staff attending cardiac arrests
    • is urgently needed 1J. Dunning, T. Strang,2 S Ariffin,3 J Jerstice,3 D Danitsch,3 and A.Levine31. Dept of Cardiothoracic Surgery, Middlesbrough, UK2. Dept of Cardiac Anaesthesia, Wythenshawe Hospital, UK3.Dept of Cardiothoracic Surgery and Anaesthesia, University Hospital ofNorth Staffordshire, UKThe European Resuscitation Council guidelines of December 2005 [1] havecalled for the training of ‘non-surgical medical staff to reopen thesternotomy’ in cases of cardiac arrest. We have commenced a course toteach these skills and a range of additional skills for the care of thecritically ill patient in the CICU [2-3]. We do not however have a clear ideaof the current level of skills possessed by CICU nurses in our region andwe therefore conducted a 3-centre survey to elucidate this more clearly.MethodsA survey was conducted in 3 Cardiac Intensive Care units. 2 shifts at eachcentre were selected to ensure high compliance. The survey asked therespondent to rank their confidence in a range of clinical skills required ineither a medical or in a cardiothoracic cardiac arrestResults61 nursing staff were questioned. 48 were staff nurses, 12 were sisters andone was a matron. The mean number of years in the CICU was 5.5 years(range1-20). Mean number of chest re-openings that they had attended was9 ( range 0->50). 79% of nurses were happy to perform externaldefibrillation but 81% did not know how to perform internal defibrillationand 40% did not know how to connect up the internal defibrillators. 39% ofnurses would not be confident to drape the patient while maintaining goodsterility and only 30% of nurses had ever put on a sterile gown and glovesto assist at a chest reopening. 69% would not feel confident to pass thecorrect instruments to a surgeon from a Thoracotomy set. 71% did notknow how to set up an IABP machine. 92% would not be confident to re-open the sternotomy incision even if clinically required, and 86% wouldnot know how to remove the sternal wires. 84% of staff members wouldnot be able to perform internal cardiac massage.While 85% had received Basic or Advanced Cardiac Life support training,only 4 nurses had ever received any formal training for cardiac arrests inpatients post cardiac surgery. 96% of nurse would go on such a course if itwas available.ConclusionsOur survey had identified critical gaps in the skill base of ourCardiothoracic Nursing staff.We advocate programmes of formal trainingin all UK cardiothoracic Intensive care units to address this deficiency.References1 Soar J, Deakin CD, Nolan JP, Abbas G, Alfonzo A, Handley AJ, LockeyD, Perkins GD, Thies K. Cardiac arrest in special circumstances.Resuscitation 2005; 67S1: S135—S1702 Dunning J, Nandi J, Ariffin S, Jerstice J, Danitsch D, Levine A. TheCardiac Surgery Advanced Life Support Course (CALS) :. Ann ThoracSurg 2006; 81:1767-723. Choudhry, S, Levine A, Dunning, J. Running a cardiac SurgeryAdvanced Life Support Course. BMJ Career Focus Nov 2005;331:200-201
    • Mathematical Modelling of Thrombus Generation Curves From TEG®DataR Bateman1, R Gill2, M Herbertson3 and P Diprose 4Department of Anaesthesia, Southampton University Hospitals Trust,Tremona Road, Southampton, UKSeveral ‘velocity’ calculations describing thrombus generation have beenderived from the characteristic graph produced by thromboelastography1,2.Some of the calculated parameters are outlined below:MRTG: Maximum Rate of Thrombus Generation, TMRG: Time toMaximum Rate of Thrombus Generation, TTG: Total Thrombus Generatedand CCS: Complete Clot Strength.The purpose of our study was to compare these parameters in two groups ofpatients, where one group had received rFVIIa and the other a placebo.Methods14 sets of TEG® data were available for analysis from patients randomlyselected to rFVIIa or placebo. These data were retrospectively analysedusing a novel software package from Haemoscope Corporation. All of theTEG® data were taken from samples following separation fromcardiopulmonary by-pass and reversal of heparin, and approximately 10minutes after administration of either rFVIIa or an equivalent volume ofsaline.ResultsA summary of the results is presented in the table below:Table 1Table shows the derived values (see above) from TEG® data rFVIIa Group Placebo GroupDerived Median Range Derived Median RangeValue ValueMRTG 10.6 5.1 - MRTG 6.8 4.1 16.5 -10.7TMRTG 530 245 TMRTG 610 330 -1080 -1195TTG 704.5 493 TTG 601.7 574 -935 -750CCS 697.3 565 CCCS 598.8 437 -906 -728DiscussionThe group given rFVIIa showed a trend towards greater maximum rates ofthrombus generation and reduced times to maximum rate of thrombusgeneration. Although not statistically significant, we feel that this is aresult of the small numbers of patients involved in this study.References1. B Sorensen et al. Whole blood coagulation thromboelastograhpic profiles employing minimal tissue factor activation. Journal of Thrombosis and Haemostasis, 1:551-5582. G Rivard et al. Evaluation of the profile of thrombin generation during the process of whole blood clotting as assessed by thromboelastography. Journal of Thrombosis and Haemostasis, 3: 2039-2043
    • Impact of a Central Venous Catheter Care bundle on colonisation andbacteraemia in Intensive care patientsS Roberts1, O Al-Rawi1, SH Pennefather1, N Best2, G Smith2 and GNRussell11 Department of Anaesthesia and Intensive care, Cardiothoracic Centre,Liverpool, UK2 Department of Microbiology, Royal Liverpool University Hospital,Liverpool, UKColonisation of central venous catheters (CVC) has been shown to increaseinfection rates, hospital stay, morbidity and mortality.[1,2] In 2004 an auditof non-standardised CVC insertion and care based on individual clinicianpreference showed a high rate of CVC colonisation in our ITU patients.Therefore a CVC care bundle was introduced in 2006 and the subsequentrates of colonisation and bacteraemia re-audited.Methods CVC insertion in 2004 was based on individual preference with largevariation in skin preparation, fixation and choice of dressing. In 2006 theCVC insertion and management were standardised to form CVC carebundle which included: 1.Double skin preparation with alcoholicchlorhexidine 2. Three points catheter fixation 3.Central Guard dressings4.Use of Bionnector caps. CVC management was similarly standardisedwith twice daily inspection and replacement of non-adherent dressing aftercleaning with aqueous chlorhexidine. Data was collected prospectively onall patients in ITU for more than three days over a three month period. Theline site, duration of placement, catheter colonisation and concurrent bloodsteam related infections (BSRI) were recorded and compared to the 2004results.ResultsThe bacteriology results are shown in Table 1 2004 Audit 2006 Audit p-Value (n=186) (n=317)Total +ve Tips 83 (44.6%) 63 (19.9%) <0.0001+ve Tips per 1000 59.2 (CI: 47.2 to 39.7 (CI: 30.5 to 0.016catheter/days 73.4) 50.8)Blood Culture +ve 6.42 (CI: 2.94 to 0.63 (CI: 0.02 to 0.006per 1000 cath/days 12.20) 3.51)The commonest organisms cultured were coagulase negativestaphylococcus (CNS) . In the 2006 audit, femoral lines were most likelyto be colonised (20/43) followed by internal jugular(50/218) and subclavian(1/15)DiscussionOur observation study shows that the introduction of a standardised andsimple CVC care bundle can dramatically reduce colonisation andachieved a ten-fold reduction in catheter related bacteraemia. We stronglyrecommend the use of this approach in all critical areas. As femoral lineswere still most likely to be colonised, further studies will include the effectof chlorhexidine impregnated discs applied to catheters in this area.References1. Mermel LA. Prevention of intravascular catheter-related infections. AnnIntern Med 2000;132391-4022. Samsoondar W, Freeman JB, Coultish I, et al. Colonization ofintravascular catheters in the intensive care unit. Am J Surg1985;149:730-732
    • Early detection of cerebral hypoxia using cerebral regional oxygensaturation monitoring :Case studies in PulmonarythromboendarterectomyDr A. Ghori 1, Mr B. Thomson 2, Dr J.E. Arrowsmith 1, Mr D. Jenkins2 , Prof R.D. Latimer 11 Department of Anaesthesia, Papworth Hospital, Cambridge, UK2 Department of Cardiothoracic Surgery, Papworth Hospital, Cambridge,UKIntroductionTranscranial cerebral oxymetry is a continuous non-invasive monitor ofcerebral oxygenation. It is not dependent on a pulsatile signal and can warnof cerebral hypoxia at an early stage.Near infrared photons are directed into the cranium from optodes locatedover the forehead. These photons are scattered, but a fraction of them arereflected back to photo-detectors on the optodes. By measuring the quantityof returning photons as a function of wavelength the spectral absorption ofthe underlying tissue is determined. From this the oxygenation of theunderlying frontal lobe brain tissue is computed.Pulmonary thromboendarterectomy involves deep hypothermia, selectiveantegrade cerebral perfusion and circulatory arrest if required. The cerebralcirculation is isolated by applying clamps to the arch distal to the origin ofthe left carotid and to the aortic root. Blood flow between the clamps ismaintained at 1-1.5 l /min with a MAP of 50 mm of Hg as measured by aright radial artery cannula. Patients are cooled to 18oC, pH-stat and strictglycaemic control applied.Case ReportsWe present 6 cases involving pulmonary thomboendarterectomy, wherecerebral oxymetry alerted us to periods of cerebral hypoxia, which may nothave been detected without the monitor.Case study -While applying the distal aortic clamp the left carotid wascaught in the clamp. This led to a fall in the cerebral saturation on the leftfrontal lobe, which returned to baseline on adjusting the clamp. 80 70 60 50 40 rSO2 % 30 20 10 Left Right 0 Time 10:34:55 11:35:24 12:36:11 13:37:08 14:38:18 15:39:33In five other patients cerebral saturation monitoring led to early detection ofcerebral hypoxia. The causes identified included the left carotid being fullyor partially clamped, low haematocrit and loss of cerebral autoregulation.DiscussionGoldman(1) in a blinded retrospective and Murkin(2) in blindedrandomised prospective studies reported a significant reduction inpostoperative neurological complications with the use of cerebraloxymetry. Yao et al(3) reported that in patients undergoing cardiac surgerycerebral desaturation was associated with early postoperativeneuropsychological dysfunction. In our case studies cerebral oxymetry
    • enabled the early detection of cerebral desaturation, which may not havebeen detected if the monitor was not used. It is valuable in pulmonaryendarterectomy and aortic arch surgery, involving deep hypothermia,circulatory arrest and where perfusion to the brain may be compromised.ConclusionCerebral oxymetry enabled the detection of inadequate cerebral blood flowand oxygenation at an early stage preventing what could have beensignificant cerebral ischaemia.References 1 Goldman S, Sutter F, Ferdinand F, Trace C. Optimizing intraoperative cerebral oxygen delivery using noninvasive cerebral oximetry decreases the incidence of stroke for cardiac surgicalpatients. Heart Surgery Forum 2004:7(5)1062. 2 Murkin JM, Iglesias I, Bainbridge D, Adams S, Schaefer B, Irwin B,Fox S. Monitoring cerebral oxygen saturation significantly decreases majororgan morbidity in CABG patients: A randomized blinded study. HeartSurgery Forum 2004:7(6)515.3 Yao FF et al. Cerebral oxygen desaturation is associated with earlypostoperative neuropsychological dysfunction in patients undergoing cardiac surgery. J Cardthorac Vasc Anesth 2004;18:552-8
    • Management of anticoagulation for pulmonarythromboendarterectomy (PTE) in a patient with hereditaryantithrombin III deficiency.A. Dawson,1 R. Latimer,1 B. Thomson,2 D. Jenkins,2 K. Rege31 Department of Anaesthesia, Papworth Hospital NHS Foundation Trust,Cambridge, UK2 Department of Cardiothoracic Surgery, Papworth Hospital NHSFoundation Trust, Cambridge, UK3 Consultant Haematologist, Hinchingbrooke Hospital NHS Trust,Huntingdon, UKThe probability of developing pathological thrombosis in patients with adocumented hereditary deficiency of a natural coagulation inhibitor hasbeen reported as high as 80 to 90% by the fifth to sixth decade [1]. Thedevelopment of thrombosis around the time of potential triggering eventssuch as surgery, injury or pregnancy is especially high. In additionheparinization of antithrombin III deficient patients can be difficult due toinherent heparin resistance.We describe the management of a 35 year old patient, Mr. WA, withhereditary antithrombin III deficiency coming forward for pulmonarythromboendarterectomy. This procedure requires cardiopulmonary bypasswith the potential requirement of deep hypothermic arrest. Mr. WA hadprevious antithrombin III levels documented from 49 to 54% of normal. Hehad lost a sister to a postpartum pulmonary thromboembolism. He had apersonal history of a left leg DVT and two previous pulmonary embolisms.Mr. WA usually took warfarin anticoagulation prophylaxis but had stoppedthis as instructed three days prior to surgery.We describe the use of recombinant antithrombin III alpha asthromboembolism prophylaxis during the perioperative period.Recombinant antithrombin III alpha is currently under investigation in amuticentre, multinational phase III trial recruiting hereditary antithrombinIII deficient patients with planned exposure to high risk situations such assurgery or maternal delivery.References1. Pabinger et al. Thrombotic risk in hereditary antithrombin III, protein C,or protein S deficiency: a cooperative, retrospective study. Arteriosclerosis,Thrombosis, and Vascular Biology 1996; 16(6):742-8
    • Current myths surrounding blood product use in cardiac anaesthesia,a literature review and presentation of Papworth Hospital bloodproduct audit.A Dawson,1 C Chauvin,1 A Klein,1 C Gerrard11 Department of Anaesthesia, Papworth Hospital, Cambridge, UKMethodsPrior to the implementation of an intraoperative blood product orderingguideline we reviewed the literature regarding the validity and reliability ofintraoperative coagulation testing at predicting postoperative bleeding. Weconducted an audit of blood product transfusion and intraoperativecoagulation testing over 12 months to clarify our current practice.ResultsDuring 2005, 1430 cases were performed of which 693(48%) requiredsome form of transfusion. The vast majority of transfusions were RBC’sonly 469(68%). However of those transfused 153(22%) required platelettransfusion and 189(27%) required FFP transfusion. 76 patients receivedplatelets intraoperatively of which 66(87%) had intraoperative coagulationtesting. 86 patients received FFP intraoperatively of which 79(92%) hadintraoperative testing.The higher the acuity of cases the more likely blood products weretransfused. The emergency rate for cases requiring no transfusion, RBC’sonly, or other blood products was 1.5%, 5%, and 15% respectively.Surgeon specific overall transfusion rates ranged from 31 to 73%, mean47%. Transfusion of RBC’s only ranged from 53 to 81%, mean 67%.Platelet transfusion rates ranged from 14 to 39%, mean 23%. FFPtransfusion rates ranged from 12 to 45%, mean 26%. Surgeon A, C and Ihad notably higher transfusion rates for all products.DiscussionWe are already utilizing intraoperative testing to guide blood producttransfusion as recommended by the literature. Incorporation ofthromboelastography and laboratory testing during bypass may help torefine our transfusion rates while facilitating a more speedy delivery of offsite products.References1 Avidan et al. Comparison of structured use of routine laboratory tests ornear-patient assessment with clinical judgement in the management ofbleeding after cardiac surgery. BJA 2004; 92(2): 178-862 Williams et al. Coagulation tests during cardiopulmonary bypasscorrelate with blood loss in children undergoing cardiac surgery. Journal ofCardiothoracic and Vascular Anaesthesia 1999; 13(4): 398-404
    • Changes in CRP level following uncomplicated single valve surgeryJ. Ayala1, D. Farrar2 and A. Smith21 Clinical Fellow, 2 Consultant in Anaesthesia and Cardiac ICUDepartment of Anaesthesia,Heart Hospital / UCH Foundation Trust, UKC-Reactive Protein (CRP) is a non-specific inflammatory marker whichincreases in response to a variety of insults including cardiopulmonarybypass (CPB) and cardiac surgery [1]. The reference range of CRP values(0-5mg/dl) relates to a normal, including preoperative, population. Theexpected range in the post-operative patient has not been defined. We havepreviously examined the changes in CRP following coronary artery surgery[2]. This study was designed to examine the range of values of CRP afteruncomplicated single valve cardiac surgery.MethodsThe records of 3500 consecutive cardiac surgical patients were examined.Only patients having first time, non-emergency, single valve procedureswere included. We then excluded those with a prolonged hospital stay(more than 8 days) or who died within 30 days of operation. Pre and post-operative CRP results were collected from the remaining 170 patients. Theresults were analyzed in order to obtain median values and percentiles foreach postoperative day.ResultsData (median and percentile) are shown in the graph. Median CRP reachedpeak values in the second and third postoperative days (179 and 194 mg/dlrespectively).Figure 1. CRP following uncomplicated valve surgery 350 300 250 90th Centile 200 75th Centile Median 150 25th Centile CRP (mg/dl) 100 10th Centile 50 0 Pre op 0 1 2 3 4 5 6 Post operative dayDiscussionCRP values rise following uncomplicated valve surgery with peak valuesreached in days 2-3 postoperatively. Further analysis is required toascertain whether this early CRP profile differs from those patients whodevelop post-operative complications.References1. Gabay C, Kushner I. Acute-phase proteins and other systemic responsesto inflammation. N Engl J Med 1999; 340: 448-542. Ayala J, Smith A, Farrar D. C-reactive protein levels following cardiacsurgery in adults (abstract) ESA 2006