Evidence for three genetic loci involved in both anorexia nervosa risk and variation of body mass index

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single-nucleotide polymorphisms (SNPs) with the lowest P-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI-related loci was performed in the AN GWAMA. We detected significant associations (P-values <5 × 10-5, Bonferroni-corrected P<0.05) for nine SNP alleles at three independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; Poverall: 2.47 × 10-06/Pfemales: 3.45 × 10-07/Pmales: 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet-induced obese (DIO) mice as compared with age-matched lean controls. We observed no evidence for associations for the look-up of BMI-related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation.

Dysregulation of soluble epoxide hydrolase and lipidomic profiles in anorexia nervosa

Individuals with anorexia nervosa (AN) restrict eating and become emaciated. They tend to have an aversion to foods rich in fat. Because epoxide hydrolase 2 (EPHX2) was identified as a novel AN susceptibility gene, and because its protein product, soluble epoxide hydrolase (sEH), converts bioactive epoxides of polyunsaturated fatty acid (PUFA) to the corresponding diols, lipidomic and metabolomic targets of EPHX2 were assessed to evaluate the biological functions of EPHX2 and their role in AN. Epoxide substrates of sEH and associated oxylipins were measured in ill AN, recovered AN and gender- and race-matched controls. PUFA and oxylipin markers were tested as potential biomarkers for AN. Oxylipin ratios were calculated as proxy markers of in vivo sEH activity. Several free- and total PUFAs were associated with AN diagnosis and with AN recovery. AN displayed elevated n-3 PUFAs and may differ from controls in PUFA elongation and desaturation processes. Cytochrome P450 pathway oxylipins from arachidonic acid, linoleic acid, alpha-linolenic acid and docosahexaenoic acid PUFAs are associated with AN diagnosis. The diol:epoxide ratios suggest the sEH activity is higher in AN compared with controls. Multivariate analysis illustrates normalization of lipidomic profiles in recovered ANs. EPHX2 influences AN risk through in vivo interaction with dietary PUFAs. PUFA composition and concentrations as well as sEH activity may contribute to the pathogenesis and prognosis of AN. Our data support the involvement of EPHX2-associated lipidomic and oxylipin dysregulations in AN, and reveal their potential as biomarkers to assess responsiveness to future intervention or treatment.

Evidence for the role of EPHX2 gene variants in anorexia nervosa

Anorexia nervosa (AN) and related eating disorders are complex, multifactorial neuropsychiatric conditions with likely rare and common genetic and environmental determinants. To identify genetic variants associated with AN, we pursued a series of sequencing and genotyping studies focusing on the coding regions and upstream sequence of 152 candidate genes in a total of 1205 AN cases and 1948 controls. We identified individual variant associations in the Estrogen Receptor-ß (ESR2) gene, as well as a set of rare and common variants in the Epoxide Hydrolase 2 (EPHX2) gene, in an initial sequencing study of 261 early-onset severe AN cases and 73 controls (P=0.0004). The association of EPHX2 variants was further delineated in: (1) a pooling-based replication study involving an additional 500 AN patients and 500 controls (replication set P=0.00000016); (2) single-locus studies in a cohort of 386 previously genotyped broadly defined AN cases and 295 female population controls from the Bogalusa Heart Study (BHS) and a cohort of 58 individuals with self-reported eating disturbances and 851 controls (combined smallest single locus P<0.01). As EPHX2 is known to influence cholesterol metabolism, and AN is often associated with elevated cholesterol levels, we also investigated the association of EPHX2 variants and longitudinal body mass index (BMI) and cholesterol in BHS female and male subjects (N=229) and found evidence for a modifying effect of a subset of variants on the relationship between cholesterol and BMI (P<0.01). These findings suggest a novel association of gene variants within EPHX2 to susceptibility to AN and provide a foundation for future study of this important yet poorly understood condition.

A genome-wide association study on common SNPs and rare CNVs in anorexia nervosa

Anorexia nervosa (AN) is a mental illness with high mortality that most commonly afflicts adolescent female individuals. Clinical symptoms include chronic food refusal, weight loss and body image distortions. We carried out a genome-wide association study on 1033 AN cases and 3733 pediatric control subjects, all of whom were of European ancestry and were genotyped on the Illumina HumanHap610 platform (Illumina, San Diego, CA, USA). We confirmed that common single-nucleotide polymorphisms (SNPs) within OPRD1 (rs533123, P=0.0015) confer risk for AN, and obtained suggestive evidence that common SNPs near HTR1D (rs7532266, P=0.04) confer risk for restricting-type AN specifically. However, no SNPs reached genome-wide significance in our data, whereas top association signals were detected near ZNF804B, CSRP2BP, NTNG1, AKAP6 and CDH9. In parallel, we performed genome-wide analysis on copy number variations (CNVs) using the signal intensity data from the SNP arrays. We did not find evidence that AN cases have more CNVs than control subjects, nor do they have over-representation of rare or large CNVs. However, we identified several regions with rare CNVs that were only observed in AN cases, including a recurrent 13q12 deletion (1.5 Mb) disrupting SCAS in two cases, and CNVs disrupting the CNTN6/CNTN4 region in several AN cases. In conclusion, our study suggests that both common SNPs and rare CNVs may confer genetic risk to AN. These results point to intriguing genes that await further validation in independent cohorts for confirmatory roles in AN.

Combination therapy for type 2 diabetes: repaglinide plus rosiglitazone

AIMS

This 24-week, randomized, multicentre, open-label, parallel-group clinical trial compared efficacy and safety of repaglinide monotherapy, rosiglitazone monotherapy, and combination therapy (repaglinide plus rosiglitazone) in Type 2 diabetes after unsatisfactory response to sulphonylurea or metformin monotherapy.

METHODS

Enrolled patients (n = 252) were adults having Type 2 diabetes for at least 1 year, with HbA(1c) values > 7.0% after previous monotherapy (sulphonylurea or metformin, >/= 50% maximal dose). Prior therapy was withdrawn for 2 weeks, followed by randomization to repaglinide, rosiglitazone, or repaglinide/rosiglitazone. Study treatments were initiated with a 12-week dose optimization period (doses optimized according to labelling), followed by a 12-week maintenance period. Efficacy endpoints were changes in HbA(1c) values (primary) or fasting plasma glucose values (secondary).

RESULTS

Baseline HbA(1c) values were comparable (9.3% for repaglinide, 9.0% for rosiglitazone, 9.1% for combination). Mean changes in HbA(1c) values at the end of treatment were greater for repaglinide/rosiglitazone therapy (-1.43%) than for repaglinide (-0.17%) or rosiglitazone (-0.56%) monotherapy. Reductions of fasting plasma glucose values were also greater for combination therapy (-5.2 mmol/l, -94 mg/dl) than for repaglinide monotherapy (-3.0 mmol/l, -54 mg/dl) or rosiglitazone monotherapy (-3.7 mmol/l, -67 mg/dl). Minor hypoglycaemic events occurred in 9% of combination therapy patients, vs. 6% for repaglinide and 2% for rosiglitazone. Individual weight gains for combination therapy were correlated to HbA(1c) response.

CONCLUSIONS

The combination therapy regimen was well tolerated. In patients previously showing unsatisfactory response to oral monotherapy, glycaemic reductions were greater for the repaglinide/rosiglitazone combination regimen than for use of either repaglinide or rosiglitazone alone.

Males with anorexia nervosa: a controlled study of eating disorders in first-degree relatives

OBJECTIVE

To compare lifetime rates of full and partial anorexia nervosa and bulimia nervosa in first-degree relatives of males with anorexia nervosa and in relatives of never-ill comparison subjects.

METHODS

Rates of eating disorders were obtained for 747 relatives of 210 probands from personal structured clinical interviews and family history. Best-estimate diagnoses were determined blind to proband diagnosis and pedigree status.

RESULTS

Full and partial syndromes of anorexia nervosa aggregated in female relatives of ill probands. For the full syndrome of anorexia nervosa, the crude relative risk was 20.3 among female relatives and for partial syndrome anorexia nervosa, the crude relative risk was 3.3. In contrast, bulimia nervosa was relatively uncommon among relatives of ill probands.

CONCLUSION

Although anorexia nervosa in males is exceedingly rare, there is a pattern of familial aggregation that is highly similar to that observed in recent family studies of affected females. On the basis of these findings, there is no evidence that familial-genetic factors distinguish the occurrence of anorexia nervosa in the two sexes.

Controlled family study of anorexia nervosa and bulimia nervosa: evidence of shared liability and transmission of partial syndromes

OBJECTIVE

Lifetime rates of full and partial anorexia nervosa and bulimia nervosa were determined in first-degree relatives of diagnostically pure proband groups and relatives of matched, never-ill comparison subjects.

METHOD

Rates of each eating disorder were obtained for 1,831 relatives of 504 probands on the basis of personal structured clinical interviews and family history. Best-estimate diagnoses based on all available information were rendered without knowledge of proband status and pedigree identity. Only definite and probable diagnoses were considered.

RESULTS

Whereas anorexia nervosa was rare in families of the comparison subjects, full and partial syndromes of anorexia nervosa aggregated in female relatives of both anorexic and bulimic probands. For the full syndrome of anorexia nervosa, the relative risks were 11.3 and 12.3 in female relatives of anorexic and bulimic probands, respectively. Bulimia nervosa was more common than anorexia nervosa in female relatives of comparison subjects, but it, too, aggregated in the families of ill probands; the corresponding relative risks for bulimia nervosa were 4.2 and 4.4 for female relatives of anorexic and bulimic probands, respectively. When partial syndromes of anorexia nervosa and bulimia nervosa were considered, relative risks fell by one-half in each group of ill probands.

CONCLUSIONS

Both anorexia nervosa and bulimia nervosa are familial. Their cross-transmission in families suggests a common, or shared, familial diathesis. The additional observation that familial aggregation and cross-transmission extend to milder phenotypes suggests the validity of their inclusion in a continuum of familial liability.

Cardiopulmonary resuscitation performance of subjects over forty is better following half-hour video self-instruction compared to traditional four-hour classroom training

Cardiopulmonary resuscitation (CPR) training is not well targeted to family members of individuals at highest risk of cardiac arrest. Participants in traditional CPR classes (TRAD) average 31 years of age, while family members of cardiac patients average 55 years. Video self-instruction (VSI) can reach older individuals and others who do not participate in TRAD classes. VSI is a combination of a 34-min videotape and an inexpensive manikin intended for use in the home, where three-quarters of all out-of-hospital cardiac arrests occur. We exposed 202 subjects 40 years of age and older (mean age 59.4 years, S.D. = 10.9) to either TRAD or VSI, and tested them individually immediately following training rising validated methods including measurement by means of a Laerdal-Skillmeter manikin. According to American Heart Association (AHA) criteria, VSI subjects performed an average of 20.8% of all compressions and 25.1% of all ventilations correctly, compared with 3.4% of compressions and 1.7% of ventilations by TRAD subjects (P < 0.0001). VSI subjects performed an average of 10.1 of the total 14 CPR assessment and sequence skills correctly, compared with an average of 4.7 for TRAD (P < 0.0001). On a measure of overall performance, 62.7% of the VSI subjects were rated 'competent' or better (i.e. capable of performing CPR that 'would probably be effective'), compared to 6.1% of TRAD subjects (P < 0.0001). Only 17.8% of VSI subjects were rated as 'not competent' (i.e. unable to obtain a combination of any chest rise and any compression of the sternum) compared with 69.1% of TRAD subjects. VSI provides an effective, convenient, and inexpensive means of training persons over 40 years of age that achieves skill performance superior to TRAD.

New directions in treatment research of anorexia and bulimia nervosa

Although considerable progress has been made in the understanding and treatment of anorexia and bulimia nervosa, a substantial proportion of people with these disorders have a limited response to treatment. Treatment strategies used in eating disorders have tended to be adopted from therapies that were devised to treat other psychiatric illnesses. Recent studies suggest that eating disorders are independently transmitted familial liabilities with a unique pathophysiology. These new findings raise the possibility that an improved understanding of the pathogenesis of eating disorders will generate more specific and effective psychotherapies and pharmacologic interventions.

No coding variant of the tryptophan hydroxylase gene detected in seasonal affective disorder, obsessive-compulsive disorder, anorexia nervosa, and alcoholism

BACKGROUND

The goal of this study was to evaluate the role of genetic variation in the coding sequence of tryptophan hydroxylase (TPH) in the pathogenesis of several psychiatric diseases in which altered serotonin function has been implicated: bipolar affective disorder (BP), obsessive-compulsive disorder (OCD), anorexia nervosa (AN), seasonal affective disorder (SAD), panic disorder (PD), and alcoholism (Alc).

METHODS

Ninety-three percent of the TPH coding sequence was screened by polymerase chain reaction single-strand conformation polymorphism (SSCP) for DNA sequence variations in 128 AN, 88 OCD, 72 SAD, 45 PD, and 36 BP patients and 142 normal volunteers. Also included in the screening were 61 Alc randomly selected from a Finnish alcoholic population in which an association of a TPH intron 7 polymorphism with suicidality was previously observed. Polymorphisms detected by SSCP were characterized by DNA sequencing and by allele-specific restriction enzyme digestion. Genotyping was then performed in 34 Finnish alcoholic suicide attempters.

RESULTS

A rare silent mutation was identified in exon 10 and is designated T1095C. The C1095 allele was found in 1 OCD and in 2 AN subjects; all 3 individuals were heterozygous (C1095/T1095) for the variant allele. No association was observed between this TPH T1095C variant with either OCD, AN, Alc, or suicidality.

CONCLUSION

These results suggest that the coding sequence of the TPH gene does not contain abundant variants, and may not play a major role in vulnerability to several psychopathologies in which reduced serotonin turnover has been implicated.

Reduced binding of [18F]altanserin to serotonin type 2A receptors in aging: persistence of effect after partial volume correction

The serotonin (5-HT) neurotransmitter system, which has a widespread distribution in the central nervous system, has been implicated in regulating mood and many human behaviors. There is evidence from postmortem human studies and limited information from prior in vivo studies to support a decline in 5-HT2A receptor density with aging. We examined nine elderly (ages 61-76) and nine young (ages 18-29) healthy individuals with positron emission tomography (PET) and [18F]altanserin, a ligand with high affinity for the 5-HT2A binding site. The PET data were corrected for differences in brain tissue volume between the young and elderly subjects using a magnetic resonance (MR) imaging-based partial volume correction method. Highly significant and widespread cortical reductions in 5-HT2A specific binding were demonstrated in the elderly group relative to young controls. Regional losses averaged 61% before and 57% following correction for effects of cerebral atrophy. This finding, which is consistent with prior postmortem and in vivo studies, has both etiological and potential therapeutic implications for behavioral changes commonly observed in the elderly, including geriatric depression.

Serotonin neuronal function and selective serotonin reuptake inhibitor treatment in anorexia and bulimia nervosa

Anorexia nervosa (AN) and bulimia nervosa (BN) are disorders characterized by aberrant patterns of feeding behavior and weight regulation, and disturbances in attitudes toward weight and shape and the perception of body shape. Emerging data support the possibility that substantial biologic and genetic vulnerabilities contribute to the pathogenesis of AN and BN. Multiple neuroendocrine and neurotransmitter abnormalities have been documented in AN and BN, but for the most part, these disturbances are state-related and tend to normalize after symptom remission and weight restoration; however, elevated concentrations of 5-hydroxyindoleacetic acid in the cerebrospinal fluid after recovery suggest that altered serotonin activity in AN and BN is a trait-related characteristic. Elevated serotonin activity is consistent with behaviors found after recovery from AN and BN, such as obsessionality with symmetry and exactness, harm avoidance, perfectionism, and behavioral over control. In BN, serotonergic modulating antidepressant medications suppress symptoms independently of their antidepressant effects. Selective serotonin reuptake inhibitors (SSRIs) are not useful when AN subjects are malnourished and under-weight; however, when given after weight restoration, fluoxetine may significantly reduce the extremely high rate of relapse normally seen in AN. Nonresponse to SSRI medication in ill AN subjects could be a consequence of an inadequate supply of nutrients, which are essential to normal serotonin synthesis and function. These data raise the possibility that a disturbance of serotonin activity may create a vulnerability for the expression of a cluster of symptoms that are common to both AN and BN and that nutritional factors may affect SSRI response in depression, obsessive-compulsive disorder, or other conditions characterized by disturbances in serotonergic pathways.

Bilateral internal carotid artery dissection from vomiting

Dissection of the internal carotid artery is responsible for approximately 5% of ischemic strokes in adults. The pathophysiology of dissection can be either traumatic or spontaneous. The true incidence of spontaneous dissection is unknown. Once considered very rare, an increased awareness, combined with noninvasive evaluation by ultrasound and magnetic resonance angiography, has demonstrated a more frequent occurrence. Trivial trauma (ie, rather than external blunt or penetrating trauma) such as vomiting has rarely been documented as causing bilateral dissection. It is well recognized by neurologists but often not by other physicians. Prognosis is good, but delay in diagnosis may result in residual neurologic deficits. It should therefore be suspected early, especially in younger patients presenting with transient ischemic attacks or stroke.

In-hospital first-responder automated external defibrillation: what critical care practitioners need to know

Despite the development and widespread implementation of Basic Life Support and Advanced Cardiac Life Support, the percentage of patients who survive in-hospital cardiac arrest has remained stable at approximately 15%. Although survival rates may approach 90% in coronary care units, survival rates plummet outside of these units. The lower survival rates for cardiac arrest that occur outside of the coronary care unit may relate to the time elapsed between the onset of ventricular fibrillation and first defibrillation. The advent of automated external defibrillators has made it possible to decrease the time elapsed before first defibrillation in non-critical care areas of the hospital. First responders need only recognize that the patient is unresponsive, apneic, and pulseless before attaching and activating the automated external defibrillator. Our research shows that, as part of Basic Life Support training, non-critical care nurses can learn to use the device and can retain the knowledge and skill over time. Establishing an in-hospital automated external defibrillator program requires commitment from administration, physicians, and nursing personnel. Critical care practitioners should be aware of this technology and the literature that supports its safety and effectiveness when used by non-critical care first responders. Critical care nurses are in a unique position to effect changes that will decrease the time between the onset of cardiac arrest and first defibrillation.

In-hospital first-responder automated external defibrillation: what critical care practitioners need to know

Despite the development and widespread implementation of Basic Life Support and Advanced Cardiac Life Support, the percentage of patients who survive in-hospital cardiac arrest has remained stable at approximately 15%. Although survival rates may approach 90% in coronary care units, survival rates plummet outside of these units. The lower survival rates for cardiac arrest that occur outside of the coronary care unit may relate to the time elapsed between the onset of ventricular fibrillation and first defibrillation. The advent of automated external defibrillators has made it possible to decrease the time elapsed before first defibrillation in non-critical care areas of the hospital. First responders need only recognize that the patient is unresponsive, apneic, and pulseless before attaching and activating the automated external defibrillator. Our research shows that, as part of Basic Life Support training, non-critical care nurses can learn to use the device and can retain the knowledge and skill over time. Establishing an in-hospital automated external defibrillator program requires commitment from administration, physicians, and nursing personnel. Critical care practitioners should be aware of this technology and the literature that supports its safety and effectiveness when used by non-critical care first responders. Critical care nurses are in a unique position to effect changes that will decrease the time between the onset of cardiac arrest and first defibrillation.

Differences in salivary habituation to palatable foods in bulimia nervosa patients and controls

OBJECTIVE

Bulimia nervosa (BN) patients have been shown to experience anomalous responses to food and food cues. We investigated the response to food over time by presenting repeated food cues and measuring changes in physiological (ie, salivation) and subjective responses.

METHOD

Subjects were 18 BN women and 18 matched control women. Two palatable food stimuli, regular or frozen yogurt, that varied in macronutrient composition but had similar sensory characteristics, were presented to subjects repeatedly during a laboratory session. After two baseline salivation measures, subjects were presented with eight trials of one of the two yogurts. On Trial 9 a lemon juice dishabituator was presented, with the yogurt stimulus presented again at Trial 10.

RESULTS

We found that control subjects had decreased salivation after repeated food presentations. In comparison, BN subjects failed to show a decrease in salivation. The desire to binge increased over trials for the BN subjects, but remained stable for normals.

CONCLUSIONS

These data suggest that salivary habituation may be abnormal in BN patients.

CPR training without an instructor: development and evaluation of a video self-instructional system for effective performance of cardiopulmonary resuscitation

Traditional classroom-based instruction of cardiopulmonary resuscitation (CPR) has failed to achieve desired rates of bystander CPR. Video self-instruction (VSI) is a more accessible alternative to traditional classroom instruction (TRAD), and it achieves better CPR skill performance. VSI employs a 34-min training tape and an inexpensive manikin. VSI combines simplified and reordered content focusing on the delivery of one-rescuer CPR with the 'practice-as-you-watch' approach of an exercise video. Performance of CPR skills immediately following VSI was compared to performance immediately following TRAD using an instrumented manikin, a valid and reliable skill checklist, and an overall competency rating. Compared with TRAD subjects, VSI subjects performed more compressions correctly (P < 0.001), more ventilations correctly (P < 0.001), and more assessment and sequence skills correctly (P < 0.001). TRAD subjects delivered twice as many compressions that were too shallow, and underinflated the lungs twice as often. VSI subjects were rated 'competent' or better 80.0% of the time, compared with TRAD subjects, who achieved this rating only 45.1% of the time (P < 0.001). TRAD subjects were rated to be 'not competent' in performing CPR nearly 10 times more often than VSI subjects (P < 0.001). Subjects 40 years of age and older performed better after VSI than after TRAD. Superior skill performance among subjects exposed to VSI persisted 60 days following training. VSI has the potential to reach individuals unlikely to participate in TRAD classes because of its greater convenience, lower cost, and training in about 0.50 h compared with 3-4 h for TRAD classes.

A reliable and valid method for evaluating cardiopulmonary resuscitation training outcomes

In order to compare the quality of CPR performance after various training methods, training outcome assessment must provide meaningful data and do it in a way that is reliable. Few studies have provided details of their assessment procedures, and even fewer report on whether the measures to evaluate performance are reliable (yielding information consistently over multiple trials), or valid (measuring the outcome intended). Few studies have attempted to replicate assessment methods used by other authors. Conventional skill sheets have not been shown to assess compressions and ventilations reliably and validly. When using an instrumented manikin, skill checklists can be simplified by eliminating qualitative assessment of compressions and ventilations. Using a sample of 171 CPR trainees rated by trained evaluators, we provide details of agreement between two evaluators and use an established statistic (Cronbach's alpha) to assess the reliability of a 14-item simplified CPR checklist. The level of agreement between two raters was high (Pearson product-moment correlation = 0.87) as was the reliability estimate obtained by Cronbach's alpha (0.89). As criterion-related evidence of the validity of the CPR checklist to assess CPR performance, a correlation with a five-point subjective overall rating of CPR was estimated (Spearman correlation = 0.92). We urge standardized reporting of CPR training outcomes in order to achieve comparability across studies.

Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support

This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.

Resuscitation training: a time for reassessment

The goal of resuscitation education is to impart the knowledge and skills necessary to successfully resuscitate a victim of cardiopulmonary arrest. This goal can be accomplished only if the interactions among the instructor, learner, and curriculum are optimized. Instructors must have a clear understanding of educational theory and a thorough grasp of the program materials. Learners must be motivated and committed to developing and maintaining a high level of competence. The in-hospital chain of survival for the resuscitation response system must be reorganized to include determination of the appropriateness of resuscitation and provision of first-responder defibrillation capability. Using creativity and flexibility to meet these goals, nurses can improve the practice and potential outcome of resuscitation.

Future directions for resuscitation research. I. Advanced airway control measures

The efficacy of 'basic' airway control without equipment, using the combination of backward tilt of the head, forward displacement of the mandible, and separation of lips and teeth (i.e. the triple airway maneuver) has been well established. Direct mouth-to-mouth and mouth-to-nose ventilation must continue to be taught to the public. Further improvements are needed for pocket-size mouth-to-mouth barriers to combat infection risks. Dissemination of appropriate information on disease transmission is needed to ensure ventilation by health professionals, using exhaled air ventilation adjuncts and other devices. Much knowledge exists about the pathophysiology of airway obstruction. For patients in coma or anesthesia with airway obstruction, which resists basic airway control measures and standard tracheal intubation, available 'advanced' airway control measures should be mastered and improved. Preparedness for advanced airway control measures differs between elective management of the anticipated difficult airway for anesthesia and emergency airway control with unanticipated difficulties encountered during the ordinary sequential application of measures. Challenges include education research and development of new devices. For airway clearing, pharyngeal intubation, difficult tracheal intubation, cricothyrotomy, transtracheal jet ventilation and emergency use of oxygen - what could and should be taught, to whom, and how? Which new devices and training systems should be developed? The most important alternative to orotracheal or nasotracheal intubation recommended for the development of novel devices and teaching methods for health professionals, are cricothyrotomy (with wide enough airway to also enable spontaneous breathing of air), and translaryngeal or transtracheal oxygen jet ventilation. We recommend openness in communication and joint planning between anesthesiologists, emergency care providers, and appropriate educators, engineers and industries.

Future directions for resuscitation research. II. External cardiopulmonary resuscitation basic life support

In sudden cardiac deaths outside hospitals, the present performance of external cardiopulmonary resuscitation-basic life support (CPR-BLS), as a bridge to advanced life support (ALS) attempts for restoration of spontaneous circulation (ROSC), still yields suboptimal results. Therefore, future education research should develop more effective, simpler and quicker ways to enable everyone to acquire the necessary BLS skills. Individualized self-training by lay persons is being revived. Although airway control and direct mouth-to-mouth ventilation skills are difficult to acquire, they must continue to be taught to the lay public and health professionals, primarily for use on relatives and friends where infection risk is not a problem. In children and trauma victims, steps A and B alone may be lifesavers. The best way to ventilate and oxygenate during the initiation of brief external CPR-BLS should be re-evaluated. There is a great difference between animals and humans in the behavior of the airway and thorax during coma, and thus in the need for added positive pressure ventilation. During chest compressions in humans, steps A and B are needed. Details deserve re-evaluation. The low perfusion pressures (borderline blood flows) produced by standard external CPR remain the most serious limitation of this method. In spite of extensive efforts so far, novel laboratory research to remedy this limitation is important for the development of more effective emergency artificial circulation. The results of such studies are greatly influenced by different details in animal models. Active compression-decompression (ACD) external CPR, also called 'push-pull' CPR, with a plunger-type device used by hand or a machine, and intermittent abdominal compression (IAC) external CPR are both promising modifications of standard external CPR. Both need further experimental and clinical clarification. For BLS, developing a more effective purely manual CPR-BLS method for help in rapid ROSC should be given high priority. Portable external CPR machines need improvements. They will serve for bridging ROSC-resistant cases through transport and ALS attempts, primarily by freeing the hands of health professionals for more effective sophisticated ALS measures.

The effect of cimetidine and ranitidine on cognitive function in postoperative cardiac surgical patients

OBJECTIVE

To compare the incidence of delirium in postoperative cardiac surgical patients treated with either cimetidine or ranitidine.

METHOD

Cardiac surgery patients were randomized to receive either cimetidine or ranitidine postoperatively. Each patient underwent three Mini-Mental Status Examinations (MMSE) and the medical record was reviewed for pertinent past medical history, laboratory data, and evidence of delirium on three occasions: one day preoperatively (before H-2 blocker was given), in the early postoperative period (while receiving the H-2 blocker); usually two days postoperatively on the day of hospital discharge (several days after the H2 blocker had been discontinued).

RESULTS

Overall, both groups in the early postoperative period showed a significant decrease in the MMSE score (27.11 +/- 4.44 to 25.38 +/-2.87, mean +/- SD; t = 5.16, p < .0005), which resolved by the time of hospital discharge. There was no significant difference between cimetidine and ranitidine. Both age and preoperative MMSE score were strongly associated with the development of delirium.

CONCLUSIONS

We found no significant difference between cimetidine's versus ranitidine's effect upon cognitive functioning in the postoperative cardiac surgical patient. This was true even when controlling for age and length of stay.

Organizing and implementing a hospital-wide first-responder automated external defibrillation program: strengthening the in-hospital chain of survival

First-responder automated external defibrillation (AED) in the hospital is consistent with the American Heart Association's (AHA) early defibrillation standard or care. With trained personnel and automated external defibrillators immediately available, early defibrillation should have a greater impact on survival than early cardiopulmonary resuscitation (CPR). Therefore, in our hospitals we modified basic life support to include automated external defibrillation (BLS-AED) for all personnel who are expected to respond to a cardiac arrest, with rapid defibrillation taking priority over CPR. We describe how we organized and implemented this hospital-wide first-responder BLS-AED program. Planning the process includes gaining support from key leaders who are responsible for resuscitation practice, and identifying the target audience of the training program. Hospital unit needs for AED or conventional defibrillation and equipment must be identified, the training program developed, and existing policies and procedures modified. Several barriers to implementation may exist. Education about the efficacy and safety of AED and experience once the BLS-AED program is in place can overcome attitudes and bias. Concerns about the cost of equipment and training must be addressed. Program evaluation may include patient issues such as measuring the time to the first defibrillation and patient outcome; as well as training and retention issues.

Strengthening the in-hospital chain of survival with rapid defibrillation by first responders using automated external defibrillators: training and retention issues

STUDY OBJECTIVE

To determine whether staff outside critical care areas who were proficient in basic life support (BLS) could be easily trained to use automated external defibrillators (AEDs) and whether they would retain these skills.

DESIGN

Prospective, longitudinal cohort series.

SETTING

Two university teaching hospitals.

PARTICIPANTS

One hundred forty nurses who had previously learned BLS and constituted the staff from three medical/surgical nursing units from each study hospital.

INTERVENTIONS

The nurses were taught how to use the Heartstart 1000s, a lightweight portable shock-advisory AED, in a 2-hour class with an instructor and manikin-to-student ratio of 1:5. The course emphasized hands-on practice of the BLS-AED algorithm on a computerized manikin.

RESULTS

Using a similar scenario, each nurse was evaluated on the computerized manikin immediately after training (posttest). At 1 to 3, 4 to 6, and 7 to 9 months after the initial training, convenience samples of the cohort in three different groups were evaluated for retention. Satisfactory performance was defined as delivery of the first AED shock within 2 minutes of recognition of the arrest. At the posttest after training, 139 of 140 nurses (99%) demonstrated satisfactory performance. Of 77 nurses evaluated, 31 of 32 at 1 to 3 months, 18 of 18 at 4 to 6 months, and 24 of 27 at 7 to 9 months after initial training (95% overall) performed satisfactorily.

CONCLUSION

As has been demonstrated with prehospital emergency personnel, nurses outside critical care areas who are proficient in BLS can easily learn and retain the knowledge and skills to use AEDs. Automated external defibrillation, a BLS skill, should be incorporated into BLS programs (BLS-AED) for all hospital personnel expected to respond to a patient in cardiac arrest, with rapid defibrillation taking priority over CPR.

Are the eating disorders related to obsessive compulsive disorder?

The evidence supporting the idea that the eating disorders of anorexia and bulimia nervosa may be related to obsessive compulsive disorder is reviewed with respect to studies in phenomenology, comorbidity, neurotransmitters, central nervous system functional metabolism, and treatment and outcome. Although no definitive conclusion can be drawn, research generated from the idea has refined our thinking on the eating disorders.

Descriptive analysis of critical care units in the United States: patient characteristics and intensive care unit utilization

OBJECTIVE

To gather data about occupancy, admission characteristics, patients' ages, and types of therapy utilized in ICUs in the United States.

DESIGN AND SETTING

Survey instruments were mailed to the administrators of 4,233 hospitals to gather information from the medical director of the institutions' respective ICUs for the purpose of developing a database on ICUs in the United States. The sampling frame for this study was based on all American Hospital Association (AHA) hospitals stating they had ICUs.

MEASUREMENTS

Census questionnaires solicited information on occupancy, where the patients were admitted from, length of stay, therapies rendered, intensive care diagnoses, and resuscitation status, as well as other information.

MAIN RESULTS

Data were obtained regarding 32,850 ICU beds, with 25,871 patients from 2,876 separate ICUs in 1,706 hospitals in the United States. The census response rate was 40% of the AHA hospitals that stated they had ICUs, with specific ICU data on 38.7% of the nation's ICUs. Overall, the responding units reported a mean occupancy rate of 84% of total bed capacity and 87% of available beds. As hospital size increased, so did ICU occupancy. Nearly 17% of all of the critical care patients had been in the units for > 14 days. More precisely, 49% of all responding units indicated that they had one or more "chronic" (> 14-day length of stay) patients. Most patients were admitted to the units from the emergency room (38%), operating room/postanesthesia care unit (22%), and the general hospital floor (16%). Neonatal units were exceptions to this observation, where most patients came from the delivery room (60%). Admission from other hospitals represented a significantly larger group of patients in the cardiac care, pediatric, and neonatal units. Respondents indicated that many of their current patients were elderly, with 43% of these patients aged 65 to 84 yrs and with 4% being > or = 85 yrs of age. The 47% of patients > or = 65 yrs of age increased to 58% when the neonatal and pediatric units were eliminated from the analyses. For all units responding to the survey, the leading primary admitting intensive care diagnoses were postoperative management, ischemic heart disorder, respiratory insufficiency/failure, and prematurity. Elimination of units predominantly treating children (pediatric and neonatal) from the analysis left "adult" units with three primary admitting diagnoses: ischemic heart disease, postoperative management, and respiratory insufficiency/failure with variation according to specific unit type. The leading diagnoses in pediatric units were respiratory insufficiency/failure, postoperative management, and congenital abnormalities. For neonatal units, prematurity was the primary admitting diagnosis, accounting for 59% of these units' patients. Respondents reported 5.3 +/- 10.9% of patients had received cardiopulmonary resuscitation (CPR) before admission into the critical care unit. Only 6.0 +/- 11.9% of patients in these critical care units had instructions that CPR not be performed while in the unit.

CONCLUSIONS

This report should be viewed as the beginning step of an effort to improve both the information base available on critical care medicine and the performance of ICUs. Our survey findings provide an introduction into the everyday workings of critical care units throughout the United States. Research is required to determine which patients will benefit from intensive care and how to efficiently utilize the vast technology we have available for them in a world with limited financial resources, an aging population, and a multiplicity of societal and ethical concerns.

A single-fluor approach to DNA sequence determination using high performance capillary electrophoresis

The Tabor and Richardson strategy for enzymatic chain termination sequencing of DNA using relative peak intensity has been adapted to high performance capillary gel electrophoresis with laser induced fluorescence detection. This approach to DNA sequencing involves the use of only a single fluor and results in significant reduction in the time required to determine a DNA sequence without the use of highly complicated and expensive instrumentation. We present a modification of the Tabor and Richardson approach employing two reactions, each containing complementary mixtures of only three ddNTP's in the concentration ratio 4:2:1. The DNA sequence is determined by relative peak height and by assigning the missing ddNTP to "gaps" between the peaks. The use of only three terminators/reaction simplifies the software task of differentiating between the termination types and makes more efficient use of the available dynamic range. Both complementary mixes generate complete sequence information and the two data files are combined in order to make a more confident sequence call. This process helps to eliminate errors caused by occasional non-uniform incorporation of ddNTP's or false terminations and also alleviates some of the difficulty associated with reading through compressed regions of the electropherogram.

The problem of poor retention of cardiopulmonary resuscitation skills may lie with the instructor, not the learner or the curriculum

Many studies (several even before American Heart Association recommended in 1973 that lay public be trained in cardiopulmonary resuscitation (CPR] have documented that retention of CPR skills is poor, unaffected by modifications in curriculum or whether the students are lay or professional. We chose to investigate what actually occurs during a CPR course, and gained the following insights: despite clearly defined curricula, we found that instructors did not teach in a standardized way. Practice time was limited and errors in performance were not corrected. Instructors consistently rated the students' overall performance as acceptable; at the same time, using the same checklist, we consistently rated performance as unacceptable. The checklist is an inaccurate tool for evaluating CPR performance. Despite the poor performance that we documented, students and instructors were satisfied with the courses and believed that the level of performance was high. As a result of these studies, we discovered that the problem of poor retention of CPR skills may lie not with the learner or the curriculum, but with the instructor. But, since lives are being saved with bystander CPR, does this documented poor retention matter? Perhaps the solution is not only to improve instructor training to make certain that students receive adequate practice time and accurate skill evaluation, but also to modify the criteria for correct performance when testing for retention. These criteria should be based on the minimum CPR skills that are required to sustain life for the critical 4-8 min before defibrillation and other advanced cardiac life support are delivered.

Measuring cardiopulmonary resuscitation performance: a comparison of the Heartsaver checklist to manikin strip

Both checklists and recording manikin strips (strips) are used for evaluation of cardiopulmonary resuscitation (CPR) performance. To examine their relationship, we simultaneously evaluated single rescuer CPR of 255 subjects using both checklists and strips. For Group 1 (N = 192; general public tested in Heartsaver course) we compared the total number of initial ventilations and compressions judged to be correct by checklists with those judged to be correct by strips. For Group II (N = 63; physicians, nurses, general public tested in retention studies) we compared each subjects checklist with their own strip for evaluation of correct ventilations and compressions. In Group I, CPR was judged to be correct two to four times more frequently by checklists than by strips. In Group II, all correlations were poor. The most common disagreements were with performances evaluated as correct by checklist but not by strip. Therefore, the current checklist may be a poor instrument for measuring CPR. More accurate evaluation should improve learning and therefore improve outcome following cardiac arrest.