P. Taboulet

Acute Digitalis Intoxication — Is Pacing Still Appropriate?

Over a six year period, 92 patients intoxicated with either digitoxin or digoxin were admitted to our ICU. Fifty-one patients were treated with cardiac pacing and/or Fab fragments, and the mortality rate was 13% (14 were intoxications with digoxin, 36 with digitoxin, 1 was mixed). Forty-five cases were suicide attempts; six were accidental overdosages. Since cardiac pacing may trigger fatal arrhythmia or delay the administration of Fab fragments, we conducted a retrospective study to determine whether fatal outcomes could be related either to cardiac pacing or to unsatisfactory use of immunotherapy. In our study, prevention of life-threatening arrhythmia failed in 8% of cases with Fab and in 23% with pacing. Though Fab tended to be more effective, this difference was not significant. In our study, the main obstacles to the success of Fab were pacing-induced arrhythmias and delayed or insufficient administration of Fab. Iatrogenic accidents of cardiac pacing were frequent (14/39, 36%) and often fatal (5/39, 13%). In contrast, immunotherapy was not associated with any serious adverse effects (0/28, 0%) and was safer than cardiac pacing (p < 0.05). In conclusion, during digitalis intoxication, the pacemaker has limited preventive and curative effects, is difficult to handle, and exposes patients to severe iatrogenic accidents. Fab fragments act as a powerful antidote and are safer and much easier to use than pacing. These results encourage us to prescribe Fab fragments as first-line therapy during acute digitalis intoxication.

Treatment of acute chloroquine poisoning: A 5-year experience

OBJECTIVE To describe various aspects of prognostic and therapeutic importance in patients treated for acute chloroquine poisoning. DESIGN Retrospective study. SETTING Toxicology intensive care unit (ICU) of a university hospital. INTERVENTIONS None. PATIENTS One hundred sixty-seven consecutive patients with acute chloroquine overdose admitted to our toxicology ICU. MEASUREMENTS AND MAIN RESULTS The mean amount ingested by history was 4.5 +2- 2.8 g. and 43 (26%) of 167 patients ingested > 5 g. The mean blood chloroquine concentration on admission was 20.5 +/- 13.4 mumol/L The majority (87%) of our patients received at least one arm of a combination therapy regimen (epinephrine, mechanical ventilation, diazepam). cardiac arrest occurred in 25 patients before hospital arrival; In seven of these patients, cardiac arrest occurred immediately after injection of thiopental. The mortality rate was 8.4% overall, and was 9.3% in patients with massive ingestions (NS vs. the group as a whole). We did not find a meaningful correlation between the amount ingested as estimated by history and the peak blood chloroquine concentration; the latter was highly correlated with the mortality rate. CONCLUSIONS The mortality rate in patients with acute chloroquine poisoning, including those patients sick enough to be referred to a specialty unit such as ours, can be limited to < or = 10%. This finding appears to be true even in patients with massive ingestions. We were not able to correlate mortality with amount ingested by history, although the mortality rate does correlate with blood chloroquine concentration. While early use of diazepam, epinephrine, and mechanical ventilation in most of our patients may have contributed to the excellent overall results, these elements, either singly or in combination, do not appear to have a truly antidotal effect in acute chloroquine poisoning. Thiopental, on the other hand, should be used with great caution, if at all, in such cases.

Digoxin-specific Fab fragments as single first-line therapy in digitalis poisoning.

Objective:Despite administration of Fab fragments in digitalis poisoning, high mortality rates are consistently reported. A previous study suggested that Fab fragments prescribed as first-line therapy might improve mortality rate. Our objective was to evaluate this approach. Design:Retrospective chart review (January 1990 to January 2004). Setting:University hospital intensive care unit. Patients:Consecutive patients admitted for cardiac glycoside poisoning. Intervention:First-line therapy with Fab fragments (with or without atropine) in either curative or prophylactic doses. Measurements and Main Results:A total of 141 patients were admitted for digitalis poisoning of whom 66 received first-line Fab fragment therapy. Their median age was 74 years (25th to 75th percentiles: 51–83); 76% were women. Half were intoxicated by digitoxin and half by digoxin. Median serum concentration was 168 (108–205) ng/mL for digitoxin and 6.2 (4.3–13.5) ng/mL for digoxin. Conduction disturbances were reported in 45 cases (68%) and ventricular arrhythmia in six cases (9%). Fab fragments were administered as curative treatment in 21 patients (32%) and prophylactically in 45 patients (68%). The median cumulative dose was 4 (4–6) vials. No adverse effects were reported. Five patients (7.6%) died. Conclusions:First-line therapy with Fab fragments in patients with digitalis poisoning was associated with a low mortality rate.

Pathophysiology and Management of Self-Poisoning with Beta-Blockers

The prognosis of self-poisoning with beta-blockers is excellent, especially if medical management is started immediately but the wide variety of clinical symptoms and proposed treatments complicate the therapeutic strategy. Beta-blockers that are liposoluble or have marked anti-arrhythmic activity are more lethal (e.g. propranolol, sotalol). Similarly, pre-existing cardiac pathology or co-ingestion of psychotropic or cardioactive drugs increases mortality. The first-line symptomatic treatment is administration of atropine and volume-expanding fluids to treat bradycardia and hypotension, respectively. However atropine is often unsuccessful in reversing beta-blocker-induced bradycardia and repeated doses can provoke atropine poisoning. If symptomatic treatment fails, then antidotes should be administered in a precise order: first, high doses of glucagon, followed by isoproterenol, epinephrine, and the new inhibitors of phosphodiesterases. Mechanical ventilation should be started at the same time as pharmacological treatment in cases of severe collapse or prolonged QRS.

Clinical Features and Management of Digitalis Poisoning — Rationale for Immunotherapy

The intensity of gastrointestinal and visual symptoms together with hyperkalemia and the characteristic ECG features make diagnosis of acute digitalis intoxication relatively easy. Death results mainly from ventricular fibrillation or from ventricular asystole or pump failure. Mesenteric infarct may also occur in elderly patients. Previous assessment of outcome has shown that mortality increases in patients exhibiting five prognostic factors: 1) advanced age; 2) heart disease; 3) male sex; 4) high-degree atrioventricular block; 5) hyperkalemia. Conventional treatment includes gastric lavage, activated charcoal and supportive care. First-line antiarrhythmic therapy is usually atropine, because of bradycardia-induced arrhythmia. Ventricular pacing is a toxicodynamic treatment that may be helpful in both bradycardia-induced arrhythmia and high-degree atrioventricular block. Pacing is difficult to handle and can result in serious adverse effects. Immunotherapy has two advantages. First, a strong toxicodynamic effect due to quick reversal of digitalis-induced dysrhythmias, hyperkalemia, and myocardial depression, by reactivation of membrane ATPases. Second, a toxicokinetic effect due to accelerated renal excretion of Fab-digitalis complexes. Since this therapy is well tolerated and efficient, we recommend early administration of Fab fragments as soon as poor prognostic factors are identified.

Cardiovascular Repercussions of Seizures During Cyclic Antidepressant Poisoning

Cyclic antidepressant overdose involves a risk of generalized seizures and cardiovascular disturbances. We have conducted a retrospective study to test the hypothesis of a relationship between generalized seizures and the onset of arrhythmia, hypotension or cardiac arrest during cyclic antidepressant intoxication. Patients who had seizures after ingestion of toxic amounts of tri- or tetracyclic antidepressants were included. Limb-lead QRS complex duration and systolic blood pressure were recorded before and after seizure. Twenty-four of the 388 patients (6.2%) who were admitted to our ICU over a four-year period had seizures (2.3 +/- 2 seizures/patient). Cardiac repercussions of cyclic-induced seizure were frequent and severe. In the postictal period, broadening of the QRS duration or hypotension occurred or were exacerbated in at least 41% and 29% of cases, respectively. In three patients (12.5%), the seizure-induced cardiovascular state was life-threatening and required massive alkalinization therapy and vasopressors, and two of the three required cardiac massage or cardioversion. Prior to seizure, these three patients had severe intoxications characterized by QRS duration > or = 120 ms and systolic blood pressure < or = 80 mm Hg. The results of this work confirm the potential risk of cardiovascular deterioration after cyclic antidepressant-induced seizure and raise the question of a prophylactic approach especially towards the subgroup with unstable hemodynamic status.

Triage aux urgences par une infirmière d'accueil et d'orientation

Summary Nurse managed triage in an emergency department has not yet been formally evaluated in France. Method: We have adapted the reception and waiting area as well as trained all the nurses to patient triage using a “Nurse Classification of Emergency Patients” (NCEP). This classification is based on an evaluation of a patients clinical stability and need for medical care as defined in the clinical classification of emergency patients used by French emergency physicians. By analogy with this latter classification, the NCEP is made up of five classes corresponding with increasing priority at need for medical care (1 : low priority; 5 : high priority). We have compared -with the same staff- the duration of management and the satisfaction of patients consulting on Mondays between 8.30 AM and 12 PM before and after the creation of the triage nurse position. The duration of patient management was the sum of the waiting time within the reception area (between registration and medical examination) and the duration of the medical consultation itself. Patient satisfaction was evaluated in real time using questionnaires. We also have evaluated the workload during each period, using nursing, medical and medico-technique care ratings. Results: The workload was comparable without (n = 296) and with (n = 303) a triage nurse. Waiting time at the reception was significantly longer without than with a triage nurse for unstable patients class 3 (43 ± 39 min vs 32 ± 28 min) and class 4 (47 ± 59 min vs 12 ± 18 min) of the NCEP (p Conclusion: Creation of a triage nurse position allows a significant reduction of the waiting time for unstable patients and increases the satisfaction of the patients as a whole.

Immunotoxicotherapy : Successes, disappointments and hopes

was quite limited until the late 1960’s, when another breakthrough was to occur, in the form of development of toxin-specific antibody fragments. This exemplary story unfolded in two steps: (1) active immunization and (2) passive immunization with whole antibody, and subsequently with antibody fragments. In 1967, Butler and Chen reported that coupling of the digoxin hapten to serum albumin resulted in

A case of life-threatening lactic acidosis after smoke inhalation — interference between β-adrenergic agents and ethanol?

A 49-year-old male developed bronchospasm and severe lactic acidosis after exposition to fire smoke. The correction of lactic acidosis following β-adrenergic agents withdrawal, and the transitory increase in lactate after salbutamol reintroduction are consistent with hypersensitivity to salbutamol. However, the plasma lactate concentration (32.6 mmol/l) that we observed 9.5 h after admission is far above those currently seen after administration of β-adrenergic agents. We searched for causes able to potentiate the adverse effects of these drugs and we noticed that our patient had a high plasma ethanol level (2.4 g/l). Alcohol metabolism in the liver results in generation of high NADH/NAD+ ratios, thus reducing lactate liver clearance. This observation suggests that plasma lactate levels should be monitored closely in alcoholic patients treated with β-mimetic agents.