Effect of aprotinin on postoperative blood loss in off-pump coronary artery bypass surgery.

BACKGROUND AND AIM OF THE STUDY: Off-pump coronary artery bypass (OPCAB) enables a reduction in postoperative complications, particularly bleeding and transfusion. Nevertheless, a significant percentage of patients still needs transfusion. The effect of antifibrinolytic therapy on postoperative bleeding as part of OPCAB is still not widely described. The purpose of this study was to investigate the potential benefit of aprotinin in OPCAB. METHODS: We conducted a retrospective comparative study with a historical control group. Consecutive patients undergoing off-pump coronary bypass were divided in two groups: 40 patients were operated without any antifibinolytic drug (group C); 40 patients received aprotinin (group A) during surgery. Patients in group A received a bolus of 2 x 10(6) KIU during 30 minutes, followed by a continuous infusion of 0.5 x 10(6) KIU per hour until the end of surgery. The same protocol was used during the whole study period. RESULTS: Preoperative data of the two groups did not differ except for the number of grafts performed, which was higher in group A. Prothrombin time and activated clotting time increased in both groups after surgery. The use of packed red blood cells or fresh frozen plasma was not significantly different between both groups. Postoperative blood loss was significantly reduced in the aprotinin group (540 mL +/- 320 vs. 770 mL +/- 390, p = 0.006). No increase in postoperative troponin values was found in group A. CONCLUSIONS: Aprotinin significantly reduced postoperative blood loss without reducing the transfusion rate. Aprotinin was not associated with any increase in postoperative complications.

[Continuous infusion of remifentanil and target-controlled infusion of propofol for coronary surgery in elderly patients: comparison with continuous infusion of remifentanil and propofol]. / Perfusion continue de rémifentanil et propofol en anesthésie intraveineuse à objectif de concentration au cours de la chirurgie coronaire du sujet âgé: comparaison avec l'alfentanil et le propofol en perfusion continue.

OBJECTIVES: Comparison of the length of mechanical ventilation and postoperative complications after coronary surgery in elderly patients anaesthetised with propofol associated with either alfentanil or remifentanil. STUDY DESIGN: Retrospective study with an historic control group. PATIENTS: Three hundred thirty-eight consecutive patients (75-year-old or more) undergoing isolated coronary surgery. One hundred and fifty seven patients operated between January 1998 and June 2000 received alfentanil (1 microg/kg/minute) with a manually control infusion of propofol, 181 operated between July 2000 and 2002, remifentanil 0.25 microg/kg/minute with target controlled infusion of propofol (target blood concentration: 1.5 to 2 microg/ml). METHODS: The two groups were compared for preoperative and surgical data. The length of mechanical ventilation, stay in ICU and the main postoperative complications were compared between the two groups. RESULTS: Length of mechanical ventilation was significantly reduced in the remifentanil group (6 +/- 9 h vs. 13 +/- 63 h ; p <0.0001), 70% of the patients were extubated before the 6th postoperative hours against 53% in the alfentanil group (p =0.0023). This was not associated with a reduction of stay in ICU or postoperative complications. During surgery, an increased used of vasopressor was observed in the remifentanil group (40.2% vs 2.4% ; p <0.0001) with a postoperative elevation of blood concentration of CKMb (35.7 +/- 38.2 microg/l, vs. 27.7 +/- 31.9 microg/l, p =0.02). CONCLUSION: Elderly patients undergoing coronary surgery were extubated earlier with remifentanil. However, this had no effect on duration of ICU stay but was associated with an increased used of vasopressor.

Accurate guidance for percutaneous access to a specific target in soft tissues: preclinical study of computer-assisted pericardiocentesis.

In the field of percutaneous access to soft tissues, our project was to improve classical pericardiocentesis by performing accurate guidance to a selected target, according to a model of the pericardial effusion acquired through three-dimensional (3D) data recording. Required hardware is an echocardiographic device and a needle, both linked to a 3D localizer, and a computer. After acquiring echographic data, a modeling procedure allows definition of the optimal puncture strategy, taking into consideration the mobility of the heart, by determining a stable region, whatever the period of the cardiac cycle. A passive guidance system is then used to reach the planned target accurately, generally a site in the middle of the stable region. After validation on a dynamic phantom and a feasibility study in dogs, an accuracy and reliability analysis protocol was realized on pigs with experimental pericardial effusion. Ten consecutive successful punctures using various trajectories were performed on eight pigs. Nonbloody liquid was collected from pericardial effusions in the stable region (5 to 9 mm wide) within 10 to 15 minutes from echographic acquisition to drainage. Accuracy of at least 2.5 mm was demonstrated. This study demonstrates the feasibility of computer-assisted pericardiocentesis. Beyond the simple improvement of the current technique, this method could be a new way to reach the heart or a new tool for percutaneous access and image-guided puncture of soft tissues. Further investigation will be necessary before routine human application.

[Renal revascularization from the digestive arteries in the treatment of renovascular hypertension in high risk patients]. / Revascularisation rénale à partir des artères digestives dans le traitement de l'hypertension réno-vasculaire chez les patients à haut risque.

Five extra-anatomic hepatospleno- and gastroduodenorenal revascularizations were performed in 5 high-risk cardiac patients. The procedure followed failure of endoluminal angioplasy for osteal stenosis of the renal artery in 4 cases. All patients had a diffuse lesion of the aorta contraindicating direct aortorenal bypass. The indication for surgery was renovascular hypertension poorly-controlled with medical therapy in all 5 patients; 4 patients also had renal failure. There was no mortality in the perioperative period. Blood pressure returned to normal in 50% of the cases, and improved in the other 50%. There was a clear improvement in renal function in all patients.

Inhaled nitric oxide: effects on hemodynamics, myocardial contractility, and regional blood flow in dogs with mechanically induced pulmonary artery hypertension.

BACKGROUND: Pulmonary artery hypertension with right ventricular failure is a frequent complication that occurs immediately after heart transplantation in which the use of inhaled nitric oxide may be effective. METHODS: The effects of pulmonary artery hypertension and nitric oxide on myocardial function and on pulmonary and systemic hemodynamic parameters were evaluated in eight anesthetized dogs. Pulmonary artery hypertension was induced by successive microbead injections into the pulmonary circulation. RESULTS: Microbead injections resulted in overt pulmonary artery hypertension (pulmonary artery pressure, + 190%; pulmonary vascular resistance, + 389%; ratio of pulmonary vascular resistance to systemic vascular resistance, 0.41). RESULTS: The end-diastolic length of the right ventricular outflow tract increased significantly along with an increase in right ventricular contractility (peak first derivative of left ventricular pressure as a function of time, + 100%; outflow tract systolic shortening, + 19%). Despite this compensatory mechanism, the increased pulmonary barrier resulted in a decrease in stroke volume (-31%). Systemic effects were observed, such as an increase in heart rate that maintained the cardiac output despite a decrease in left ventricular end-diastolic length (end-diastolic length in region of left anterior descending artery, - 9%). Right myocardial and septal blood flows were also significantly increased. CONCLUSIONS: Nitric oxide administration restored the stroke volume with a decrease in pulmonary artery hypertension and an improvement of the pulmonary vascular resistance to systemic vascular resistance ratio. Systemic blood pressure and coronary perfusion remained unaffected. This selective effect on the pulmonary circulation should be considered a major advantage of nitric oxide inhalation in the treatment of right ventricular dysfunction in acute pulmonary hypertension.

Comparison between acute hypoxia-induced and mechanically-induced pulmonary artery hypertension on the hemodynamics, myocardial contractility and regional blood flow in dogs.

Two groups of eight anesthetized dogs with pulmonary artery hypertension (PAH) were compared. PAH was induced by submitting one group (HP) to hypoxia (FiO2 range: 6-10%) and the other group (ME) to microemboli through glass microbead injection into the pulmonary circulation. Hypoxia-induced PAH was moderate (PAP: +65%; PVR: +152%) contrasting with marked PAH after microbead injection (PAP: +190%; PVR: +389%). For similar effects on left ventricular contractility (LV dP/dt max and segmental myocardial shortening), heart rate and systemic vascular resistance, left ventricular end-diastolic pressure showed significant differences between the two groups (HP group: +75%, ME group: -9%), and so did left ventricular end-diastolic length (HP: +9%, ME: -11%). Thus, contrary to the injection of microbeads, hypoxia did not give rise to any pulmonary barrier, and consequently the changes in cardiac output (HP: +19%, ME: -15%) and hepatic blood flow (HP: +383%, ME: -77%) were significantly different. Hypoxia, and not microbead injection, was responsible for systemic hypertension (MAP: +34% and -4%, respectively). The microbead model resulted in a significantly higher PVR/SVR ratio compared to the hypoxic model (HP: 0.14, ME: 0.41). Hypoxia increased left and right myocardial blood flows whereas microbead injection affected only right ventricular blood flow, leading to significantly different RV/LV endocardial perfusion ratios (HP: +10%, ME: +98%). We conclude that microbead-induced PAH is more appropriate than hypoxia-induced PAH for hemodynamic and pharmacological studies.

[Voluntary barium poisoning]. / Intoxication volontaire par le baryum.

A 45-year-old man attempted to commit suicide by ingesting a large amount of barium. In some hours, he experienced generalized muscle weakness with hypokalaemia, treated by large dose of potassium (440 mmol in the first day). This weakness resulted in difficulties in swallowing and respiratory failure requiring mechanical ventilation. An anuric renal insufficiency started early, requiring haemodialysis for three weeks. It was induced probably by renal toxicity of barium and recovered completely. Later, the patient experienced an extrapyramidal syndrome initiated by tremor and myoclonia. Hypertonia induced a parkinsonian rheumatism, fixing the two hands in an irreducible position. There was also a contracture of superior sphincter of oesophagus, with severe disturbance of deglutition, ending after three months only. MRI study showed a bilateral hypersignal in basal ganglia and thalamus. It remains unknown whether this neurological syndrome was toxic or ischaemic. This patient remained under mechanical ventilation for three months because of disturbances of deglutition. He was discharged to his home at the 6th month. One year later he was still adynamic, but able to carry our rather precise movements.