Papers by Alain Deschamps
Journal of Cardiothoracic and Vascular Anesthesia
Journal of Cardiothoracic and Vascular Anesthesia
OBJECTIVE In vivo protamine titration (IVPT) is based on the observation of a plateau on the deca... more OBJECTIVE In vivo protamine titration (IVPT) is based on the observation of a plateau on the decay curve of the celite activated clotting times (ACTs) during protamine infusion for heparin reversal. The aim of the present study was to determine the optimal protamine/heparin ratio to reverse anticoagulation using IVPT curves. DESIGN Prospective, randomized study. SETTING Tertiary care university hospital. PARTICIPANTS The study comprised 138 patients undergoing elective cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS The control group was given a protamine infusion of 1.3 mg per 1 mg (100 U) of heparin over 21 minutes. ACT was measured every 3 minutes. In the test group, the protamine dose was prepared using the same ratio as for the control group, and ACT values were measured every 3 minutes until a plateau was reached (2 consecutive ACT values <160 s), at which time the protamine infusion was stopped. The protamine/heparin ratio, blood losses, transfusions, and heparin concentrations were recorded. RESULTS The protamine dose was lower in the test group (456.00 ± 105.66 mg [control group] v 295.25 ± 100.60 mg [test group]; p < 0.0001). The mean protamine/heparin ratios were 1.30 ± 0.10 (control group) and 0.81 ± 0.22 (test group) (p < 0.0001). Heparin concentrations were greater in the test group 15 minutes (0.10 [0-0.2] U/mL v 0 [0-0.1] U/mL; p = < 0.0001) and 3 hours (0 [0-0.1] U/mL v 0 [0-0] U/mL; p = 0.0002) after protamine infusion. There was no difference in the blood losses and transfusion requirements. CONCLUSIONS IVPT is safe and efficient in this low-risk population.
F1000Research
Background: There is some evidence that electroencephalography guidance of general anesthesia ca... more Background: There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery. There is limited evidence in this regard for cardiac surgery. A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death. However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods: The Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites. The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery. One approach is based on current standard anesthetic practice and the other o...
Journal of Cardiothoracic and Vascular Anesthesia
Near-infrared spectroscopy (NIRS) is an emerging noninvasive monitoring modality based on chromop... more Near-infrared spectroscopy (NIRS) is an emerging noninvasive monitoring modality based on chromophore absorption of infrared light. Because NIRS provides instantaneous information on cerebral and somatic tissue oxygenation, it becomes mandatory to identify rapidly the etiology of impaired regional oxygenation and thus perfusion. To do so, the use of whole-body ultrasound (WHOBUS) represents a significant advance in the management of patients experiencing cerebral or somatic desaturation. This narrative review describes the authors' experience since 2002 in the use of combined NIRS and WHOBUS. A practical approach in the use of both modalities and their respective limitations is described.
Journal of Cardiothoracic and Vascular Anesthesia
Right ventricular (RV) dysfunction is a cause of increased morbidity and mortality in both cardia... more Right ventricular (RV) dysfunction is a cause of increased morbidity and mortality in both cardiac surgery and noncardiac surgery and in the intensive care unit. Early diagnosis of this condition still poses a challenge. The diagnosis of RV dysfunction traditionally is based on a combination of echocardiography, hemodynamic measurements, and clinical symptoms. This review describes the method of using RV pressure waveform analysis to diagnose and grade the severity of RV dysfunction. The authors describe the technique, optimal use, and pitfalls of this method, which has been used at the Montreal Heart Institute since 2002, and review the current literature on this method. The RV pressure waveform is obtained using a pulmonary artery catheter with the capability of measuring RV pressure by connecting a pressure transducer to the pacemaker port. The authors describe how RV pressure waveform analysis can facilitate the diagnosis of systolic and diastolic RV dysfunction, the evaluation of RV-arterial coupling, and help diagnose RV outflow tract obstruction. RV pressure waveform analysis also can be used to guide pharmacologic treatment and fluid resuscitation strategies for RV dysfunction.
Canadian journal of anaesthesia = Journal canadien d'anesthesie, Jan 19, 2018
Journal of Cardiothoracic and Vascular Anesthesia
Objective: We evaluated the incidence of post-operative non-ischemic seizures associated with the... more Objective: We evaluated the incidence of post-operative non-ischemic seizures associated with the use of tranexamic acid (TXA) and the possibility of prevention with a low dose regimen of TXA.
Journal of Cardiothoracic and Vascular Anesthesia
To identify risk factors associated with radial-to-femoral pressure gradient during cardiac surge... more To identify risk factors associated with radial-to-femoral pressure gradient during cardiac surgery with cardiopulmonary bypass (CPB). This is a retrospective, observational study. Single specialized cardiothoracic hospital in Montreal, Canada. Consecutive patients that underwent heart surgery with CPB between 2005 and 2015 (n = 435). None. A radial-to-femoral pressure gradient occurred in 146 patients of the 435 patients (34%). Based on the 10,000 bootstrap samples, simple logistic regression models identified the 17 most commonly significant variables across the bootstrap runs. Using these variables, a backward multiple logistic model was performed on the original sample and identified the following independent variables: body surface area (m) (odds ratio [OR] 0.08, 95% confidence interval [CI] 0.030-0.232), clamping time (minutes) (OR 1.01, 95% CI 1.007-1.018), fluid balance (for 1 liter) (OR 0.81, 95% CI 0.669-0.976), and preoperative hypertension (OR 1.801, 95% CI 1.131-2.868). A radial-to-femoral pressure gradient occurs in 34% of patients during cardiac surgery. Patients at risk seem to be of smaller stature, hypertensive, and undergo longer and more complex surgeries.
Anesthesia and analgesia, Aug 7, 2017
In cardiac surgery, pulmonary hypertension is an important prognostic factor for which several tr... more In cardiac surgery, pulmonary hypertension is an important prognostic factor for which several treatments have been suggested over time. In this systematic review and meta-analysis, we compared the efficacy of inhaled aerosolized vasodilators to intravenously administered agents and to placebo in the treatment of pulmonary hypertension during cardiac surgery. We searched MEDLINE, CENTRAL, EMBASE, Web of Science, and clinicaltrials.gov databases from inception to October 2015. The incidence of mortality was assessed as the primary outcome. Secondary outcomes included length of stay in hospital and in the intensive care unit, and evaluation of the hemodynamic profile. Of the 2897 citations identified, 10 studies were included comprising a total of 434 patients. Inhaled aerosolized agents were associated with a significant decrease in pulmonary vascular resistance (-41.36 dyne·s/cm, P= .03) and a significant increase in mean arterial pressure (8.24 mm Hg, P= .02) and right ventricular ...
Canadian journal of anaesthesia = Journal canadien d'anesthesie, Jan 15, 2016
Assessing fluid responsiveness is important in the management of patients with hemodynamic instab... more Assessing fluid responsiveness is important in the management of patients with hemodynamic instability. Passive leg raising (PLR) is a validated dynamic method to induce a transient increase in cardiac preload and predict fluid responsiveness. Variations in end-tidal carbon dioxide (ETCO2) obtained by capnography correlate closely with variations in cardiac output when alveolar ventilation and carbon dioxide production are kept constant. In this prospective observational study, we tested the hypothesis that variations in ETCO2 induced by a simplified PLR maneuver can track changes in the cardiac index (CI) and thus predict fluid responsiveness. A five-minute standardized PLR maneuver was performed in 90 paralyzed hemodynamically stable cardiac surgical patients receiving mechanical ventilation. Cardiac index was measured by thermodilution before and one minute after PLR. End-tidal CO2 measurements using capnography were obtained during the entire PLR maneuver. Fluid responsiveness w...
Can J Anaesth, 2007
Purpose To determine whether or not intravenous nitroglycerin (IV NTG) can prevent a decrease in ... more Purpose To determine whether or not intravenous nitroglycerin (IV NTG) can prevent a decrease in near-infrared spectros-copy (NIRS) values during cardiopulmonary bypass Methods We conducted a randomized double-blinded study in a tertiary academic center including 30 patients with a Parsonnet score ≥ 15 scheduled for a high-risk cardiac surgery. The patients were randomized to receive either IV NTG (initial dose of 0.05 µg·kg-1 ·min-1, followed by 0.1 µg·kg-1·min-1) or placebo after anesthetic induction until the end of The primary outcome was a decrease of 10% in NIRS values during CPB. Results Despite the absence of between-group difference in the mean cerebral oxygen saturation during there was a significant decrease in NIRS values during CPB in the placebo group, whereas mean NIRS values were maintained in the IV NTG group (-16.7%vs 2.3% in the NTG,P = 0.019). Major hemodynamic variables were similar at corresponding time periods in both groups, while patients in the IV NTG group had higher CK-MB values and experienced greater blood loss during the first 24 hr postoperatively. Conclusion Intravenous nitroglycerin administration before and during CPB may prevent a decrease in NIRS values associated with CPB in high-risk cardiac surgery. Further studies are warranted to determine the efficacy and the risks associated with IV NTG infusion for this indication during CPB in high-risk patients. Objectif Déterminer si la nitroglycérine intraveineuse (NTG IV) peut empêcher ou non une diminution des valeurs de la spectroscopie par infrarouge (NIRS) pendant la circulation extracorporelle (CEC). Méthode Nous avons mené une étude randomisée à double insu dans un centre universitaire tertiaire incluant 30 patients présentant un score de Parsonnet ≥ 15 et devant subir une chirurgie cardiaque à haut risque. Les patients ont été randomisés en deux groupes: NTG IV (dose initiale de 0,05 µg·kg-1 ·min-1, suivie de 0,1 µg·kg-1 ·min-1), ou placebo après l’induction de l’anesthésie et jusqu’à la fin de la CEC. Le résultat primaire a été une diminution de 10% des valeurs de NIRS pendant la CEC. Résultats Malgré l’absence de différence inter-groupe dans la saturation d’oxygène cérébrale moyenne durant la CEC, une diminution significative des valeurs de NIRS pendant la CEC a été observée dans le groupe placebo, alors que les valeurs moyennes de NIRS se sont maintenues dans le groupe NTG IV (-16,7% vs 2,3 % dans le groupe NTG, P = 0,019). Les variables hémodynamiques principales ont été semblables pour des périodes temporelles correspondantes dans les deux groupes, bien que les patients du groupe NTG IV aient présenté des valeurs CK-MB plus élevées et perdu davantage de sang durant les premières 24 h postopératoires. Conclusion L’administration de nitroglycérine intraveineuse avant et pendant la CEC pourrait empêcher une diminution des valeurs de NIRS associées à la CEC dans les chirurgies cardiaques à haut risque. Des études supplémentaires sont nécessaires afin de déterminer l’efficacité et les risques associés à une infusion NTG IV pour cette indication pendant la CEC chez des patients à haut risque.
Can J Anaesth, 2007
Purpose To evaluate the correlation between the progression of somatosensory blockade and change... more Purpose To evaluate the correlation between the progression of somatosensory blockade and changes in autonomic outflow following the onset of labour epidural analgesia. Methods Twelve labouring parturients consented to participate in the study. Baseline electrocardiogram, blood pressure (BP) and respiratory rate were recorded for ten minutes. The epidural consisted of 0.125% bupivacaine with 50 μg of fentanyl (total volume 20 mL). Measurements
Anesthesiology, 2016
Background Cerebral oxygen desaturation during cardiac surgery has been associated with adverse p... more Background Cerebral oxygen desaturation during cardiac surgery has been associated with adverse perioperative outcomes. Before a large multicenter randomized controlled trial (RCT) on the impact of preventing desaturations on perioperative outcomes, the authors undertook a randomized prospective, parallel-arm, multicenter feasibility RCT to determine whether an intervention algorithm could prevent desaturations. Methods Eight Canadian sites randomized 201 patients between April 2012 and October 2013. The primary outcome was the success rate of reversing cerebral desaturations below 10% relative to baseline in the intervention group. Anesthesiologists were blinded to the cerebral saturation values in the control group. Intensive care unit personnel were blinded to cerebral saturation values for both groups. Secondary outcomes included the area under the curve of cerebral desaturation load, enrolment rates, and a 30-day follow-up for adverse events. Results Cerebral desaturations occu...
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Papers by Alain Deschamps