Intra-operative protective mechanical ventilation in lung transplantation: a randomised, controlled trial.

Primary graft dysfunction occurs in up to 25% of patients after lung transplantation. Contributing factors include ventilator-induced lung injury, cardiopulmonary bypass, ischaemia-reperfusion injury and excessive fluid administration. We evaluated the feasibility, safety and efficacy of an open-lung protective ventilation strategy aimed at reducing ventilator-induced lung injury. We enrolled adult patients scheduled to undergo bilateral sequential lung transplantation, and randomly assigned them to either a control group (volume-controlled ventilation with 5 cmH2 O, positive end-expiratory pressure, low tidal volumes (two-lung ventilation 6 ml.kg-1 , one-lung ventilation 4 ml.kg-1 )) or an alveolar recruitment group (regular step-wise positive end-expiratory pressure-based alveolar recruitment manoeuvres, pressure-controlled ventilation set at 16 cmH2 O with 10 cmH2 O positive end-expiratory pressure). Ventilation strategies were commenced from reperfusion of the first lung allograft and continued for the duration of surgery. Regular PaO2 /FI O2 ratios were calculated and venous blood samples collected for inflammatory marker evaluation during the procedure and for the first 24 h of intensive care stay. The primary end-point was the PaO2 /FI O2 ratio at 24 h after first lung reperfusion. Thirty adult patients were studied. The primary outcome was not different between groups (mean (SD) PaO2 /FI O2 ratio control group 340 (111) vs. alveolar recruitment group 404 (153); adjusted p = 0.26). Patients in the control group had poorer mean (SD) PaO2 /FI O2 ratios at the end of the surgical procedure and a longer median (IQR [range]) time to tracheal extubation compared with the alveolar recruitment group (308 (144) vs. 402 (154) (p = 0.03) and 18 (10-27 [5-468]) h vs. 15 (11-36 [5-115]) h (p = 0.01), respectively). An open-lung protective ventilation strategy during surgery for lung transplantation is feasible, safe and achieves favourable ventilation parameters.

Clinical benefits of a specialised clinic for hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common monogenic cardiac condition, with a range of investigation and management options available. Recent research has recommended management within multidisciplinary-dedicated HCM centres. AIM: To assess the clinical impact of attendance at a specialised clinic on the management of HCM. METHODS: A retrospective study of patients attending the HCM Clinic @ The Alfred during the first 2 years of operation was performed. Outcome measures comprised improvements in management of HCM as a result of attending the clinic including risk stratification and further investigations, medication changes, referral for implantable cardioverter-defibrillators (ICD) and septal reduction therapy, and screening of first-degree relatives (FDR). RESULTS: Following specialised clinic attendance, there was an increase in patients investigated with 24-h Holter monitoring by 39%, stress echocardiography by 21% and cardiac magnetic resonance imaging by 70%. Medications were optimised in 47% of patients. Six per cent of patients underwent ICD implantation and 13% underwent septal myectomy. Seventy new FDR were screened identifying 10 new cases of HCM. CONCLUSIONS: Attendance at our specialised HCM clinic leads to facilitation of cardiac investigations, optimisation of medical therapy, streamlining of referrals for ICD implantation and septal reduction therapy, and improved family screening. Referral to a specialised clinic offering comprehensive management should be considered for all patients with HCM.

Surgical correction of posterior leaflet tethering in ischemic mitral regurgitation.

Ischemic mitral regurgitation is a common complication in ischemic heart disease. It is generally accepted that intervention for the mitral valve is required if there is moderate to severe regurgitation. Generally, this would involve the placement of an annuloplasty ring or band to cinch down the dilated posterior annulus. More recently, attention has been drawn to the common problem of posterior leaflet tethering in these ischemic patients and the need to specifically address this pathology. A novel method has recently been described whereby the posteromedial papillary muscle is hitched up toward the annulus by a suture and then supported with a partially flexible annuloplasty ring. The purpose of this report is to show that this technique is easily performed and reproducible in other centres, and that it produces good short to medium term results. The report details the results achieved in six consecutive patients with at least moderate mitral regurgitation and posterior leaflet tethering.

Mechanical circulatory support is associated with loss of platelet receptors glycoprotein Ibα and glycoprotein VI.

Essentials Relationship of acquired von Willebrand disease (VWD) and platelet dysfunction is explored. Patients with ventricular assist devices and on extracorporeal membrane oxygenation are investigated. Acquired VWD and platelet receptor shedding is demonstrated in the majority of patients. Loss of platelet adhesion receptors glycoprotein (GP) Ibα and GPVI may increase bleeding risk. SUMMARY: Background Ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) are associated with bleeding that is not fully explained by anticoagulant or antiplatelet use. Exposure of platelets to elevated shear in vitro leads to increased shedding. Objectives To investigate whether loss of platelet receptors occurs in vivo, and the relationship with acquired von Willebrand syndrome (AVWS). Methods Platelet counts, coagulation tests and von Willebrand factor (VWF) analyses were performed on samples from 21 continuous flow VAD (CF-VAD), 20 ECMO, 12 heart failure and seven aortic stenosis patients. Levels of platelet receptors were measured by flow cytometry or ELISA. Results The loss of high molecular weight VWF multimers was observed in 18 of 19 CF-VAD and 14 of 20 ECMO patients, consistent with AVWS. Platelet receptor shedding was demonstrated by elevated soluble glycoprotein (GP) VI levels in plasma and significantly reduced surface GPIbα and GPVI levels in CF-VAD and ECMO patients as compared with healthy donors. Platelet receptor levels were also significantly reduced in heart failure patients. Conclusions These data link AVWS and increased platelet receptor shedding in patients with CF-VADs or ECMO for the first time. Loss of the platelet surface receptors GPIbα and GPVI in heart failure, CF-VAD and ECMO patients may contribute to ablated platelet adhesion/activation, and limit thrombus formation under high/pathologic shear conditions.

Postoperative radial artery angiography for coronary artery bypass surgery.

OBJECTIVE: To compare radial artery (RA) patency with internal mammary artery (IMA) patency for coronary artery bypass surgery in our early experience. METHODS: Symptomatic as well as asymptomatic patients with > or =1 RA coronary graft underwent postoperative angiography. Each anastomosis was considered separately. A string sign referred to a diffusely narrowed conduit, which did not fill the grafted coronary artery, as well as all occluded conduits. The raw value of P was adjusted for the testing of multiple hypotheses (P'). The patency data for each conduit was divided into two parts. 'Cut-off' stenosis for a conduit was the lowest dividing coronary stenosis at which a difference in patency rate with P< or =0.05 occurred. RESULTS: One-hundred-and-twenty-nine patients had 137 radial arteries and 157 angiograms. Only the most recent angiogram was analyzed for each patient at 13+/-0.7 months (n=129). Overall patency for arterial conduit 91% (n=404) was not different from venous conduit 91% (n=42) and patency for RA 90% (n=226) was not different from IMA 92% (n=178), (P'=0.999). Cut-off stenosis for RA was 70% and IMA was 40%. Patent arterial conduit had a mean coronary stenosis of 85% and non-patent conduit 64%, (P'<0.001). Right coronary territory patency was 82 vs. 94% for other territories (P'=0.022). No overall differences in patency were noted for patients with sequential anastomoses, symptoms or coronary disease at the anastomosis at the time of surgery. Reversible ischaemia was detected in the distribution of only two of 14 string signs in patients undergoing sestamibi exercise protocol following angiogram. CONCLUSION: There were no differences in patency between radial artery and internal mammary artery at 13 months post-operative. Lower coronary stenosis and right coronary territory predicted lower patency. The clinical importance of a string sign remains to be determined.

Impact of warm ischemia time on survival after heart transplantation.

BACKGROUND: There is little data available on the specific effects of warm ischemia time (WIT) as opposed to cold ischemia or storage time. With current research endeavors focusing on warm continuous perfusion, storage of donor hearts, and utilization of hearts from non-heart-beating donors, the impact of WIT on outcomes is increasingly relevant. The aim of this study was to analyze our results in cardiac transplantation with specific focus on the impact of WIT. METHODS: A retrospective review of 206 patients who underwent orthotopic heart transplantation at our institution between June 2001 and November 2010 was performed. Donor, recipient, and operative factors were analyzed. The main outcome variables were all cause mortality, survival, and primary graft failure. RESULTS: WIT of >80 minutes was associated with reduced survival compared with a shorter WIT of <60 minutes. Multivariate analysis showed increasing donor age to be the most significant variable associated with increased risk of mortality (hazard ratio 1.04; P = .004) per year of increasing donor age. CONCLUSIONS: This study has demonstrated a reduced survival in heart transplant recipients with increased WIT. This finding may be of particular relevance to potential future heart transplantation using organs procured from non-heart-beating donors.

Practical management of anticoagulation, bleeding and blood product support for cardiac surgery. Part one: bleeding and anticoagulation issues.

There are many challenging problems related to bleeding and anticoagulation in cardiac surgery. Practical guidelines, which are based on available evidence, can help to direct management issues of post-bypass bleeding, perioperative anticoagulation and the use of haemostatic agents. The patient's bleeding history is the most useful preoperative screening test of haemostasis. The input of a haematologist is often valuable in a number of areas, such as preoperative assessment of patients with a significant history of bleeding, or past history of heparin-induced thrombocytopenia, a lupus anticoagulant, or recent venous thromboembolism. Cardiothoracic surgeons, anaesthetists, perfusionists and haematologists can ensure 'best practice' by being actively involved in the development of 'local' transfusion and anticoagulation guidelines, hospital transfusion committee policies, and audits.