Management of atrial tachyarrhythmias in the critically ill: a comparison of intravenous procainamide and amiodarone.

OBJECTIVE: To compare the efficacy and safety of intravenous (IV) amiodarone and procainamide for the treatment of atrial tachyarrhythmias (AT) in the critically ill. DESIGN: In this prospective study, patients were allocated to drug treatment on the basis of hospital identification number, even for procainamide and odd for amiodarone. SETTING: Patients were recruited from a teaching hospital ICU and did not include postoperative cardiac patients. PATIENTS AND PARTICIPANTS: 26 patients with AT sustained for at least 1 h and failure to respond to correction of possible precipitating factors were entered in the study. Exclusion criteria were systolic blood pressure (SBP) < 80 mmHg, and known hypersensitivity to either drug. Two patients with chronic atrial fibrillation (who received amiodarone) were later excluded from the analysis. In the final analysis, 14 patients received procainamide and 10 amiodarone. INTERVENTIONS: IV amiodarone (3 mg/kg followed by 10 mg/kg/24 h, with repeat dose of 3 mg/kg at 1 h if no response) or i.v. procainamide (10 mg/kg at 1 mg/kg/min followed by infusion of 2-4 mg/min for 24 h, with repeat dose of 5 mg/kg at 1 h if no response). MEASUREMENTS AND RESULTS: In the procainamide group 10/14 (71%) and in the amiodarone group 7/10 (70%) had converted to sinus rhythm by 12 h. There was no significant difference in response between the groups. SBP was not significantly different from baseline after administration of either drug. CONCLUSIONS: Procainamide and amiodarone appear to be safe and equally effective in the treatment of AT in the critically ill.

Hypocortisolaemia and adrenocortical responsiveness at onset of septic shock.

OBJECTIVE: To characterise the plasma cortisol profile and adreno-cortial responsiveness (short Synacthen test) of patients in septic shock. DESIGN: Retrospective assessment using case-notes and ICU charts. SETTING: University teaching hospital ICU. PATIENTS: 68 septic shock patients with plasma cortisol and/or short Synacthen test measured at ICU-admission or onset of shock post ICU-admission. Patients were identified from a total population of 155 patients who had PCL and/or SST measured over a 4.5 year period. INTERVENTION: None. MEASUREMENTS AND RESULTS: Patients with septic shock had a plasma cortisol ranging from 210-8900 nmol/l and mortality of 56%. There were 22 (32%) below (low) and 46 (68%) above (high) a 'critical' plasma cortisol of 500 nmol/l. Using stepwise logistic regression, mortality was adequately predicted by and increased with, increasing plasma cortisol and onset of shock remote from ICU-admission. Short Synacthen tests were available in 33 patients: 11 responders (cortisol increment > 200 nmol/l above baseline 30 min after 0.25 mg intravenous Synacthen) and 22 hypo-responders. Mortality in patients was adequately predicted by and increased with a decrease in cortisol increment post-Synacthen. Thirteen patients (plasma cortisol 606 +/- [SD] 297 nmol/l) had complete haemodynamic profiles before inotropic therapy; no relationship was demonstrated between plasma cortisol and circulatory variables. Follow-up revealed no cases of Addison's disease. CONCLUSIONS: In septic shock, 'hypocortisolaemia' is not uncommon and does not predict a high mortality; adrenocortical hypo-responsiveness may be associated with poor outcome.

A high flow turbine CPAP system.

A continuous high flow CPAP system incorporating a turbine blower is described. The system achieves inspiratory flow rates of 150 l/min or more by means of reticulated gas flow and inspired oxygen fractions of 0.21-0.95. Positive airway pressure is provided by weighted disc valves and a modified aviation-type CPAP face mask provides electronic communication with the patient. The mobility of the system also enables its use as an intermittent physiotherapy aid. Work of breathing of the system, as assessed by total pressure fluctuations is at a minimum.

Transcutaneous aortovelography. Potentially useful technique in management of critically ill patients.

Pilot evaluation of the clinical use of transcutaneous aortovelography has been undertaken and suggests that this technique will be useful in the assessment of left ventricular function in the acutely ill patient. Changes in waveform as a result of therapy or alteration in clinical condition can frequently be noted by critical visual assessment. Increasing clinical experience suggests that quantification will permit interpretation of less obvious changes in the recorded waveform. Transcutaneous aortovelography has the simplicity, speed, and safety afforded by a non-invasive technique.

An unusual cause for cardiac arrest.

We report a case of organophosphate poisoning presenting as a cardiac arrest. The diagnosis was delayed due to the absence of a history of insecticide ingestion and the unusually acute presentation. Cardiac arrest with bradycardia poorly responsive to adrenaline and responsive to high dose atropine should alert the clinician to the possibility of an anticholinesterase poisoning. Early diagnosis is essential in order to manage these patients appropriately and increase the probability of survival.

Cost calculation and prediction in adult intensive care: a ground-up utilization study.

The ability of various proxy cost measures, including therapeutic activity scores (TISS and Omega) and cumulative daily severity of illness scores, to predict individual ICU patient costs was assessed in a prospective "ground-up" utilization costing study over a six month period in 1991. Daily activity (TISS and Omega scores) and utilization in consecutive admissions to three adult university associated ICUs was recorded by dedicated data collectors. Cost prediction used linear regression with determination (80%) and validation (20%) data sets. The cohort, 1333 patients, had a mean (SD) age 57.5 (19.4) years, (41% female) and admission APACHE III score of 58 (27). ICU length of stay and mortality were 3.9 (6.1) days and 17.6% respectively. Mean total TISS and Omega scores were 117 (157) and 72 (113) respectively. Mean patient costs per ICU episode (1991 dollar AUS) were dollar 6801 (dollar 10311), with median costs of dollar 2534, range dollar 106 to dollar 95,602. Dominant cost fractions were nursing 43.3% and overheads 16.9%. Inflation adjusted year 2002 (mean) costs were dollar 9343 (dollar AUS). Total costs in survivors were predicted by Omega score, summed APACHE III score and ICU length of stay; determination R2, 0.91; validation 0.88. Omega was the preferred activity score. Without the Omega score, predictors were age, summed APACHE III score and ICU length of stay; determination R2, 0.73; validation 0.73. In non-survivors, predictors were age and ICU length of stay (plus interaction), and Omega score (determination R2, 0.97; validation 0.91). Patient costs may be predicted by a combination of ICU activity indices and severity scores.

Epinephrine as an inotropic agent in septic shock: a dose-profile analysis.

OBJECTIVE: To characterize the acute actions and physiologic dose profile of epinephrine, as a single inotrope, in patients with septic shock. DESIGN: Prospective clinical study. The relationship between epinephrine dose and cardiovascular variables was analyzed using repeated-measures analysis of variance. SETTING: ICU in a university teaching hospital. PATIENTS: Eighteen patients with septic shock, mean age 64 +/- 8 (SD) yrs, and with a mean admission Acute Physiology and Chronic Health Evaluation (APACHE II) score of 23 (range 14 to 35). INTERVENTIONS: Initial volume loading and the measurement of a baseline hemodynamic profile were followed by the administration of an epinephrine infusion at 3 microgram/min with subsequent increments of 3 micrograms/min and the determination of a hemodynamic profile after each dose increment. Therapy was titrated to clinical goals of perfusion and restoration of premorbid systolic arterial BP. MEASUREMENTS AND MAIN RESULTS: After volume loading, mean hemodynamic indices were as follows: mean arterial pressure (MAP) 62 +/- 7 mm Hg; cardiac index 3.8 +/- 1.1 L/min/m2; left ventricular stroke work index 25 +/- 11 g.m/m2; oxygen delivery (Do2) index 460 +/- 168 mL/min/m2; and oxygen consumption (VO2) index 165 +/- 64 mL/min/m2. In the dose range of 3 to 18 microgram/min, epinephrine produced linear increases in average heart rate, MAP, cardiac index, left ventricular stroke work index, stroke volume index, VO2, and DO2. No effect was noted on pulmonary artery occlusion pressure (PAOP), mean pulmonary arterial pressure, or systemic vascular resistance index. CONCLUSIONS: Epinephrine increases DO2 in septic shock by increasing cardiac index without an effect on systemic vascular resistance index or PAOP.