Prognostic value of serum cholinesterase in organophosphate poisoning.

OBJECTIVE: To determine whether serum cholinesterase level has a prognostic value in human acute organophosphorus poisoning. DESIGN: Cohort (prospective) prognosis study. SETTING: Medical ICU at University Hospital. PATIENTS: Thirty consecutive patients admitted to the ICU for acute organophosphate poisoning. MEASUREMENTS: Serum cholinesterase level was measured in all patients at the time of hospital admission. Severity of intoxication was assessed by the total dose of atropine required to relieve poisoning manifestations, the Simplified Acute Physiology Score, the need for assisted ventilation, and by a specific grading system previously validated that identified two groups of patients: group 1 (low severity, n = 18) and group 2 (high severity, n = 12). RESULTS: Serum cholinesterase level did not correlate with the total dose of atropine or with the Simplified Acute Physiology Score. Mean serum cholinesterase level was not significantly different between group 1 and group 2 patients (448 +/- 409 U/L in group 1 compared with 611 +/- 575 U/L in group 2 (p = NS); it was also not significantly different between patients with and without mechanical ventilation support (567 +/- 571 vs 470 +/- 409, respectively). CONCLUSION: Serum cholinesterase levels have no prognostic value in acute organophosphate poisoning. Thus, a grading system to identify high-risk patients based on this measurement is most likely unreliable.

Cardiac dysfunction and pulmonary edema following scorpion envenomation.

Cardiac dysfunction with pulmonary edema following scorpion envenomation (SE) has been documented only in a few isolated case reports. We conducted a systematic hemodynamic study in five consecutive patients (mean age, 21.6 +/- 8 years) presenting with pulmonary edema occurring a few hours (9.6 +/- 5.2 hours) after SE. All patients had increased pulmonary capillary wedge pressure (mean, 25 +/- 1.8 mm Hg) while the systemic vascular resistance was elevated only in one. The stroke volume index was markedly depressed (21.7 +/- 3.6 ml/sq m) whereas cardiac index was normal or slightly decreased (2.5 +/- 0.4 L/min/sq m). Cerebral infarct and sudden cardiac arrest were the cause of death in two patients. In the three survivors, all the hemodynamic disturbances and respiratory abnormalities disappeared within a few days. We conclude that cardiac dysfunction was found in all five patients and this was reversible in the three surviving the acute episode.

Cardiac index vs oxygen-derived parameters for rational use of dobutamine in patients with congestive heart failure.

In patients with congestive heart failure (CHF), catecholaminergic agents may exert thermogenic effects that limit their beneficial effects in terms of global tissue oxygenation. Oxygen extraction ratio (O2ER) or mixed venous blood saturation (SvO2) might take into account better than cardiac index (CI) the resultant effect of such agents on peripheral oxygenation. We tested this hypothesis in a series of 20 patients with severe CHF and normal blood lactate levels undergoing pulmonary artery catheterization and receiving incremental doses of dobutamine: 0 (Do), 5 (D5), 10 (D10), and 15 micrograms/kg/min (D15). A significant dose-effect relationship (p < 0.01) was found between dose of dobutamine and CI (CI = 0.06 dose + 1.82). By contrast, no dose-effect relationship was observed between dobutamine dose and either O2ER or SvO2. Indeed, a biphasic profile was observed for O2ER and SvO2. From D0 to D10, O2ER decreased (from 45 +/- 6 to 35 +/- 7 percent) and SvO2 increased (from 52 +/- 7 to 62 +/- 7 percent). From D10 to D15, no further change was observed for both parameters. This latter finding was related to a significant increase in VO2 at D15 (p < 0.01). In these normolactatemic patients with unchanged VO2 from D0 to D10 while DO2 linearly increased (from D0 to D15), the increase in VO2 at D15 was probably due to an increase in oxygen demand induced by the drug. Our results suggest that dobutamine at a dose of 15 micrograms/kg/min can induce an increase in O2 demand that might offset the improvement in CI. Thus, in patients with CHF, oxygen-derived parameters such as O2ER and SvO2 should be more appropriate than CI to assess the efficacy of dobutamine.

Right ventricular dysfunction following severe scorpion envenomation.

OBJECTIVE: Evaluation of right ventricular (RV) performance in patients presenting with pulmonary edema following scorpion envenomation. DESIGN: Cohort study. SETTING: Medical intensive care unit of a teaching hospital. PATIENTS: Eight consecutive adult patients stung by yellow scorpion Androctonus australis and presenting with pulmonary edema at hospital admission. INTERVENTIONS: In all patients, standard hemodynamic parameters and RV volumes were measured using a pulmonary artery catheter equipped with a rapid responding thermistor enabling measurement of RV ejection fraction (RVEF). MEASUREMENTS: Hemodynamic evaluation was performed at the time of hospital admission prior to any therapeutic intervention and just before the removal of the pulmonary catheter (2.3 +/- 0.5 days after admission) in the surviving patients (n = 7). RESULTS: All patients had a decreased RVEF (24 +/- 7%) and cardiac index (2.44 +/- 0.5 L/min/m2) and increased pulmonary artery occlusion pressure (23 +/- 6 mm Hg). Right ventricular end-systolic pressure/volume ratio was decreased (.56 +/- .19 mm Hg/mL/m2), suggesting an altered RV contractility. Follow-up evaluation performed in survivors, without any inotropic support, showed hemodynamic changes reflecting a trend toward full recovery. Right ventricular ejection fraction and cardiac index improved markedly (from 24 +/- 7% to 39 +/- 10% and from 2.44 +/- 0.5 to 4 +/- .3 L/min/m2, respectively). Pulmonary artery occlusion pressure, peak systolic pulmonary artery pressure, and mean pulmonary artery pressure decreased significantly from baseline values (12 +/- 3 mm Hg, 29 +/- 5 mm Hg, and 20 +/- 4 mm Hg, respectively). Right ventricular end systolic pressure/volume ratio remained almost constant, suggesting that afterload enhancement accounted predominantly for RVEF improvement. CONCLUSION: These data show that RV function impairment is associated with left ventricular dysfunction, suggesting similarities between left ventricular and RV alterations following severe scorpion envenomation providing further arguments to the hypothesis of scorpionic myocarditis.

A controlled trial of nebulized salbutamol and adrenaline in acute severe asthma.

OBJECTIVE: To compare efficacy and safety of nebulisation of adrenaline (2 mg over 10 min) and salbutamol (5 mg over 10 min) in acute severe asthma. DESIGN: Prospective randomized and double blind study. SETTING: Intensive care unit of a University teaching hospital. PATIENTS AND PARTICIPANTS: 22 asthmatic patients presenting to the emergency room with acute severe asthma. INTERVENTIONS: Patients were randomly assigned to receive either adrenaline (n = 11) or salbutamol (n = 11) via a nebulizer. Additional treatment comprised hydrocortisone hemisuccinate (100 mg) and supplemental oxygen (71/min). The efficacy and safety of both drugs were evaluated at 20 and 40 min. RESULTS: A statistically significant increase in the Peak Expiratory Flow (PEF) was achieved at the 20th min in both groups (from 85 +/- 38 l/min to 120 +/- 45 l/min; p < 0.001; and from 107 +/- 28 l/min to 145 +/- 19 l/min; p < 0.001; in adrenaline group and salbutamol group respectively). With both drugs, PEF further increased at 40 min to a level that was statistically significant when compared to the 20 min evaluation. The magnitude of the absolute variation in PEF was similar with both drugs. Both drugs induced a significant decrease in heart rate, respiratory frequency and PaCO2 while the increase of PaO2/FIO2 ratio was not significant. The decrease of respiratory frequency at 40 min was more important with salbutamol (p = 0.03). No side effects were recorded in both groups. CONCLUSION: After a single dose, nebulized adrenaline (2 mg) proved as effective and safe as salbutamol (5 mg) in acute severe asthma.

Assessment of left ventricular function in severe scorpion envenomation: combined hemodynamic and echo-Doppler study.

OBJECTIVE: To assess left ventricular function in patients presenting with pulmonary edema following scorpion envenomation. DESIGN: Cohort study. SETTING: Medical intensive care unit of a teaching hospital. PATIENTS: Nine consecutive adult patients stung by Androctonus australis and presenting with pulmonary edema entered the study. Fourteen normal volunteers comprised the control group. INTERVENTIONS: Upon admission, all patients had right heart catheterization and, within the first 8 h, a Doppler echocardiographic study. Results of Doppler echocardiographic studies were compared to those of controls. MEASUREMENTS AND RESULTS: Usual hemodynamic information (heart and vascular pressures, derived data and tissue oxygenation parameters), left ventricular dimensions and indicators of systolic function, and Doppler-derived parameters of left ventricular filling and diastolic function were obtained upon admission. Serial echocardiographic measurements were repeated daily until full clinical recovery (eight patients) or death (one patient). All patients had a hemodynamic profile of acute congestive heart failure (mean PAOP = 24 +/- 2 mmHg; mean SVI = 22 +/- 7 ml/m2; mean CI = 2.5 +/- 0.5 l/min/m2). However, SVR were not increased (mean = 22 +/- 3 U/m2). Left ventricle was hypokinetic in all patients with transient mitral regurgitation present in five patients. Left ventricular systolic function was markedly depressed (FS = 12 +/- 6%; EF = 26 +/- 12%). An associated diastolic dysfunction is suggested by Doppler records of mitral inflow. Left ventricular systolic function evolved toward normalization within 6 +/- 2 days preceded by full clinical recovery. CONCLUSIONS: These data suggest that pulmonary edema in scorpion envenomation is of hemodynamic origin and is related to a severe and prominent impairment of left ventricular systolic function.

Hellp syndrome: incidence and maternal-fetal outcome--a prospective study.

OBJECTIVE: To determine the incidence of Hellp syndrome (HS) and the maternal fetal outcome associated with its occurrence. DESIGN: A prospective study during a 6-month period. SETTING: The department of obstetrics and gynecology and the Intensive Care Unit of a 700 bed teaching hospital. PATIENTS: Sixty-two consecutive preeclamptic and eclamptic women. MEASUREMENTS AND RESULTS: All patients were systematically investigated for the biological markers of HS. The effects of the occurrence of HS on maternal and fetal prognosis were evaluated by comparing for prognosis indicators usually assessed in gravidic hypertension, pre-eclamptic and eclamptic woman who exhibited HS (HS+ subgroup) with HS free patients (HS- subgroup). HS was found in 12 out of the 62 pre-eclamptic and eclamptic women (19.3%). Its occurrence was associated with higher maternal mortality (16.7% vs 0%; p = 0.03), a greater incidence of eclamptic crisis (50% vs 20%; p = 0.03), severe hypertension (33% vs 8%; p = 0.03) and episodes of acute renal failure (66% vs 30%; p = 0.02). Mean proteinuria was also higher in HS+ patients (4.6 +/- 3.3 vs 2.2 +/- 2.5 g/day; p = 0.001). However, fetal outcome was not significantly altered. CONCLUSION: Pre-eclampsia and eclampsia may be more severe in the presence of HS with a worsening of maternal prognosis while fetal outcome seems not altered.

[C-reactive protein in bacterial meningitis in adults]. / La protéine c-réactive dans les méningites bactériennes de l'adulte.

In order to assess the benefits of serial assays of C-reactive protein in the course of bacterial meningitis in adults, daily blood samples were taken for CRP measurement during 10 days in 21 consecutive patients (mean age: 24 +/- 8 years) hospitalized for bacterial meningitis principally due to Neisseria meningitidis (n = 15). The highest CRP level (178 +/- 38 mg/l) was present on admission, followed by a regular decrease occurring in uncomplicated meningitis until normal level was achieved on day 9. The CRP kinetics was not influenced by the type of causative micro-organism. This study shows that CRP kinetics in adults is similar to that reported in children. The benefit of CRP assays in optimizing the duration of antibiotic treatment of meningitis needs to be more carefully assessed.

[Dose-effect of adrenaline nebulization in asthma: comparative study with salbutamol]. / Effet-dose de la nébulisation d'adrénaline dans l'asthme: étude comparative avec le salbutamol.

UNLABELLED: The aim of this randomized cross-over trial was to evaluate the dose effect and systemic absorption of epinephrine nebulized at 2 and 5 mg in comparison with salbutamol (5 mg). Thirteen asthmatic patients (29 +/- 15 years, 4 men and 9 women) were randomly assigned to receive one nebulization of each of the three treatment regimens at 24 h interval. The evaluation concerned forced expiratory volume in 1 second (FEV1), heart rate, respiratory rate and arterial pressure. All measurements were done at baseline, every 15 minutes during the first hour, and hourly thereafter until return to baseline FEV1. Serum potassium was measured at baseline (T0) and sixty minutes after (T60). Plasma levels of epinephrine were measured at T0, T20, T60. Fifteen minutes after the beginning of nebulization FEV1 improved significantly over baseline in the three groups. These changes were similar in the three groups until T45, while FEV1 improvement was significantly greater in A5 and S groups than A2 group (+640 +/- 470 ml, +721 +/- 349 ml, +406 +/- 306 ml in A5, S and A2 groups respectively, p < 0.01). Bronchodilation lasted significantly longer with salbutamol than with epinephrine (p < 0.05). No side effects were recorded in spite of substantial and dose-dependent systemic absorption of epinephrine. CONCLUSION: Increasing epinephrine doses produces greater bronchodilation without additional side effects. However this bronchodilation lasts shorter than with salbutamol.

High-dose hydrocortisone hemisuccinate in scorpion envenomation.

STUDY OBJECTIVE: Scorpion envenomation is a common life-threatening hazard in tropical and subtropical countries. Standard treatment is not clearly defined. Many therapies, such as steroids, are prescribed without experimental justification. We sought to assess the efficacy of systematic administration of intravenous hydrocortisone hemisuccinate (50 mg/kg) in scorpion envenomation. METHODS: Six hundred consecutive envenomated patients older than 10 years who presented to the ED of a nonteaching secondary hospital in an area of Tunisia endemic for scorpion envenomation were randomly assigned to receive hydrocortisone hemisuccinate 50 mg/kg (n = 305) or placebo (n = 295) in addition to standard medical care. Patients in the two groups had similar clinical characteristics on initial clinical evaluation. Each was categorized as grade 1 (absence of systemic symptoms) or grade 2 (systemic symptoms of scorpion envenomation). Patients were treated in the ED for up to 4 hours or in the ICU, depending on clinical severity. Steroid and placebo groups were compared according to mortality rate, change of severity grade 4 hours after presentation and treatment, and duration of hospital stay. RESULTS: Distribution of patients with respect to severity grade was similar in the two groups at the 4-hour clinical evaluation. We detected no significant difference at the time of discharge between steroid-and placebo-treated patients with respect to mortality (one patient in each group) or duration of hospital stay. Extra costs incurred through steroid administration totaled US $989,000. CONCLUSION: Our findings do not support the use of intravenous high-dose steroids in scorpion-envenomated patients. The discontinuation of this practice would reduce costs substantially.

Predictive value of severity scoring systems: comparison of four models in Tunisian adult intensive care units.

OBJECTIVES: To compare the performance of four severity scoring systems: the Acute Physiology and Chronic Health Evaluation (APACHE) II, the new versions of the Mortality Prediction Model (MPM0 and MPM24), and the Simplified Acute Physiology Score (SAPS) II. DESIGN: A prospective cohort study. SETTING: Three Tunisian intensive care units (ICUs). PATIENTS: Consecutive, unselected adult patients (n = 1325). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Overall, observed death rates were higher than predicted by all models except MPM0. All the evaluated scoring systems had good discrimination power as expressed by area under the receiver operating characteristics curve, but their calibration was less perfect when compared with original validation reports. There were no major differences between the models with regard either to discrimination or calibration performance. CONCLUSION: Despite an overall good discrimination, APACHE II, MPM0, MPM24, and SAPS II showed a less satisfactory calibration in our Tunisian sample of ICU patients. Part of the models inaccuracy could be related to quality of care problems in our ICUs, but this issue needs further analysis.

Efficacy of serotherapy in scorpion sting: a matched-pair study.

BACKGROUND/OBJECTIVE: Although evidence of scorpion antivenin effectiveness in the clinical setting is lacking, scorpion antivenin is generally considered the only specific treatment for scorpion sting irrespective of its clinical severity. We conducted a matched-pair study to assess the efficacy of systematic administration of scorpion antivenin. METHODS: Among 600 stung patients who participated in a study on the efficacy of high-dose hydrocortisone after scorpion sting, 135 (cases) had been treated with 10 to 20 mL intravenous scorpion antivenin (neutralizing 10 LD50 venom/mL). Controls were matched on disease severity on arrival to the emergency department. The severity of envenomation was graded I or II according to the absence (grade I) or the presence (grade II) of systemic manifestations of scorpion envenomation. Assessment of scorpion antivenin efficacy was based on the rate of changing severity grade in both groups (clinical improvement or worsening during an observation period of at least 4 hours). RESULTS: Both groups were similar with respect to clinical severity (36 patients were graded II in each group), age, sex, time-lapse between scorpion sting and ED arrival, and the administration of adjunctive therapy such as hydrocortisone. By the 4-hour evaluation, 50% and 64% of patients initially graded II exhibited a substantial clinical improvement in cases and controls, respectively, suggesting similar effects in cases and controls. There was no difference in preventive effects: 13% and 10% of cases and controls developed systemic manifestations of scorpion envenomation during the 4-hour observation period; 23% of cases and 17% controls were hospitalized by this time. There was no difference in the duration of hospitalization. Three cases developed anaphylactic shock as a consequence of scorpion antivenin administration, while 1 scorpion antivenin-untreated patient died from refractory shock. CONCLUSION: Systematic administration of scorpion antivenin irrespective of clinical severity did not alter the clinical course of scorpion sting. A prospective study is needed concerning the response of the more severe scorpion envenomations.