Preeclampsia and Related Problems

Hypertensive disorders of pregnancy can be classified as chronic hypertension (present before pregnancy), gestational hypertension (onset after 20 weeks of pregnancy), and preeclampsia (onset after 20 weeks of pregnancy, along with proteinuria and other organ dysfunction). Preeclampsia and related disorders are a major cause of maternal and fetal morbidity and mortality. Preeclampsia is believed to result from an angiogenic imbalance in the placenta circulation. Antenatal screening and early diagnosis may help improve outcomes. Severe preeclampsia is characterized by SBP ≥160 mm Hg, or DBP ≥110 mm Hg, thrombocytopenia (platelet count <100 × 109/L), abnormal liver function, serum creatinine >1.1 mg/dL, or a doubling of the serum creatinine concentration in the absence of other renal diseases, disseminated intravascular coagulation, pulmonary edema, new-onset headache, or visual disturbances. Severe preeclampsia or eclampsia (preeclampsia with seizures) needs ICU management and is the main cause of morbidity and mortality. Severe hypertension can also result in life-threatening intracranial hemorrhage. Blood pressure control, seizure prevention, and appropriate timing of delivery are the cornerstones of the management of preeclampsia. Besides intravenous antihypertensive drugs, intravenous magnesium sulfate is the drug of choice to prevent or treat seizures, when preparing for urgent delivery. At present, delivery remains the most effective treatment for preeclampsia, and organ dysfunction rapidly recovers after delivery. Novel therapeutic interventions are under development to reduce complications.

How to cite this article

Narkhede AM, Karnad DR. Preeclampsia and Related Problems. Indian J Crit Care Med 2021;25(Suppl 3):S261-S266.

Tropical Infections in the Indian Intensive Care Units: The Tip of the Iceberg!

How to cite this article: Karnad DR, Patil VP, Kulkarni AP. Tropical Infections in the Indian Intensive Care Units: The Tip of the Iceberg! Indian J Crit Care Med 2021; 25(Suppl 2):S115–S117.

An Approach to a Patient with Tropical Infection in the Intensive Care Unit

How to cite this article: Karnad DR, Amin P. An Approach to a Patient with Tropical Infection in the Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2):S118–S121.

Intensive Care Management of Severe Tetanus

Tetanus is caused by an exotoxin, tetanospasmin, produced by Clostridium tetani, an anaerobic gram-positive bacillus.

Tetanospasmin prevents the release of inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the spinal cord, brainstem motor nuclei, and the brain, producing muscle rigidity and tonic spasms.

Trismus (lockjaw), dysphagia, laryngeal spasms, rigidity of limbs and paraspinal muscles, and opisthotonic posture are common.

Frequent severe spasms triggered by touch, pain, bright light, or sounds may produce apnea and rhabdomyolysis.

Autonomic overactivity occurs in severe tetanus causing labile hypertension, tachycardia, increased secretions, sweating, and urinary retention. Dysautonomia is difficult to manage and is a common cause of mortality; magnesium sulfate infusion is often used.

Antibiotics (penicillin or metronidazole) and wound care reduce toxin production and human tetanus immune globulin neutralizes the circulating toxin.

Nasogastric tube placement for feeding and medications is needed.

Early elective tracheostomy is performed in moderate or severe tetanus to prevent aspiration and laryngeal stridor.

Benzodiazepines help reduce rigidity, spasms, and autonomic dysfunction. Large doses of diazepam (0.2–1 mg/kg/h) are administered via nasogastric tube.

Neuromuscular blocking agents and mechanical ventilation are used for refractory spasms.

Mortality ranges from 5% to 50%.

How to cite this article: Karnad DR, Gupta V. Intensive Care Management of Severe Tetanus. Indian J Crit Care Med 2021; 25(Suppl 2):S155–S160.

Validation of electrocardiographic criteria for identifying left ventricular dysfunction in patients with previous myocardial infarction

Background

Eleven criteria correlating electrocardiogram (ECG) findings with reduced left ventricular ejection fraction (LVEF) have been previously published. These have not been compared head‐to‐head in a single study. We studied their value as a screening test to identify patients with reduced LVEF estimated by cardiac magnetic resonance (CMR) imaging.

Methods

ECGs and CMR from 548 patients (age 61 + 11 years, 79% male) with previous myocardial infarction (MI), from the DETERMINE and PRE‐DETERMINE studies, were analyzed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each criterion for identifying patients with LVEF ≤ 30% and ≤ 40% were studied. A useful screening test should have high sensitivity and NPV.

Results

Mean LVEF was 40% (SD = 11%); 264 patients (48.2%) had LVEF ≤ 40%, and 96 patients (17.5%) had LVEF ≤ 30%. Six of 11 criteria were associated with a significant lower LVEF, but had poor sensitivity to identify LVEF ≤ 30% (range 2.1%–55.2%) or LVEF ≤ 40% (1.1%–51.1%); NPVs were good for LVEF ≤ 30% (range 82.8%–85.9%) but not for LVEF ≤ 40% (range 52.1%–60.6%). Goldberger's third criterion (RV4/SV4 < 1) and combinations of maximal QRS duration > 124 ms + either Goldberger's third criterion or Goldberger's first criterion (SV1 or SV2 + RV5 or RV6 ≥ 3.5 mV) had high specificity (95.4%–100%) for LVEF ≤ 40%, although seen in only 48 (8.8%) patients; predictive values were similar on subgroup analysis.

Conclusions

None of the ECG criteria qualified as a good screening test. Three criteria had high specificity for LVEF ≤ 40%, although seen in < 9% of patients. Whether other ECG criteria can better identify LV dysfunction remains to be determined.

Goal-directed Therapy: Does It Work in Postcardiac Surgery Patients, Unlike in Sepsis?

How to cite this article: Saraf S, Karnad DR. Goal-directed Therapy: Does It Work in Postcardiac Surgery Patients, Unlike in Sepsis? Indian J Crit Care Med 2020;24(5):287-288.

Reference values of ECG parameters derived from 906 echocardiographically confirmed healthy Indian children: A population-based study from Gujarat

INTRODUCTION

There are few published studies on reference ranges of ECG parameters in children; some ethnic differences have been described.

METHODS

We studied digital 12‑lead ECGs (1000 samples/s) from 906 healthy rural Indian children (467 boys: 439 girls) aged 5-15 years. PR, QRS, and QT were measured using superimposed median beat. Age-wise normal limits (median, 2nd and 98th percentile) were defined.

RESULTS

Heart rate decreased while PR interval and QRS duration increased with age. QTcB interval remained unchanged from 5 to 12 years and decreased thereafter due to QTcB shortening in boys but not in girls. "Juvenile T wave pattern" was seen in 95% of children aged 5-8 years in lead V1 and 55-60% in V2, V3; it decreased with age. RV dominance (R/S > 1) in lead V1 was seen in 13% at 5 years, 1% at 10 years and none at 14 years.

CONCLUSION

Reference ranges in Indian children are similar to those in other ethnic groups.

Individual-Specific QT Interval Correction for Drugs With Substantial Heart Rate Effect Using Holter ECGs Extracted Over a Wide Range of Heart Rates

Although fixed QT correction methods are typically used to adjust for the effect of heart rate on the QT interval in thorough QT/QTc studies, individual-specific QT correction (QTcI = QT/RR^I ) is advisable for drugs that increase the heart rate by >5 to 10 beats/minute (bpm). QTcI is traditionally derived using resting drug-free electrocardiograms (ECGs) collected at prespecified times. However, the resting heart rate range in healthy individuals is narrow, and extrapolation of inferences from these data to higher heart rates could be inappropriate. Accordingly, the QTcI derived from triplicate ECGs extracted at prespecified times (the traditional [T] method, yielding QTcIT) was compared with QTcIs obtained using ECGs with a wider heart rate range (alternative Holter [H] method, yielding QTcIH) from 24-hour Holter recordings from 40 healthy individuals selected from a central ECG laboratory database. For QTcIH, 10-second ECGs were extracted at stable heart rates in the ranges of 51-60, 61-70, 71-80, and 81-90 bpm (9 ECGs in each bin = 36 ECGs). An independent set of 40 ECGs with heart rates from 51 to 90 bpm was extracted from each individual to validate the accuracy of QTcI by the 2 methods. For the validation set, the QTcIH was a better QT correction method (slope of QTc vs heart rate closer to zero) than QTcIT. The mean difference between QTcIT and QTcIH increased from 3.1 milliseconds at 65 bpm to 10.0 milliseconds at 90 bpm (P < 0.01). The QTcIT exceeded QTcIH at heart rates > 60 bpm. Employment of the QTcIH may be more appropriate for studies involving drugs that increase heart rate.

Chikungunya: Report from the task force on tropical diseases by the World Federation of Societies of intensive and critical care medicine

Chikungunya is an arbovirus that is transmitted by the Aedes mosquito causing a febrile illness with periodic outbreaks in large parts of the world. In the last decade it has become a public health concern in a host of countries and has affected international tourists. In the vast majority of cases Chikungunya presents as an acute febrile illness, associated with rash, headache, myalgia and debilitating arthralgia or even polyarthritis. A small proportion of patients present atypically with nervous, ocular, renal, myocardial, respiratory and renal system involvement and may require ICU management. Over the years the epidemic potential of the virus has become apparent with spread related to an increase in global travel and the successful adaptation of the Aedes mosquito to the urban and sylvan environments in numerous countries. These epidemics have affected millions of people across the globe. Treatment is usually symptomatic and supportive.

Tropical diseases in the ICU: A syndromic approach to diagnosis and treatment

Tropical infections form 20-30% of ICU admissions in tropical countries. Diarrheal diseases, malaria, dengue, typhoid, rickettsial diseases and leptospirosis are common causes of critical illness. Overlapping clinical features makes initial diagnosis challenging. A systematic approach involving (1) history of specific continent or country of travel, (2) exposure to specific environments (forests or farms, water sports, consumption of exotic foods), (3) incubation period, and (4) pattern of organ involvement and subtle differences in manifestations help in differential diagnosis and choice of initial empiric therapy. Fever, rash, hypotension, thrombocytopenia and mild derangement of liver function tests is seen in a majority of patients. Organ failure may lead to shock, respiratory distress, renal failure, hepatitis, coma, seizures, cardiac arrhythmias or hemorrhage. Diagnosis in some conditions is made by peripheral blood smear examination, antigen detection or detection of microbial nucleic acid by PCR. Tests that detect specific IgM antibody become positive only in the second week of illness. Initial therapy is often empiric; a combination of intravenous artesunate, ceftriaxone and either doxycycline or azithromycin would cover a majority of the treatable syndromes. Additional antiviral or antiprotozoal medications are required for some specific syndromes. Involving a physician specializing in tropical or travel medicine is helpful.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012."

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012".

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Comparison of the spatial QRS-T angle derived from digital ECGs recorded using conventional electrode placement with that derived from Mason-Likar electrode position

BACKGROUND

The spatial QRS-T angle is ideally derived from orthogonal leads. We compared the spatial QRS-T angle derived from orthogonal leads reconstructed from digital 12-lead ECGs and from digital Holter ECGs recorded with the Mason-Likar (M-L) electrode positions.

METHODS AND RESULTS

Orthogonal leads were constructed by the inverse Dower method and used to calculate spatial QRS-T angle by (1) a vector method and (2) a net amplitude method, in 100 volunteers. Spatial QRS-T angles from standard and M-L ECGs differed significantly (57°±18° vs 48°±20° respectively using net amplitude method and 53°±28° vs 48°±23° respectively by vector method; p<0.001). Difference in amplitudes in leads V4-V6 was also observed between Holter and standard ECGs, probably due to a difference in electrical potential at the central terminal.

CONCLUSION

Mean spatial QRS-T angles derived from standard and M-L lead systems differed by 5°-9°. Though statistically significant, these differences may not be clinically significant.

Detecting moxifloxacin-induced QTc prolongation in thorough QT and early clinical phase studies using a highly automated ECG analysis approach

BACKGROUND AND PURPOSE

Exposure-response (ER) modelling (concentration-QTc analysis) is gaining as much acceptance as the traditional by-time analysis of the placebo-adjusted change from baseline in the QTc interval (ΔΔQTcF). It has been postulated that intensive ECG analysis and ER modelling during early-phase drug development could be a cost-effective approach of estimating QT liability of a new drug, in a small number of subjects.

EXPERIMENTAL APPROACH

We used a highly automated analysis of ECGs from 46 subjects from a crossover thorough QT/QTc study to detect ΔΔQTcF with moxifloxacin. Using these data, we also simulated (bootstrapped) 1000 datasets of a parallel study with eight subjects receiving moxifloxacin and eight others receiving placebo.

KEY RESULTS

The slope from the concentration-QTc analysis for moxifloxacin in 46 subjects was 4.12 ms of ΔΔQTcF per μg(-1) mL(-1) ; at mean Cmax of 2.95 μg·mL(-1) , estimated ΔΔQTcF was 13.4 ms (90% confidence interval 11.3, 15.4 ms). In the 1000 simulated datasets, in 996 datasets, ER modelling showed that the upper bound of the 90% confidence interval for ΔΔQTcF at geometric mean Cmax exceeded 10 ms. In 895 of these 996 datasets, the slope of the ER relationship was statistically significantly positive. Thus, with a small sample size (eight subjects on active drug and eight on placebo), moxifloxacin-induced QTc prolongation was demonstrated using ER analysis with statistical power of >80%.

CONCLUSIONS AND IMPLICATIONS

Our study adds to the growing body of data supporting intensive ECG collection and analysis in early-phase studies to estimate QT liability.

Critical Illness in Pregnancy: Part II: Common Medical Conditions Complicating Pregnancy and Puerperium

The first of this two-part series on critical illness in pregnancy dealt with obstetric disorders. In Part II, medical conditions that commonly affect pregnant women or worsen during pregnancy are discussed. ARDS occurs more frequently in pregnancy. Strategies commonly used in nonpregnant patients, including permissive hypercapnia, limits for plateau pressure, and prone positioning, may not be acceptable, especially in late pregnancy. Genital tract infections unique to pregnancy include chorioamnionitis, group A streptococcal infection causing toxic shock syndrome, and polymicrobial infection with streptococci, staphylococci, and Clostridium perfringens causing necrotizing vulvitis or fasciitis. Pregnancy predisposes to VTE; D-dimer levels have low specificity in pregnancy. A ventilation-perfusion scan is preferred over CT pulmonary angiography in some situations to reduce radiation to the mother's breasts. Low-molecular-weight or unfractionated heparins form the mainstay of treatment; vitamin K antagonists, oral factor Xa inhibitors, and direct thrombin inhibitors are not recommended in pregnancy. The physiologic hyperdynamic circulation in pregnancy worsens many cardiovascular disorders. It increases risk of pulmonary edema or arrhythmias in mitral stenosis, heart failure in pulmonary hypertension or aortic stenosis, aortic dissection in Marfan syndrome, or valve thrombosis in mechanical heart valves. Common neurologic problems in pregnancy include seizures, altered mental status, visual symptoms, and strokes. Other common conditions discussed are aspiration of gastric contents, OSA, thyroid disorders, diabetic ketoacidosis, and cardiopulmonary arrest in pregnancy. Studies confined to pregnant women are available for only a few of these conditions. We have, therefore, reviewed pregnancy-specific adjustments in the management of these disorders.

Are women more susceptible than men to drug-induced QT prolongation? Concentration-QTc modelling in a phase 1 study with oral rac-sotalol

AIM

To study the differences in QTc interval on ECG in response to a single oral dose of rac-sotalol in men and women.

METHODS

Continuous 12-lead ECGs were recorded in 28 men and 11 women on a separate baseline day and following a single oral dose of 160 mg rac-sotalol on the following day. ECGs were extracted at prespecified time points and upsampled to 1000 Hz and analyzed manually in a central ECG laboratory on the superimposed median beat. Concentration-QTc analyses were performed using a linear mixed effects model.

RESULTS

Rac-sotalol produced a significant reduction in heart rate in men and in women. An individual correction method (QTc I) most effectively removed the heart rate dependency of the QTc interval. Mean QTc I was 10 to 15 ms longer in women at all time points on the baseline day. Rac-sotalol significantly prolonged QTc I in both genders. The largest mean change in QTc I (ΔQTc I) was greater in females (68 ms (95% confidence interval (CI) 59, 76 ms) vs. 27 ms (95% CI 22, 32 ms) in males). Peak rac-sotalol plasma concentration was higher in women than in men (mean Cmax 1.8 μg ml(-1) (range 1.1-2.8) vs. 1.4 μg ml(-1) (range 0.9-1.9), P = 0.0009). The slope of the concentration-ΔQTc I relationship was steeper in women (30 ms per μg ml(-1) vs. 23 ms per μg ml(-1) in men; P = 0.0135).

CONCLUSIONS

The study provides evidence for a greater intrinsic sensitivity to rac-sotalol in women than in men for drug-induced delay in cardiac repolarization.

Intravenous administration of ulinastatin (human urinary trypsin inhibitor) in severe sepsis: a multicenter randomized controlled study

Purpose

Ulinastatin, a serine protease inhibitor, inhibits several pro-inflammatory proteases and decreases inflammatory cytokine levels and mortality in experimental sepsis. We studied the effect of ulinastatin on 28-day all-cause mortality in a double-blind trial in patients with severe sepsis in seven Indian hospitals.

Methods

Patients with sepsis were randomized within 48 h of onset of one or more organ failures to receive intravenous administration of ulinastatin (200,000 IU) or placebo 12 hourly for 5 days.

Results

Of 122 randomized subjects, 114 completed the study (55 receiving ulinastatin, 59 receiving placebo). At baseline, the mean APACHE II score was 13.4 (SD = 4.4), 48 (42 %) patients were receiving mechanical ventilation, 58 (51 %) were on vasopressors, and 35 % had multiple organ failure. In the modified intention-to-treat analysis (patients receiving six or more doses of study drugs), 28-day all-cause mortality was 7.3 % with ulinastatin (4 deaths) versus 20.3 % (12 deaths) with placebo (p = 0.045). On multivariate analysis too, treatment with ulinastatin (odds ratio 0.26, 95 % CI 0.07–0.95; p = 0.042) independently decreased 28-day all-cause mortality. However, the mortality difference did not reach statistical significance in the intention-to-treat analysis [10.2 % (6/59 deaths) with ulinastatin versus 20.6 % (13/63 deaths) in the placebo group; p = 0.11]. The ulinastatin group had lower incidence of new-onset organ failure (10 vs. 26 patients, p = 0.003), more ventilator-free days (mean ± SD 19.4 ± 10.6 days vs. 10.2 ± 12.5 days, p = 0.019), and shorter hospital stay (11.8 ± 7.1 days vs. 24.2 ± 7.2 days, p < 0.001).

Conclusions

In this pilot study, intravenous administration of ulinastatin reduced mortality in patients with severe sepsis in the modified intention-to-treat analysis, but not in the intention-to-treat analysis.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-014-3278-8) contains supplementary material, which is available to authorized users.

Comparison of two methods of estimating reader variability in QT interval measurements in thorough QT/QTc studies

BACKGROUND

Two methods of estimating reader variability (RV) in QT measurements between 12 readers were compared.

METHODS

Using data from 500 electrocardiograms (ECGs) analyzed twice by 12 readers, we bootstrapped 1000 datasets each for both methods. In grouped analysis design (GAD), the same 40 ECGs were read twice by all readers. In pairwise analysis design (PAD), 40 ECGs analyzed by each reader in a clinical trial were reanalyzed by the same reader (intra-RV) and also by another reader (inter-RV); thus, variability between each pair of readers was estimated using different ECGs.

RESULTS

Inter-RV (mean [95% CI]) between pairs of readers by GAD and PAD was 3.9 ms (2.1-5.5 ms) and 4.1 ms (2.6-5.4 ms), respectively, using ANOVA, 0 ms (-0.0 to 0.4 ms), and 0 ms (-0.7 to 0.6 ms), respectively, by actual difference between readers and 7.7 ms (6.2-9.8 ms) and 7.7 ms (6.6-9.1 ms), respectively, by absolute difference between readers. Intra-RV too was comparable.

CONCLUSIONS

RV estimates by the grouped- and pairwise analysis designs are comparable.

Reader variability in QT measurement due to measurement error and variability in leads selection: a simulation study comparing 2-way vs. 3-way interaction ANOVA model

Reader variability (RV) results from measurement differences or variability in lead used for QT measurements; the latter is not reflected in conventional methods for estimating RV. Mean and SD of QT intervals in 12 leads of 100 ECGs measured twice were used to simulate data sets with inter-RV of 5, 10, 15, 20, and 25 ms and intra-RV of 3, 6, 9, 12, and 15 ms. Six hundred twenty-five data sets were simulated such that different leads were used in Read1 and Read2 in 0, 10%, 20%, 30%, 40% of ECGs by 25 readers. RV was estimated using ANOVA interaction models: three-way model using Reader, ECG and lead as factors, and 2-way model using reader and ECG as factors. Estimates from three-way model accurately matched inter- and intra-RV that were introduced during simulation regardless of percent of ECGs with lead selection variability. The two-way model provides identical estimates when both reads are in same leads, but higher, more realistically estimates when measurements are made in different leads.

Morphological abnormalities in baseline ECGs in healthy normal volunteers participating in phase I studies

BACKGROUND & OBJECTIVES

Morphological abnormalities in 12-lead electrocardiograms (ECGs) are seen in subgroups of healthy individuals like athletes and air-force personnel. As these populations may not truly represent healthy individuals, we assessed morphological abnormalities in ECG in healthy volunteers participating in phase I studies, who are screened to exclude associated conditions.

METHODS

ECGs from 62 phase I studies analyzed in a central ECG laboratory were pooled. A single drug-free baseline ECG from each subject was reviewed by experienced cardiologists. ECG intervals were measured on five consecutive beats and morphological abnormalities identified using standard guidelines.

RESULTS

Morphological abnormalities were detected in 25.5 per cent of 3978 healthy volunteers (2495 males, 1483 females; aged 18-76 yr); the presence was higher in males (29.3% vs. 19.2% in females; P<0.001). Rhythm abnormalities were the commonest (11.5%) followed by conduction abnormalities (5.9%), axis deviation (4%), ST-T wave changes (3.1%) and chamber enlargement (1.4%). Incomplete right bundle branch block (RBBB), short PR interval and right ventricular hypertrophy were common in young subjects (<20 yr) while atrial fibrillation, first degree atrioventricular block, complete RBBB and left anterior fascicular block were more prevalent in elderly subjects (>65 yr). Prolonged PR interval, RBBB and intraventricular conduction defects were more common in males while sinus tachycardia, short PR interval and non-specific T wave changes were more frequent in females.

INTERPRETATION & CONCLUSIONS

Morphological abnormalities in ECG are commonly seen in healthy volunteers participating in phase I studies; and vary with age and gender. Further studies are required to determine whether these abnormalities persist or if some of these disappear on follow up.

Semiautomated QT interval measurement in electrocardiograms from a thorough QT study: comparison of the grouped and ungrouped superimposed median beat methods

INTRODUCTION

We postulated that it may be easier to identify earliest Q onset and latest T offset when the median beats from 12 leads are separated vertically by 5 to 10 mm (ungrouped superimposed median beat [SMB] method) rather than when their baselines closely (but rarely perfectly) overlap (grouped SMB method).

METHODS

Three readers manually adjudicated annotations placed by an automated algorithm, using grouped (gSMB) and ungrouped (uSMB) methods in 2658 electrocardiograms (ECGs) recorded in 38 subjects in a crossover design thorough QT study at predose and 6 time points postdosing with placebo or moxifloxacin.

RESULTS

Placebo-subtracted, moxifloxacin-induced QTcF prolongation was comparable with both methods. Maximum QTcF prolongation was seen at 2 hours--10.5 milliseconds (90% confidence interval, 7.9-13.1 milliseconds) with gSMB and 12.9 milliseconds (90% confidence interval, 9.9-15.8 milliseconds) by uSMB. Both methods showed good agreement; mean QT was 4 milliseconds greater by uSMB. Interreader variability of absolute differences in QT measurements was 1 millisecond lower with the uSMB method (6.8 ± 5.7 milliseconds by gSMB and 5.9 ± 4.5 milliseconds by uSMB).

CONCLUSION

Mean QT was 4 milliseconds longer, and interreader variability, 1 millisecond lower with uSMB. Otherwise, both methods were comparable and detected the moxifloxacin effect.

Cardiovascular risk of oral antidiabetic drugs: current evidence and regulatory requirements for new drugs

BACKGROUND

Better control of diabetes mellitus reduces microvascular complications, but has limited effect on macrovascular complications including cardiovascular mortality. A spate of controversial reports has shown that some new oral antidiabetic drugs may paradoxically increase cardiovascular events and mortality. We review here published data on cardiac safety of currently available oral antidiabetic drugs.

METHODS

Literature search was performed for "cardiovascular risk" and "antidiabetic drugs" or individual oral antidiabetic drugs.

RESULTS

Some sulfonylureas increase cardiovascular risk presumably by preventing protective ischemic cardiac preconditioning. Rosiglitazone increases risk of myocardial infarction and death possibly by increasing serum triglycerides and LDL-cholesterol levels. Muraglitazar increased risk of cardiovascular death, myocardial infarction, or stroke due to as yet unidentified reasons. Only insulin sensitizing drugs like metformin and pioglitazone have been consistently shown to reduce cardiovascular risk. Beneficial effects of tight glucose control with insulin or insulin secretagogues on macrovascular complications are inconsistent; their benefits may be negated by increased risk of hypoglycemia which in turn increases adverse cardiovascular events. Increased cardiovascular risk of some antidiabetic drugs was missed during drug development and detected only on meta-analysis of clinical trial data. Regulatory agencies in North America and Europe have therefore proposed stringent guidelines for study design, data analysis and quantification of cardiovascular risk of new antidiabetic drugs.

CONCLUSIONS

Physicians should weigh the cardiovascular risk against potential benefits when prescribing antidiabetic medications. The proposed regulatory measures will ensure approval of safer drugs, but may also lengthen the drug development cycle or even deter development of potentially useful drugs.

Comparison of anxiety, depression, and post-traumatic stress symptoms in relatives of ICU patients in an American and an Indian public hospital

Context:

An intensive care unit (ICU) admission of a patient causes considerable stress among relatives. Whether this impact differs among populations with differing sociocultural factors is unknown.

Aims:

The aim was to compare the psychological impact of an ICU admission on relatives of patients in an American and Indian public hospital.

Settings and Design:

A cross-sectional study was carried out in ICUs of two tertiary care hospitals, one each in major metropolitan cities in the USA and India.

Materials and Methods:

A total of 90 relatives visiting patients were verbally administered a questionnaire between 48 hours and 72 hours of ICU admission that included the Hospital Anxiety and Depression Scale (HADS), Beck Depression Inventory-II (BDI-II) and Impact of Events Scale-Revised (IES-R) for post-traumatic stress response.

Statistical Analysis:

Statistical analysis was done using the Mann-Whitney and chi-square tests.

Results:

Relatives in the Indian ICU had more anxiety symptoms (median HADS-A score 11 [inter-quartile range 9-13] vs. 4 [1.5-6] in the American cohort; P<0.0001), more depression symptoms (BDI-II score 14 [8.5-19] vs. 6 [1.5-10.5], P<0.0001) but a comparable post-traumatic stress response (IES-R score>30). 55% of all relatives had an incongruous perception regarding “change in the patient's condition” compared to the objective change in severity of illness. “Change in worry” was incongruous compared to the perception of improvement of the patient's condition in 78% of relatives.

Conclusions:

Relatives of patients in the Indian ICU had greater anxiety and depression symptoms compared to those in the American cohort, and had significant differences in factors that may be associated with this psychological impact. Both groups showed substantial discordance between the perceived and objective change in severity of illness.

Comparison of 5 methods of QT interval measurements on electrocardiograms from a thorough QT/QTc study: effect on assay sensitivity and categorical outliers

INTRODUCTION

We studied moxifloxacin-induced QT prolongation and proportion of categorical QTc outliers when 5 methods of QT measurement were used to analyze electrocardiograms (ECGs) from a thorough QT study.

METHODS

QT interval was measured by the threshold, tangent, superimposed median beat, automated global median beat, and longest QT methods in a central ECG laboratory in 2730 digital ECGs from 39 subjects during placebo and moxifloxacin treatment.

RESULTS

All 5 methods were able to demonstrate statistically significant moxifloxacin-induced QTcF prolongation. However, lower bound of 95% 1-sided confidence interval of QTcF prolongation did not exceed 5 milliseconds with the longest QT method. More QTcF outliers were observed with the longest QT and tangent methods, whereas the other 3 methods were comparable. QTcF values greater than 500 milliseconds were observed only with moxifloxacin by the tangent method, and with moxifloxacin and placebo by the longest QT method.

CONCLUSION

The method of QT measurement must be considered when interpreting individual thorough QT/QTc studies.

Limb lead interchange in thorough QT/QTc studies

The investigators analyzed 85,133 electrocardiograms (ECGs) recorded in 484 subjects from 5 thorough QT/QTc studies (3 using Holter devices, 2 using 12-lead ECGs) for inadvertent limb lead interchanges using a dedicated quality control process in a central ECG laboratory. Limb lead interchanges were present in 2919 (3.4%) ECGs in 17.9% of subjects and were more frequent with Holter devices (7.5% vs 0.8%, P < .0001), where leads remain connected for prolonged periods, affecting data from several time points. Left arm-left leg interchange was seen in 54% of 12-lead ECGs and right arm-left arm interchange in 38%. The ECG device itself could identify 21.7% of interchanges, whereas experienced readers blinded to subject and visit identified 79% of interchanges; 21% of interchanges were identified only during the quality control process. If correctly identified, QT measurement could be performed in a precordial lead. If undiagnosed, incorrect QT interval measurements and morphological diagnosis may confound results.

Effect of number of replicate electrocardiograms recorded at each time point in a thorough QT study on sample size and study cost

In a "thorough QT/QTc" (TQT) study, several replicate electrocardiograms (ECGs) are recorded at each time point to reduce within-subject variability. This decreases the sample size but increases the cost of ECG analysis. To determine the most cost-effective number of ECG replicates, the authors retrospectively analyzed data from the placebo and moxifloxacin arms of a TQT study with crossover design. Six replicate ECGs were recorded at 7 time points on day -1 (baseline day), day 1, and day 3 in 124 normal healthy volunteers who were randomized to receive moxifloxacin or placebo on day 1 and the other treatment on day 3. QT interval was corrected for heart rate by the Fridericia (QTcF) and individual subject-specific (QTcI) formulas. Within-subject and between-subject standard deviations for QTcF obtained by repeated-measures analysis of covariance were 9.5 and 13.3 milliseconds with 1 replicate; 7.8 and 12.7 milliseconds with 2 replicates; 7.3 and 12.3 milliseconds with 3 replicates; 6.9 and 12.2 milliseconds with 4 replicates; 6.8 and 11.9 milliseconds with 5 replicates; and 6.6 and 11.8 milliseconds with 6 replicates. Within- and between-subject variance with QTcI also declined with increasing replicates. Sample size benefit based on these estimates was negligible beyond 4 replicates. The study cost was least with 3 or 4 replicates, depending on per-ECG and per-subject costs.

Update on the evaluation of a new drug for effects on cardiac repolarization in humans: issues in early drug development

Following reports of death from cardiac arrhythmias with drugs like terfenadine and cisapride, the International Conference for Harmonization formulated a guidance (E14) document. This specifies that all new drugs must undergo a 'thorough QT/QTc' (TQT) study to detect drug-induced QT prolongation, a surrogate marker of ventricular tachycardia, especially torsades de pointes (TdPs). With better understanding of data from several completed TQT studies, regulatory requirements have undergone some changes since the E14 guidance was implemented in October 2005. This article reviews the implications of the E14 guidance and the changes in its interpretation including choice of baseline QT, demonstration of assay sensitivity, statistical analysis of the effect of new drug and positive control, and PK-PD modelling. Some issues like use of automated QT measurements remain unresolved. Pharmaceutical companies too are modifying Phase 1 studies to detect QTc liability early in order to save time and resources. After the E14 guidance, development of several drugs that prolong QTc by >5 ms is being abandoned by sponsors. However, all drugs that prolong the QT interval do not increase risk of TdP. Researchers in regulatory agencies, academia and industry are working to find better biomarkers of drug-induced TdP which could prevent many useful drugs from being prematurely abandoned. Drug-induced TdP is a rare occurrence. With fewer drugs that prolong QT interval reaching the licensing stage, knowing which of these drugs are torsadogenic is proving to be elusive. Thus, paradoxically, the effectiveness of the E14 guidance itself has made prospective validation of new biomarkers difficult.

Oropharyngeal cleansing with 0.2% chlorhexidine for prevention of nosocomial pneumonia in critically ill patients: an open-label randomized trial with 0.01% potassium permanganate as control

BACKGROUND

Oral cleansing with chlorhexidine decreases the incidence of nosocomial pneumonia in patients after cardiac surgery. However, evidence of its benefit in ICU patients is conflicting.

METHODS

Patients admitted to the ICU of an Indian tertiary care teaching hospital were randomized to twice-daily oropharyngeal cleansing with 0.2% chlorhexidine or 0.01% potassium permanganate (control) solution. Effects on the incidence of nosocomial pneumonia during ICU stay (primary outcome) and length of ICU stay and in-hospital mortality (secondary outcomes) were studied.

RESULTS

Five hundred twelve patients were randomized to either the chlorhexidine group (n = 250) or the control group (n = 262). Of the 471 subjects who completed the protocol, nosocomial pneumonia developed in 16 of 224 subjects (7.1%) in the chlorhexidine group and 19 of 247 subjects (7.7%) in the control group (p = 0.82; relative risk, 0.93; 95% confidence interval, 0.49 to 1.76); intention-to-treat analysis of 21 patients in whom the cleansing protocol was not followed revealed similar results. There was no significant difference between the study and control groups in the median day of development of pneumonia (5.0 days: interquartile range [IQR], 3.0 to 7.7 vs 5.0 days: IQR, 3.0 to 6.0, respectively), median ICU stay (5.0 days: IQR, 3.0 to 8.0 vs 6.0 days: IQR, 3.0 to 8.0, respectively), and mortality (34.8% vs 28.3%, respectively). On subgroup analysis, there was no significant difference in the primary and secondary outcomes in patients on mechanical ventilation, tracheal intubation, and coma (Glasgow coma scale <or= 8). During the study period, nosocomial pneumonia developed in fewer subjects (35 of 471 subjects [7.4%]) than in the 3 months preceding and following the study (98 of 452 subjects [21.7%]; p < 0.001; relative risk, 0.34; 95% confidence interval, 0.24 to 0.49).

CONCLUSIONS

Oropharyngeal cleansing with 0.2% chlorhexidine solution was not superior to oral cleansing with the control solution. However, the decreased incidence of nosocomial pneumonia during the study period suggests a possible benefit of meticulous oral hygiene in ICU patients.

Z-score for benchmarking reader competence in a central ECG laboratory

BACKGROUND

ECGs from thorough QT studies must be read in a central laboratory by trained experts. Standards of expertise are not presently defined. We, therefore, studied the use of Z-scores to define reader competence.

METHODS

Two hundred ECGs were read by 24 experts and the mean and standard deviation (SD) of QT measurements calculated for each ECG. Z-scores ([QT(reader)- mean QT(experts)]/ SD(experts)) for each ECG and mean of absolute Z-scores of all ECGs read by a reader were calculated. The highest mean absolute Z-score of experts was considered the cutoff to define competence. Hundred of these standardized ECGs were used to assess performance of readers from the central laboratory.

RESULTS

All experts had mean absolute Z-scores < or = 1.5. Using this cutoff, one of 28 experienced readers and 7 of 15 trainees had unacceptable Z-scores. After re-training, all achieved Z-scores <1.5. Comparing histograms of actual Z-scores of the 100 ECGs of readers with unacceptable scores with that of the reader with the best Z-score showed two patterns. Readers with histograms having a peak and tails similar to that of the best reader, but with leftward or rightward shift, consistently made shorter or longer QT measurements, respectively. A histogram with a flatter peak and wider tails, suggested that measurements were long in some ECGs and short in others.

CONCLUSION

Mean absolute Z-score is useful to assess competence for measuring the QT interval on ECGs. Analysis of histograms can pinpoint problems in QT measurements.

Differences between QT and RR intervals in digital and digitized paper electrocardiograms: contribution of the printer, scanner, and digitization process

BACKGROUND

Prints of electrocardiograms (ECGs) are often sent to core laboratories, where they are scanned, converted to a digital format, and read on-screen. These ECGs may differ from the original ECG because of variability introduced by the printer, scanner, or digitization software.

METHODS

Digital ECGs were recorded in 50 volunteers simultaneously using electrocardiographs from 2 different manufacturers. QT and RR intervals were measured on-screen on the digitized ECGs. To study the contribution of individual steps in the digitization process, differences in RR interval between 2 prints each of 50 digital ECGs, 2 scanned files of 50 prints, 2 digitized files from 50 scanned files, and 2 readings of 50 digitized ECGs (intrareader variability) were analyzed.

RESULTS

Repeatability coefficient for RR interval measurement was 18.5 milliseconds for machine 1 and 21 milliseconds for machine 2. Contributions of the printer were 6.5 milliseconds for machine 1 and 9.0 milliseconds for machine 2, digitization process was 5.5 milliseconds, and reader variability was 8.0 milliseconds. Variability of the scanner was negligible.

CONCLUSIONS

The printer and digitization process account for significant differences in interval measurements in digitized ECGs.

A pilot study of the association of pharmacokinetic and pharmacodynamic parameters of warfarin with the dose in patients on long-term anticoagulation

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Warfarin is a widely used anticoagulant with a low therapeutic index. There is wide interindividual variation in the pharmacokinetics and pharmacodynamics of warfarin which is also reflected in the warfarin dose requirement. CYP2C9 and VKORC1 polymorphisms have been shown to affect warfarin dose requirement. However a large amount of the variation in warfarin dose remains unaccounted for.

WHAT THIS STUDY ADDS

Our findings suggest that in patients who are on long-term warfarin therapy, INR : plasma 7-hydroxywarfarin concentration correlates well with warfarin requirement and also accounts for a large amount of variation in warfarin dose.

AIMS

To assess the correlation between plasma total warfarin concentration, plasma 7-hydroxywarfarin concentration and INR and the weekly doses of warfarin in patients on long-term anticoagulation.

METHODS

Twenty-five patients on long-term anticoagulation with warfarin were studied. Plasma total warfarin and 7-hydroxywarfarin concentrations and INR were determined. Equations were derived with the weekly warfarin dose as the dependent variable and plasma total warfarin concentration : plasma 7-hydroxywarfarin concentration, INR : plasma total warfarin concentration and INR : plasma 7-hydroxywarfarin concentration as independent variables.

RESULTS

There was a good correlation between INR : plasma total warfarin concentration and the weekly dose of warfarin (y = 46.73e(-0.30x), r(2) = 0.65). There was a better correlation between INR : plasma 7-hydroxywarfarin concentration and the weekly dose of warfarin (y = 156.52x(-0.63), r(2) = 0.74)

CONCLUSIONS

Pharmacokinetic parameters along with INR seem to correlate with the weekly doses of warfarin in patients on long-term anticoagulation. These parameters may therefore be useful for predicting warfarin doses.

Captopril in the treatment of cardiovascular manifestations of indian red scorpion (Mesobuthus tamulus concanesis Pocock) envenomation

OBJECTIVES

To study outcome of patients with scorpion envenomation treated with oral captopril in the ICU of a Tertiary Care, University Hospital in Mumbai.

METHODS

Retrospective analysis of all patients with scorpion sting admitted to Medical Intensive Care Unit of a tertiary care university hospital in Mumbai between 1993 and 2003.

RESULTS

Of 38 patients with cardiovascular manifestations, six had tachycardia alone and 8 had hypertension; these patients received oral captopril 12.5-25 mg thrice daily with no deaths. Pulmonary oedema with normal blood pressure and high central venous pressure (CVP) was seen in 10 patients. Five patients had hypotension, low CVP but no pulmonary oedema; with fluid infusion, these patients had correction of low CVP and hypotension, but developed pulmonary oedema. Pulmonary oedema resolved in all 15 patients with captopril (6.25-25 mg thrice daily): one patient died of ventricular tachycardia. Nine patients had cardiogenic shock; 6 patients, whose blood pressure improved with dopamine received, captopril; 1 of these 6 died. The other three patients did not respond to maximum vasopressor therapy and could not be given captopril; all three died. Four of the 5 deaths occurred in patients weighing < 25 kg suggesting that severity of cardiovascvlar manifestations also depends on body weight of the victim.

CONCLUSION

Afterload reduction with oral captopril is safe and effective in scorpion envenomation with cardiovascular manifestations. Results are similar to those with other vasodilators.

Heparin or local thrombolysis in the management of cerebral venous sinus thrombosis?

SUMMARY

Patients with acute cerebral venous sinus thrombosis treated with Heparin or in situ thrombolysis in our department were evaluated in an attempt to rationalize treatment with heparin or thrombolysis. 279 patients with angiographically proven acute cerebral venous sinus thrombosis were included in the study. Patients were classified into mild and severe clinical grade. The study was divided into three phases. Phase I included 27 patients treated with systemic heparin. Phase II included 72 patients, 30 in severe grade and 42 in mild. 26 were thrombolysed with 14 in severe and 12 in mild grade. Phase III included 180 patients treated according to a defined protocol. 133 were in mild grade and 47 in severe. 67 patients were thrombolysed. In the thrombolysed group 27 patients were in mild grade and 40 in severe. 113 patients were treated with systemic heparin. Following acute management all were anticoagulated for six months. The baseline characteristics were found to be same in all three phases. On comparison of outcome in Phase III with Phase 1 the likelihood ratio was found to be statistically significant in favor of Phase III (p<0.0001). The likelihood ratio was found to be statistically significant in mild and severe clinical grade in favor of thrombolysis in Phase III (p 0.039 in mild and p 0.00001 in Severe clinical grade). This ratio was insignificant (p=0.716) for intracranial bleed; however, local puncture site bleeding was found to be significant in the thrombolysed group (0.00005).

Tropical infections in the ICU

Certain arthropod-borne infections are common in tropical regions because of favorable climatic conditions. Water-borne infections like leptospirosis are common due to contamination of water especially during the monsoon floods. Infections like malaria, leptospirosis, dengue fever and typhus sometimes cause life threatening organ dysfunction and have several overlapping features. Most patients present with classicial clinical syndromes: fever and thrombocytopenia are common in dengue, malaria and leptospirosis; coagulopathy is frequent in leptospirosis and viral hepatitis. Hepatorenal syndrome is seen in leptospirosis, falciparum malaria and scrub typhus. The pulmonary renal syndrome is caused by falciparium malaria, leptospirosis, Hantavirus infection and scrub typhus. Fever with altered mental status is produced by bacterial meningitis, Japanese B encephalitis, cerebral malarial, typhoid encephalopathy and fulminant hepatic failure due to viral hepatitis. Subtle differences in features of the organ failure exist among these infections. The diagnosis in some of these diseases is made by demonstration of antibodies in serum, and these may be negative in the first week of the illness. Hence empiric therapy for more than one disorder may be justified in a small proportion of cases. In addition to specific anti-infective therapy, management of organ dysfunction includes use of mechanical ventilation, vasopressor drugs, continuous renal replacement therapy and blood products. Timely transfer of these patients to well-equipped ICUs with experience in managing these cases can considerably decrease mortality and morbidity.