Effective prevention of atrial fibrillation by continuous atrial overdrive pacing after coronary artery bypass surgery.

OBJECTIVES: The present study was aimed to evaluate the efficacy of a specific algorithm with continuous atrial dynamic overdrive pacing to prevent atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. BACKGROUND: Atrial fibrillation occurs in 30% to 40% of patients after cardiac surgery with a peak incidence on the second day. It still represents a challenge for postoperative prevention and treatment and may have medical and cost implications. METHODS: Ninety-six consecutive patients undergoing CABG for severe coronary artery disease and in sinus rhythm without antiarrhythmic therapy on the second postoperative day were randomized to have or not 24 h of atrial pacing through temporary epicardial wires using a permanent dynamic overdrive algorithm. Holter ECGs recorded the same day in both groups were analyzed to detect AF occurrence. RESULTS: No difference was observed in baseline data between the two study groups, particularly for age, male gender, history of AF, ventricular function, severity of coronary artery disease, preoperative beta-adrenergic blocking agent therapy or P-wave duration. The incidence of AF was significantly lower (p = 0.036) in the paced group (10%) compared with control subjects (27%). Multivariate analysis showed AF incidence to increase with age (p = 0.051) but not in patients with pacing (p = 0.078). It decreased with a better left ventricular ejection fraction only in conjunction with atrial pacing (p = 0.018). CONCLUSIONS: We conclude that continuous atrial pacing with an algorithm for dynamic overdrive reduces significantly incidence of AF the second day after CABG surgery, particularly in patients with preserved left ventricular function.

Comparative effects on hemodynamics of enoximone (MDL 17,043), dobutamine and nitroprusside in severe congestive heart failure.

To assess their comparative effects on hemodynamics, nitroprusside, dobutamine and enoximone were sequentially administered to 10 patients with severe congestive heart failure. Nitroprusside, dobutamine (at 10 micrograms/kg/min) and enoximone (at 2 mg/kg) increased stroke volume index to a similar extent (31%, 34% and 36%, respectively). Enoximone produced less tachycardia than dobutamine and, consequently, a smaller improvement in cardiac index. Mean arterial pressure was not altered by dobutamine but was reduced 9% by enoximone, 2 mg/kg. This finding accounts for the larger (although not significant) increase in left ventricular stroke work index observed with dobutamine compared with enoximone. Ventricular filling pressures and vascular resistances were significantly decreased by all 3 drugs (p = 0.001). All 3 drugs improved cardiac pump function when assessed by the increase in stroke index to a similar extent; however, enoximone (2 mg/kg) resulted in less hypotension than nitroprusside (mean arterial pressure -9% vs -22%, p = 0.0001) and in less tachycardia than dobutamine 10 micrograms/kg/min. Those differences in mode of action account for the variations observed in the heart rate-blood pressure product (dobutamine 10 micrograms/kg/min, +18%, enoximone 2 mg/kg, -5%, p = 0.003). Enoximone thus appears to be of great value in the management of severe congestive heart failure by its combination of vasodilatory and inotropic properties. Enoximone (2 mg/kg) provides a clinically significant increase in cardiac index, a clear reduction of ventricular filling pressures, a moderate reduction of mean arterial pressure and only minor changes of heart rate and of rate pressure product.

A dose-response study of intravenous enoximone in congestive heart failure.

Previous clinical studies with intravenous enoximone have used cumulative dosing to quantify enoximone's hemodynamic effects. The magnitude and duration of the hemodynamic effects of single intravenous doses of enoximone were evaluated in patients with congestive heart failure. Sixty patients, who were in New York Heart Association functional classes III and IV, received single intravenous doses of enoximone, either 0.25 (12 patients), 0.5 (13 patients), 1 (14 patients), 1.5 (10 patients) or 2 mg/kg (11 patients). Cardiac index was increased by 20% with the 0.25 mg/kg dose and by 48% and 42% with the 1.5 and 2 mg/kg doses, respectively. These increases were statistically significant (Student's paired t test with Bonferroni's correction, p less than 0.007) for 1 hour after 0.25 and 0.5 mg/kg, for 2 hours after 1 mg/kg and for 4 hours after 1.5 and 2 mg/kg. Enoximone also reduced pulmonary artery diastolic pressure by 19% with 0.25 mg/kg and by 29% with 2 mg/kg. The duration of effect varied from 1 hour with 0.25 mg/kg to 4 hours with 2 mg/kg. Enoximone produced no consistent or dose-related effects on heart rate or blood pressure. Eighteen adverse reactions were reported by 15 patients, of which 11 were minor and transient (vein pain, flushes, nausea). In 5 patients ventricular or supraventricular arrhythmias were observed, including nonsustained ventricular tachycardia and extrasystoles; 3 of these patients had evidence of arrhythmias before enoximone. Laboratory studies before and after treatment showed no drug-related effects. Dose-related effects on the magnitude and duration of hemodynamic responses to intravenous enoximone were evident within the dose range of 0.25 to 2 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Knotting of intracardiac flow-directed balloon catheter. Simple surgical method of removal.

A complete knot occurred in a 7F flow-directed balloon catheter inserted through the right internal jugular vein. The patient was intubated and placed under positive pressure ventilation. After gaining surgical exposure of the venipuncture site, a purse-string of Prolene 4--0 suture was placed around it. The patient was placed in the Trendelenburg position and the knotted catheter withdrawn, while the purse-string suture was immediately tightened avoiding uncontrollable hemorrhage or massive air embolism.

Intravenous amiodarone in the treatment of various arrhythmias following cardiac operations.

In a group of 95 patients having cardiac operations with extracorporeal circulation, intravenous (IV) amiodarone, administered in doses of 2.5 to 5 mg/kg, was used in the treatment of various perioperative arrhythmias. Conversion to sinus rhythm was achieved in 55 (61%) of 90 patients with supraventricular arrhythmias, the other patients showing a satisfactory slowing of their heart rate. Total suppression and control was obtained in 18 patients with persistent ventricular extrasystoles associated with various supraventricular arrhythmias. Amiodarone was administered in five patients with life-threatening ventricular arrhythmias resistant to other antiarrhythmic agents: Suppression was obtained in one of two patients with recurrent ventricular tachycardias and control was achieved in three patients with repetitive ventricular tachycardia and ventricular fibrillation, allowing the effective use of intra-aortic balloon counterpulsation (IABP) needed for hemodynamic support. Seven patients experienced minor side effects such as nausea or flushing. No complete atrioventricular (AV) block was noted. Significant hypotension occurred at the end of the IV injection in 17 (18%) patients. In all but five patients, hypotenion was transient, without clinical complications. In the five others, adrenergic drugs in four cases and IABP in one case were necessary. Those five patients had marked cardiomegaly with poor myocardial contractility. IV bolus injection of amiodarone seems prohibited in such patients; constant infusion would be preferable.

Percutaneous intraaortic balloon pumping: initial experience.

The necessity of surgical procedures for insertion as well as for removal of the balloon catheter remains a serious disadvantage of IABP. The percutaneous technique of insertion and removal of a specially designed balloon catheter is therefore of a great interest. Our initial clinical experience shows that this is simple, rapid and safe and can be performed at the bedside in a few minutes by any physician experienced with arterial catheterization. Its hemodynamic efficiency is identical. No specific complications were encountered although two cases of pulmonary embolism were recorded. A causal relationship between pulmonary embolism and the percutaneous removal of a balloon catheter must therefore be considered.

Effect of dopamine on gastrointestinal motility during critical illness.

OBJECTIVE: To document the action of dopamine on gastrointestinal motility in mechanically ventilated patients. DESIGN: Crossover, randomized, placebo-controlled study. SETTING: General intensive care unit (ICU) in a university hospital. PATIENTS: Twelve mechanically ventilated patients in a stable hemodynamic condition, with no contraindication to enteral feeding. INTERVENTIONS: Dopamine (4 microg/kg per minute) and placebo were infused over 8 h (4 h fasting, followed immediately by 4 h nasogastric feeding at 100 kcal per hour) on two consecutive days, in a random order. Pressure changes in the gastric antrum (four sites) and in the duodenum (two sites) were recorded by perfused catheter manometry. Each session started with the institution of dopamine or placebo infusion. MEASUREMENTS AND RESULTS: The migrating motor complex and its three successive phases were identified (phase I, period of quiescence; phase II, period of irregular contractile activity; phase III or activity front, period of high-frequency, regular contractions). Contractions and activity fronts at each site were quantified during fasting and feeding. The mean duration of the fasting migrating motor complex was determined in the duodenum, as well as the contribution of each phase (phases I, II, III) to the length of the complete cycle. The propagation characteristics of each activity front were assessed visually. The number of contractions was lower in the antrum (p = 0.024) and phase III motor activity higher in the duodenum [incidence of activity fronts (p = 0.008); number of phase III contractions (p = 0.009)] during dopamine infusion than with placebo. These modifications observed under dopamine were related to decreased antral contractions during fasting (p = 0.050), increased incidence of activity fronts during feeding (p = 0.031), and increased number of phase III contractions during fasting (p = 0.037). In both groups (placebo and dopamine) activity fronts rarely started in the antrum, and abnormally propagated activity fronts were found in the duodenum in some patients. CONCLUSIONS: Low-dose dopamine adversely affects gastroduodenal motility in mechanically ventilated critically ill patients.

Gastric acidity and duodenogastric reflux during nasojejunal tube feeding in mechanically ventilated patients.

OBJECTIVE: In order to prevent gastric microbial overgrowth, which may complicate nasogastric feeding, administration of nutrients more distally into the gut has been advocated in intensive care patients, as it offers the advantage of keeping the stomach empty and acid. In this study, we assessed the impact of jejunal feeding upon gastic pH in a group of mechanically ventilated, critically ill patients, with special focus on duodenogastric reflux as a possible cause of gastric alkalinization during jejunal nutrition. DESIGN: Prospective experimental study. SETTING: Multidisciplinary intensive care unit of a university hospital. PATIENTS AND METHODS: Gastric pH was recorded by continuous pHmetry over a 4-h period of fasting followed by a 4-h period of nasojejunal feeding at 100 kcal/h in 21 mechanically ventilated, critically ill patients. To determine the contribution of duodenogastric reflux to modifications of gastric acidity, the diet was traced with [(111)In] DTPA (pentetic acid) in 11 of these 21 patients; gastric contents were aspirated every 30 min, then analysed for measurement of radioactivity, glucose, and bile acid concentration. MEASUREMENTS AND RESULTS: Median intragastric pH increased slightly from 1.59 (1.20-2.73; interquartile range) (fasting) to 2.33 (1.65-4.64) (feeding) (p = 0.013), and the length of time that the pH was 4 or above increased from 1 (0-24) to 9 (0-142) min (p = 0.026). The variability of pH values and the number of acute alkalinization episodes did not change between the two phases. In 10 of 11 patients in which the diet was labeled with [(111)In] DTPA, reflux was documented at a given time of the feeding period. Bile acid concentrations in the stomach increased from 392 (61-1076) (fasting) to 1446 (320-2770) micromol/l (feeding) (p = 0.010) and mean glucose concentration increased from 59 (28-95) to 164 (104-449) mg/dl (p = 0.006). CONCLUSION: Duodenogastric reflux is common in mechanically ventilated critically ill patients with nasojejunal feeding tubes. It occurs both during fasting and during nasojejunal feeding. During nasojejunal feeding, moderate alkalinization of the gastric contents occurs as a result of bile and nutrient reflux.

Chronic obstructive pulmonary disease patients with invasive pulmonary aspergillosis: benefits of intensive care?

OBJECTIVES: Invasive pulmonary aspergillosis (IPA) is increasingly recognized as a cause of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD) treated with corticosteroids. For these patients admission in intensive care unit (ICU) is often required for life-support and mechanical ventilation. Whether this approach improves outcome is unknown. DESIGN AND SETTING: Retrospective study in a university hospital intensive care unit. PATIENTS: Between November 1993 and December 1997, 23 COPD patients were admitted in our ICU and received antifungal agents for possible IPA. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The clinical features and the outcome were reviewed. Diagnosis of IPA was classified as confirmed (positive lung tissue biopsy and/or autopsy) or probable (repeated isolation of Aspergillus from the airways with consistent clinical and radiological findings). Among the 23 patients treated for Aspergillus, 16 fulfilling these criteria for IPA were studied. Steroids had been administered at home to all patients but one and were increased during hospitalization in all. Twelve patients suffered a worsening of their bronchospasm precipitating acute respiratory failure. During ICU stay all patients required mechanical ventilation for acute respiratory failure. Although amphotericin B deoxycholate was started when IPA was suspected (0.5-1.5 mg/kg per day), all patients died in septic shock (n = 5) or in multiple-organ failure. CONCLUSIONS: The poor prognosis of intubated COPD patients with IPA, in spite of antifungal treatment suggests that further studies are required to define the limits and indications for ICU management of these patients.

Prophylaxis of supraventricular and ventricular arrhythmias after coronary artery bypass grafting with low-dose sotalol.

BACKGROUND: Supraventricular tachyarrhythmia (SVT) commonly occurs shortly after coronary artery bypass grafting (CABG), but ventricular arrhythmias are less documented. METHODS: On the 1st postoperative day, 206 consecutive eligible patients were prospectively randomized to a sotalol group (80 mg b.i.d.; n = 103) or a control group without beta-blockade or antiarrhythmic drugs (n = 103). RESULTS: The SVT incidence (predominantly atrial fibrillation) accounted for 16% in the sotalol group versus 48% (p < 0.00001). Multivariate analysis showed that sotalol reduced the SVT incidence (p < 0.00001, odds ratio, 0.20; 95% confidence interval, 0.09 to 0.42), whereas a lower preoperative left ventricular ejection fraction (p = 0.019) and older age (p = 0.031) were independent risk factors of SVT occurrence. The Holter electrocardiographic analysis (24 hours) demonstrated that sotalol (32 versus 92; p = 0.031) decreased the median number of ventricular events, mostly isolated premature ventricular beats. Neither ventricular proarrhythmia effect nor "torsades de pointes" were detected. Despite strict hemodynamic-based selection, sotalol had to be discontinued in 8 patients (7.8%), for reasons related to asthma in 3 or cardiac reasons in 5. CONCLUSIONS: Oral low-dose sotalol provided considerable and reliable protection in selected nondepressed cardiac function patients, reducing the occurrence of both supraventricular and ventricular arrhythmias after CABG.

Duodenal motor response to continuous enteral feeding is impaired in mechanically ventilated critically ill patients.

In order to investigate the duodenal motor response to continuous enteral feeding during critical illness, we recorded the duodenal contractions of 12 mechanically ventilated critically ill patients during a 4 h fasting period immediately followed by another 4 h period of continuous (100 kcal/h) nasogastric feeding with a polymeric diet. Duodenal motility was recorded by manometry (perfused catheter technique) and the migrating motor complexes (MMC) were identified by their activity front (period of high frequency, regular contractions). The incidence and the mean duration of activity fronts as well as the mean duration of the MMC (time interval separating two successive activity fronts) recorded during both periods were compared. The incidence of activity fronts (fasting: median: 2.5, interquartile range: 5.5; feeding: median: 2, interquartile range: 3.5), their duration (fasting: 6.2 +/- 1.6 min; feeding: 5.8 +/- 1.6 min), and the mean duration of the MMC (fasting: 50.9 +/- 24.7 min; feeding: 49.1 +/- 20.3 min) were similar during both periods. We conclude that in these patients, the fasting pattern of motility is not interrupted by the continuous nasogastric administration of a polymeric diet. Since the activity fronts of the MMCs are highly propulsive, we suggest that their abnormal persistence during feeding may play a role in the pathophysiology of unexplained diarrhoea in some critically ill patients.

Pneumococcal aortic valvar endocarditis with atrio-ventricular perforation.

A case of pneumococcal endocarditis, complicated by a left ventricular-right atrial fistula and a rapidly progressing cardiac failure in a 56 year-old man, is reported here. In the acute period, an aortic valve prosthesis was installed and the atrio-ventricular fistula was closed with patches of pericardium. After serious post-operative complications, the patient left the clinic, cured of his bacterial endocarditis. He unfortunately died two months later of a massive myocardial infarction caused by a previously unrecognized atheromatous stenosis of the anterior descending branch and occlusion of the circumflex vessel. The authors discuss the bacteriological, anatomopathological and clinical aspects of this rare complication of bacterial endocarditis in light of the current available literature.

[Risk factors, postoperative mortality and morbidity in pulmonary surgery]. / Facteurs de risque, mortalité et morbidité postopératoires en chirurgie pulmonaire.

In this retrospective study, the influence of preoperative risk factors on mortality and morbidity after pulmonary surgery is analysed. Sixty-five consecutive pulmonary resections are studied and compared with data from the literature. Age and lung function abnormalities are well known risk factors but a severe selection minimizes their negative effects: a good cardio-circulatory condition and the prediction of an acceptable postoperative lung function allows a mortality reduction down to 5% and minimizes the frequency of postoperative respiratory insufficiency. The importance of a good preoperative training of the patient and of the early detection and immediate treatment of any postoperative complication are stressed.

[Patient, family, nurses and intensive care unit: review of the literature and state of a practice "in the field"]. / Patient, famille, soignants et unité de soins intensifs: revue de la littérature et état d'une pratique "sur le terrain".

An increasing interest in psychological and interactional aspects of intensive care unit stay is found in the recent literature. On one hand, seriousness and acuteness of the pathology, on the other hand, environment specificity as well as their respective consequences result in the fact that the ICU is a peculiar context for the patient and his family. The patient experiences a stressful event which probably differs from the one experienced in other types of wards. The family and its needs during this critical period are the focus of an increasing number of studies. A corresponding occupational stress for the caregivers is now widely acknowledged.

Prevention by ticlopidine of platelet consumption during extracorporeal circulation for heart surgery and lack of effect on operative and postoperative bleeding.

We studied the effects of ticlopidine, a platelet antiaggregant drug, on platelet consumption during and after extracorporeal circulation (ECC) and on the operative and postoperative blood loss in a double-blind, placebo-controlled trial on 20 patients who underwent open-heart surgery for implantation of a valvular prosthesis. We monitored the changes in platelet count during and after ECC, the need for platelet transfusions to compensate for excessive consumption, and the operative and postoperative blood loss. We also followed the cephalin-kaolin time, the prothrombin time, the fibrinogen level, the fibrin/fibrinogen degradation products, and the euglobulin lysis time. Ticlopidine effectively reduced operative and post-ECC thrombopenia and prolonged the bleeding time. Apart from these changes, no differences in coagulation tests were observed between the ticlopidine-treated group and the placebo group. No side effects were observed. There was no significant difference between the groups concerning operative and postoperative blood loss, indicating that ticlopidine does not induce a hemorrhagic diathesis. Ticlopidine therapy may be of value during the first postoperative days because it prevents clotting on valvular prosthesis and complications such as systemic embolization. However, more trials and controlled studies are needed before such therapy can be recommended for routine use.

Reversible myocardial dysfunction in a patient with alcoholic ketoacidosis: a role for hypophosphatemia.

A 39-year-old woman had alcoholic ketoacidosis complicated by reversible life-threatening myocardial dysfunction. This complication occurred a few hours after correction of acidosis in association with severe hypophosphatemia. A marked improvement in clinical, echocardiographic, and hemodynamic features was associated with the normalization of the serum phosphorus level. This case illustrates a rare complication of hypophosphatemia, emphasizing the need for emergency physicians to consider this metabolic disorder in the treatment of patients with alcoholic ketoacidosis. The pathogenesis of hypophosphatemia in alcoholic ketoacidosis, its potential role in myocardial dysfunction, and its therapeutic implications in emergencies are discussed.

Efficacy of enoximone in the management of refractory low-output states following cardiac surgery.

Fifteen consecutive patients with post-cardiac surgery low-output states refractory to catecholamine inotropic support and intra-aortic balloon counter-pulsation (seven patients), were given enoximone (MDL 17,043, a phosphodiesterase inhibitor), 1 to 2 mg/kg, as a slow intravenous bolus injection, followed by a continuous infusion of 3 to 10 microg/kg/min. Enoximone resulted in a marked improvement in clinical and hemodynamic conditions. Despite the severity of their initial status, all the patients survived their acute circulatory failure and all but two were discharged from the hospital. Hemodynamic improvement was observed as early as 15 minutes after the drug administration and reflected the previously reported inotropic and vasodilatory properties of enoximone. No serious adverse effects were observed. Enoximone thus appears safe and effective in the management of post-cardiac surgery low-output states. Its effects are additive to those of high-dose catecholamines.

Patent foramen ovale: a cause of significant post-coronary artery bypass grafting morbidity.

We describe two patients who underwent coronary artery bypass grafting complicated by postoperative hypoxemia due to a patent foramen ovale with right-to-left shunting. We discuss different hypotheses to explain the shunt: decreased right ventricular compliance, right atrial geometric changes due to septal distension or ischemia, exceeding filling pressure and localised haemorragic pericardial tamponade and low atrial pressure when correcting aortic stenosis. We emphasize the close interplay of pericardectomy and the four cardiac chambers including the distortion of the heart axis. The contrast echo produced by microbubbles of air is the safest and the most accurate procedure to detect the shunt. The two patients progressed positively with an extracorporeal circulation of short duration and without complications linked to the intervention. We conclude that postoperative unexplained hypoxemia must always exclude diagnosis of right-to-left shunting due to a patent foramen ovale (PFO).

La Nocardiose A Propos D'Une Observation. Revue De La Litterature.

We report the observation of a cutaneous, pulmonary and osseous nocardiosis in a 45-year-old man. He was iatrogenously immunocompromised because of a "self-medication" with 32 mg per day of methy Iprednisolone during 30 months for gouty arthropathies. Under treatment with several antibiotics, a favourable evolution was obtained.