Daniel J. Isaacman

Effect of number of blood cultures and volume of blood on detection of bacteremia in children.

OBJECTIVE To determine whether bacteremia can be detected more rapidly and completely by (1) obtaining two blood cultures instead of one and/or (2) collecting a larger volume of blood. STUDY DESIGN Prospective comparison of different strategies in 300 patients undergoing blood culture for suspected bacteremia. Each patient had two samples of blood, A (2 ml) and B (9.5 ml), obtained sequentially from separate sites. The B sample was divided into three aliquots: B1 (2 ml), B2 (6 ml), and ISO (1.5 ml, quantitative culture). RESULTS A pathogen was isolated from one or more blood cultures in 30 patients (10% of cases). When measured at 24 hours, the pathogen recovery rate for the B2 sample (72%) was higher than that for the individual small-volume samples (A = 37%, B1 = 33%; p < 0.01 for each comparison) and for the combination of the two small-volume samples (A + B1 = 47%; p = 0.04). At final (7-day) reading the pathogen recovery rate for the B2 sample (83%) was higher than that for B1 (60%; p = 0.02) and similar to the recovery rate observed with the combination of the two small-volume cultures (A + B1 = 73%; p = 0.55). CONCLUSIONS Increasing the volume of blood inoculated into blood culture bottles improves the timely detection of bacteremia in pediatric patients and spares the patients the cost and pain of an additional venipuncture.

Surveillance for invasive pneumococcal disease during 2000-2005 in a population of children who received 7-valent pneumococcal conjugate vaccine

Objectives: To assess the incidence of invasive pneumococcal disease (IPD) in all children younger than 5 years of age in the Northern California Kaiser Permanente (NCKP) health care system during a 5-year surveillance period (2000–2005) after the introduction in April 2000 of routine use of 7-valent pneumococcal conjugate vaccine (PCV7). Methods: This was a laboratory-based surveillance study of all children younger than 5 years of age in the NCKP health care system from April 2000 to March 2005. The comparison group was all children younger than 5 years of age in the NCKP health care system from April 1996 to March 2000. Data obtained from clinical databases included microbiologic identification and susceptibility testing; serotyping of isolates; immunization records; and IPD diagnoses for inpatients and outpatients. IPD was defined as a positive culture of Streptococcus pneumoniae from a normally sterile body site. Results: For all serotypes, the mean annual incidence of IPD during the postlicensure surveillance period was 15.3 cases/100,000 person-years (105 p-y) compared with 62.5 cases/105 p-y in the prelicensure years of 1996–2000. The average incidence of IPD caused by vaccine serotypes was reduced from 50.1 cases/105 p-y during the prelicensure years to 4.9 cases/105 p-y during the postlicensure period. The average incidences of IPD caused by cross-reactive and by nonvaccine serotypes were 5.8 and 5.3 cases/105 p-y, respectively, during the prelicensure years and 2.5 and 6.2 cases/105 p-y, respectively, during the postlicensure period. Of the 131 IPD cases observed during the postlicensure surveillance period, bacteremia (50.4%) and pneumonia (31.3%) were the most common diagnoses. During the 5-year postlicensure surveillance period, only 3 subjects who were identified to be fully vaccinated for age with PCV7 (3 doses by 7 months of age or 4 doses by 18 months of age) developed vaccine-serotype IPD. Conclusion: The incidence of IPD has significantly decreased in a large population of children after the introduction of PCV7. Vaccine-type IPD was rare in patients who received full 4-dose immunization with PCV7. There is no clear evidence of a significant increase in nonvaccine-serotype IPD. Introduction of a 4-dose infant schedule of PCV7 into this population has resulted in a marked and sustained reduction of IPD in children.

Local anesthetic and stylet styles: factors associated with resident lumbar puncture success.

OBJECTIVE. To assess the effects of procedural techniques, local anesthetic use, and postgraduate training level on lumbar puncture (LP) success rates. METHODS. In this prospective observational study, medical students and residents (“trainees”) reported techniques used for infant LPs in an urban teaching emergency department. Data on postgraduate year, patient position, draping, total and trainee numbers of attempts, local anesthetic use, and timing of stylet removal were collected. Logistic regression analysis was used to identify predictors of successful LP, with success defined as the trainee obtaining cerebrospinal fluid with <1000 red blood cells per mm3. RESULTS. We collected data on 428 (72%) of 594 infant LPs performed during the study period. Of 377 performed by trainees, 279 (74%) were successful. Local anesthesia was used for 280 (74%), and 225 (60%) were performed with early stylet removal. Controlling for the total number of attempts, LPs were 3 times more likely to be successful among infants >12 weeks of age than among younger infants (odds ratio [OR]: 3.1; 95% confidence interval [CI]: 1.2–8.5). Controlling for attempts and age, LPs performed with local anesthetic were twice as likely to be successful (OR: 2.2; 95% CI: 1.04–4.6). For infants ≤12 weeks of age, early stylet removal improved success rates (OR: 2.4; 95% CI: 1.1–5.2). Position, drape use, and year of training were not significant predictors of success. CONCLUSIONS. Patient age, use of local anesthetic, and trainee stylet techniques were associated with LP success rates. This offers an additional rationale for pain control. Predictors identified in this study should be considered in the training of physicians, to maximize their success with this important procedure.

Nonurgent pediatric emergency department visits: Care-seeking behavior and parental knowledge of insurance

Objectives The goals of this study were to describe the factors associated with utilization of emergency services for nonurgent illnesses by insured children in a pediatric emergency department (PED) and to assess parental knowledge of their insurance and its influence on care-seeking behaviors. Methods We conducted a prospective, descriptive survey of parents of insured children evaluated for nonurgent illnesses in an urban PED. Results A total of 251 surveys were completed. The primary reason chosen by the parent for the PED visit was convenience in 62.8% of cases, a perceived true emergency in 33.6%, and lack of other access to a physician in 3.6%. Parents choosing the PED for perceived emergencies were more likely to state that the illness was life threatening or required hospital admission than those who came because of convenience (33/84 vs. 28/157;P < 0.001). Only 38.7% stated that they were educated as to what problems are considered emergencies by their insurance carriers. PED referrals for nonurgent complaints are required by the insurance carrier for 74.9% of the population; however, only 37.2% of the parents stated that referrals were necessary. Primary care physician (PCP) contact was made prior to the visit by 45.4% of parents. Of those who called the PCP, 72.6% stated that they were referred to the PED. Of the parents who believed that a referral was required, those stating that the problem was an emergency were more likely to have contacted the PCP than those who came because of convenience (27/37 vs. 22/46;P < 0.037). Conclusions Parents frequently do not understand their insurance coverage as it relates to emergency care utilization. This lack of knowledge influences their care-seeking behaviors for nonurgent illnesses. Convenience is a significant factor in PED utilization for nonurgent complaints.

Lack of effect of changing needles on contamination of blood cultures

To determine whehter changing needles during the collection of blood cultures to 1 of 3 groups: no needle changes (blood instilled directly into culture media through the needle used for venipuncture); 1 needle change (before inoculation into the first of 2 culture bottles); and 2 needle changes (before inoculation into each of 2 culture bottles). Each patients skin was cleansed with povidoneiodine for 60 seconds before venipuncture. We found similar rates of contamination among the 3 groups: no change, 2 of 92 (2.2%); 1 change, 0 of 106 (0.0%); 2 changes, 2 of 105 (1.9%). The combined contamination rate of all 3 groups (1.3%) was significantly lower than the prestudy rate of contamination (4.4%), based on 315 blood cultures (P = 0.04). These data suggest that careful skin preparation is a more important factor than changing needles in reducing contamination during blood culture collection.

Pain, position, and stylet styles: infant lumbar puncture practices of pediatric emergency attending physicians.

Objectives: Lumbar punctures (LPs) are common emergency department (ED) procedures. Few pediatric studies exist to define training, guide practice, or indicate preferred methods for infants. While pain control is recommended, no recent studies indicate prevalence of analgesic use since the advent of topical anesthetics. We surveyed academic pediatric ED physicians to assess training and technique preferences and to highlight pain control usage. Methods: A total of 398 physicians were randomly selected from the 621 e-mail accessible members of the AAP Section on Pediatric Emergency Medicine. Questions concerning physician training, analgesia, and technique were either sent by regular mail or via e-mail link to a Web-based survey. Results: Of 359 deliverable surveys, there were 188 physician responses (52.4%) with differential response rates by survey format [58 e-mail (36%) and 130 regular mail responses (66%); P < 0.05]. Almost a third will advance the needle without the stylet in place. Two-thirds of physicians do not routinely use analgesia for neonatal LPs. Those using pain control were trained more recently (median 12 years vs. 15 years postresidency; P = 0.04). Analgesia use was the most common practice changed since residency. Conclusions: Analgesia is underused for infant LPs. Advancing the needle without a stylet is not uncommon. Response rate to regular mail surveys was much higher.

Utility of collecting blood cultures through newly inserted intravenous catheters.

We prospectively examined the utility of obtaining blood cultures through newly inserted intravenous catheters in 99 children who required both a blood culture and placement of an intravenous catheter. Two blood cultures were collected from each patient, one through a freshly inserted intravenous catheter and another through a butterfly needle at a separate venipuncture site. A standardized technique of skin preparation with povidone-iodine was used. The rate of contamination was 1.0% (95% confidence intervals, 0 to 3.0%) for each method. Ten patients had blood cultures yielding true pathogens; in five of these bacteremic children, only one of two sets of blood cultures was positive. We conclude that blood cultures can be collected through freshly placed intravenous catheters without increasing the risk of contamination. These results also raise the possibility that obtaining two blood cultures instead of a single culture may improve the detection of bacteremia in children.

Effect of a research nurse on patient enrollment in a clinical study.

Objectives To assess the effect of adding a shared research nurse on patient enrollment in an ongoing clinical study. Design Before/after comparison of recruitment rates and consent rates involving patients eligible for a study of blood culture collection strategies for methods on the detection of bacteremia and determination of inter-rater agreement regarding study eligibility between the research nurse and primary investigator. Setting An urban pediatric emergency department (ED). Participants Patients presenting to the ED between February 1,1991, and February 1,1993, with suspected bacteremia. Intervention Addition of a research nurse to the study group to identify, educate, and enroll eligible study patients. Main outcome measure Patient enrollment rates. Results Successful enrollment of eligible study patients was 14% (40/281) during the year prior to the addition of the research nurse and 50% (126/253) after the addition (P < 0.001). Refusal rates were 21% (22/106) when recruitment was carried out by the nurse and 15% (13/86) when done by physicians (P = 0.41). Review of records to identify eligible study patients showed agreement between the study nurse and physician on 78/80 (97.5%) of the charts reviewed (K = 0.94). Conclusions Addition of a shared research nurse increased recruitment of patients and demonstrated equivalent judgment of the research nurse and physician investigators regarding patient eligibility for the study. This arrangement demonstrates a practical and effective means of increasing the efficiency of ED-based clinical research.

A simple intervention for improving telephone contact of patients discharged from the emergency department

Objective To determine if emergency department (ED) follow-up contact rates can be improved by confirming a best contact telephone number with the patient prior to discharge. Design/Setting Prospective comparison of intervention and control groups taken from convenience samples of ED patients from Childrens Hospital of Pittsburgh (CHP) and Childrens Hospital of Wisconsin (CHW). Participants One hundred eighty-eight (188) patients (138 from CHP and 50 from CHW) who had x-rays and laboratory studies done in the ED were interviewed by the investigators prior to discharge (intervention group) and 305 control patients (256 from CHP, 49 from CHW) identified from ED log books. Intervention Prior to discharging the patient from the ED, the investigators verified and/or corrected the best contact number for a follow-up phone call with each intervention patient. Within 24 hours of each visit, a follow-up call was made to each intervention and control patient during one of three time intervals spaced between 8 AM and 10 PM. Results A total of 29 patients, or 15.4%, of the intervention group, gave a telephone number that differed from the one listed in the patients medical record. Of the CHP group, 93.5% (129/138) of intervention patients and 78.5% (201/256) of control patients were successfully contacted (P < 0.001). Of the CHW group, 96% (48/50) of intervention patients, and 94% (46/49) of control patients were successfully contacted (P = NS). Successful contact of control patients was greater in CHW than CHP (46/49 vs 201/256, P = 0.02). Conclusions A significant proportion of telephone numbers listed in the ED medical records are incorrect, but the frequency of inaccuracy may be institution-dependent. Confirming the patients “best contact” number can significantly increase the successful contact of ED patients.

Group B streptococcal retropharyngeal cellulitis in a young infant: a case report and review of the literature

The diagnosis of retropharyngeal cellulitis and abscess, although most common in children under 6 years of age, is often misdiagnosed in the newborn or early infancy period. The clinical signs of drooling, neck swelling, dysphagia, and torticollis may be absent or not easily identifiable. The following case report details a 2 1/2-month-old infant who presented with fever and irritability, and was subsequently diagnosed with group B streptococcal retropharyngeal cellulitis. Retropharyngeal cellulitis and abscess should be considered in the differential diagnosis of infants and young children who present with fever and irritability, particularly when lumbar puncture results are normal. This case also serves to highlight a rare manifestation of late-onset group B steptococcal disease.