Ming Yuan Hong

Different impact of the appropriateness of empirical antibiotics for bacteremia among younger adults and the elderly in the ED

OBJECTIVESnTo investigate the clinical impact of age on bacteremia among adults visiting the emergency department (ED).nnnMETHODSnBacteremic adults visiting the ED from January 2008 to December 2008 were identified retrospectively. Demographic characteristics, severity, bacteremic pathogens with in vitro susceptibility, antimicrobial agents, and outcomes determined from chart records were analyzed as a case-control study.nnnRESULTSnOf 518 eligible bacteremic adults, 288 (55.6%) elderly patients (≥65 years old) were case patients and 230 younger patients (<65 years) were regarded as control patients. The 28-day mortality rate was higher in the case patients than that in the control patients (11.8% vs 6.1%, P = .02). The proportion of inappropriate empirical antibiotic therapy between the survivors and nonsurvivors was similar in control patients (69.4% vs 64.3%, P = .77); but for the case patients, the proportion of inappropriate empirical antibiotic therapy in the survivors was lower than that in the non-survivors (27.6% vs 44.1%, P = .04). Of note, inappropriate empirical antibiotic therapy was also one of independent risk factors of 28-day mortality by the multivariate analyses in the case patients (odds ratio [OR] 3.65; P = .049). Other independent predictors of 28-day mortality in case patients included a high Pittsburgh bacteremia score (≥4 points; OR 22.16; P < .001), bacteremia due to foci other than urinary tract infection (OR 9.07; P = .002), malignancy (OR 10.87; P < .001), coronary artery disease (OR 5.68; P = .01), and high serum creatinine (>1.5 mg/dL; OR 3.44; P = .04).nnnCONCLUSIONSnFor bacteremic adults, this study demonstrated the impact of inappropriate empirical antibiotic therapy on patients outcome in the elderly was greater than that in the younger adults.

Pitfalls in using serum C-reactive protein to predict bacteremia in febrile adults in the ED

OBJECTIVESnThe diagnostic performance of serum C-reactive protein (CRP) in prediction of bacteremia among febrile patients visiting an emergency department (ED) was analyzed.nnnMETHODSnDuring randomly selected 96 days between August 2006 and July 2007, a prospective study of febrile adults visiting the ED of a medical center was conducted to analyze the clinical characters associated with bacteremia.nnnRESULTSnOf the total 454 febrile adults enrolled, their mean age was 54.1 years, and 232 (54.6%) were women. Major comorbidities included cardiovascular disease (137 patients, or 30.1%) and diabetes mellitus (105, or 23.1%). Seventy-four patients (16.2%) had true bloodstream infections with the predominance of monomicrobial gram-negative bacteremia in 49 patients (10.7%). Four risk factors, including low platelet count (<100 000/mm(3); odds ratio [OR], 4.19; 95% confidence interval [CI], 1.85-9.47; P = .001), high blood urea nitrogen (>20 mg/dL; OR, 4.61; 95% CI, 2.56-8.31; P < .001), high fever (>39.0°C; OR, 3.67; 95% CI, 2.05-6.59; P < .001), and high Pittsburg bacteremia scores (≧4 points; OR, 2.95; 95% CI, 1.01-8.57; P = .04) were independently associated with bacteremic episodes. Of note, high CRP (>150 mg/dL; OR, 1.75; 95% CI, 0.73-3.99; P = .21) was not an independent risk factor. In further analysis, the difference of serum CRP levels between bacteremic and nonbacteremic adults was significant only when the period from fever onset to ED arrival was more than 12 hours.nnnCONCLUSIONSnThe CRP level was not reliable to distinguish the bacteremia from nonbacteremic infection, whereas duration after fever onset was less than 12 hours. Clinicians must consider the history of fever onset to improve the accuracy of early prediction of serum CRP before the microbiological results of blood cultures is available.

Atypical presentations of dengue disease in the elderly visiting the ED

OBJECTIVEnThe objective was to compare the clinical characteristics of elderly and young adult patients with dengue in the emergency department (ED).nnnMETHODSnDemographic characteristics, clinical presentation, disease severity, laboratory characteristics, and outcomes were analyzed prospectively as a case-control study.nnnRESULTSnOf the 193 adults with serologically confirmed dengue disease in 2007, 31 (16.1%) were elderly patients (aged ≥65) and 162 were young adults (aged <65). More dengue hemorrhagic fever (12.9% vs 2.5%, P = .02), a longer ED stay (13.3 vs 8.6 hours, P = .004), a longer hospital stay (7.4 vs 3.4 days, P < .001), a higher Simplified Acute Physiology Score II in the ED (29.7 vs 17.4, P < .001), and a higher rate of at least 1 comorbidity (61.8 vs 22.8%, P < .001) were found in the elderly. However, the length of the intensive care unit stay (elderly 0.7 vs young adults 0.3 day, P = .47) and the 14-day mortality rate (0% vs 0.6%, P = 1.00) were similar. Of note, in terms of clinical presentations of dengue in the ED, there were more elderly patients with isolated fever (41.9% vs 17.9%, P = .003) and fewer with typical presentation (41.9% vs 75.9%, P = <.001) than there were young adults.nnnCONCLUSIONSnThe present study found a higher number of atypical presentations, a longer hospitalization, and a higher degree of clinical illness in elderly patients with dengue.

Factors Related to Missed Diagnosis of Incidental Scabies Infestations in Patients Admitted Through the Emergency Department to Inpatient Services

OBJECTIVESnScabies is highly contagious and requires prompt diagnosis and implementation of infection control measures to prevent transmission and outbreaks. This study investigated the clinical and administrative correlates associated with missed diagnosis of scabies in an emergency department (ED).nnnMETHODSnThis was a retrospective study of patients with incidental scabies infestations who were admitted to a university hospital via the ED during a 4-year period.nnnRESULTSnA total of 135 inpatients were identified as having scabies; among them, 111 patients (82%) had visited the ED. Scabies were diagnosed during the ED stay in 39 of 111 patients (35%), while the diagnosis was missed in the ED in 72 patients (65%). Although no geographic clusters suggestive of nosocomial scabies transmission were registered, 160 medical workers and one hospitalized patient received prophylactic treatment due to direct skin-to-skin contact with inpatient scabies cases during the study period. Overcrowding (odds ratio [OR]u2009= 8.4; 95% confidence interval [CI]u2009= 1.9 to 38.0) and time constraints (ORu2009= 8.2; 95% CIu2009= 1.9 to 34.7) in the ED were associated with a missed diagnosis of scabies during ED stay. Patients with lower illness severity scores were at higher risk for failure to diagnose and to treat scabies prior to hospital admission (ORu2009= 5.7; 95% CIu2009= 1.6 to 20.9).nnnCONCLUSIONSnMissed diagnoses of scabies during ED stay may result in nosocomial spread and increase the unnecessary use of prophylactic treatments. ED overcrowding, time constraints, and less severe illness compromise ED recognition of scabies. Health care workers should be especially alert for signs of scabies infestations under these conditions.

Empirical third-generation cephalosporin therapy for adults with community-onset Enterobacteriaceae bacteraemia: Impact of revised CLSI breakpoints

Third-generation cephalosporins (3GCs) [ceftriaxone (CRO) and cefotaxime (CTX)] have remarkable potency against Enterobacteriaceae and are commonly prescribed for the treatment of community-onset bacteraemia. However, clinical evidence supporting the updated interpretive criteria of the Clinical and Laboratory Standards Institute (CLSI) is limited. Adults with community-onset monomicrobial Enterobacteriaceae bacteraemia treated empirically with CRO or CTX were recruited. Clinical information was collected from medical records and CTX MICs were determined using the broth microdilution method. Eligible patients (n=409) were categorised into de-escalation (260; 63.6%), no switch (115; 28.1%) and escalation (34; 8.3%) groups according to the type of definitive antibiotics. Multivariate regression revealed five independent predictors of 28-day mortality: fatal co-morbidities based on McCabe classification [odds ratio (OR)=19.96; P<0.001]; high Pitt bacteraemia score (≥4) at bacteraemia onset (OR=13.91; P<0.001); bacteraemia because of pneumonia (OR=5.45; P=0.007); de-escalation after empirical therapy (OR=0.28; P=0.03); and isolates with a CTX MIC≤1mg/L (OR=0.17; P=0.02). Of note, isolates with a CTX MIC≤8mg/L (indicated as susceptible by previous CLSI breakpoints) were not associated with mortality. Furthermore, clinical failure and 28-day mortality rates had a tendency to increase with increasing CTX MIC (γ=1.00; P=0.01). Conclusively, focusing on patients with community-onset Enterobacteriaceae bacteraemia receiving empirical 3GC therapy, the present study provides clinically critical evidence to validate the proposed reduction in the susceptibility breakpoint of CTX to MIC≤1mg/L.

Push-fast recommendation on performing CPR causes excessive chest compression rates, a manikin model

BACKGROUNDnIncreasing chest compression rate during cardiopulmonary resuscitation can affect the workload and, ultimately, the quality of chest compression. This study examines the effects of compression at the rate of as-fast-as-you-can on cardiopulmonary resuscitation (CPR) performance.nnnMETHODSnA crossover, randomized-to-order design was used. Each participant performed chest compressions without ventilation on a manikin with 2 compression rates: 100 per minute (100-cpm) and push as-fast-as you-can (PF). The participants performed chest compressions at a rate of either 100-cpm or PF and subsequently switched to the other after a 50-minute rest.nnnRESULTSnForty-two CPR-qualified nonprofessionals voluntarily participated in the study. During the PF session, the rescuers performed CPR with higher compression rates (156.8 vs 101.6 cpm), more compressions (787.2 vs 510.8 per 5 minutes), and more duty cycles (51.0% vs 41.7%), but a lower percentage of effective compressions (47.7% vs 57.9%) and a lower compression depth (35.6 vs 38.0 mm) than they did during the 100-cpm session. The CPR quality deteriorated in numbers and percentile of effective compression since the third minute in the PF session and the fourth minute in the 100-cpm session. The percentile of compressions with adequate depth in the 100-cpm sessions was higher than that in the PF sessions during the second, third, and fourth minutes of CPR.nnnCONCLUSIONnPush-fast technique showed a significant decrease in the percentile of effective chest compression compared with the 100-cpm technique during the 5-minute hand-only CPR. The PF technique exhibited a trend toward increased fatigue in the rescuers, which can result in early decay of CPR quality.

Propensity score-matched analysis comparing the therapeutic efficacies of cefazolin and extended-spectrum cephalosporins as appropriate empirical therapy in adults with community-onset Escherichia coli, Klebsiella spp. and Proteus mirabilis bacteraemia

In this study, the therapeutic efficacy of cefazolin was compared with that of extended-spectrum cephalosporins (ESCs) (cefotaxime, ceftriaxone and ceftazidime) as appropriate empirical therapy in adults with community-onset monomicrobial bacteraemia caused by Escherichia coli, Klebsiella spp. or Proteus mirabilis (EKP). Compared with cefazolin-treated patients (nu2009=u2009135), significantly higher proportions of patients in the ESC treatment group (nu2009=u2009456) had critical illness at bacteraemia onset (Pitt bacteraemia score ≥4) and fatal co-morbidities (McCabe classification). Of the 591 patients, 121 from each group were matched using propensity score matching (PSM) based on the following independent predictors of 28-day mortality: fatal co-morbidities (McCabe classification); Pitt bacteraemia score ≥4 at bacteraemia onset; initial syndrome of septic shock; and bacteraemia due to pneumonia. After appropriate PSM, no significant differences were observed in the early clinical failure rate (10.7% vs. 7.4%; Pu2009=u20090.37), the proportion of critical illness (Pitt bacteraemia score ≥4) (0% vs. 0%; Pu2009=u20091.00) and defervescence (52.6% vs. 42.6%; Pu2009=u20090.13) on Day 3 between the cefazolin and ESC treatment groups. Similarly, no significant differences were observed in the mean of time to defervescence (4.1 days vs. 4.9 days; Pu2009=u20090.15), late clinical failure rate (18.2% vs. 10.7%; Pu2009=u20090.10) and 28-day crude mortality rate (0.8% vs. 3.3%; Pu2009=u20090.37) between the two groups. These data suggest that the efficacy of cefazolin is similar to that of ESCs when used as appropriate empirical antimicrobial treatment for community-onset EKP bacteraemia.

Electromyography activity of selected trunk muscles during cardiopulmonary resuscitation

BACKGROUNDnUnderstanding trunk muscle activity during chest compression may improve cardiopulmonary resuscitation (CPR) training strategies of CPR or prevent low back pain. This study investigates the trunk muscle activity pattern of chest compression in health care providers to determine the pattern alternation during chest compression.nnnMETHODSnThirty-one experienced health care providers performed CPR for 5 minutes at a frequency of 100 compressions per minute. An electromyography (EMG) system was used to record muscle activity in the first minute, the third minute, and the fifth minute. Electrodes were placed bilaterally over the pectoralis major, latissimus dorsi, rectus abdominis, erector spinae, and gluteus maximus. We calculated the root mean square (RMS) value and maximal amplitude of the EMG activity, median frequency, and delivered force.nnnRESULTSnThe maximal amplitude of EMG of the pectoralis major, erector spinae, and rectus abdominis showed large muscle activity above 45% of maximal voluntary contraction under chest compression. There were no significant differences in the RMS value of one chest compression cycle (RMS100%) and median frequency for all muscles at the first, third, and fifth minutes. Only gluteus maximus showed significant imbalance. The EMG ratios (erector spinae/rectus abdominis; erector spinae/gluteus maximus) increased significantly over time. The delivered force, compression depth, and number of correct depth decreased significantly over time.nnnCONCLUSIONnWe suggest that the muscle power training for the pectoralis major, erector spinae, and rectus abdominis could be helpful for health care providers. Keeping muscle activity balance of bilateral gluteus maximus and maintaining the same level of EMG ratios might be the keys to prevent low back pain while performing CPR.

Prognostic values of blood ammonia and partial pressure of ammonia on hospital arrival in out-of-hospital cardiac arrests

PURPOSESnOutcome prediction for out-of-hospital cardiac arrest (OHCA) is of medical, ethical, and socioeconomic importance. We hypothesized that blood ammonia may reflect tissue hypoxia in OHCA patients and conducted this study to evaluate the prognostic value of ammonia for the return of spontaneous circulation (ROSC).nnnMETHODSnThis prospective, observational study was conducted in a tertiary university hospital between January 2008 and December 2008. The subjects consisted of OHCA patients who were sent to the emergency department (ED). The primary outcome was ROSC. The prognostic values were calculated for ammonia levels and the partial pressure of ammonia (pNH(3)), and the results were depicted as a receiver operating characteristics curve with an area under the curve.nnnRESULTSnAmong 119 patients enrolled in this study, 28 patients (23.5%) achieved ROSC. Ammonia levels and pNH(3) in the non-ROSC group were significantly higher than those in the ROSC group (167.0 μmol/L vs 80.0 μmol/L, P < .05; 2.61 × 10(-5) vs 1.67 × 10(-5) mm Hg, P < .05, respectively). The predictive capacity of area under the curve for ammonia and pNH(3) for non-ROSC was 0.85 (95% confidence interval, 0.75-0.95) and 0.73 (95% confidence interval, 0.61-0.84), respectively. The multivariate analysis confirmed that ammonia and pNH(3) are independent predictors of non-ROSC. The prognostic value of ammonia was better than that of pNH(3). The cutoff level for ammonia of 84 μmol/L was 94.5% sensitive and 75.0% specific for predicting non-ROSC with a diagnostic accuracy of 89.9%.nnnCONCLUSIONSnHyperammonemia on ED arrival is independently predictive of non-ROSC for OHCA patients. The findings may offer useful information for clinical management.

Timing of appropriate empirical antimicrobial administration and outcome of adults with community-onset bacteremia

BackgroundEarly administration of appropriate antimicrobials has been correlated with a better prognosis in patients with bacteremia, but the optimum timing of early antibiotic administration as one of the resuscitation strategies for severe bacterial infections remains unclear.MethodsIn a retrospective cohort study, adults with community-onset bacteremia at the emergency department (ED) were analyzed. Effects of different cutoffs of time to appropriate antibiotic (TtAa) administration after arrival at the ED on 28-day mortality were examined, after adjustment for independent predictors of mortality identified by multivariate regression analysis.ResultsAmong 2349 patients, the mean (interquartile range) TtAa was 2.0 (<1 to 12) hours. All selected cutoffs of TtAa, ranging from 1 to 96xa0hours, were significantly associated with 28-day mortality (adjusted odds ratio (AOR), 0.54–0.65, all Pu2009<u20090.001), after adjustment of the following prognostic factors: fatal comorbidities (McCabe classification), critical illness (Pitt bacteremia score (PBS) ≥4) on arrival at the ED, polymicrobial bacteremia, extended-spectrum beta-lactamase-producer bacteremia, underlying malignancies or liver cirrhosis, and bacteremia caused by pneumonia or urinary tract infections. The adverse impact of TtAa on 28-day mortality was most evident at the cutoff of 48xa0hours, as the lowest AOR was identified (0.54, Pu2009<u20090.001). In subgroup analyses, the most evident TtAa cutoff (i.e., the lowest AOR) remained at 48xa0hours in mildly ill (PBSu2009=u20090; AOR 0.47; Pu2009=u20090.04) and moderately ill (PBSu2009=u20091–3; AOR 0.55; Pu2009=u20090.02) patients, but shifted to 1xa0hour in critically ill patients (PBS ≥4; AOR 0.56; Pu2009<u20090.001).ConclusionsThe time from triage to administration of appropriate antimicrobials is one of the primary determinants of mortality. The optimum timing of appropriate antimicrobial administration is the first 48xa0hours after non-critically ill patients arrive at the ED. As bacteremia severity increases, effective antimicrobial therapy should be empirically prescribed within 1xa0hour after critically ill patients arrive at the ED.