In Vivo Protamine Titration Using Activated Coagulation Time to Neutralize Heparin Anticoagulation in Cardiac Surgery: Proof of Concept.

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.

Myocardial Protection in Mitral Valve Surgery: Comparison Between Minimally Invasive Approach and Standard Sternotomy.

OBJECTIVE: To compare antegrade and retrograde cardioplegia administration in minimally invasive mitral valve surgery (MIMS) and open mitral valve surgery (OMS) for myocardial protection. DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The study comprised 118 patients undergoing MIMS and 118 patients undergoing OMS. INTERVENTIONS: The data of patients admitted for MIMS from 2006 to 2010 were reviewed. Patients undergoing isolated elective OMS from 2004 to 2006 were used as a control group. Cardioplegia in the MIMS group was delivered via the distal port of the endoaortic clamp and an endovascular coronary sinus catheter positioned using echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia were used in OMS. Data regarding myocardial infarction (MI) (creatine kinase [CK]-MB, troponin T, electrocardiography); myocardial function; and hemodynamic stability were collected. MEASUREMENTS AND MAIN RESULTS: There was no difference in the perioperative MI incidence between both groups (1 in each group, p = 0.96). No statistically significant difference was found for maximal CK-MB (35.9 µg/L [25.1-50.1] v 37.9 µg/L [28.6-50.9]; p = 0.31) or the number of patients with CK-MB levels >50 µg/L (29 v 33; p = 0.55) or CK-MB >100 µg/L (3 v 4; p = 0.70) between the OMS and MIMS groups. However, maximum troponin T levels in the MIMS group were significantly lower (0.47 µg/L [0.32-0.79] v 0.65 µg/L [0.45-0.94]; p = 0.0007). No difference in the incidence of difficult weaning from bypass and intra-aortic balloon pump use between the MIMS and OMS groups was found. CONCLUSIONS: Antegrade and retrograde cardioplegia administration during MIMS and OMS provided comparable myocardial protection.

Intraoperative changes in regional wall motion: can postoperative coronary artery bypass graft failure be predicted?

OBJECTIVE: To evaluate the accuracy of new intraoperative regional wall motions abnormalities (RWMAs) detected by transesophageal echocardiography (TEE) to predict early postoperative coronary artery graft failure. DESIGN: A retrospective study. SETTING: A tertiary care university hospital. PATIENTS: Five thousand nine hundred ninety-eight patients who underwent coronary artery bypass graft (CABG) surgery. INTERVENTIONS: An evaluation of RWMAs recorded with intraoperative TEE before and after cardiopulmonary bypass (CPB) in patients who had coronary angiography for suspected postoperative myocardial ischemia based on electrocardiogram (ECG), CK-MB, troponin T, hemodynamic compromise, low cardiac output, and malignant ventricular arrhythmia. Sensitivity, specificity, positive and negative predictive values, odds ratio, 95% confidence interval, and chi-square analysis were used. MEASUREMENTS AND MAIN RESULTS: Thirty-nine patients (0.7%) underwent early coronary angiography for the suspicion of early graft dysfunction. Of the 32 patients with diagnosed early graft dysfunction, 5 patients (15.6%) had shown new intraoperative RWMAs as detected by TEE, 21 patients (65.6%) had no new RWMAs, no report was available in 5 patients (15.6%), and 1 examination (3.1%) was excluded because of poor imaging quality. The sensitivity of TEE to predict graft failure was 15.6%, the specificity was 57.1%, and the positive predictive and negative values were 62.5% and 12.9%, respectively. The odds ratio and 95% confidence interval was 0.1190 (0.0099-1.4257) when TEE was positive compared with coronary angiography. No association was found between new RWMAs detected with TEE and graft failure as documented with coronary angiography (p = 0.106). CONCLUSIONS: In this retrospective study, RWMAs detected with TEE were of limited value to predict early postoperative CABG failure.

Posttraumatic left ventricular tachycardia arising from the anterior papillary muscle in an otherwise healthy child.

After being struck by a car at the age of 7, an otherwise healthy boy developed recalcitrant, albeit hemodynamically, well-tolerated ventricular tachycardia. An electrophysiological study with 3-dimensional electroanatomic mapping was performed under transesophageal echocardiographic guidance at 10 years of age. Nonautomatic focal ventricular tachycardia was mapped to the left anterolateral papillary muscle, where it was successfully ablated. To our knowledge, this report represents the first description of papillary muscle ventricular tachycardia in a child, and of blunt thoracic trauma as a potential trigger.

The endovascular coronary sinus catheter in minimally invasive mitral and tricuspid valve surgery: a case series.

OBJECTIVES: To determine the safety and efficacy of a standardized approach to the use of an endovascular coronary sinus (CS) catheter during minimally invasive cardiac surgery. DESIGN: Case series. SETTING: University hospital. PARTICIPANTS: Patients undergoing mitral and/or tricuspid valve surgery using a minimally invasive cardiac surgery approach. INTERVENTIONS: An endovascular CS catheter was placed to enable the administration of retrograde cardioplegia using transesophageal echocardiography (TEE), fluoroscopy, and CS pressure measurements. MEASUREMENTS AND MAIN RESULTS: Data were collected from 96 patient records. A total of 95 (99.0%) endovascular coronary sinus catheters were positioned. The mean time to insert the catheter into the sinus ostium under TEE guidance was 6.3 ± 8.4 minutes. Confirmation of adequate positioning with fluoroscopy took an average of 9.1 ± 10.6 minutes for a mean total procedure time of 16.1 ± 14.1 minutes. Successful positioning, as defined by the ability to generate a perfusion pressure in the CS greater than 30 mmHg during surgery, was achieved in 87.5% of cases. During positioning, ventricularization of the CS pressure curve was observed in 86.0% of cases. The presence of ventricularization was associated with an increase in positioning success (odds ratio = 15.8; 95% confidence interval, 3.713-67.239). One patient developed extravasation of contrast agent after CS catheter placement, without evidence of CS rupture. CONCLUSIONS: Endovascular CS catheter insertion can be performed with a high rate of success for positioning and a low complication rate. During positioning, obtaining ventricularization is associated with an increased success rate.

Comprehensive Canadian review of the off-label use of recombinant activated factor VII in cardiac surgery.

BACKGROUND: This observational study sought to identify the off-label use pattern of recombinant activated factor VII (rFVIIa) in cardiac surgery and to identify predictors of its effectiveness and risk. METHODS AND RESULTS: At 18 Canadian centers, 522 nonhemophiliac cardiac surgical patients received rFVIIa during the period 2003 through 2006; data were available, and retrospectively collected, on 503 patients. The median (quartile 1, quartile 3) units of red blood cells transfused from surgery to therapy and in the 24 hours after therapy were 8 (5, 12) and 2 (1, 5), respectively (P<0.0001). Mortality rate was 32%, and mortality or major morbidity rate was 44%. These rates were within expected ranges (mortality, 27% to 35%; mortality or morbidity, 39% to 48%), which were calculated with a separate cohort of cardiac surgical patients who did not receive rFVIIa used as reference. Independent predictors of complications included instability before therapy (multiple inotropes or intra-aortic balloon pump) and increasing red blood cell units transfused before and after therapy. Variables independently associated with nonresponse included abnormal coagulation parameters and >15 red blood cell units transfused before therapy. CONCLUSIONS: In Canada, rFVIIa is used primarily when standard interventions have failed to control bleeding. In this setting, rFVIIa is associated with reduced blood product transfusions and, after risk adjustment, does not appear to be associated with increased or decreased complication rates. The effectiveness of the drug may be enhanced if it is given early in the course of refractory blood loss in the setting of adequate amounts of circulating coagulation factors.

Coagulation monitoring.

Monitoring hemostasis is now possible by different modalities, of which the point of care devices seem most helpful to the clinician in the operating room. Most of these monitors are being used in the cardiac population, and their significance in other fields remains to be assessed.

Desflurane does not accelerate recovery from operations of short duration: a practice audit.

PURPOSE: Desflurane, a newer inhalation anesthetic agent, has been promoted as a superior drug because patients will awaken sooner after anesthesia. This has only been proven in operations of long duration (i.e., more than one hour). We assessed our experience using desflurane in short out-patient surgery with a retrospective analysis of a single surgeon's elective laparoscopic cholecystectomy patients. METHODS: With Institutional consent, we performed a retrospective comparison of the postoperative recovery of patients who received desflurane/air/oxygen to historical control patients who received isoflurane/N2O/oxygen. RESULTS: Patient preoperative characteristics were similar in the two groups. Duration of surgery and the time from the end of surgery to patient leaving the operating room for the desflurane and isoflurane/N2O groups were (in minutes) 42.7 +/- 13.5 and 9.6 +/- 4.6 vs 47.2 +/- 15.1 and 8.5 +/- 4.1 respectively (P = NS). Total Aldrete scores upon presentation to the postanesthesia care unit (PACU) were 8.1 +/- 1.4 and 7.9 +/- 1.8 for the two groups respectively (P = NS). The percentage of patients who arrived in the PACU with consciousness scores of 2, 1, 0 for the desflurane and isoflurane/N2O groups were 20.4, 75.5, and 4.1 vs 14.6, 73.2 and 12.2 respectively (P = NS). Mean length of stay in the PACU for the two groups was 160 +/- 111 and 156 +/- 114 min (P = NS). CONCLUSION: Our results show that in short procedures the use of desflurane does not necessarily result in faster patient recovery or discharge from the PACU.