Lit Bits: May 3, 2008

From the recent medical literature...

1. What is the placebo worth? The doctor-patient relationship is a crucial part of its value

Spiegel D, Harrington A. BMJ 2008;336:967-968.

George Bernard Shaw described a miracle as "an event that creates faith." Belief is a powerful tool, and many factors influence it. A recent study testing pain relief from analgesics showed that merely telling people that a novel form of codeine they were taking (actually a placebo) was worth $2.50 (£1.25; 1.58) rather than 10 cents increased the proportion of people who reported pain relief from 61% to 85.4%. When the "price" of the placebo was reduced, so was the pain relief. A meta-analysis of decades of clinical trials proposed that the placebo effect was more hype than reality. However, the resulting backlash against it has had the implicit effect of clarifying what is best practice with regard to the placebo.

Hovering over much of the research is a practical question for clinicians—what does all this mean for patient care? In the accompanying randomised controlled trial, Kaptchuk and colleagues undertake a dismantling approach to the examination of placebo effects.4 In 262 adults with irritable bowel syndrome, they examined the effects of placebo acupuncture in circumstances that involved observation only (evaluating a "Hawthorne effect"), sham acupuncture alone, and an enriched relationship with the treating doctor along with the sham procedure. The proportion of patients who reported moderate or substantial improvement on the irritable bowel syndrome global improvement scale was 3% in the observation group, 20% in the procedure alone group, and 37% in the augmented intervention group (P less than 0.001 for trend).

Clearly the group with the greatest relief of symptoms was the one that received not only sham acupuncture but 45 minutes of quality contact with a clinician. This contact involved questions about the patient’s symptoms and beliefs about them, a "warm, friendly manner," empathy, and communication of confidence and positive expectations. In contrast, the doctor-patient relationship in the sham acupuncture only group sounds like a caricature of procedure based medicine practised under strict time limitations: the practitioners explained that this was "a scientific study" and they had been instructed not to talk about it with patients.

Global improvement scores were higher and quality of life and amelioration in symptom severity were almost doubled in people receiving augmented care, which raises some interesting questions. Perhaps the ratcheting down of the time that doctors spend with patients and our modern overemphasis on drugs and procedures is "penny wise and pound foolish." Patients might respond better to real as well as placebo interventions if they were associated with a good doctor-patient relationship. Although the increased time and concern may enhance the effects of the placebo, it also changes the context of associations with the treatment—the doctor may enhance the effect of the sham needle, but the needle also becomes a reminder of the enriched relationship.

That this study chose to evaluate placebo effects associated with an unconventional treatment raises further interesting questions. It is already widely assumed by sceptics that most if not all of the benefit of "alternative" or integrative medicine comes from the placebo effect. It is then assumed that demonstration of a powerful placebo effect, without proving a specific effect, is enough to consign the treatment to the realm of quackery.

But what if we asked a different question? Is it possible that the alternative medical community has tended historically to understand something important about the experience of illness and the ritual of doctor-patient interactions that the rest of medicine might do well to hear? Many people may be drawn to alternative practitioners because of the holistic concern for their wellbeing they are likely to experience, and many may also experience appreciable placebo responses. Why shouldn’t we try to understand what alternative practitioners know and do, as this may help explain why so many patients are prepared to pay to be treated by them, even when many of the treatments are unproven?

In seeking such understanding we should think about the conditions for which patients often seek alternative treatment, and what that might teach us. Patients with irritable bowel syndrome have a chronic condition that can deeply affect their quality of life. They usually have a story to tell about their suffering and want it to be heard, and an empathetic ear may be just what they need. Both the emotional and physical needs of a patient needing emergency surgery, however, might be very different. Such patients might well have a strong placebo response to a calm, orderly, high-tech hospital environment and a kind but focused doctor who does not stop long to chat but instead brings his or her full attention to the pressing business at hand.

Whatever the specifics, the take home message is clear. We treat patients in a social and psychophysiological context that can either improve or, alas, worsen outcome. The meanings and expectations created by the interactions of doctors and patients matter physically, not just subjectively. Recent brain imaging research on pain and the placebo effect has shown functional connectivity between specific brain regions that process attention (the anterior cingulate gyrus) and pain (periaqueductal grey), involving endogenous opiate receptors. Techniques such as hypnosis improve a range of objective symptoms of irritable bowel syndrome and produce subjective reductions in distress. The word "placebo" is Latin for "I will please." On the basis of these and related studies, it seems fair to conclude that a good doctor-patient relationship can tangibly improve patients’ responses to treatment, placebo or otherwise.

2. Removable Splints May Be as Good as Casts for Minor Wrist Fractures in Children

Anthony J. Brown, MD. April 25, 2008 — A review of trial data suggests that removable splints offer a more tolerable, but equally effective alternative to casts in treating minor fractures of the wrist in children.

A review of 10 randomized or quasi-randomized trials involving 827 children suggests that removable splints, either plastic or plaster, generally keep the fractures aligned as well as casts, but with greater comfort and less restriction, allowing children to bathe and participate in other activities.

The findings, which appear in the April 16th online issue of The Cochrane Library, also suggest that above-elbow casts are no better than less-restrictive below-elbow casts. Arm position in above-elbow casts had no effect on the risk of deformity, according to the results of one trial.

Percutaneous wire fixation helps prevent fracture redisplacement, three trials found, but it is unclear if this intervention actually improves function.

"There are minor, or buckle, fractures of the wrist, particularly in toddlers and preschool infants, which are currently being over-treated with a plaster cast and clinical follow-up," lead author Dr. Alwyn Abraham, an orthopedic surgeon with Leicester Royal Infirmary in the UK, said in a statement. "Provided these are accurately diagnosed in an emergency department, these minor fractures can be treated with a removable splint. Removal can be done at home with no further follow-up."

However, according to Dr. Leon Benson, spokesman for the American Academy of Orthopaedic Surgeons, the ability to remove these splints, which makes them more comfortable and may help patients avoid a clinic visit, is also their biggest problem.

"Yes, you can treat a child's buckle fracture with a splint, but I don't," Dr. Benson said in a statement. "In my experience, a child under 10 is not going to keep a splint on, and who is going to take responsibility for that fact — the doctor? And, given that fact, what parent wants to sit on pins and needles waiting for it to happen when a safe plaster casts insures it won't?"

Cochrane Database Syst Rev. Published online April 16, 2008.

3. Is Screening Radiography Necessary to Detect Retained Foreign Bodies in Adequately Explored Superficial Glass-Caused Wounds?

Weinberger LN, et al. Ann Emerg Med. 2008;51:666-667.

The Bottom Line

According to the available evidence, from 0.6% to 4.3% of superficial wounds have retained foreign body detected by radiography after adequate exploration or visualization. Because there is no standard definition of what constitutes a superficial wound, physician discretion is advised to make this determination. If a 4% miss rate would not be acceptable in your practice environment, then all glass-caused wounds, including superficial wounds that may be adequately explored and completely visualized, require routine radiography. Particular caution should be exercised in wounds with foreign body sensation, with head or foot location, and caused by motor vehicle collision or puncture because these may be associated with retained foreign body. Because wounds are a common cause for malpractice litigation in emergency medicine, a large prospective trial with standardized, well-defined variables would be needed to more definitively answer this question.

4. Legislation would require California hospitals to frequently assess conditions of EDs

Source: The American College of Emergency Physicians (http://www.acep.org)

Date: April 07, 2008. California's Daily Breeze (4/8, Evans) reports that State Assemblyman Ted Lieu (D-El Segundo) has introduced "Assembly Bill 2207, [which] would require hospitals to assess the condition of their" emergency departments (EDs) "every three hours, and take corrective measures immediately." Should the ED be "full, the hospital would have to move patients into other areas of its facility until conditions improve." Under the legislation, "[h]ospitals would also be allowed to move patient beds into hallways, a practice that is currently allowed only under the most extreme crowding conditions." Dr. Irv Edwards, former president of the American College of Emergency Physicians, said that EDs "have become makeshift holding wards for patients who often wait hours to be moved or treated, which further compounds crowding."

For more information, please visit: http://www.dailybreeze.com/ci_8846706

5. Role of Bedside Transvaginal Ultrasonography in the Diagnosis of Tubo-ovarian Abscess in the ED

Adhikari S, et al. J Emerg Med 2008;34:429-433.

Tubo-ovarian Abscess (TOA) is a complication of pelvic inflammatory disease (PID) requiring admission, i.v. antibiotics and, possibly, aspiration or surgery. The purpose of this study was to describe the role of emergency department (ED) bedside transvaginal ultrasonography (US) in the diagnosis of TOA.

This was a retrospective review of non-pregnant ED patients presenting with pelvic pain who were diagnosed with TOA using bedside transvaginal US. ED US examinations were performed by emergency medicine residents and ultrasound-credentialed attending physicians within 1 h after clinical assessment. ED US logs were reviewed for the diagnosis of TOA. Medical records were reviewed for risk factors, medical and sexual history, physical examination findings, laboratory results, additional diagnostic testing, hospital course, and a discharge diagnosis of TOA by the admitting gynecology service.

A total of 20 patients with TOA were identified over a 3-year period. Ages ranged from 14 to 45 years (mean 27 years). Seven (35%) patients reported a prior history of PID or sexually transmitted disease, and 1 (5%) was febrile. All had lower abdominal tenderness and 9 (45%) had cervical motion or adnexal tenderness. The sonographic abnormalities included 14 (70%) with a complex adnexal mass, 5 (25%) with echogenic fluid in the cul-de-sac, and 3 (15%) patients with pyosalpinx. The discharge diagnosis was TOA by the admitting gynecology service for all patients.

Our study illustrates the limitations of clinical criteria in diagnosing TOA and supports the use of bedside US when evaluating patients with pelvic pain and symptoms that do not meet classic Centers for Disease Control and Prevention criteria for PID.

6. Physician Clinical Impression Does Not Rule Out Spontaneous Bacterial Peritonitis in Patients Undergoing ED Paracentesis

Chinnock, et al. Ann Emerg Med. 2008; in press.

Clinical bottom line: Peritoneal fluid analysis should be done routinely after all ED paracentesis because detection of spontaneous bacterial peritonitis by clinical means is poor and the incidence is significant.

Introduction
Diagnostic paracentesis is an important emergency department (ED) procedure in evaluating for spontaneous bacterial peritonitis in the patient with ascites. In addition, therapeutic paracentesis is a mainstay of treatment for ameliorating the discomfort associated with large-volume ascites. Although many patients have their therapeutic paracentesis performed in a scheduled outpatient clinic setting, an increasingly large number of patients without access to primary or specialty care are coming to the ED for therapeutic paracentesis. In the outpatient clinic ED setting, 2 studies examining asymptomatic patients presenting for a therapeutic paracentesis showed a combined 2.5% incidence of spontaneous bacterial peritonitis (defined as absolute neutrophil count over 250 cells/mm3) in 545 patients. This low incidence of spontaneous bacterial peritonitis in the outpatient setting contrasts with that observed in the hospitalized patient.

Studies have demonstrated a 12% incidence of spontaneous bacterial peritonitis in patients admitted with decompensated cirrhosis and an 18% incidence in patients admitted with hepatic encephalopathy. It is unknown where the ED patient presenting for paracentesis fits in this spectrum; therefore, the role of routine ascites fluid analysis for spontaneous bacterial peritonitis in the ED patient is less clear. Because mortality is 20% even in treated spontaneous bacterial peritonitis patients, it is important not to miss the diagnosis. To our knowledge, no studies exist that examine which patients who present to the ED might be safe candidates for therapeutic paracentesis without ascites fluid analysis. The aim of this study, therefore, is to prospectively determine whether patient clinical characteristics or physician assessment of likelihood of spontaneous bacterial peritonitis is highly sensitive for the detection of spontaneous bacterial peritonitis and thus could reliably rule out spontaneous bacterial peritonitis in the ascites patient.

Methods
We conducted a prospective, observational study of ED patients with ascites undergoing paracentesis. Predefined clinical characteristics including historical features and ED vital signs were recorded. Each patient was assessed by 2 separate, blinded physicians for severity of abdominal tenderness and overall clinical suspicion for spontaneous bacterial peritonitis. The primary outcome measures were sensitivity, specificity, and likelihood ratios (LR) of the individual clinical characteristics and the physician assessments. Spontaneous bacterial peritonitis was defined by absolute neutrophil count greater than 250 cells/mm3 or positive fluid culture result.

Results
There were 285 separate physician assessments in 144 patients enrolled with complete data. Spontaneous bacterial peritonitis was diagnosed in 17 (11.8%) patients. Physician clinical impression had a sensitivity of 76% (95% confidence interval [CI] 62% to 91%) and specificity of 34% (95% CI 28% to 40%) for the detection of spontaneous bacterial peritonitis. The lowest negative LR was associated with the presence of any abdominal pain or tenderness (negative LR=0.4); however, the presence of pain/tenderness was also observed in 85% of patients without spontaneous bacterial peritonitis. Six patients (4.2%) with spontaneous bacterial peritonitis had at least 1 physician assessment of little to no risk for spontaneous bacterial peritonitis, and 3 of the 6 subsequently died during their hospitalization.

Conclusion
Clinical characteristics and physician assessment were insufficient in the diagnosis or exclusion of spontaneous bacterial peritonitis in the ED patient undergoing diagnostic or therapeutic paracentesis. This finding supports routine laboratory fluid analysis after ED paracentesis.

7. Absorbable Sutures for Repair of Pediatric Facial Lacerations

Cosmetic outcomes with absorbable sutures are similar to those with nonabsorbable sutures.

Absorbable sutures offer several advantages over nonabsorbable sutures — including ease of use, less skin reactivity, and lower cost — but their use in children has not been well studied. In a prospective, randomized trial, researchers compared the two types of sutures for repair of acute pediatric facial lacerations of 1 to 5 cm. Patients were excluded if the lacerations had irregular borders, resulted from mammalian bites, were contaminated, occurred more than 8 hours before presentation, or could be repaired with a topical adhesive.

Children (age range, 1–18 years) were randomized to wound closure with either 5–0 or 6–0 fast-absorbing surgical gut or nonabsorbable nylon. At 3-month follow-up, wounds were photographed, and three pediatric emergency physicians who were blinded to group assignment assessed cosmetic appearance (the primary outcome) using a 100-mm continuous cosmesis visual analog scale (VAS; with a score of 100 representing the best scar). A between-group difference of 15 mm was defined as being clinically important. Wounds were assessed at 5 to 7 days for infection (defined as requirement for systemic antibiotics) and dehiscence (defined as requirement for additional sutures).

Overall, 23 of 49 patients in the absorbable-suture group and 24 of 39 in the nonabsorbable-suture group completed the study. Baseline demographic and wound characteristics were similar between the two groups and between patients who did and did not complete follow-up. At 3 months, mean VAS scores between the absorbable-suture and nonabsorbable-suture groups differed by only 1.4 mm (92.3 mm and 93.7 mm). Correlation among the blinded observers was good (r=0.42). Two patients, both in the absorbable-suture group, had wound dehiscence. No wound infections occurred.

Comment: The study fell short of its target sample size of 27 patients in each group completing the study; thus, it did not have adequate power to detect a true difference in primary outcome. However, that the two suture strategies are equivalent is very likely, at least for highly vascular facial wounds. Absorbable sutures do not require subsequent visits for removal, and fears that they might increase wound inflammation seem to be unfounded. EPs should consider absorbable sutures to be a reasonable option for repair of pediatric facial lacerations that are not amenable to topical adhesives.

— Jill M. Baren, MD. Published in Journal Watch EM April 25, 2008. Citation: Luck RP et al. Pediatr Emerg Care 2008;24:137.

8. Nesiritide: A Costly Placebo for Decompensated HF Patients

Acutely Decompensated Heart Failure in a County ED: A Double-Blind Randomized Controlled Comparison of Nesiritide Versus Placebo Treatment

Miller AH, et al. Ann Emerg Med 2008;51: 571-578.

Conclusion: Administration of nesiritide for acutely decompensated congestive heart failure in a county ED was no better than standard therapy alone for return to the ED or hospitalization at 30 days.

Abstract: http://www.annemergmed.com/article/S0196-0644(07)01852-5/abstract

9. Glucose Monitoring: Not Productive?

Self-monitoring of glucose levels in type 2 diabetes fails on two counts: It has no effect on clinical outcomes, and it lowers quality of life, according to two BMJ studies.

One study comprised nearly 200 people with newly diagnosed disease not requiring insulin. They were randomized either to glucose monitoring or no monitoring. After a year, the groups showed no differences in glycated hemoglobin or self-reported hypoglycemic episodes. Depression scores were higher among the monitored group, however.

The second study evaluated cost data from some 450 patients randomized either to standard care, or to "less intensive" self-monitoring, or to "more intensive" monitoring. After a year, costs were significantly higher in the monitored groups, and quality-of-life scores were lower. Clinical outcomes did not differ among groups.

An editorialist, citing the axiom that interventions should be tested before introduction to practice, writes: "Self-monitoring of blood glucose in type 2 diabetes provides an example of the difficulties that arise if this principle is not followed."

BMJ article on clinical efficacy of glucose monitoring (Free): http://www.bmj.com/cgi/content/full/bmj.39534.571644.BE
BMJ article on cost effectiveness of glucose monitoring (Free): http://www.bmj.com/cgi/content/full/bmj.39526.674873.BE

10. Am I Passing MRSA to My Patients?

A literature review finds that healthcare workers play a role in MRSA transmission, and the authors make screening recommendations.

Methicillin-resistant Staphylococcus aureus (MRSA) has become ubiquitous in emergency departments, but the role of healthcare workers in its transmission is unclear. To assess likelihood of MRSA colonization, infection, and transmission among healthcare workers, researchers performed a comprehensive literature search and identified 127 investigations involving 33,318 screened healthcare workers.

Only 18 studies failed to detect MRSA in healthcare workers. Inadequate hand-washing, chronic skin diseases, and having worked in countries with endemic MRSA were identified as risk factors for MRSA carriage. The overall MRSA carriage rate was 4.6%, and most colonization was on the hands or in the nasopharynx of affected healthcare workers. Of these carriers, 5.1% had clinical infections. Healthcare-worker transmission of MRSA to patients was deemed likely in 63 of 68 studies (93%) that performed genotyping. Transmission occurred from both transiently and persistently colonized workers. Eight studies documented transmission to workers’ family members. According to data from one systematic review, nasal mupirocin led to MRSA eradication in 91% of 143 treated workers within 48 to 96 hours.

Although acknowledging that the cost might be prohibitive, the authors recommend healthcare-worker screening, especially for all staff during outbreak investigations, for all new employees, and for all staff on high-risk units (e.g., intensive care units, burn units, and surgical wards). In cases of eradication failure or frequent relapses, the authors recommend testing household contacts (including pets) and home environments.

Comment: Not only can we become colonized or infected with MRSA from our patients, but also we can infect them and even become the source of community MRSA clusters. Healthcare personnel have an essential responsibility for meticulous attention to hand hygiene before and after every patient contact and proper adherence to contact precautions. Both are critical to stopping the rampant spread of MRSA.

— Kristi L. Koenig, MD. Published in Journal Watch EM April 18, 2008. Citation: Albrich WC and Harbarth S. Lancet Infect Dis 2008;8:289.

11. Serum D-Dimer is a Sensitive Test for the Detection of Acute Aortic Dissection: A Pooled Meta-Analysis

Marill KA. J Emerg Med. 2008;34:367-376.

Acute aortic dissection is a rare but devastating condition with high mortality. Unfortunately, there is no sensitive screening indicator of disease in common use. The objective of this study was to assess the sensitivity and utility of the serum D-dimer as a test for acute aortic dissection.
A pooled analysis was performed of all original research studies testing the sensitivity of serum D-dimer for acute aortic dissection. A search of MEDLINE, EMBASE, and the Cochrane Register using the terms “aortic dissection” and “d-dimer” was made of all English language publications. All original reports of consecutively enrolled patients with acute aortic dissection and a measured serum D-dimer were included. Case reports were excluded. A value of 0.5 microgram per milliliter was defined as the threshold for a positive D-dimer. The primary outcome was the pooled sensitivity of the D-dimer test for acute aortic dissection.

There were 21 original reports of patients with acute aortic dissection and D-dimer measurements. Eleven studies were included and a total of 349 acute aortic dissection patients were described. The sensitivity of the D-dimer test was 327/349, 94% (95% confidence interval 91–96), and the point estimate was essentially unchanged in a sensitivity analysis, 183/192, 95% (95% confidence interval 91–98). Specificity ranged from 40% to 100%.

Serum D-dimer is sensitive for acute aortic dissection and potentially represents a useful test for patients who present with a low likelihood of this disease.

12. Bacteremia in Previously Hospitalized Patients: Prolonged Effect From Previous Hospitalization and Risk Factors for Antimicrobial-Resistant Bacterial Infections

Chen SY, et al. Ann Emerg Med. 2008;51:639-646.

Study objective
Patients who came from the community but were recently discharged from the hospital have a higher risk of contracting antimicrobial-resistant bacterial infections. Our objectives are to determine the time from previous hospital discharge that affects subsequent antimicrobial susceptibility pattern and risk factors for antimicrobial-resistant infection in bacteremia in recently discharged patients.

Methods
Excluding patients of hospital-acquired, patients with regular health care–associated exposure, and patients whose previous hospitalization was not at our hospital, a total of 789 nonduplicated bacteremia episodes from community adult patients were enrolled in a 1-year study period. Antimicrobial-resistant bacteria, including multidrug-resistant Gram-negative bacilli, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci causing bacteremia, were logistically analyzed according to different posthospitalization periods (3 to 90 days, 91 to 180 days, 181 to 360 days, and no hospitalization in the past 360 days) to identify the independent effect from previous hospitalization on subsequent antimicrobial-resistant bacteremia.

Results
Of the 789 bacteremia patients, the proportion of antimicrobial-resistant bacteremia is 14.6% (95% confidence interval [CI] 9.8% to 19.4%) for 3 to 90 days, 9.6% (95% CI 1.6% to 17.6%) for 91 to 180 days, and 6.4% (95% CI 0% to 13.4%) for 181 to 360 days since last hospitalization and 1.0% (95% CI 0.1% to 1.9%) for no hospitalization within the last 360 days. Risk of antimicrobial-resistant bacteremia decreased monthly after discharge by an odds ratio of 0.83 (95% CI 0.76 to 0.90) (P less than 0.01). Previous carriage of antimicrobial-resistant bacteria in the past 360 days and previous stay at ICU in the past 180 days were independent risk factors for antimicrobial-resistant bacteremia in previously hospitalized patients.

Conclusion
Previous hospitalization affects the antimicrobial susceptibility of subsequent bacteremia up to 360 days after hospital discharge. Presence of risk factors for antimicrobial-resistant bacteremia in previously hospitalized patients may help emergency physicians in selecting empirical antimicrobial agents and prompting infection control precautions.

13. A Decision Rule for Predicting Bacterial Meningitis in Children with Cerebrospinal Fluid Pleocytosis When Gram Stain Is Negative or Unavailable

Bonsu BK, et al. Acad Emerg Med. 2008;15:437-444.

Objectives: Among children with cerebrospinal fluid (CSF) pleocytosis, the task of separating aseptic from bacterial meningitis is hampered when the CSF Gram stain result is unavailable, delayed, or negative. In this study, the authors derive and validate a clinical decision rule for use in this setting.

Methods: This was a review of peripheral blood and CSF test results from 78 children (less than 19 years) presenting to Children’s Hospital Columbus from 1998 to 2002. For those with a CSF leukocyte count of more than 7/μL, a rule was created for separating bacterial from viral meningitis that was based on routine laboratory tests, but excluded Gram stain. The rule was validated in 158 subjects seen at the same site (Columbus, 2002–2004) and in 871 subjects selected from a separate site (Boston, 1993–1999).

Results: One point each (maximum, 6 points) was assigned for leukocytes above 597/μL, neutrophils above 74%, glucose below 38 mg/dL, and protein above 97 mg/dL in CSF and for leukocytes above 17,000/mL and bands to neutrophils above 11% in peripheral blood. Areas under receiver-operator-characteristic curves (AROCs) for the resultant score were 0.98 for the derivation set and 0.90 and 0.97, respectively, for validation sets from Columbus and Boston. Sensitivity and specificity pairs for the Boston data set were 100 and 44%, respectively, at a score of 0 and 97 and 81% at a score of 1. Likelihood ratios (LRs) increased from 0 at a score of 0 to 40 at a score of 4 or more.

Conclusions: Among children with CSF pleocytosis, a prediction score based on common tests of CSF and peripheral blood and intended for children with unavailable, negative, or delayed CSF Gram stain results has value for diagnosing bacterial meningitis.

14. Neurosurgical Consultation: A Must for Suspected CSF Shunt Malfunction

The shunt series and CT scanning have low sensitivity for detecting shunt malfunction.

Mater A, et al. CJEM 2008;10:131-5

Objective: Cerebrospinal fluid (CSF) shunt malfunction is one of the most common life-threatening neurosurgical conditions. In the emergency department (ED), imaging techniques to identify shunt malfunction include the shunt series (SS) and CT scanning of the head. We sought to determine the test characteristics of the SS and CT scan for identifying children with shunt malfunction.

Methods: We retrospectively reviewed the medical records of children with a CSF shunt who presented to our tertiary care pediatric emergency department and received an SS during a 2-year period from Jan. 1, 2001, to Dec. 31, 2002. A pediatric neuroradiologist reviewed all SS and CT scans. We defined shunt malfunction as present if the child underwent operative shunt revision.

Results: We identified 437 ED visits by 280 children. Forty-seven SS were read as abnormal. A CT scan was performed in 386 (88.3%) cases and 80 were abnormal. Shunt malfunction was identified in 131 (30.0%) children. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of the SS for identifying cases of shunt malfunction were 30.0%, 95.8%, 72.3%, 75.1%, 7.1 and 0.7, respectively; for the CT scan, they were 61.0%, 82.7%, 64.5%, 80.5%, 3.5 and 0.5, respectively.

Conclusion : La sensitivité de la neuroimagerie est faible quand il s'agit de diagnostiquer un dysfonctionnement de shunt. Une consultation neurochirurgicale est nécessaire si l'on soupçonne cliniquement un tel dysfonctionnement, malgré les résultats normaux de l'imagerie.

Or if you prefer English: Neuroimaging has a low sensitivity for identifying shunt malfunction. Neurosurgical consultation should be sought if shunt malfunction is clinically suspected, despite normal imaging.

15. Are racial disparities in ED analgesia improving? Yes!

Quazi S, et al. Amer J Emerg Med. 2008;26:462-464.

Objective
Ethnic disparities in emergency department (ED) analgesic use have been noted previously; the purpose of this study was to determine if current ED practice has been altered subsequent to the widespread recognition of these inequalities.

Methods
Using data from the National Hospital Ambulatory Care Survey, we analyzed ED analgesic treatment with respect to race for the complaints of headache (HA) and long bone fractures (LBF) for 1995 to 1999 (period A) and compared that with data for 2000 to 2003 (period B). We compared the use of “any analgesics” and “opioids” among blacks, whites, and Hispanics.

Results
For both HA and LBF, improvements over time were noted in all 3 ethnic subgroups. A statistically significant increase was documented in the treatment of HA among Hispanics using any analgesia (71.3% vs 80.8%, P = .011). Although individual differences between the 2 periods in the LBF cohort were not statistically significant for any of the 3 ethnic groups, there was an overall improvement noted when combining all ethnicities: among all patients treated for LBF, 66% received some analgesic and 42.8% received opioid analgesia during period A vs 75% and 51%, respectively, during period B (all P < .001). Furthermore, in the latest study period, there were no differences in the frequency of analgesic administration for LBF with respect to race (blacks, 43%; whites, 48%; Hispanics, 43.8%; P > .1).

Conclusion
There is evidence that previously described racial inequalities in analgesic use have decreased over time.

16. Inadequate provision of postintubation anxiolysis and analgesia in the ED

Bonomo JB, et al. Amer J Emerg Med. 2008;26:469-472.

Introduction
Patients intubated in the emergency department (ED) often have extended ED stays. We hypothesize that ED intubated patients receive inadequate postintubation anxiolysis and analgesia after rapid sequence induction (RSI).

Methods
This was a retrospective cohort study of every adult intubated in a tertiary-care ED (July 2003-June 2004). Patients were included if they underwent RSI, remained in the ED for more than 30 minutes post intubation, and survived to admission. Presuming a mean patient weight of 70 kg, we defined adequacy of anxiolysis and analgesia on the provision postintubation of weight-based doses of lorazepam (0.77 mg/h) or midazolam (4.2 mg/h) and fentanyl (35 μg/h), referenced from pharmaceutical texts. Demographic data, time in ED, and dosage of each medication given were abstracted. The proportion, with 95% confidence intervals (CIs), of patients receiving inadequate anxiolysis and analgesia were computed.

Results
One hundred seventeen patients met the inclusion criteria. Mean time in the ED was 4.2 hours (SD ± 3.1 hours). Thirty-nine patients received no anxiolytic (33%, CI 25%-43%), and 62 received no analgesic (53%, CI 44%-62%). Twenty-three patients received neither anxiolytic nor analgesic (20%, CI 13%-28%). Of 70 patients given postintubation vecuronium, 67 received either no or inadequate anxiolysis or analgesia (96%, CI 87%-99%). Overall, 87 of 117 patients received no or inadequate anxiolysis (74%, CI 65%-82%); and 88 of 117 received no or inadequate analgesia (75%, CI 66%-83%).

Conclusion
Patients undergoing RSI in the ED frequently receive inadequate postintubation anxiolysis and analgesia.

17. Evidence Behind the 4-Hour Rule for Initiation of Antibiotic Therapy in Community-Acquired Pneumonia

Yu KT, et al. Ann Emerg Med. 2008;51: 651-662.e2.

Study objective
US regulatory authorities mandate delivery of antibiotics within 4 hours of arrival for patients being admitted to the hospital with community-acquired pneumonia. This evidence-based emergency medicine review examines the scientific evidence pertaining to this requirement.

Methods
We searched MEDLINE, EMBASE, the Cochrane Library, other databases, and bibliographies. We selected articles allowing comparison of inpatient or 30-day mortality among patients receiving early versus delayed antibiotics. We prospectively categorized studies according to whether they were retrospective or prospective and whether they adjusted for severity with the Pneumonia Severity Index. We evaluated the precision with which the interval to initiation of antibiotic therapy was defined and the compliance of retrospective studies with standard reporting criteria for chart reviews.

Results
We identified 13 observational studies reporting comparative outcomes in patients receiving early versus delayed antibiotic initiation, of which 10 allowed calculation of our primary outcome. Of the 4 prospective studies, 1 allowed severity adjustment using the Pneumonia Severity Index score. Among the retrospective studies, definition of time to antibiotic therapy was frequently imprecisely defined, and compliance with standard reporting criteria for chart review was scanty in the subgroup lacking severity adjustment. Odds ratios (ORs) for mortality varied widely. One methodologically weak study reported a large benefit of early antibiotics (OR for mortality antibiotics within 4 hours versus greater than 4 hours 0.24; 95% confidence interval [CI] 0.08 to 0.71). The one study that used prospective enrollment and severity adjustment using the Pneumonia Severity Index observed a contrary result (adjusted OR for mortality, antibiotics within 4 hours versus greater than 4 hours 1.99; 95% CI 1.22 to 13.45). Results from studies reporting an 8-hour cutoff also varied in magnitude and direction of effect.

Conclusion
Evidence from observational studies fails to confirm decreased mortality with early administration of antibiotics in stable patients with community-acquired pneumonia. Although timely administration of antibiotics to patients with confirmed community-acquired pneumonia should be encouraged, an inflated sense of priority of the 4-hour time frame is not justified by the evidence.

18. The Anatomic Relationship of Femoral Vein to Femoral Artery in Euvolemic Pediatric Patients by Ultrasonography: Implications for Pediatric Femoral Central Venous Access

Warkentine FH, et al. Acad Emerg Med. 2008;15:426-430.

Background: Knowledge of the femoral vein (FV) anatomy in pediatric patients is important in the selection of appropriate size central line catheters as well as the approach to central venous access. This knowledge may avoid potential complications during central line access.

Objectives: To describe the relationship of the FV to the femoral artery (FA). To measure FV diameter and FV depth using ultrasonography (US) in newborns, infants, and children up to 9 years of age.

Methods: This study was a prospective descriptive study at a tertiary care children’s hospital. A convenience sample of euvolemic children was enrolled aged 0–9 years presenting to an urban pediatric emergency department. All patients underwent a standardized US evaluation using a Sonosite Titan bedside machine by a single emergency physician. The FA and FV were identified by four criteria: relative positions, FV compressibility, FV enlargement by Valsalva maneuver, and absence of FV pulsatility. The position of the FV relative to the FA was described as being completely overlapped by the FA, having partial (less than 50%) overlap by the FA, and having no overlap by the FA. The FV depth was measured from the skin to the superior border of the vein using the US machine’s caliper function.

Results: A total of 84 patients were studied. The FV was found to be completely overlapped by the FA in 8% of subjects and partially overlapped by the FA in 4% of subjects. The mean FV diameter ranged from 4.5 mm in young infants to 10.8 mm in patients 9 years of age. The mean FV depth ranged from 6.5 mm in neonates to 11.2 mm in patients 9 years of age.

Conclusions: External landmarks were not always predictive of internal anatomy. The FV was completely or partially overlapped by the FA in 12% of cases. Thus, visualization of femoral vessels should be recommended prior to attempting pediatric femoral central venous access.

19. The Impact of Arm Position on the Measurement of Orthostatic Blood Pressure

Guss, DA, et al. J Emerg Med. 2008;34:377-382.

Blood pressure is a standard vital sign in patients evaluated in an Emergency Department. The American Heart Association has recommended a preferred position of the arm and cuff when measuring blood pressure. There is no formal recommendation for arm position when measuring orthostatic blood pressure. The objective of this study was to assess the impact of different arm positions on the measurement of postural changes in blood pressure.

This was a prospective, unblinded, convenience study involving Emergency Department patients with complaints unrelated to cardiovascular instability. Repeated blood pressure measurements were obtained using an automatic non-invasive device with each subject in a supine and standing position and with the arm parallel and perpendicular to the torso. Orthostatic hypotension was defined as a difference of 20 or more mm Hg systolic or 10 or more mm Hg diastolic when subtracting standing from supine measurements. There were four comparisons made: group W, arm perpendicular supine and standing; group X, arm parallel supine and standing; group Y, arm parallel supine and perpendicular standing; and group Z, arm perpendicular supine and parallel standing. There were 100 patients enrolled, 55 men, mean age 44 years. Four blood pressure measurements were obtained on each patient.

The percentage of patients meeting orthostatic hypotension criteria in each group was: W systolic 6% (95% CI 1%, 11%), diastolic 4% (95% CI 0%, 8%), X systolic 8% (95% CI 3%, 13%), diastolic 9% (95% CI 3%, 13%), Y systolic 19% (95% CI 11%, 27%), diastolic 30% (95% CI 21%, 39%), Z systolic 2% (95% CI 0%, 5%), diastolic 2% (95% CI 0%, 5%). Comparison of Group Y vs. X, Z, and W was statistically significant (p less than 0.0001).

Arm position has a significant impact on determination of postural changes in blood pressure. The combination of the arm parallel when supine and perpendicular when standing may significantly overestimate the orthostatic change. Arm position should be held constant in supine and standing positions when assessing for orthostatic change in blood pressure.

20. Do Patients with AMI Benefit from Treatment with Clopidogrel?

Worster A, et al. J Emerg Med. 2008;34:479-483.

Case
A 49-year-old man presents to your Emergency Department with a 2-h history of chest pain upon awakening that morning. The electrocardiogram demonstrates an acute anterior myocardial infarction (MI). The patient is given aspirin and considered for thrombolytic therapy. Percutaneous coronary intervention (PCI) is currently not available at your institution and a transfer will take at least 2 h to complete.

Clinical Question
In this patient with acute anterior MI, would the addition of clopidogrel improve outcomes such as death, recurrent MI, or infarct-related coronary artery occlusion without increasing the risk of major bleeding?

Context
Although clear benefits have been achieved with PCI in acute ST-elevation MI (STEMI), not all Emergency Department patients have access or are eligible. These patients likely have access to fibrinolytic therapy. Approximately 20% of patients treated with fibrinolytic therapy for STEMI will fail to achieve initial adequate reperfusion of the infarct-related coronary artery. This results in a two-fold increase in mortality rates. A three-fold increase in mortality is seen after reocclusion of the artery. Reocclusion occurs in up to 8% of patients during their admission. Platelet activation and aggregation occur after plaque rupture in acute MI and contribute to the formation and growth of the coronary-artery thrombosis. The effectiveness of platelet inhibitors in the treatment of acute MI was first demonstrated in a large-scale clinical trial (ISIS-2) in 1988 using ASA (acetylsalicylic acid). Clopidogrel, an adenosine diphosphate-receptor antagonist, also inhibits the activation and aggregation of platelets. In fact, it has been shown to prevent death and ischemic complications in a variety of patients with coronary artery disease, including patients with symptomatic atherosclerotic disease, with unstable angina, with MI without ST-segment elevation (NSTEMI), and in those who have undergone percutaneous coronary intervention.

Evidence Search
Using PubMed clinical queries, category: therapy, and scope: narrow, the keywords “Clopidogrel Myocardial Infarction Fibrinoly*” were entered and 19 items were displayed. Two clinical trial abstracts (CLARITY and COMMIT) were acquired and appraised.

Conclusion
Physicians should strongly consider the addition of clopidogrel (as well as aspirin) for patients with acute myocardial infarction receiving fibrinolytic therapy as well as those receiving PCI. This makes sense from pathophysiologic and pharmacologic points of view and, most importantly, is supported by these two recent, large, randomized controlled trials demonstrating clinical benefit without a significant increase in adverse events. Because surgeons may be reluctant to take clopidogrel-treated patients to CABG, it would be wise for emergency physicians to fully understand their practice environment preference on this issue.

Commentary by Peter Rosen, MD

Although I appreciate the analysis and conclusions of the authors of this article, I still have some reservations about accepting the conclusions without some caveats. First of all, no evidence is worthwhile until the reader has integrated it into a personal clinical experience. What I mean by this caveat is that each physician has memorable clinical cases that must be used to modify the conclusions that other physicians are trying to promulgate. The conclusions in this article are based in part on a large multicenter study from China [COMMIT]. My experience with multicenter studies in the United States is that there are no two centers whose practices are identical. Therefore, without more knowledge of who runs the intensive care unit and Cardiac Care Unit, how the diagnosis of myocardial infarction is established, and what are the individual hospital complications of the drug, it is hard to compare to US institutions, where the culture and system of care is quite different from China, for example.

Secondly, in the COMMIT study, we are not given a description of variance in the types of myocardial infarction between the study and the control groups. For example, if the study group had a larger incidence of inferior wall infarction, the built-in bias of the population studies would hide a large difference in complications of the therapy.

Thirdly, I remain skeptical about the reported hemorrhagic complication rates. I doubt many cardiovascular surgeons will now believe they do not need to delay CABG for at least 5 days on clopidogrel-treated patients. Furthermore, because the need for CABG is almost always discovered during PCI, a patient who had just received clopidogrel in the Emergency Department would likely not be taken for emergency surgery. Delaying the decision to administer clopidogrel, therefore, to the immediate post-PCI period makes the most sense.

Finally, and this is a criticism of virtually all the reperfusion studies from any country, there is nowhere that one can determine the exact hospital mortality of the myocardial infarction population. We know from studies before reperfusion that inferior wall infarction had, at worst, about a 10% mortality, whereas anterior wall infarctions had a mortality that in some studies approached 50%. All the perfusion studies reported a decrease in mortality, but if the decrease was from 30% to 20% for inferior wall, and from 50% to 40% for anterior, we would want to know why the control mortalities are so high. Similarly, in these studies on platelet inhibition, if the mortalities decrease, but are still higher than untreated infarction patients, perhaps we need to understand whether we are looking at the real parameters of difference.

There is no way to be totally confident of clinical evidence; we must do the best we can to interpret, analyze, and improve our practice. The best approach is still thoughtful analysis measured against true clinical experience.

COMMIT: Chen ZM, Jiang LX, Chen YP, et al. COMMIT (Clopidogrel and Metoprolol in Myocardial Infarction Trial) collaborative group. Addition of clopidogrel to aspirin in 45,852 patients with acute myocardial infarction: randomised placebo-controlled trial. Lancet. 2005;366:1607–1621.

CLARITY: Sabatine MS, Cannon CP, Gibson CM, et al.. Addition of clopidogrel to aspirin and fibrinolytic therapy for myocardial infarction with ST-segment elevation. N Engl J Med. 2005;352:1179–1189.

21. Energy drinks contain dangerous amounts of caffeine

Nagajothi N, et al. Amer J Med. 2008;121:e3-e4.

A 23-year-old woman with no medical history was brought to the hospital for palpitations and chest tightness shortly after consuming a GNC Speed Shot and a Mountain Dew.

On arrival, she looked anxious with a blood pressure of 120/55 mm Hg and heart rate of 219 beats/min. Physical examination and laboratory workup were unremarkable. Her electrocardiogram showed a narrow complex tachycardia with a ventricular rate of 219 beats/min. Carotid sinus massage and Valsalva maneuvers were unsuccessful in terminating the tachycardia. On administration of 6 mg of adenosine by rapid intravenous push, she converted to normal sinus rhythm.

Many "energy drinks" contain excessive amounts of caffeine, sometimes several times the amount contained in a cup of coffee. It is important for the public to be more aware of the potential adverse effects of these energy drinks, alone or in combination with other caffeine-containing products, because fatal and serious events have been reported.

Full-text: http://www.amjmed.com/article/S0002-9343(07)01186-2/fulltext