Are low-molecular-weight heparins useful for the prophylaxis and treatment of arterial thrombi?

The pharmacologic specificity of low-molecular-weight heparins (LMWHs) has enabled multiple attractive developments in the prophylaxis and treatment of arterial thrombosis. Their high antithrombotic potency associated with a potentially lower induced bleeding risk, the lack of platelet interaction, the prevention of myointimal hyperplasia, and the lower incidence of heparin-induced thrombocytopenia, are major advantages. New studies in cardiology and vascular surgery demonstrate a high efficacy for LMWHs associated with a low risk.

Plasma ionized calcium in brain-dead patients.

Background: The mechanism of brain death-induced myocardial dysfunction remains debatable. Hypocalcemia is known to induce reversible myocardial dysfunction. However, the incidence of hypocalcemia and its effect on myocardial function during brain death is unknown.

Determinants of systolic pressure variation in patients ventilated after vascular surgery.

Objective: To discover the predominant determinant of systolic pressure variation during positive-pressure ventilation in mechanically ventilated patients after a vascular surgical procedure.

Design: Case control study.

Setting: Postanesthesia care unit at a university hospital.

In vitro effects of eltanolone on rat myocardium.

Background: Eltanolone is a new short-acting intravenous induction agent. However, its effects on intrinsic myocardial contractility remain unknown.

Methods: The effects of eltanolone and its solvent (soya bean emulsion) on the intrinsic contractility of rat left ventricular papillary muscles were investigated in vitro (Krebs-Henseleit solution, 29 degrees C, pH 7.

Mechanisms of increased myocardial contractility with hypertonic saline solutions in isolated blood-perfused rabbit hearts.

Hypertonic saline improves organ perfusion and animal survival during hemorrhagic shock because it expands plasma volume and increases tissue oxygenation. Because both decreased and increased myocardial performance have been reported with hypertonic saline, the effects of hyperosmolarity and the mechanism accounting for it were investigated in isolated blood-perfused rabbit hearts. Coronary blood flow (CBF), myocardial contractility, relaxation, and oxygen consumption were measured during administration of blood perfusates containing 140-180 mmol sodium concentrations ([Na+]).

Circulating cardiac troponin T in potential heart transplant donors.

Background: Brain death may induce myocardial dysfunction, the mechanisms of which are not yet fully understood. Circulating cardiac troponin T is considered a highly sensitive and specific marker of myocardial cell injury.

Methods And Results: We prospectively measured circulating cardiac troponin T in 100 brain-dead patients and measured the left ventricular ejection fraction area (LVEFa), using transesophageal echocardiography.

Systemic gas embolism complicating pulmonary contusion. Diagnosis and management using transesophageal echocardiography.

Systemic air embolism has been frequently reported after penetrating thoracic trauma. In blunt thoracic trauma, systemic air embolism has been rarely diagnosed, and then only after an invasive procedure such as thoracotomy. Transesophageal echocardiography has been recently introduced for the early assessment of trauma patients and is considered a sensitive noninvasive procedure to diagnose air embolism.

Inferences about respiratory muscle use after cardiac surgery from compartmental volume and pressure measurements.

Background: After upper abdominal surgery, patients have been observed to have alterations in respiratory movements of the rib cage and abdomen and respiratory shifts in pleural and abdominal pressure that suggest dysfunction of the diaphragm. The validity of making such deductions about diaphragm function from these observations is open to discussion.

Methods: In eight adult patients, American Society of Anesthesiologists physical status 2, scheduled for elective cardiac surgery, we measured respiratory rate, tidal volume, rib cage and abdominal cross-section changes, and esophageal (Pes) and gastric (Pga) pressures preoperatively, 1 day postoperatively, and 5 days postoperatively.

Cardiovascular consequences of severe hypophosphataemia in brain-dead patients.

Hypophosphataemia is known to induce reversible myocardial dysfunction, but the incidence of hypophosphataemia and its effect on myocardial function during brain death are unknown. In 90 consecutive brain-dead patients, we measured plasma concentrations of phosphate and left ventricular ejection fraction area (LVEFa), using transoesophageal echocardiography. In 15 severely hypophosphataemic (< 0.

Myocardial effects of propofol in hamsters with hypertrophic cardiomyopathy.

Background: Propofol is a short-acting intravenous induction agent that induces cardiovascular depression but without significant effect on intrinsic myocardial contractility in various species. However, its effects on diseased myocardium remain unknown.

Methods: The effects of propofol (1, 3, and 10 micrograms.

[Combination of propofol-sufentanil on somatosensory evoked potentials in surgery of the spine].

Objectives: Most anaesthetics depress cortical somatosensory evoked potentials (CSEPs). However, the modification of CSEPs during total intravenous anaesthesia using propofol remaining still unknown, justified this trial.

Type Of Study: Open, prospective, clinical study.

[Effects of platelet-rich plasma on hemostasis and transfusion requirement in vascular surgery].

Objective: To assess the effect of intraoperative autologous platelet-rich plasma (PRP) transfusion on haemostasis, blood loss and blood requirements during vascular surgery.

Study Design: Randomized clinical trial.

Patients: Twenty patients undergoing elective abdominal infrarenal aortic aneurysmectomy, using autologous transfusion techniques (predonation programme and/or preoperative normovolaemic haemodilution and/or intraoperative use of a cell-saver), were randomly allocated either into the PRP group (n = 10) or the Control group (n = 10).

Aprotinin to decrease bleeding and intraoperative blood transfusion requirements during descending thoracic and thoracoabdominal aortic aneurysmectomy using cardiopulmonary bypass.

The purpose of this retrospective study was to assess the efficacy of aprotinin, an antifibrinolytic agent, in reducing bleeding and blood transfusion requirements in patients undergoing descending thoracic or thoracoabdominal aortic aneurysmectomy using cardiopulmonary bypass (CPB). Sixty-nine consecutive patients underwent thoracic or thoracoabdominal aneurysmectomy using CPB in a 2-year period. None of the 29 patients operated on in 1990 (group 1) received aprotinin, whereas all 40 patients operated on in 1991 (group 2) were placed on a high-dose regimen of aprotinin.

Influence of chronic angiotensin-converting enzyme inhibition on anesthetic induction.

Background: Several cases of hypotension have been reported in patients who received angiotensin-converting enzyme inhibitors (ACEIs) before a surgical procedure, suggesting that interactions between ACEIs and anesthesia may be neither beneficial nor predictable. To determine if continuation of ACEI therapy until the morning of surgery leads to an unacceptable decrease in blood pressure on induction, we investigated 51 vascular surgical patients that were chronically treated for hypertension with either captopril or enalapril.

Methods: After randomization, ACEI therapy was either continued until the morning of surgery or stopped at the time of the preanesthetic visit, at least 12 h (captopril) or 24 h (enalapril) before surgery.

Fiberoptic bronchoscopy in brain-dead organ donors.

Criteria for selecting lung donors include normal chest X-ray and adequate gas exchange, but normal bronchoscopy is not always required. Thus, we conducted a prospective study of fiberoptic bronchoscopy in 72 brain-dead donors scheduled for multiple organ procurement. Chest X-ray was considered normal in 37 donors (51%), and PaO2 was > 400 mm Hg with an FIO2 of 100% in 34 donors (47%).

High-frequency jet ventilation vs continuous positive airway pressure for differential lung ventilation in patients undergoing resection of thoracoabdominal aortic aneurysm.

Twenty patients, scheduled for surgical resection of thoracoabdominal aortic aneurysm were divided into two groups according to the type of differential lung ventilation used during graft replacement of the descending thoracic aorta. In the high-frequency jet ventilation (HFJV) group of ten patients, HFJV was applied to the left lung once collapsed and retracted by the surgeon, the patient lying in the right lateral decubitus and being intubated by a Carlens' tube. In the continuous positive airway pressure (CPAP) group of ten patients, CPAP was applied to the left lung at the same mean airway pressure as HFJV (1 kPa).

Inhaled nitric oxide reverses the increase in pulmonary vascular resistance induced by permissive hypercapnia in patients with acute respiratory distress syndrome.

Background: The aim of this prospective study was to determine if inhaled nitric oxide (NO) would reverse the increase in pulmonary arterial pressures and in pulmonary vascular resistance induced by acute permissive hypercapnia in patients with acute respiratory distress syndrome.

Methods: In 11 critically ill patients (mean age 59 +/- 22 yr) with acute respiratory distress syndrome (Murray Score > or = 2.5), the lungs were mechanically ventilated with NO 2 ppm during both normocapnic and hypercapnic conditions.

Intraoperative autologous transfusion in emergency surgery for spine trauma.

Although numerous studies have reported the use of intraoperative blood salvage in elective spine, cardiac, and vascular surgery, very few have assessed its efficiency during emergency surgery after spine trauma. We therefore retrospectively analyzed 238 cases of patients with spine trauma who had emergency surgery. Three variables were significantly associated with the risk of perioperative blood transfusion: thoracolumbar spine injury, a preoperative hematocrit < 35%, and an Injury Severity Score > 20.

Haematological effects of postoperative autotransfusion in spinal surgery.

A prospective, randomized, controlled study was performed to determine the haematological and biochemical changes and clinical safety of postoperative autotransfusion (Solcotrans Orthopedic Plus system) in patients undergoing spinal surgery. Fifty patients were studied and were randomly allocated to Control (n = 25) and Solcotrans (n = 25) groups. Both groups had their postoperatively drained blood collected into the Solcotrans reservoir but only the Solcotrans group had this salvaged blood considered for reinfusion.

Inhaled nitric oxide in acute respiratory failure: dose-response curves.

Objective: To determine the dose-response curve of inhaled nitric oxide (NO) in terms of pulmonary vasodilation and improvement in PaO2 in adults with severe acute respiratory failure.

Design: Prospective randomized study.

Setting: A 14-bed ICU in a teaching hospital.

Aprotinin could promote arterial thrombosis in pigs: a prospective randomized, blind study.

Haemostatic properties of aprotinin could be associated with an increased risk of thrombosis. A randomized, blinded study was conducted to consider the potential thrombogenicity of aprotinin, using the Folts' model on femoral arteries in 12 pigs. The flow variations were measured by a pulsed Doppler in anaesthetised animals.