Michel Durand

Immediate prehospital hypothermia protocol in comatose survivors of out-of-hospital cardiac arrest

Therapeutic hypothermia (TH) improves the outcomes of cardiac arrest (CA) survivors. The aim of this study was to evaluate retrospectively the efficacy and safety of an immediate prehospital cooling procedure implemented just after the return of spontaneous circulation with a prehospital setting. During 30 months, the case records of comatose survivors of out-of-hospital CA presumably due to a cardiac disease were studied. A routine protocol of immediate postresuscitation cooling had been tested by an emergency team, which consisted of an infusion of large-volume, ice-cold intravenous saline. We decided to assess the efficacy and tolerance of this procedure. A total of 99 patients were studied; 22 were treated with prehospital TH, and 77 consecutive patients treated with prehospital standard resuscitation served as controls. For all patients, TH was maintained for 12 to 24 hours. The demographic, clinical, and biological characteristics of the patients were similar in the 2 groups. The rate of patients with a body temperature of less than 35 degrees C upon admission was 41% in the cooling group and 18% in the control group. Rapid infusion of fluid was not associated with pulmonary edema. After 1 year of follow-up, 6 (27%) of 22 patients in the cooling group and 30 (39%) of 77 patients in the control group had a good outcome. Our preliminary observation suggests that in comatose survivors of CA, prehospital TH with infusion of large-volume, ice-cold intravenous saline is feasible and can be used safely by mobile emergency and intensive care units.

Prognostic factors for extracorporeal cardiopulmonary resuscitation recipients following out-of-hospital refractory cardiac arrest. A systematic review and meta-analysis

PURPOSE Association estimates between baseline characteristics and outcomes are imprecise and inconsistent among extracorporeal cardiopulmonary resuscitation (ECPR) recipients following refractory out-of-hospital cardiac arrest (OHCA). This systematic review and meta-analysis aimed to investigate the prognostic significance of pre-specified characteristics for OHCA treated with ECPR. METHODS The Medline electronic database was searched via PubMed for articles published from January 2000 to September 2016. The electronic search was supplemented by scanning the reference lists of retrieved articles and contacting field experts. Eligible studies were historical and prospective cohort studies of adult patients undergoing ECPR following OHCA. RESULTS Fifteen primary studies were included, totaling 841 participants. The median prevalence of the primary outcome (i.e., short- or long-term survival for five studies and cerebral performance for ten studies) was 15% (range, 0-50%). The primary outcome was associated with an increased odds ratio of initial shockable cardiac rhythm (2.20; 95% confidence interval [CI], 1.30-3.72; P=0.003), shorter low-flow duration (geometric mean ratio, 0.90; 95% CI, 0.81-0.99; P=0.04), higher arterial pH value (difference, 0.12; 95% CI, 0.03-0.22; P=0.01) and lower serum lactate concentration (difference, -3.52mmol/L; 95% CI, -5.05 to -1.99; P<0.001). No significant association was found between the primary outcome and patient age (the odds of female gender and bystander CPR attempt. CONCLUSION Observational evidence from published primary studies indicates that shorter low-flow duration, shockable cardiac rhythm, higher arterial pH value and lower serum lactate concentration on hospital admission are associated with better outcomes for ECPR recipients after OHCA.

Coronary artery bypass grafting with left internal mammary artery and right gastroepiploic artery, with and without bypass

BACKGROUND Total arterial and off-pump revascularization are increasingly used in coronary artery bypass grafting. This study describes our experience with the exclusive use of both left internal thoracic artery and gastroepiploic artery by means of a median sternotomy, with and without cardiopulmonary bypass, in a subgroup of patients with two-vessel disease. METHODS From January 1995 to July 2000, 171 consecutive patients were reviewed in a prospective database. Ninety-one patients underwent coronary artery bypass grafting without cardiopulmonary bypass (group A), and 80 patients were operated on under cardiopulmonary bypass with aortic cross-clamp and cardioplegia (group B). RESULTS Patient data were similar in both groups except for the Euroscore (mean; 3.4+/-6.1, group A versus 2.5+/-4.5, group B; Euroscore > 6: 26.4%, group A versus 10%, group B; p < 0.05) and ejection fraction (mean, 54.6%+/-15.8%, group A versus 63.1%+/-12.7%, group B; p < 0.001). Severe aortic calcification was present in 6 group A patients, versus no patient in group B. Operative time was shorter in group A (185 versus 213 minutes, p < 0.0001), with less distal anastomoses (2.26 versus 2.5, p < 0.05). Conversion to cardiopulmonary bypass occurred in 1 patient, who was excluded from the study. Bleeding was higher in group A (852.6+/-288 mL versus 712.4+/-274 mL, p < 0.05), but transfusion was similar in both groups. Atrial fibrillation, postoperative inotropic support, and hospital stay were similar in both groups. Myocardial infarction was less frequent in group A (1 versus 4). Postoperative intraaortic balloon pump was used in 2 patients (group B). One patient died (group A) and 1 had an embolic stroke (group B). After discharge, 2 more patients died (group A, day 91; group B day 141), and 1 patient suffered an embolic stroke (group B). One patient in each group presented with dysfunction of the gastroepiploic artery graft requiring successful percutaneous transluminal angioplasty on the right posterolateral artery. CONCLUSIONS These results suggest that off-pump coronary artery bypass grafting using the left internal thoracic artery and gastroepiploic artery is safe even in high-risk patients. This approach allows an absolute no-touch technique of the aorta.

Extracorporeal life support as a bridge to high-urgency heart transplantation

Barth E, Durand M, Heylbroeck C, Rossi‐Blancher M, Boignard A, Vanzetto G, Albaladejo P, Chavanon O. Extracorporeal life support as a bridge to high‐urgency heart transplantation. 
Clin Transplant 2011 DOI: 10.1111/j.1399‐0012.2011.01525.x. 
© 2011 John Wiley & Sons A/S.

Effect of topical vasodilators on gastroepiploic artery graft.

BACKGROUND Mobilization of the gastroepiploic artery (GEA) often results in a vasospasm with reduction of early graft flow. In order to prevent or suppress this highly reactive arterys spasm, we have compared the effect of 4 vasodilators, used in external application to prepare the GEA graft, prior to myocardial revascularization. METHODS WE performed a double-blind clinical study to compare the effects of external application of vasodilators on gastroepiploic artery grafts. Fifty patients, whose gastroepiploic artery was used for coronary artery bypass grafting, were randomized into 5 groups of 10 patients. Gastroepiploic artery free flow and hemodynamic measurements were evaluated immediately after harvesting, before any pharmacological manipulation, and 10 minutes after the topical application of vasodilators, respectively: papaverine, linsidomine, nicardipine, glyceryl trinitrate, and normal saline solution. RESULTS A significant increase in free flow occurred in all groups except for the normal saline solution group with measurements from 26.1+/-3.6 mL/min to 26.4+/-6.5 mL/min; p = 0.9. The most important increase in flow before and after local application occurred with glyceryl trinitrate and papaverine: from 25.5+/-2 mL/min to 50+/-6.1 mL/min (p < or = 0.01) and from 36.8+/-3.2 mL/min to 62+/-7.8 mL/min (p < 0.01) respectively. Nicardipine and linsidomine produced a less significant increase in flow: from 33.1+/-3.6 mL/min to 47.7+/-8.9 mL/min (p < 0.05) and from 28+/-3.8 mL/min to 39.8+/-7.5 mL/min (p < 0.05) respectively. When comparing percentage of flow increase, glyceryl trinitrate appeared to be significantly more efficient than nicardipine and linsidomine (p < 0.01 versus both groups). Although papaverine was more efficient than nicardipine and linsidomine, it did not reach statistical significance. CONCLUSIONS During intraoperative preparation of the GEA graft, glyceryl trinitrate and papaverine to a lesser extent, used as topical vasodilators, appear to be more efficient in external application to increase the free flow of the GEA.

Quantitative pupillometry and transcranial Doppler measurements in patients treated with hypothermia after cardiac arrest

BACKGROUND Predicting outcome after cardiac arrest (CA) is particularly difficult when therapeutic hypothermia (TH) is used. We investigated the performance of quantitative pupillometry and transcranial Doppler (TCD) in this context. METHODS This prospective observational study included 82 post-CA patients. Quantitative assessment of pupillary light reflex (PLR) and TCD measurements of the two middle cerebral arteries were performed at admission (day 1) and after 24h (day 2) during TH (33-35°C) and sedation. Neurological outcome was assessed at 3 months using cerebral performance category (CPC) scores; patients were classified as having good (CPC 1-2) or poor (CPC 3-5) outcome. Prognostic performance was analyzed using area under the receiver operating characteristic curve (AUC-ROC). RESULTS Patients with good outcome (n=27) had higher PLR amplitude than patients with poor outcome (n=55) both at day 1, 13% (10-18) (median, 25th-75th percentile) vs. 8% (2-11) (P<0.001), and at day 2, 17% (13-20) vs. 8% (5-13) (P<0.001), respectively. The AUC-ROC curves at days 1 and 2 were 0.76 (95% confidence interval [CI] 0.65-0.86) and 0.82 (95% CI 0.73-0.92), respectively. The best cut-off values of PLR amplitude to predict a 3-month poor outcome were <9% and <11%, respectively. A PLR amplitude of <7% at day 2 predicted a 3-month poor outcome with a specificity of 100% (95% CI 86-100) and a sensitivity of 42% (95% CI 28-58). No differences in TCD measurements were found between the two patient groups. CONCLUSION PLR measurements might be informative in the prediction of outcome of post-CA patients even under sedation and hypothermia.

Evaluation of the effect of one large dose of erythropoietin against cardiac and cerebral ischemic injury occurring during cardiac surgery with cardiopulmonary bypass: a randomized double-blind placebo-controlled pilot study

Cardiac surgery and cardiopulmonary bypass (CPB) induce ischemia–reperfusion and subsequent cellular injury with inflammatory reaction. Clinical and experimental studies suggest that recombinant human erythropoietin (EPO) independently of its erythropoietic effect may be used as a cytoprotective agent against ischemic injury. We tested the hypothesis that one large dose of EPO administered shortly before CPB prevents the elevation of cardiac and cerebral ischemic blood markers as well as the systemic inflammatory response induced by cardiac surgery with CBP through this randomized double‐blind placebo‐controlled pilot trial. Fifty patients scheduled for coronary artery bypass graft (CABG) surgery with CPB were randomly allocated to EPO or control groups. EPO (800 IU/kg intravenously) or placebo (saline) was administered before CPB. The primary end point was to study the effect of EPO administration on several blood markers of myocardial and cerebral ischemia in relation to CABG with CPB. In both groups, surgery increased plasma concentrations of cardiac (troponin T, NT‐proBNP, and creatine kinase MB) and cerebral (S100β protein) markers ischemic as well as the pro‐inflammatory marker interleukin‐6. Compared with the placebo, EPO administration before CPB did not prevent an increase of all these markers following CPB. In conclusion, one large dose of EPO, given shortly before CPB, did not protect against cardiac and cerebral ischemia and inflammatory response occurring during CABG surgery with CPB. Although the long‐term clinical implications remain unknown, the findings do not support use of EPO at this dose as a cytoprotective agent in patients undergoing cardiac surgery.

Effect of low-dose positive inotropic drugs on human internal mammary artery flow.

BACKGROUND Dobutamine (a beta-receptor agonist), enoximone (a type III selective phosphodiesterase inhibitor), and epinephrine (an alpha- and beta-mimetic) frequently are used in the perioperative management of patients undergoing coronary artery bypass grafting. METHODS We performed a double-blind clinical study to compare the effects on internal mammary artery free flow of low doses of these three positive inotropic drugs. Thirty patients in whom the left internal mammary artery was used for coronary artery bypass grafting were randomized into three groups. Internal mammary artery free flow and hemodynamic measurements were evaluated before and 10 minutes after the intravenous infusion of dobutamine (3 microg x kg(-1) x min(-1)), enoximone (200 microg/kg), or epinephrine (0.05 microg x kg(-1) x min(-1)). RESULTS A significant increase in free flow occurred only in the dobutamine group (33 +/- 7.5 and 42.2 +/- 7.9 mL/min before and after drug infusion, respectively; p = 0.013). Comparison of the increase in flow between the groups, however, showed no difference. These drugs, at doses designed to produce a positive inotropic effect, caused little increase in the free flow of the internal mammary artery. CONCLUSIONS The use of dobutamine, enoximone, and epinephrine as low-dose positive inotropic treatments in the perioperative and postoperative periods of coronary artery bypass grafting should depend on their positive inotropic effects rather than their vasodilative effects on the arterial grafts.

Extracorporeal life support for massive pulmonary embolism during pregnancy

Massive pulmonary embolism is a leading cause of death during pregnancy. While the prevention of thromboembolic disease during the peripartum period is codified, there is no consensus regarding its treatment. We report two cases of pregnant women who had massive pulmonary embolisms (PE) and shock treated with veno-arterial extracorporeal life support (ECLS) and heparin therapy. Haemodynamic and oxygenation parameters were rapidly restored. The patients completely recovered and the pregnancies continued. The patients did not develop pulmonary hypertension. ECLS can be considered as a successful treatment option of massive pulmonary embolism during pregnancy.

Right ventricular function after coronary surgery with or without bypass.

Abstract  Background and objective: Myocardial protection during aortic clamp period may sometimes be inadequate, especially for the right. The aim of this study was to compare right ventricle function after cardiac surgery with or without bypass. Methods: Patients undergoing multivessel coronary surgery with proximal severe right coronary lesion were included in a prospective observational cohort study including 29 patients undergoing coronary surgery with or without bypass. All patients were monitored with a pulmonary artery catheter with continuous right ventricular function. Right ventricular ejection fraction was measured at the arrival in ICU, 1, 3, 6, and 18 hours later. Results: The number of grafts that was higher in the bypass group (4.0 ± 1.3) than in the off‐pump group (2.6 ± 0.6, p = 0.001). In the on‐pump group, the right ventricular ejection fraction significantly decreased from 32.9 ± 2.8 at arrival in ICU to 26.1 ± 2.4, 6 hours later whereas in the off‐pump group, it did not significantly change (32.4 ± 1.8 to 31.9 ± 2.3). Meanwhile, at the same time intervals, CVP was significantly lower in the off‐pump group. Conclusions: In patients with severe right coronary stenosis, off‐pump cardiac surgery seemed to provide better right ventricular protection.