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tasis/pneumonia was 6.4% (8/125). There was no bleedingor catheter site infection, and no local anaesthetic toxicity.All patients were on oral Capadex or Panadeine Forte. Six-teen percent (20/125) were discharged with supplementalOxycodone.

Discussion: The Painbuster® in-wound catheter localanaesthetic delivery system is a simple and reliable tech-nique for post-thoracic surgery analgaesic. There is noidentifiable major risk associated with its use and byvirtue of its placement intraoperatively, anaesthetic timeis reduced and case flow is improved.

doi:10.1016/j.hlc.2008.11.027

18

Brain Stem Death induced pulmonary hypertension—More pronounced and prolonged than left ventricularchanges in an ovine model

J.F. Fraser, M. Nataatmadja, M. Passmore, A. Corley, J.Dunning, F. Kermeen

The Critical Care Research Group & Department of CardiacSurgery, The Prince Charles Hospital, Brisbane, Australia

Introduction: Primary graft dysfunction is a major causeof mortality following lung transplantation (LTx). BrainStem Death (BSD) is known to be involved in this organdysfunction. The systemic haemodynamic changes asso-

19

Right atrial pacing for prevention of postoperative atrialfibrillation following coronary artery bypass grafting: Aprospective observational trial

Pawan Singhal, Nand Kejriwal

Waikato Hospital, Hamilton, New Zealand

Introduction: Atrial fibrillation (AF) is the common com-plication after coronary artery bypass grafting (CABG),the incidence reported between 20 and 40% in first weekfollowing surgery. Occurrence of AF is associated withhaemodynamic compromise, risk of stroke, prolongationof hospital stay and increased costs. Conventional clinicalpractice is to treat AF after its onset in the postopera-tive period. However effective prophylaxis can result inreduced morbidity and hospital stay, with resultant costsavings. The limited efficacy of pharmacological treatmentto prevent postoperative AF has stimulated research intoalternative prophylactic strategies for the arrhythmias.Several studies in the nonoperative settings, have sug-gested that atrial pacing may decrease the incidence ofparoxysmal AF.

This prospective study was designed to assess the effi-cacy of prophylactic right atrial pacing in the prevention ofpostoperative AF following coronary artery bypass graft-ing (CABG).

ciated with BSD are well described, but less is known ofthe effects in the pulmonary system. We investigated theeffect of BSD on the pulmonary circulation.

Methods: Six sheep were anaesthetised prior toplacement of intravascular and intracranial monitoringcatheters. BSD was achieved by graduated inflation of aFoley catheter with 30 ml of saline. Intracranial pressurewas maintained above systolic blood pressure for 30 minto achieve BSD. All cardiovascular and respiratory datawas recorded simultaneously.

Results: Immediately following balloon inflation, post-BSD mean systemic arterial pressure (MsAP) rose to 230%of pre-BSD values (SD 47.3%). Thirty min later post-BSD MsAP was consistently less than the pre-BSD MsAP(82%—SD 29%). Mean pulmonary artery pressure (MpAP)was elevated to 358% of original pressures (SD 168%).This rise persisted at 30 min post-BSD parameters (mean135%).

Rises in MpAP in our novel model of BSD were muchlarger in magnitude and more sustained than rises seenin MsAP.

Discussion: Acute prolonged pulmonary hypertensionin donors may explain the high incidence of right ven-tricular dysfunction seen post-heart transplant and beassociated with PGD in LTx. This may represent a targetfor therapeutic intervention, aiming to minimise right ven-tricular dysfunction and ischaemic reperfusion injury inlungs in the recipient, improving both number of organstransplantable and function of these organs post trans-plantation.

doi:10.1016/j.hlc.2008.11.028

Methods: All patients who had isolated first time CABGon cardiopulmonary bypass between January 2007 andJune 2007, operated by one surgeon were included in thisstudy (study group). During the same period, isolatedCABG carried out by other surgeons and not paced servedas control. The patients in the study group were paced elec-tively for 96 h in postoperative period. The incidence ofpostoperative atrial fibrillation was compared in patientswho had right atrial pacing (study group) with the patientswho were not paced (control group). Patients with historyof AF were excluded from the study.

A total of 90 patients underwent isolated CABG in the 6months period. Five patients were excluded from the studybecause of preoperative AF. In the study group (n = 24)right atrial pacing was commenced at rate of 90/min aftertransferring the patient to ICU and was continued for 96 h.Pacing parameters were checked every day. Beta-blockerswere administered on the first postoperative day to allpatients in both groups unless contraindicated. The endpoints of the study were occurrence of AF, death in post-operative period or discharge from the hospital.

Results: Preoperative risk factors did not differ betweenthe two groups but aortic cross clamp and cardiopul-monary bypass times were higher in the study group. Inthe study group 5 patients could not be paced becauseof persistent tachycardia (4 patients) or failure of atrialelectrodes (1 patient). There was a statistically significantdifference in the incidence of postoperative atrial fibril-lation from 31.1% in patients receiving no postoperativepacing to 5.2% (p < 0.05) in patients who had right atrialpacing.

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Discussion: Postoperative atrial pacing significantlyreduced the incidence of atrial fibrillation following coro-nary artery bypass grafting. The procedure can be easilyapplied in the clinical setting. However a prospectiverandomised trial is needed to assess the efficacy of pro-phylactic right atrial pacing in decreasing the incidence ofpostoperative atrial fibrillation.

doi:10.1016/j.hlc.2008.11.029

20

Inferior ventricular septal ruptureAn alternative technique for an old problem

N. Roubos, J.C. Negri

Alfred Hospital Cardiothoracic Unit, Melbourne, Australia

Introduction: Ventricular septal rupture (VSR) is a seriousand usually fatal complication of 1–3% of acute myocar-dial infarctions [1]. Rapid diagnosis and surgical repaircan treat this problem with early mortality rates of 10–36%reported [2–4]. From our institution’s experience of VSR,we report an alternative surgical repair method for inferiordefects.

Methods: Between February 2002 and June 2007, 18patients were surgically treated for VSD. Two werecongenital (1 perimembranous, 1 muscular) and 16 postin-farct. Of these, 7 were inferior and 9 anterior in location.Apptfaehr

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an anteroapical approach with ventriculotomy through anoninfarcted area is a safe alternative method for repairof postinfarct ventricular septal rupture.

Reference

[1] Birnbaum Y, Fishbein MC, Blanche C, Siegel RJ. Ventricularseptal rupture after acute myocardial infarction. N Engl J Med2002;347(18):1426–32.

[2] Dalrymple-Hay MJ, Monro JL, Livesey SA, Lamb RK. Postin-farction ventricular septal rupture: the Wessex experience.Semin Thorac Cardiovasc Surg 1998;10(2):111–6.

[3] David TE, Armstrong S. Surgical repair of postinfarctionventricular septal defect by infarct exclusion. Semin ThoracCardiovasc Surg 1998;10(2):105–10.

[4] Cooley DA. Postinfarction ventricular septal rupture. SeminThorac Cardiovasc Surg 1998;10(2):100–4.

[5] Madsen JC, Daggett Jr WM. Repair of postinfarction ven-tricular septal defects. Semin Thorac Cardiovasc Surg1998;10(2):117–27.

doi:10.1016/j.hlc.2008.11.030

21

Cardio-pulmonary bypass causes dampening of neu-trophil responsiveness—A prospective observationalstudy

J 1,2,3,4, 1,2,3,4 1,2,3,4

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ll underwent surgical repair using an exclusion bovineericardial patch technique. In 3 of the 7 inferior VSRatients, an incision was made anteroapically as opposed

o the more commonly described posterior or transin-arct approach. The rupture was repaired through thispproach in the commonly described fashion using anxclusion bovine pericardial patch sutured and glued toealthy edges of the rupture to achieve a tension freeepair.

Results: All 3 patients undergoing the alternative tech-ique weaned from bypass without incident and weretable in the ICU with adequate ventricular function ando residual VSD. One patient died at day 10 from ischaemicowel due to an intra aortic balloon pump complication.he remaining 2 patients have had a good long term post-perative outcome.Discussion: A current recommendation is that VSR be

pproached directly through the infarcted territory forepair [5]. However, we have found the anteroapicalpproach useful because it affords good visibility andccess not only to the ruptured area in inferior VSR butlso to the mitral subvalvular structures. In addition, itllows the heart to remain in a neutral position so that therea to be repaired is not distorted as there is no need toanipulate the heart to expose the infarcted surface. This

llows the patch to be sutured more accurately to the defectithout tension or distortion. Application of glue is alsoore accurate and complete when applied to the patch innon-distorted state. No embolic complications related to

he use of glue were seen using this method. In addition,here was no evidence of impairment of ventricular func-ion or residual or recurrent VSD. We have observed that

.F. Fraser , L. Fung , R. Mitchinson , P.oods 1,2,3,4, P. Fayers 1,2,3,4

The Critical Care Research Group & Department of Cardiacurgery, The Prince Charles Hospital, Brisbane, AustraliaAustralian Red Cross Blood Service, Brisbane, AustraliaBonfils Blood Centre & University of Colorado, Denver, UnitedtatesThe University of Queensland, Brisbane Australia

Introduction: The scientific study of neutrophils (PMNs),hich have a pivotal role in CABG associated inflamma-

ion, has been relatively limited. Previous studies haveocused on the peri-operative and 24 hr period posturgery, and mainly on the L-selectin (CD62L) and inte-rins CD11b and CD18. Our serial study of 5 functionally

mportant surface molecules reveals that changes causedy CABG may endure up to 5 days and have clinical impli-ations.

Methods: Thirty patients scheduled for elective coronaryrtery bypass graft (CABG) surgery at The Prince Charlesospital were recruited to the study at admission. This

roup consisted of 9 females (51–82 years) and 21 males35–79 years). Morning blood samples were collected fromatients prior to surgery and post-operatively on days 1, 3nd 5.PMNs were isolated within 4 hours of collection and

nalysed to:

(a) determine NADPH oxidase activity;b) quantify surface expression of CD16 (Fc�RIII), CD43,

CD62L, CD18 and CD11b (Mac-1 or CR3) on the PMNsurface.