Contrast harmonic imaging improves the evaluation of left ventricular function in ventilated patients: comparison with transesophageal echocardiography.

AIMS: The study examined the value of contrast echocardiography (CE) in the assessment of left ventricular (LV) wall motion in ventilated patients in comparison with transesophageal (TOE) and standard fundamental transthoracic imaging (SE). METHODS: Transthoracic echocardiograms were done in 40 ventilated patients. Wall motion was evaluated using the recommendations of the American Society of Echocardiography on SE, CE and TOE. A visualization score was assigned on a scale of 2-0 for each of 16 segments. The segment was assigned a value of 2 if the segment was seen in both systole and diastole, 1 if seen only in systole or diastole, and 0 if not seen at all. A confidence score was also given for each segment with each technique (unable to evaluate; not sure; sure). The ejection fraction (EF) was estimated visually for each technique, and a confidence score was also applied to the EF. RESULTS: Visualization score 0 was present in 6.2 segments/patient on SE, 1.2 on CE (P<0.0001) and 1.1 on TOE (P<0.0001). An average of 6.5 segments were read with surety on SE, 11.5 on CE (P<0.0001) and 12.3 on TOE ( P<0.0001 ). There was no significant difference for CE vs TOE. EF was uninterpretable in 32% on SE, 0% on CE (P<0.001 and 0% on TOE (P<0.001). The EF was read with surety in 53% of patients on SE, 88% on CE (P < 0.0001) and 93% with TOE (P<0.0001) with no difference for CE vs TOE. Thus, wall motion was seen with more confidence on CE and TOE. CONCLUSIONS: In the ventilated patients with suboptimal transthoracic echocardiograms for the evaluation of the LV function, CE provides image quality of regional and global LV function similar to that achieved with TOE echocardiography.

Antithrombin III in patients with severe sepsis: a pharmacokinetic study.

OBJECTIVES: To evaluate the safety, pharmacokinetics, and the practicability of two different antithrombin III (AT III) high-dose regimens in patients with severe sepsis. DESIGN: Prospective, open, randomized, 2 parallel groups, multinational clinical trial. SETTING: Eleven academic medical center intensive care units (ICU) in Austria, Belgium, Denmark, Germany, Norway and Sweden. PATIENTS: Thirty-three patients with severe sepsis who received standard supportive care and antimicrobial therapy, in addition to the administration of AT III. INTERVENTIONS: Patients received an intravenous loading dose of 6,000 IU AT III followed by either intermittent bolus infusions of 1,000 IU AT III every 4 h or a continuous infusion of 250 IU AT III/h for 4 days, resulting in a total dose for both dosage regimens of 30,000 IU AT III. MEASUREMENTS: All patients were evaluated for safety and all but one for pharmacokinetics. RESULTS AND CONCLUSIONS: The administration of AT III was safe and well tolerated. The overall 28-day all-cause mortality was 30% (43% intermittent bolus infusions; 21% continuous infusion). The mean probability of dying according to the SAPS II was 48%. The difference in mortality between both groups was within the range of chance. AT III plasma levels were elevated from low baseline levels to above 120% soon after onset of AT III therapy and remained at these levels for the treatment phase of 4 days. Functional and immunologic levels of AT III corresponded very well. With an overall median volume of distribution of 4.5 l (range: 2.4-6.5 l), AT III only moderately extended beyond plasma. The overall median elimination half-life was 18.6 h (range: 5.1-37.4). Overall, median response was 1.75% per IU/kg (range: 1.14-2.8). The variability of elimination parameters was quite noteworthy (CV = 41-59%), whereas distribution-related parameters showed a moderate variability (CV = 24%). In spite of this variability, both high-dose IV regimens reliably provided AT III levels above 120% for all but one patient. An increased mortality was observed for patients with a distribution volume exceeding 4.5 l (or a response < 1.7% per IU/kg). AT III distribution volumes above 4.5 l might indicate a capillary leak phenomenon. The continuous infusion regimen was slightly preferred by the investigators with regard to practicability.

Absence of myocardial protection with prostacyclin during cardiac arrest.

Prostacyclin (PGI2) has been shown to present myocardial protective effects which could be beneficial during cardiac arrest. We tested this hypothesis in a closed-chest dog model in which electromechanical dissociation (EMD) can be predictably observed after 90 to 120 seconds of ventricular fibrillation without chest compression. Six dogs were pretreated with a PGI2 infusion at a rate of 1 mcg/kg/min and six other dogs served as control animals. After 60 seconds of ventricular fibrillation, EMD was already observed in 3 PGI2-treated dogs but in no control dog. After 90 seconds of ventricular fibrillation, EMD was present in 2 PGI2-treated dogs and in 2 control dogs, so that 4 control but only one PGI2-treated animal survived after 90 seconds of ventricular fibrillation. Ventricular defibrillation was also not facilitated in PGI2-treated dogs. The present study does not support PGI2 administration in cardiopulmonary resuscitation.

Haemodynamic, gasometric and haematological effects of air infusion in dogs: leukotriene inhibition with U-60,257.

Air embolization has been shown to produce a reversible permeability-type of pulmonary oedema. The present study investigated the haemodynamic, gasometric and haematological changes associated with air infusion in the spontaneously breathing dog (weight 31 +/- 5 kg). Air was infused at a rate of 10 ml X min-1 for 60 min (10 dogs) or 180 min (5 dogs). During the air infusion, a dramatic increase in pulmonary artery pressure was associated with only a moderate increase in right atrial pressure and limited decreases in arterial pressure and in cardiac output. A marked decrease in end-tidal PCO2 reflected the increase in dead space. These changes were stable during air infusion, but rapidly reversed after the end of infusion. However, hypoxaemia, defined by a decreased PaO2/PAO2 ratio, deteriorated with time and was only partially reversible. At histological examination, interstitial pulmonary oedema was present around the pulmonary arterioles. Air infusion was associated with rapid decreases in circulating leukocytes and platelets and complement activation. Since leukotriene release might be associated with leukocyte activation in this model, seven additional dogs were pretreated by inhalation of 10 mg of the leukotriene inhibitor U-60,257. The increase in pulmonary vascular resistance and in pulmonary shunt were moderately reduced and the drop in circulating leukocytes and platelets was strikingly abolished in the treated animals. Air infusion in the spontaneously breathing dog represents a model of very stable and reversible pulmonary hypertension. It can reproduce important pathophysiological features implicated in the development of pulmonary oedema.(ABSTRACT TRUNCATED AT 250 WORDS)

Increase in PaO2 following intravenous administration of propranolol in acutely hypoxemic patients.

To define the effects of beta-blockade therapy on PaO2, arterial blood gas levels were determined before and after therapeutic administration of propranolol in 44 acutely ill patients. With a FIo2 of 0.33 +/- 0.08, the PaO2 increased from 89.6 +/- 3.6 to 95.3 +/- 3.8 mmHg (p less than 0.01), 10 minutes after intravenous administration of 1 to 3 mg of propranolol. Simultaneous hemodynamic measurements obtained in six patients demonstrated a dramatic decrease in venous admixture, associated with decreases in cardiac output and mixed venous Po2. Propranolol administration generally results in a moderate increase in PaO2, which is related to a significant decrease in pulmonary shunt. The clinical implications of these findings are limited by the expected decrease in tissue oxygen delivery after beta-blockade therapy.

Use of labetalol during anesthesia for pheochromocytoma removal.

Labetalol, an alpha and beta adrenergic blocking drug, was used during anesthesia for removal of a very large pheochromocytoma which was predominantly epinephrine secreting. The 70-year-old female patient suffered from angina pectoris and chronic bronchitis. A preoperative treatment including an alpha-adrenolytic drug was administered but beta-adrenergic blockers were avoided because of the risk of cardiac decompensation and bronchoconstriction. During the operation, hypertensive peaks were easily controlled by bolus injections of labetalol 20 mg. The removal of the tumor was followed by a transient moderate hypotension. Heart rate remained stable throughout the operation. No hemodynamic problems occurred during the postoperative period. With regard to this case, a summary of the literature concerning the properties of labetalol is presented.

Naloxone and alcohol intoxication in the dog.

1 The effects of naloxone upon ethanol-induced coma have been investigated in dogs. In a double blind study, 15 mongrel dogs received ethanol i.v. (4 g/kg) followed by a single dose of naloxone (12 micrograms/kg). 2 Naloxone failed to affect either the duration of respiratory arrest or the time to recovery of motor coordination. In similar animals treated with the narcotic analgesic, fentanyl, naloxone induced a dramatic and complete reversal of the narcotic effects within 30 seconds. 3 It is concluded that, if naloxone has any effect in alcoholic coma, it is not comparable with its dramatic action in narcotic coma.

[Comparison between the mobile emergency care systems of the Free University of Brussels and the Catholic University of Leuven]. / Comparaison entre les services d'aide médicale urgente de l'Université Libre de Bruxelles et la Katholieke Universitiet Leuven.

Populations concerned with mobile emergency care systems have the same age distribution in Leuven and in Brussels. Interventions for trauma are more frequent in Leuven and cardiac emergencies more frequent in Brussels, but these digfferences decrease when only critical patients are taken into consideration. The origin of calls is quite different in Brussels and in Leuven. The mobile emergency care system is underused in Brussels. The distribution of emergencies is influenced by the information and the formation of firemen, physicians and public.