Amine Matta

Levosimendan in Congenital Cardiac Surgery: A Randomized, Double-Blind Clinical Trial

OBJECTIVEnIn this study, the authors used a continuous infusion of either levosimendan or milrinone as inotropic support after corrective congenital cardiac surgery. The hemodynamic and biochemical parameters were compared.nnnDESIGNnA prospective, randomized, double-blind clinical study.nnnSETTINGnA university hospital.nnnPARTICIPANTSnForty-one patients between 0 and 5 years old requiring inotropic support for corrective congenital heart surgery under cardiopulmonary bypass (CPB) were enrolled in this trial. Thirty-six patients completed the study.nnnINTERVENTIONSnPatients were randomized in a double-blind fashion to a continuous infusion of either levosimendan at 0.05 μg/kg/min or milrinone at 0.4 μg/kg/min started at the onset of CPB. Epinephrine was started at 0.02 μg/kg/min after aortic cross-clamp release in both groups.nnnMEASUREMENTS AND MAIN RESULTSnThere was no significant difference between serum lactate levels of groups. The rate-pressure index (the product of heart rate and systolic blood pressure), which is an indicator of myocardial oxygen demand, was significantly lower at 24 hours and 48 hours postoperatively in the levosimendan group (p < 0.001) in comparison to the milrinone group. Although not significantly different, the troponin values in the levosimendan group were less at 1 hour (median [P(25)-P(75)]: 20.7 [15.3- 48.3] v 34.6 [23.8- 64.5] ng/mL and 4 hours postoperatively: 30.4 [17.3-59.9] v 33.3 [25.5-76.7] ng/mL).nnnCONCLUSIONnLevosimendan is at least as efficacious as milrinone after corrective congenital cardiac surgery in neonates and infants.

Multilevel somatosensory evoked potentials (SEPs) for spinal cord monitoring in descending thoracic and thoraco-abdominal aortic surgery

The usefulness of somatosensory evoked potential (SEP) monitoring as a means of preventing paraplegia in descending aorta surgery was evaluated in 47 consecutive cases operated on for isthmic (14 cases), thoracic (22 cases), or thoraco-abdominal (11 cases) repair. An aortic dissection was found in 11 cases (acute in 6). Somatosensory evoked potentials were obtained by unilateral left and right posterior tibial nerve (PTN) stimulation at the ankle and recordings were performed on four channels: peripheral nerve, lumbar spinal, brain-stem, and cortical recordings. Our experience led to the following current strategy: the establishment of atrio(aorto)-femoral(aortic) bypass (29 cases), proximal and distal aortic cross-clamping, aortic repair with reimplantation of the culprit artery(ies) as indicated by SEP alterations. Five types of SEP alterations were defined on the basis of the neural level involved: type I (27.7% of cases) = distal spinal ischemia due to proximal aortic cross-clamping in the absence of bypass; type II (21.3%) = PTN ischemia due to left common femoral artery cross-clamping; type III (12.8%) = segmental spinal ischemia due to the exclusion of critical feeding arteries; type IV (4.3%) = ischemia in the left carotid artery territory; type V (4.3%) = global brain hypoperfusion due to systemic hypotension. Forty-five patients survived the operation and could be tested for neurological dysfunction. Three patients presented a postoperative spinal cord deficit, but this deficit was already present preoperatively in one case, so that the actual incidence of a new paraplegia in our series was 2/45 cases (4.4%). One of the two cases was clearly a delayed paraplegia with SEP alterations appearing several hours after the operation. Somatosensory evoked potentials were evaluated on the basis of their sensitivity, specificity, and impact on the surgical strategy. Regarding SEP sensitivity, we did not encounter any unexpected immediate paraplegia, but the critical factor appeared to be the duration of SEP absence due to spinal cord ischemia, which, according to the literature, should never exceed 30 min; after a longer absence, SEP return does not guarantee neurological recovery. Somatosensory evoked potential specificity was also 100%, but only 58% of the abnormalities found were actually consequent to spinal cord ischemia, the rest of the abnormalities being consequent to peripheral nerve or brain ischemia. Finally, SEP monitoring had a significant impact on surgical strategy in 19% of the cases. It is concluded that distal aortic perfusion and multilevel SEP monitoring play a significant role in preventing paraplegia in descending aorta surgery.

Fibrinogen concentration significantly decreases after on-pump versus off-pump coronary artery bypass surgery: a systematic point-of-care ROTEM analysis

OBJECTIVESnStudies have emphasized the importance of normal fibrinogen concentrations in surgical patients. The primary hypothesis of this study was that fibrinogen levels significantly decrease in on-pump coronary artery bypass graft (CABG) surgery versus off-pump coronary artery bypass graft (OPCAB) surgery. The second objective was to show that ROTEM (TEM International, GmbH, Munich, Germany) rapidly detects these abnormalities compared with standard tests.nnnDESIGNnA prospective, nonrandomized study.nnnSETTINGnA university hospital.nnnPARTICIPANTSnForty-two and 62 patients in the CABG and OPCAB groups, respectively, undergoing first-time bypass surgery were included.nnnINTERVENTIONSnCABG versus OPCAB surgery.nnnMEASUREMENTS AND MAIN RESULTSnRoutine coagulation tests and ROTEM values were measured before anesthesia (T0), after the first dose of heparin (T1), after protamine (T2), upon intensive care unit arrival (T3), and 4 hours postoperatively (T4). The outcome measures were followed until 4 hours postoperatively. Fibrinogen concentrations were significantly lower in the CABG versus the OPCAB group at T2 (170 ± 44 v 243 ± 73 mg/dL, p < 0.001) and T3 (179 ± 42 v 232 ± 68 mg/dL, p < 0.001). This was confirmed by significantly lower FIBTEM maximal clot firmness values at T2 (9 ± 4 v 14 ± 5 mm, p < 0.001) and T3 (9 ± 4 v 13 ± 6 mm, p < 0.001). In the CABG group, patients received significantly more transfusions of all blood products except fresh frozen plasma.nnnCONCLUSIONSnFibrinogen concentration significantly decreases after cardiopulmonary bypass. ROTEM helps in its fast detection.

Anaphylactic shock in a beta-blocked child: usefulness of isoproterenol.

Like adults, children taking beta‐blockers are at risk for serious hemodynamic instability in case of anaphylaxis. We report a case of severe bradycardia associated with anaphylactic shock after aprotinin in a beta‐blocked child, which was resistant to intravenous epinephrine and vascular filling but was treated successfully with isoproterenol.

The dose of hydroxyethyl starch 6% 130/0.4 for fluid therapy and the incidence of acute kidney injury after cardiac surgery: A retrospective matched study

The safety of hydroxyethyl starches (HES) is still under debate. No studies have compared different dosing regimens of HES in cardiac surgery. We analyzed whether the incidence of Acute Kidney Injury (AKI) differed taking into account a weight-adjusted cumulative dose of HES 6% 130/0.4 for perioperative fluid therapy. This retrospective cohort study included all adult patients undergoing elective or emergency cardiac surgery with or without cardiopulmonary bypass. Exclusion criteria were patients on renal replacement therapy (RRT), cardiac trauma surgery, heart transplantation, patients with ventricular assist devices, subjects who required a surgical revision for bleeding and those whose medical records were incomplete. Primary endpoint was AKI following the creatinine based RIFLE classification. Secondary endpoints were 30-day mortality and RRT. Patients were divided into 2 groups whether they had received a cumulative HES dose of < 30 mL/kg (Low HES) or ≥ 30 mL/kg (High HES) during the intra- and postoperative period. A total of 1501 patients were analyzed with 983 patients in the Low HES and 518 subjects in the High HES group. 185 (18.8%) patients in the Low HES and 119 (23.0%) patients in the High HES group developed AKI (P = 0.06). In multivariable regression analysis the dose of HES administered per weight was not associated with AKI. After case-control matching 217 patients were analyzed in each group. AKI occurred in 39 (18.0%) patients in the Low HES and 50 (23.0%) patients in the High HES group (P = 0.19). In conditional regression analysis performed on the matched groups a lower weight-adjusted dose of HES was significantly associated with a reduced incidence of AKI [(Odds Ratio (95% CI) = 0.825 (0.727–0.936); P = 0.003]. In the absence of any safety study the cumulative dose of modern HES in cardiac surgery should be kept less than 30 mL/kg.

An increase in endogenous erythropoietin concentrations has no cardioprotective effects in patients undergoing coronary artery bypass graft surgery

OBJECTIVEnPreliminary data showed an increase in endogenous erythropoietin (EPO) concentrations after acute normovolemic hemodilution (ANH) in patients undergoing coronary artery bypass graft (CABG) surgery. Numerous studies have shown the organ protective properties of EPO. The aim of this study was to investigate the cardioprotective effects of these increased EPO concentrations that resulted from ANH during cardiac surgery.nnnDESIGNnA prospective, randomized, blind study.nnnSETTINGnA university hospital.nnnPARTICIPANTSnA total of 93 patients undergoing isolated CABG surgery with or without cardiopulmonary bypass (CPB).nnnINTERVENTIONSnSubjects with CPB were randomized into the control (C) or ANH group. Those in the off-pump coronary artery bypass group underwent no treatment. In the ANH group, a precalculated amount of blood was withdrawn and replaced by colloids after the induction of anesthesia.nnnMEASUREMENTS AND MAIN RESULTSnHemodynamic parameters were recorded intra- and postoperatively. Troponin concentrations were measured as a routine parameter postoperatively. Upon intensive care unit arrival, the EPO levels were higher in the ANH group than in the C group. There was no significant difference between the troponin values of the C and the ANH groups at 4 hours postoperatively.nnnCONCLUSIONSnIn patients undergoing CABG surgery on CPB, an increase in endogenous EPO concentrations in the physiologic range has no cardioprotective effects.

Cerebral NIRS and superior vena cava ScvO2 should not be compared

SIR—We thank Drs. Makkar and Singh for their interest in our published report (1). They asked whether there was perioperative analgesia in children with cerebral palsy. We precisely pointed out that ‘patients assigned to the control group received caudal blocks with the same dose of local anesthetics for postoperative analgesia at the end of surgery’ in the methods section. Indeed, the control group, who received caudal blocks at the end of surgery for ethical considerations and postoperative analgesia, did not require more analgesics than the caudal group in the postoperative care unit. Additionally, all patients in our study (caudal and controls) who were judged to be in pain [OPS (2) ‡ 4] by the anesthetist in charge of the postoperative care unit were administered rescue i.v. fentanyl (0.5– 1.0 lgÆkg). During the intraoperative phase, the control group must have been provided adequate intraoperative anesthesia with sevoflurane, while bispectral index (BIS) values were maintained between 45 and 55. Although opioids are superior to the inhalation anesthetic from an analgesic point of view, the inhalation anesthetic agent has not only hypnotic but also analgesic properties, like opioids. Although the aim of our study was to evaluate the effect of caudal block on sevoflurane requirement, excluding other analgesics, while maintaining adequate anesthesia using BIS, the control group was also provided with a caudal block at the end of surgery, because of ethical considerations.

Management of prekallikrein deficiency during cardiac surgery

Dear Sirs, The contact factor system includes factor XII (FXII), high-molecular-weight kininogen (HMWK), and prekallikrein (PK). Even in the absence of one of these factors, no bleeding tendency during surgery has been reported (1). This physiological system is rather thought to exert anticoagulant, profibrinolytic, pro-inflammatory, and anti-adhesive activities (2). In vitro coagulation tests for heparin monitoring, such as the activated partial thromboplastin time (aPTT) and the activated clotting time (ACT), rely on the presence of contact activation factors to the extent that a deficiency in one of the contact factors renders heparin monitoring with these assays unreliable. Cardiac surgical procedures requiring systemic anticoagulation have been successfully performed for decades using heparin. Heparin shares features of an ideal anticoagulant in that the onset of its activity is rapid, its anticoagulant action is readily reversed using protamine sulfate, and its activity can be conveniently measured using the activated coagulation time (ACT, normal value: 100–140 seconds [sec]) (3). Protamine administration has been associated with a spectrum of adverse effects: histamine-related hypotension, mild to severe anaphylactoid reactions, marked hypersensitivity, etc. Moreover, protamine has anticoagulant effects when given alone or in excess of heparin. The dose of protamine should therefore be carefully controlled based on the ACT (4). It is current practice in many institutions, including ours, to administer a single bolus of heparin (300 UI/kg) in order to achieve the therapeutic ACT target (more than 300 sec for off-pump procedures and more than 400 sec for on-pump procedures) (5–7). ACT is then monitored during the surgical procedure, and additional doses of heparin are administered if needed. At the end of the procedure, the dose of protamine is adjusted in order to achieve an ACT value that approximates the pre-heparin level. While little is known about the sensitivity of ACT to individual coagulation factor

Does Postoperative Cardiac Troponin-I Have Any Prognostic Value in Predicting Midterm Mortality After Congenital Cardiac Surgery?

OBJECTIVESnThis study evaluated the prognostic value of postoperative cardiac troponin-I (cTnI) in predicting all-cause mortality up to 3 months after normothermic congenital cardiac surgery.nnnDESIGNnProspective observational study.nnnSETTINGnUniversity hospital.nnnPARTICIPANTSnAll children ages 0 to 10 years.nnnINTERVENTIONSnNone.nnnMEASUREMENTS AND MAIN RESULTSncTnI was measured after the induction of anesthesia but before the surgery, at the pediatric intensive care unit arrival, and at 4, 12, and 24 hours postoperatively. Follow-up was extended up to 6 months. Overall, 169 children were analyzed, of whom 165 were survivors and 4 were nonsurvivors. cTnI levels were significantly higher in nonsurvivors only at 24 hours (p = 0.047). Children undergoing surgery with cardiopulmonary bypass (CPB) had significantly higher cTnI concentrations compared with those without CPB (p<0.001). Logistic regression analysis was performed on the 146 children in the CPB group with the following predictive variables: CPB time, postoperative cTnI concentrations, the presence of a cyanotic malformation, and intramyocardial incision. None of the variables predicted mortality. Postoperative cTnI concentrations did not predict 6 months׳ mortality. Only cTnI at 24 hours predicted the length of stay in the pediatric intensive care unit.nnnCONCLUSIONSnThis study did not find that postoperative cTnI concentration predicted midterm mortality after normothermic congenital heart surgery. (ClinicalTrials.gov identifier: NCT01616394).

Transcatheter aortic valve implantation (TAVI): short- and long-term outcomes with respect to the type of procedure and the anaesthetic management

Results and discussion: 44patients were classified into two groups according to 75% quartile of RT(85.5sec): ER (RT < 85.5 sec, n=33) and DR (RT> 85.5sec, n=11). The DR group had significantly smaller body surface area (p< 0.05) and lef t ventricular diameter (p< 0.05), and more complicated with intraventricular out flow obstruction, and lower SvO2 immediately before RP. The multivariate logistic regression model identified SvO2 as an independent predictor of the delayed recovery af ter RP (OR 0.767, CI 0.4830.928). During TAVI, maintaining systemic oxygen supply-demand balance during surgery may overcome the preoperative disadvantageous factors.