Thursday, May 24, 2007

Lit Bits: May 24, 2007

From the recent medical literature...

1. PCI Hospitals Associated with Survival Benefit After Myocardial Infarction

Myocardial infarction patients first admitted to hospitals that perform PCI have better survival than those who go to non-PCI hospitals, according to a French study in the Archives of Internal Medicine.

The prospective observational study compared the outcomes of about 1200 patients admitted to PCI hospitals and about 700 admitted to non-PCI hospitals during 1 month in 2000. Patients admitted to PCI hospitals had lower in-hospital mortality (7% vs. 12%) and 1-year mortality (13% vs. 20%).

Patients admitted to PCI hospitals were more likely to receive primary PCI (36% vs. 1%) or PCI within 48 hours (54% vs. 6%). They were also more likely to receive evidence-based acute and discharge medicines.

"Most of the survival benefit of admission to a PCI hospital was explained by the use of PCI and evidence-based discharge medications," the authors write.

Archives of Internal Medicine article (Free abstract; full text requires subscription):

2. Odansetron Versus Metoclopramide for Nausea and Vomiting in the ED

Haensel C, et al. Acad Emerg Med. 2007;14, Supplement 1: S16-17 (full manuscript not yet published).

Objectives: Nausea and vomiting is a common ED complaint. Most of the literature involves post-operative and oncology patients. The objective is to compare the efficacy of usual (4 mg) and low (2 mg) dose ondansetron and 10 mg metoclopramide in relief of nausea and vomiting in ED patients.

Methods: This is a prospective, randomized, double-blind study of adult ED patients with nausea and at least 1 episode of vomiting within 12 hours of presentation. A validated 100 mm visual analog nausea scale (VAS) was used prior to medication and 30 minutes post-treatment. Patients also rated their nausea post-treatment on a subjective scale. All patients received at least 500 cc of saline IV. Endpoints were complete relief of nausea, significant reduction of initial VAS, subjective change in nausea, and adverse events. Analysis by ANOVA and Kruskal-Wallis.

Results: A total of 132 patients were enrolled over a 12 month period in 2005-2006. Initial VAS scores were similar with a mean of 66.4 mm. All 3 groups had a significant and similar reduction in VAS with a mean final VAS score of 33.6 mm, p less than 0.0001. There was no difference between the groups. A total of 55.3% obtained at least 50% relief and 18.2% obtained complete relief, with no difference between groups. More nausea was experienced by 7.6% in the post-treatment odansetron groups and none in the metoclopramide group. None of the patients had an adverse reaction, 95% CI = 0.0 to 2.2%.

Conclusions: Low and usual dose odansetron and metoclopramide are efficacious in ED patients with nausea and vomiting. No adverse events occurred with either drug. Significant cost savings with similar efficacy would occur by using low-dose odansetron or metoclopramide.

3. Expanding the use of topical anesthesia in wound management

Topical anesthesia eliminates the need for injection of anesthetic. Most studies on the use of topical anesthesia were done on children, using 3 active ingredients (lidocaine, epinephrine, tetracaine, or tetracaine, adrenaline, cocaine) for relatively small wounds of the face and scalp.

To demonstrate that topical anesthesia is effective and safe in adults of all ages and for larger wounds, using a preparation with 2 active ingredients, topical lidocaine and epinephrine (TLE).

One hundred patients were enrolled in a randomized controlled trial, with 50 in each group. The study group received TLE using a unique method of “sequential layered application.” The control group received 2% lidocaine infiltration anesthesia. Patients rated the pain from the application of anesthesia and from suturing, using a 0 to 10 visual analog pain scale. Follow-up interviews were conducted to assess for complications and to rate patients' wound repair experience.

Patients in the study group reported significantly less pain from TLE application, with 66% reporting no pain vs 0% reporting no pain from the infiltration in the control group (P less than .001). There was no difference in pain during wound repair between the 2 groups (P = .59). On follow-up, 95% of patients contacted in the TLE group rated their experience in regard to pain as “excellent,” compared to 5% of patients in the control group (P less than .001).

Topical lidocaine and epinephrine “sequential layered application” is an effective, safe, and less painful method of anesthesia for a wide variety of lacerations. Patients recall their experience with this technique very favorably.

Gaufberg SV, et al. Amer J Emerg Med 2007;25: 379-384.

4. Review Finds Lower Dose Best for Prophylactic Aspirin

Aspirin doses should not exceed 75 to 81 mg/day when the drug is used to prevent cardiovascular disease, a JAMA systematic review finds.

The authors sought the balance point between aspirin's cardioprotective effects and the known complications of the drug, which they say is taken preventively by over one-third of U.S. adults. Their literature review leads them to conclude that, although multiple studies confirm the increasing incidence of adverse effects with increasing dosage, "no such dose relationship has been identified for efficacy."

"Currently, the clinical data are most supportive of a 75- or 81-mg daily dose," they write.

JAMA article (Free abstract; full text requires subscription):

5. The Ottawa Aggressive Protocol for ED Management of Acute A Fib

Stiell IC, et al. Acad Emerg Med. 2007;14, Supplement 1: S9 (full manuscript not yet published)

Objectives: There is no consensus as to the optimal emergency department (ED) management of acute atrial fibrillation (AAF) or atrial flutter (AAFL). Our objective was to examine the efficacy and safety of the Ottawa Aggressive Protocol to convert and discharge ED patients with AAF/AAFL.

Methods: This 5-year cohort study included consecutive visits to a university hospital ED for adults presenting with acute-onset AAF/AAFL and who were managed with the Ottawa Aggressive Protocol. Patients were identified from the National Ambulatory Care Reporting System (NACRS) database. The Aggressive Protocol was overseen by the attending emergency physicians and included: (1) IV procainamide as infusion of 1 gram over 1 hour; (2) electrical cardioversion if necessary, by ED staff; (3) discharge from the ED with outpatient cardiology follow-up. Outcomes included conversion, adverse events, and relapse. The authors conducted descriptive data analyses with 95% CIs.

Results: Characteristics of the 660 eligible patient visits were mean age 64.5 years, mean heart rate 113.4, and mean duration symptoms 8.9 hours, AAF 95.2%, AAFL 4.9%. Overall, 96.8% of patients were discharged home from the ED and 90.3% were discharged in normal sinus rhythm. The respective discharge rates were 97.0% and 93.5% for those in AAF and 93.8% and 87.5% for those in AAFL. All patients received procainamide with a conversion rate of 58.3% (AAF 59.9%, AAFL 28.1%). Electrical cardioversion was attempted in 36.8% of visits with a success rate of 91.7% (AAF 91.0%, AAFL 100%). Adverse events occurred in 7.6% of cases: hypotension 6.7%, bradycardia 0.3%, AAF relapse within 7 days 8.6%, Torsades de Pointes 0%, cerebrovascular accident 0%, mortality 0%.

Conclusions: This is the largest reported study of AAF/AAFL in the ED and demonstrates that the Ottawa Aggressive Protocol is extremely effective for the rapid cardioversion and discharge of patients by ED physicians. This protocol is safe and could lead to a significant decrease in hospital admissions.

6. COX-2 Inhibitor plus PPI Reduces Bleeding in High-Risk Patients

Adding a proton-pump inhibitor to celecoxib treatment in patients at very high risk for ulcer bleeds greatly reduces the incidence of bleeding, according to a Lancet report.

Some 270 patients taking nonselective NSAIDS for arthritis and presenting with upper-GI bleeding underwent randomization — after their ulcers had healed — to treatment with either celecoxib (200 mg twice daily) plus esomeprazole (20 mg twice daily), or celecoxib alone, for a year. The 13-month incidence of recurrent ulcer bleeding was 0% in the combination-therapy group and 8.9% in the controls.

Commentators write that "the finding provides clear guidance for those individuals at greatest gastrointestinal risk who require an NSAID." They add that the new gastrointestinal data should not be interpreted "without careful consideration of competing risks from the cardiovascular perspective."

Lancet article (Free abstract with one-time registration; full text requires subscription):

7. Study Links TV Viewing with Learning Difficulties in Adolescence

Adolescents who watch a lot of television may be at increased risk for attention and learning problems and failure to go beyond high school, a study finds.

The prospective study, published in the Archives of Pediatrics & Adolescent Medicine, used a community-based sample of some 700 mothers and their children. The offspring were interviewed at mean ages of 14, 16, and 22. After controlling for family characteristics and earlier cognitive difficulties, researchers found that frequent TV viewing at age 14 was associated with indicators of subsequent attention and learning difficulties and academic failure. Youngsters who watched 3 or more hours a day were twice as likely to fail to get postsecondary education as those who watched less than an hour.

The authors said healthcare professionals should encourage youths to spend less than 3 hours a day watching TV. The American Academy of Pediatrics recommends no more than 1 to 2 hours a day of television.

AAP's "Children, Adolescents, and Television" --

8. Stroke Among Patients With Dizziness, Vertigo, and Imbalance in the ED: A Population-Based Study

Kerber KA, et al. Stroke 2006;37:2484–7

As part of the Brain Attack Surveillance in Corpus Christi (BASIC) project, this study sought to determine the percentage of stroke patients who presented to the Emergency Department (ED) with the complaints of dizziness, vertigo, or imbalance. This large population-based study examined all patients over the age of 44 years who presented to the ED or were directly admitted to the hospital between January 2000 and June 2003 with the previously mentioned isolated dizziness symptoms (DS) in Nueces County, Texas. The association of age, sex, race/ethnicity, and isolated dizziness symptoms with stroke or transient ischemic attack (TIA) was then determined using multivariable logistic regression.

A total of 1666 patients were included in the study, with 3.2% (53 of 1666) ultimately diagnosed with stroke/TIA. Of those diagnosed, 23 presented with dizziness as the chief complaint, 18 with vertigo, 11 with imbalance, and 1 with more than one of the above symptoms. Isolated DS without additional neurological findings was a strong negative predictor of stroke/TIA (odds ratio [OR] 0.05; 95% confidence interval [CI] 0.02–0.11), whereas male sex was associated with an increased association with stroke/TIA (OR 2.5; 95% CI 1.4–4.4). Patients diagnosed with stroke/TIA were also found to be significantly older (69.3 ± 11.7 vs. 65.3 ± 12.9, p = 0.02). No significant difference in race/ethnicity was found between the stroke and non-stroke groups.

When compared to dizziness, patients with imbalance were found to have an increased risk of stroke/TIA (OR 3.7; 95% CI 1.3–10.7), whereas no increased risk was found between those with vertigo versus dizziness (OR 0.9; 95% CI 0.4–2.0). The authors acknowledge several limitations to this study, including lack of evaluation of the majority of study patients in the ED by a neurologist, lack of magnetic resonance imaging on most study patients leading to possible undiagnosed strokes, and lack of comparison of symptom onset, duration, aggravating/alleviating factors, headache, and auditory symptoms between groups.

The authors conclude that dizziness and vertigo are not associated with stroke/TIA, whereas patients who present with imbalance, those with additional neurologic findings, male gender, and older age are at the highest risk for possible stroke/TIA.

9. A risk score to predict silent AMI in patients with CAD under aspirin therapy presenting with UGI hemorrhage

Silent myocardial ischemia (SMI) is a relatively common complication in patients with coronary artery disease (CAD) under aspirin therapy presenting with upper gastrointestinal hemorrhage (UGIH).

This study was conducted to develop and prospectively validate a risk prediction score to identify SMI in patients undergoing aspirin therapy for CAD presenting with UGIH in the emergency department (ED).

This was a 2-phase noninterventional study. In the derivation phase, adults with CAD under aspirin therapy (100 mg once daily) presenting to the ED with UGIH were retrospectively recruited. By multiple logistic regression analysis, we derived a risk score from 224 patients that predicts the patients' risk of SMI. In the validation phase, we prospectively validated this score using receiver operating characteristic curves with data from 110 patients. We also developed a fast-track screening procedure from this score.

There were 56 patients (25.0%) and 29 patients (26.4%) with SMI in the derivation and validation sets, respectively. Independent multivariate predictors of SMI were age of older than 75 years, severity of CAD, systolic blood pressure of less than 110 mm Hg, diastolic blood pressure of less than 85 mm Hg, hematocrit of less than 30%, and blood urea nitrogen–creatinine ratio of more than 30. The area under receiver operating characteristic curve for the rule was 0.93 in the derivation set and 0.96 in the validation set. At the cutoff value of 5 points or higher, the sensitivity and specificity of the fast-track screening procedure for SMI were 96.6% and 86.4%, respectively. The positive and negative predictive values were 71.8% and 98.6%, respectively.

This simple risk prediction score is easily calculated and is based on rapidly available clinical and laboratory data in the ED. It can be used to stratify patients undergoing aspirin therapy for CAD presenting with UGIH by risk of SMI.

Chen C, et al. Amer J Emerg Med 2007;25:406-413.

10. Albuterol Better Than Epinephrine for Emergency Treatment of Bronchiolitis

By Megan Rauscher. NEW YORK (Reuters Health) May 16 - In the emergency department treatment of infants with bronchiolitis, nebulized albuterol/salbutamol results in more successful discharges than does nebulized epinephrine, according to a double-blind randomized study reported at the annual meeting of the Society for Academic Emergency Medicine in Chicago.

"Because bronchiolitis is very common - it resulted in 149,000 hospital admissions in the U.S. in 2002 -- and racemic albuterol is cheap, the results of this study may have a big impact overall," principal investigator Dr. Paul Walsh of the University of California, Los Angeles told Reuters Health.

Prior outpatient studies that have looked at the emergency department treatment of bronchiolitis were all small and showed either no benefit or a benefit for epinephrine, Dr. Walsh noted. "Most people anticipated that a large study would answer the question and elevate epinephrine to the standard of care. But as has happened before in medicine, one large rigorous trial not only failed to replicate the results of small studies, it actually overturned them," he said.

For their study, the investigators excluded children with bronchiolitis so mild as not to require treatment or so severe as to need intubation, and those older than 18 months of age. Ultimately, the study included 703 infants that received saline mist followed by either nebulized epinephrine and two saline nebulizers (n = 351) or three albuterol nebulizers (n = 352).

"Albuterol was associated with more successful discharges than epinephrine -- an 18% difference in need for admission," Dr. Walsh said. "The benefit, although pretty clearcut, is modest."

It's worth noting, he added, that the trial was stratified on disease severity, which previous work had suggested might be important. "In this study, the benefit was seen across all severity-of-illness groups. Even in all subgroups analyzed, the results remained the same."

"I was as surprised as my collaborators at the results and I suspect many pediatric emergency physicians will be at these results. The take-home message for emergency physicians is that, when confronted with a child with bronchiolitis, try albuterol first," Dr. Walsh concluded.

11. Ultrasound Used to Confirm ETT Placement

A. The Sensitivity and Specificity of Transcricothyroid Ultrasonography to Confirm ETT Placement in a Cadaver Model

Confirmation of endotracheal (ET) tube placement is critical when performing emergency airway management. No single confirmation strategy has emerged as ideal in all circumstances. Our objective in this study was to assess the sensitivity and specificity of a novel approach to verify endotracheal intubation using transcricothyroid ultrasonography (US). We performed a prospective, randomized double-blinded trial in a human cadaver model.

A 7.5-MHz curvilinear probe was placed longitudinally over the cricothyroid membrane as cadavers were randomly intubated in either the trachea or esophagus in two phases: 1) as the intubation was being performed (dynamic) and, 2) after intubation had been completed (static). Volunteer emergency medicine (EM) residents, blinded to tube placement, assessed for esophageal vs. tracheal ET placement using dynamic and static US views. Sensitivity, specificity, positive predictive value, and negative predictive value for detecting esophageal ET placement with 95% confidence intervals were calculated.

Seven EM residents made a total of 70 dynamic and 70 static assessments of ET position using transcricothyroid US. Dynamic assessment resulted in 97% sensitivity and 100% specificity for detecting esophageal ET placement. Static assessment resulted in only 51% sensitivity and 91% specificity. This pilot study suggests that dynamic transcricothyroid US is a potentially accurate method of confirming ET placement during the intubation process. Further investigation in live humans is warranted to validate these data.

Ma G, et al. J Emerg Med 2007;32:405-407.

B. Transtracheal 2-D Ultrasound for Identification of Esophageal Intubation

This prospective, blinded, observational, efficacy study is one of the first to evaluate ultrasound in detecting esophageal intubation, a significant source of morbidity and mortality. We utilized a convenience sample of patients undergoing elective surgery during July 2004 in an urban teaching hospital. Trained Emergency Physician sonographers performed transtracheal ultrasounds of intubations to identify esophageal intubation. In 35 of the 40 patients enrolled, there was intubation of the trachea, whereas esophageal intubation occurred in five patients. Sonographers correctly identified all five esophageal intubations, for a sensitivity of 100% (95% confidence interval [CI] 48–100). Ultrasound correctly identified 34 of 35 tracheal intubations and misidentified one resulting in a specificity of 97% (95% CI 90–100). It seems that transtracheal ultrasound may be an efficacious adjunct for detecting esophageal intubation.

Milling TJ, et al. J Emerg Med 2007;32:409-414.

12. A Multicenter Comparison of Tap Water versus Sterile Saline for Wound Irrigation

Moscati RM, et al. Acad Emerg Med 2007 14: 404-409.

Objectives: To compare wound infection rates for irrigation with tap water versus sterile saline before closure of wounds in the emergency department.

Methods: The study was a multicenter, prospective, randomized trial conducted at two Level 1 urban hospitals and a suburban community hospital. Subjects were a convenience sample of adults presenting with acute simple lacerations requiring sutures or staples. Subjects were randomized to irrigation in a sink with tap water or with normal saline using a sterile syringe. Wounds were closed in the standard fashion. Subjects were asked to return to the emergency department for suture removal. Those who did not return were contacted by telephone. Wounds were considered infected if there was early removal of sutures or staples, if there was irrigation and drainage of the wound, or if the subject needed to be placed on antibiotics. Equivalence of the groups was met if there was less than a doubling of the infection rate.

Results: A total of 715 subjects were enrolled in the study. Follow-up data were obtained on 634 (88%) of enrolled subjects. Twelve (4%) of the 300 subjects in the tap water group had wound infections, compared with 11 (3.3%) of the 334 subjects in the saline group. The relative risk was 1.21 (95% confidence interval = 0.5 to 2.7).

Conclusions: Equivalent rates of wound infection were found using either irrigant. The results of this multicenter trial evaluating tap water as an irrigant agree with those from previous single institution trials.

13. Denver study hints hearts don't keep beat with iPods

Researchers say the music devices interfered with pacemakers in nearly 30 percent of their test group. By Karen Auge, The Denver Post

DENVER — Attention, iPod users: Your music might be breaking Grandpa's heart - and not just because he doesn't care for the lyrics.

A study of 83 volunteers with pacemakers found the music devices interfered with the pacemakers nearly 30 percent of the time.

The results of the study, conducted by Michigan high school student Jay Thayer and Dr. Krit Jongnarangsin, a University of Michigan cardiologist, were presented Thursday at the Heart Rhythm Society meeting in Denver. The society is a professional group focusing on irregular heart rhythm. In most cases, the iPod interference caused pacemakers to misread the heart's pacing. In one, the pacemaker stopped altogether.

The iPod - like microwave ovens, cellphones and other electronic devices - appears to cause a problem by creating an electromagnetic field that interferes with the electric function of the pacemakers, Thayer said. "That seems to be the root," he said.

Thayer said the University of Michigan engineering department is looking into the electromagnetic effects of the iPod. In the study, Thayer and Jongnarangsin placed iPods 2 inches from the chests of 83 volunteers with pacemakers and then turned on the music.

Thayer, 17, said the average age of volunteers in his study was 77.

"We set the headphones on their shoulders so we didn't blow out their eardrums," he said, and then turned up the Frank Sinatra tunes. Most participants didn't use iPods, but "a lot of them had grandkids that use iPods," he said.

Thayer, who said he hopes to become a physician, like his mother and father, got interested in the iPod/pacemaker issue when one of his father's pacemaker-using patients raised the question.

Thayer said he and his father searched for an answer but couldn't find any research on the topic.

Apple reports that it has sold 100 million iPods since launching them in 2000. It's not clear how many iPod users have pacemakers. Cupertino, Calif.-based Apple declined to comment.

Jongnarangsin said he treats many elderly patients with pacemakers but that none have ever inquired about the compatibility of the music devices. The question the two researchers will now address is just how close is too close when it comes to iPods and pacemakers.

First, Thayer has to graduate from high school.

14. ED Management of Acute Pain Episodes in Sickle Cell Disease

Tanabe P, et al. Acad Emerg Med 2007 14: 419-425

Objectives: To characterize the initial management of patients with sickle cell disease and an acute pain episode, to compare these practices with the American Pain Society Guideline for the Management of Acute and Chronic Pain in Sickle-Cell Disease in the emergency department, and to identify factors associated with a delay in receiving an initial analgesic.

Methods: This was a multicenter retrospective design. Consecutive patients with an emergency department visit in 2004 for an acute pain episode related to sickle cell disease were included. Exclusion criteria included age younger than 18 years. A structured medical record review was used to abstract data, including the following outcome variables: analgesic agent and dose, route, and time to administration of initial analgesic. Additional variables included demographics, triage level, intravenous access, and study site. Mann–Whitney U test or Kruskal–Wallis test and multivariate regression were used to identify differences in time to receiving an initial analgesic between groups.

Results: There were 612 patient visits, with 159 unique patients. Median time to administration of an initial analgesic was 90 minutes (25th to 75th interquartile range, 54–159 minutes). During 87% of visits, patients received the recommended agent (morphine or hydromorphone); 92% received the recommended dose, and 55% received the drug by the recommended route (intravenously or subcutaneously). Longer times to administration occurred in female patients (mean difference, 21 minutes; 95% confidence interval = 7 to 36 minutes; p = 0.003) and patients assigned triage level 3, 4, or 5 versus 1 or 2 (mean difference, 45 minutes; 95% confidence interval = 29 to 61 minutes; p = 0.00). Patients from study sites 1 and 2 also experienced longer delays.

Conclusions: Patients with an acute painful episode related to sickle cell disease experienced significant delays to administration of an initial analgesic.

15. US-guided supraclavicular block for the treatment of upper extremity fractures, dislocations, and abscesses in the ED

Emergency department (ED) patients with fractures, dislocations, or abscesses of the upper extremities often require closed reduction or incision and drainage to treat these conditions. Procedural sedation is often necessary when infiltration of local anesthetic provides insufficient analgesia. Anesthesiologists commonly perform supraclavicular brachial plexus nerve blocks to achieve analgesia for upper extremity surgery. We report a series of 5 ED patients in whom supraclavicular brachial plexus nerve blocks using real-time ultrasound guidance provided excellent analgesia and obviated the need for procedural sedation.

Stone MB, et al. Amer J Emerg Med 2007;25:472-475.

16. WHO Releases Global Health Statistics

The World Health Organization has released its 2007 compendium of health statistics.

Among the highlights:

--Life expectancy at birth in 2005 ranged from 37 in Sierra Leone to 80 in San Marino for men and from 37 in Swaziland to 86 in Japan for women. U.S. life expectancy was 75 for men and 80 for women.

--The leading causes of death in 2030 are projected to be cancers, ischemic heart disease, stroke, HIV/AIDS, and chronic obstructive pulmonary disease. Tobacco-related deaths are projected to rise from 5.4 million in 2005 to 6.4 million in 2015 and 8.3 million in 2030.

--Ten percent of the world's children under age 5 years suffer wasting as a result of malnutrition, according to 2005 data.

--In 2004, the world spent $4.1 trillion on health.

--In 2002, depression accounted for 4.5% of the total burden of disease worldwide.

WHO report (Free PDFs):

17. Education Tool Entitled "tPA for Stroke - Potential Benefit, Risk, and Alternatives" Now Available

AAEM has created an Education Tool entitled ‘tPA for Stroke - Potential Benefit, Risk, and Alternatives,’ which can be viewed at

The document is designed to help emergency physicians inform patients and family members about the pros and cons of tPA for stroke in appropriate patients.

American Academy of Emergency Medicine

18. Unanticipated Death After Discharge Home From the ED

Sklar DP, et al. Ann Emerg Med. 2007;49:735-745.

Editor’s Capsule Summary
What is already known on this topic: Death of a patient shortly after emergency department (ED) discharge is every emergency physician’s fear, but little is known about the frequency of such events or factors that might contribute to them.

What question this study addressed: The frequency of death occurring within 7 days of ED discharge, whether the death was unexpected, and, if so, whether a medical error may have been contributory.

What this study adds to our knowledge: In this review of almost 400,000 patients discharged from an academic medical center during a 10-year period, roughly 30 per 100,000 patients died within 7 days of ED discharge, 20 per 100,000 unexpectedly and 9 per 100,000 with a potentially contributory medical error. Atypical presentations, exacerbation of chronic disease, abnormal vital signs, and substance abuse were common themes.

How this might change clinical practice: These data may inform efforts to decrease medical errors and identify high-risk patients, such as developing better methods for assessing the significance of abnormal vital signs.

19. Predicting ETT Size by Length in Newborns

The objective of this study was to determine the relationship of length to endotracheal tube (ETT) size in newborns and to use this relationship to develop a tool for predicting ETT size.

The study, a prospective derivation, and validation of a predictive model, took place in the neonatal intensive care units (NICUs) in two urban teaching hospitals. Subjects included: ETT derivation set − 39 intubated neonates admitted to the NICU; Validation set − 69 intubated newborns from the same NICU. Leak percentages were measured in intubated neonates where the actual ETT size did not correlate with the tape-determined ETT size. Interventions were length, weight, and leak measurements. A prototype tape was developed using the derivation set and published anthropometric studies. The accuracy of the tape was validated on a separate set of newborns.

The average relative difference between tape-predicted weight and actual weight was 9.5% (confidence interval [CI] = 8.3–10.6%) and was evenly distributed throughout all the weight groups. The tape predicted actual ETT size in 96% of cases (CI 86.3–99.5%) and was correct within 1 tube size (1/2 mm) in 100% (CI 94.8–100%). The only error in prediction of ETT size was in underestimation. Length-based weight estimations were tested on 100 subjects and predicted actual weight within 20% in 94% of cases. We concluded that length is an accurate predictor of ETT size and weight in term and preterm newborns and may be useful in situations in which weights are unobtainable, such as emergency resuscitation.

Luten R, et al. J Emerg Med 2007;32:342-347.

20. Risk Factors for Traumatic or Unsuccessful LPs in Children

Nigrovic LE, et al. Ann Emerg Med 2007; 49:762-771.

Study objective: Traumatic and unsuccessful lumbar punctures can cause substantial diagnostic ambiguity that may lead to unnecessary antibiotic use and hospitalization, in addition to patient discomfort. Risk factors for obtaining traumatic and unsuccessful lumbar punctures have been studied in a limited fashion only. We sought to determine patient, physician, and procedural factors associated with traumatic and unsuccessful lumbar punctures in children.

Methods: The study included a prospective cohort of all children undergoing lumbar punctures in a single emergency department between July 2003 and January 2005. Our main outcome was either a traumatic lumbar puncture (cerebrospinal fluid RBC counts ≥10,000 cells/mm3) or unsuccessful lumbar puncture (failure of the procedure to yield fluid for cell counts) after the first lumbar puncture attempt. We performed multiple logistic regression analyses to identify independent predictors of traumatic or unsuccessful lumbar punctures.

Results: Of the 1,474 eligible lumbar punctures, 1,459 (99%) were included in the analysis. Of these, 513 (35%) were traumatic or unsuccessful on the first attempt. After adjustment for patient characteristics, physician and procedural factors associated with an increased risk of a traumatic or unsuccessful lumbar puncture included less physician experience (adjusted odds ratio for an ordinal decrease in experience 1.08; 95% confidence interval [CI] 1.01 to 1.15), lack of local anesthetic use (adjusted odds ratio 1.6; 95% CI 1.1 to 2.2), advancement of the spinal needle with stylet in place versus stylet removed (adjusted odds ratio 1.3; 95% CI 1.04 to 1.7), and increased patient movement (adjusted odds ratio 2.1; 95% CI 1.6 to 2.6).

Conclusion: Of the factors associated with traumatic or unsuccessful lumbar punctures in children, advancement of the spinal needle with the stylet in place and lack of local anesthetic use are the most modifiable. Modification of these procedural factors may reduce the risk of traumatic or unsuccessful lumbar punctures in children.