Carlo Sorbara

Small-dose recombinant activated factor VII (NovoSeven) in cardiac surgery.

Recombinant activated factor VII (rFVIIa) has been used at different doses in cardiac surgery patients. We tested the efficacy of small-dose rFVIIa in patients with intractable bleeding after cardiac surgery. The study group comprised 15 cardiac surgery patients with intractable bleeding treated with small-dose (1.2 mg) rFVIIa as a slow IV bolus at the end of complete step-by step transfusion protocol. Fifteen matched patients undergoing the same transfusion protocol in the pre-rFVIIa era represented the control group. Blood loss at the end of the transfusion protocol was a primary outcome. Median, 25th–75th 24-h blood loss percentiles were 1685 (1590–1770) mL versus 3170 (2700–3850) mL in study group and controls, respectively (P = 0.0004). Transfused red blood cells, fresh-frozen plasma, and platelets in the study group and controls were as follows: 7 (4–8) U versus 18 (12–21) U (P = 0.001); 7.5 (6–11) U versus 11 (9–15) U (P = 0.003); 0 (0–4) U versus 9 (6–13) U (P = 0.001). In addition, significant improvements of prothrombin time (P = 0.015), international normalized ratio (P = 0.006), activated partial prothrombin time (P = 0.01), and platelet count (P = 0.003) were detected in the study group versus controls. Finally, patients receiving rFVIIa showed a reduced intensive care unit length of stay (&khgr;2 = 15.9, P = 0.0001) and had infrequent surgical re-exploration (&khgr;2 = 16.2,P < 0.0001). Small-dose rFVIIa showed satisfactory results in cardiac patients with intractable bleeding. Further randomized studies are necessary to confirm our findings.

Repair of tetralogy of Fallot in the first six months of life: Transatrial versus transventricular approach

BACKGROUND This report describes our experience with primary correction of tetralogy of Fallot in infants. METHODS Fifty-one consecutive infants younger than 6 months underwent primary correction of tetralogy of Fallot between January 1978 and October 1994. Mean age at repair was 4.2 months. Four were neonates. Correction was accomplished through a right ventriculotomy in the first consecutive 22 patients (43%; group A); since 1991, a combined transatrial-transpulmonary approach was used in 29 consecutive patients (57%; group B). A transannular patch was necessary in 33 infants (65%) 16 of group A (73%) and 17 of group B (59%). RESULTS There was one early death from possible left anterior descending coronary artery distortion in group A and no deaths in group B. Two patients required early reoperation for systemic-to-pulmonary artery collateral ligation (postoperative day 6) and permanent pacemaker implantation (postoperative day 30). There were no late deaths. All 50 survivors are currently asymptomatic and in New York Heart Association class I. Three patients required late reoperations 36 months, 30 months, and 13 months after repair for (1) subaortic stenosis and dysfunctioning dysplastic mitral valve, (2) residual pulmonary artery branch stenosis, and (3) residual right ventricular outflow obstruction. Four patients underwent balloon dilation and stent insertion (1 patient) for peripheral pulmonary artery stenosis 1.5 year to 12 years (mean, 5 years) after initial repair. Actuarial freedom from need for reintervention at 4 years was 78.4% in group A and 85.7% in group B. Two-dimensional and Doppler echocardiographic follow-up studies showed a residual mild to moderate pulmonary artery branch stenosis in 4 patients in group A, and a recurrent subaortic stenosis in 1 patient in group A. Right ventricular peak systolic pressure was less than 40 mm hg in all but 3 asymptomatic patients who had a residual pulmonary artery branch stenosis. Right ventricular end-systolic and end-diastolic volumes showed larger volumes and reduced ejection fraction in group A compared with group B. CONCLUSIONS This limited experience with repair of tetralogy of Fallot in patients less than 6 months of age demonstrates that the transatrial-transventricular approach is possible in neonates and young infants with a very low mortality and morbidity and also a low incidence of residual lesions. Follow-up echocardiographic data suggest that right ventricular function is better preserved in those patients who underwent the transatrial-transpulmonary repair.

Microembolic signals and strategy to prevent gas embolism during extracorporeal membrane oxygenation

BackgroundExtracorporeal membrane oxygenation (ECMO) supplies systemic blood perfusion and gas exchange in patients with cardiopulmonary failure. The current literature lacks of papers reporting the possible risks of microembolism among the complications of this treatment.In this study we present our preliminary experience on brain blood flow velocity and emboli detection through the transcranial Doppler monitoring during ECMO.MethodsSix patients suffering of heart failure, four after cardiac surgery and two after cardiopulmonary resuscitation were treated with ECMO and submitted to transcranial doppler monitoring to accomplish the neurophysiological evaluation for coma.Four patients had a full extracorporeal flow supply while in the remaining two patients the support was maintained 50% in respect to normal demand.All patients had a bilateral transcranial brain blood flow monitoring for 15 minutes during the first clinical evaluation.ResultsMicroembolic signals were detected only in patients with the full extracorporeal blood flow supply due to air embolism.ConclusionsWe established that the microembolic load depends on gas embolism from the central venous lines and on the level of blood flow assistance.The gas microemboli that enter in the blood circulation and in the extracorporeal circuits are not removed by the membrane oxygenator filter.Maximum care is required in drugs and fluid infusion of this kind of patients as a possible source of microemboli. This harmful phenomenon may be overcome adding an air filter device to the intravenous catheters.

Intraoperative plasmapheresis in cardiac surgery

OBJECTIVE To determine the effects of intraoperative plasmapheresis on total transfusion requirements, mediastinal drainage, and coagulation. DESIGN The trial was prospective, randomized, and controlled. SETTING Inpatient cardiac surgery at a university medical center. PARTICIPANTS Two hundred ninety-three consecutive patients undergoing cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS Intraoperative plasmapheresis (IP) was performed in 147 patients before heparinization; platelet-rich plasma was reinfused immediately after heparin reversal. MEASUREMENTS AND MAIN RESULTS Mediastinal chest tube drainage during the first 12 postoperative hours was significantly less in the IP group (p = 0.022), but no difference was noted in total postoperative blood loss between the two groups. The amount of packed red cells and fresh frozen plasma transfused to the IP group in the intensive care unit was significantly lower (p = 0.02, p = 0.002, respectively); 51.4% of patients required no transfusion compared with the control group (34.5%) (p = 0.006). No differences were noted for data collected in the intensive care unit in terms of the mean duration of chest tube drainage, ventilator time, or any hematologic variables at baseline or at any subsequent time in the study. CONCLUSIONS After cardiac surgery, intraoperative plasma-pheresis reduces early postoperative bleeding and decreases the need for homologous transfusions.

Dynamic monitors of brain function: a new target in neurointensive care unit.

IntroductionSomatosensory evoked potential (SEP) recordings and continuous electroencephalography (EEG) are important tools with which to predict Glasgow Outcome Scale (GOS) scores. Their combined use may potentially allow for early detection of neurological impairment and more effective treatment of clinical deterioration.MethodsWe followed up 68 selected comatose patients between 2007 and 2009 who had been admitted to the Neurosurgical Intensive Care Unit of Treviso Hospital after being diagnosed with subarachnoid haemorrhage (51 cases) or intracerebral haemorrhage (17 cases). Quantitative brain function monitoring was carried out using a remote EEG-SEP recording system connected to a small amplification head box with 28 channels and a multimodal stimulator (NEMO; EBNeuro, Italy NeMus 2; EBNeuro S.p.A., Via P. Fanfani 97/A - 50127 Firenze, Italy). For statistical analysis, we fit a binary logistic regression model to estimate the effect of brain function monitoring on the probability of GOS scores equal to 1. We also designed a proportional odds model for GOS scores, depending on amplitude and changes in both SEPs and EEG as well as on the joint effect of other related variables. Both families of models, logistic regression analysis and proportional odds ratios, were fit by using a maximum likelihood test and the partial effect of each variable was assessed by using a likelihood ratio test.ResultsUsing the logistic regression model, we observed that progressive deterioration on the basis of EEG was associated with an increased risk of dying by almost 24% compared to patients whose condition did not worsen according to EEG. SEP decreases were also significant; for patients with worsening SEPs, the odds of dying increased to approximately 32%. In the proportional odds model, only modifications of Modified Glasgow Coma Scale scores and SEPs during hospitalisation statistically significantly predicted GOS scores. Patients whose SEPs worsened during the last time interval had an approximately 17 times greater probability of a poor GOS score compared to the other patients.ConclusionsThe combined use of SEPs and continuous EEG monitoring is a unique example of dynamic brain monitoring. The temporal variation of these two parameters evaluated by continuous monitoring can establish whether the treatments used for patients receiving neurocritical care are properly tailored to the neurological changes induced by the lesions responsible for secondary damage.

Repair of aortico-left ventricular tunnel originating from the left aortic sinus

We report on a case of an 11-year-old asymptomatic child with aortico-left ventricular tunnel arising from the left aortic sinus. Preoperative transesophageal echocardiography showed a dilated aortic root with mild aortic valve incompetence and demonstrated the course of the tunnel, which originated from the left coronary sinus entering the outlet portion of the left ventricular outflow tract. Patch closure of the aortic end of the tunnel eliminated left ventricular volume overload with immediate marked reduction of cardiomegaly. At 10-month follow-up the child is asymptomatic and receiving no oral medications. Control two-dimensional Doppler echocardiography shows trivial central aortic valve incompetence.

Propofol-fentanyl versus isoflurane-fentanyl anesthesia for coronary artery bypass grafting: Effect on myocardial contractility and peripheral hemodynamics

To avoid intraoperative awareness and postoperative respiratory depression from high-dose opioid anesthesia, propofol (P), or isoflurane (I) has been combined with moderate-dose opioid with varying results. However, the effects of both P and I on myocardial contractility and left ventricular afterload have not been completely quantified. The end-systolic pressure-diameter relationship (ESPDR) of the left ventricle (LV) is a reliable method to quantitatively assess LV contractility because it is relatively independent of changes in preload and incorporates afterload changes. The purpose of this study was to quantify the cardiodynamic effects of propofol-fentanyl (PF) anesthesia in comparison with isoflurane-fentanyl (IF) anesthesia in patients undergoing coronary artery bypass grafting (CABG). Thirty patients with normal or moderately impaired LV function (ejection fraction > or = 40% with LV end-diastolic pressure < or = 18 mmHg, no preoperative akinesia or dyskinesia) undergoing elective CABG were studied. After premedication with flunitrazepam, 2 mg orally, all patients were induced with thiopental, 1 mg/kg, fentanyl, 20 micrograms/kg, and vecuronium, 0.1 mg/kg, and were ventilated with oxygen/air (F(1)O2 0.6). Anesthesia was maintained throughout the procedure with a zero-order intravenous (IV) continuous infusion of P, 3 mg/kg/h (PF group), or with isoflurane inhalation of 0.6% (IF group), supplemented by intermittent boluses (5 micrograms/kg) of fentanyl (up to a total maintenance dose of 30 micrograms/kg). After intubation, a cross-section of the LV was visualized by two-dimensional transesophageal echocardiography and an m-mode echocardiogram was obtained at the maximum anterior-posterior diameter. The radial artery pressure tracing and the ECG were simultaneously recorded with the M mode.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive venous air embolism in the semi-sitting position during surgery for a cervical spinal cord tumor: anatomic and surgical pitfalls

Although venous air embolism (VAE) in neurological surgery is mainly associated with posterior fossa procedures, this complication may also occur, with comparable severity, in the posterior cervical spine approach in patients who are semi-sitting. We report a patient with a massive VAE that occurred in the semi-sitting position during a posterior approach to an extended cervical-thoracic level (C3-T2) intramedullary tumor, which interrupted the surgical procedure. We discuss the possible causes of air embolism, the anatomic and pathogenetic mechanisms, treatment and preventive measures.

Intraoperative neurophysiological monitoring of the afferent pain pathway in cardiac surgery patients

OBJECTIVE No specific and sensitive method is available in routine clinical practice to detect pain in anaesthetised patients during surgery. The main aim of the present study was to investigate whether intraoperative somatosensory evoked potentials, the bispectral index, electroencephalogram, blood pressure and heart rate change during painful stimulation in cardiac surgery patients. METHODS After induction of anaesthesia, 37 cardiac surgery patients were subjected to increasing electrical stimulation of both the median nerves and subsequent intravenous infusion of remifentanil to suppress this painful stimulation. RESULTS The higher intensities of electrical stimulation significantly modified the cortical evoked potentials, the electroencephalogram spectral edge frequency and blood pressure. We also observed the appearance of a middle-latency component in the somatosensory evoked cortical potentials between 60 and 70 ms. These neurophysiological and clinical responses were significantly reduced by remifentanil administration. CONCLUSIONS The data suggest that somatosensory evoked potentials might be used to detect and monitor painful stimulation during surgery, unlike the bispectral index, which does not seem to be highly sensitive to intraoperative pain. SIGNIFICANCE Measurement of intraoperative somatosensory evoked potentials provides a specific and sensitive method to monitor the afferent pain pathway in anaesthetised patients.

Pump flow changes do not impair sublingual microcirculation during cardiopulmonary bypass.

OBJECTIVE The flow rate of the cardiopulmonary bypass (CPB) pump used in cardiac surgery often undergoes inherent fluctuations ranging from 10% to 20% of its theoretic value. However, the effects of such alterations remain unknown. In the present study, the authors investigated whether such variations could induce changes in the microvascular flow, which is considered a primary indicator of poor perfusion. DESIGN A prospective, observational, clinical study. SETTING A university-affiliated teaching hospital. PARTICIPANTS Thirty adult patients undergoing elective cardiac surgery with CPB. INTERVENTIONS Analysis of the sublingual microcirculation during CPB using a pump flow rate of 80% or 100% of the theoretic value. MEASUREMENTS AND MAIN RESULTS Sidestream dark field (SDF) imaging was used to record 2 video clips of the sublingual microcirculation in each patient. The videos were recorded at the same site at 80% and 100% of the theoretic flow rate. Microvascular analysis displaying the De Backer score, the microvascular flow index, the total vessel density, the perfused vessel density, and the proportion of perfused vessels was performed. Moreover, the mean arterial pressure (MAP), SvO(2), and PaCO(2) were evaluated. No significant changes in the measured parameters were noted at the 2 different flow rates. CONCLUSIONS Changes in the CPB pump flow rate within 20% (80%-100%) of its theoretic value do not alter the sublingual microcirculation. Thereafter, it is conceivable that during perioperative adjustments of the CPB pump rate, blood flow autoregulation mechanisms are activated so that limited changes in the pump flow can be considered safe not only at the sublingual site but also for the entire microcirculation.