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Introduction: We sought to determine the potential reduction in door-to-balloon time (DTB) by allowing paramedics to perform prehospital ST-Elevation Myocardial Infarction (STEMI) notification using brief communications via emergency medical services (EMS) 9-1-1 dispatchers as soon as they saw a STEMI on 12-lead electrocardiogram (EKG). Our hypothesis was that earlier cardiac catheterization lab (CCL) activation would improve overall DTB and avoid delays arising from on-scene issues or the time required to deliver a full report. Methods: The study setting was a single suburban community teaching hospital, which is a regional percutaneous coronary intervention (PCI) center with more than 120,000 Emergency Department (ED) visits/year and is serviced by a single tiered-response, advanced life support (ALS) paramedic-level agency. STEMI notifications from July 2009 to July 2012 occurred by either standard direct EMS-to-physician notification or by immediate 9-1-1 dispatch notification. In the 9-1-1 dispatcher-aided notification method, paramedics were asked to provide a brief one-sentence report using their lapel microphones upon immediate realization of a diagnostic EKG (usually within 1-2 minutes of patient contact). This report to the 9-1-1 dispatcher included the patient’s sex, age, and cardiologist (if known). The dispatcher then called the emergency department attending and informed them that a STEMI was being transported and that CCL activation was needed. We used retrospective chart review of a consecutive sample of patients from an existing STEMI registry to determine whether there was a statistically significant difference in DTB between the groups. Results: Eight hundred fifty-six total STEMI alert patients arrived by EMS during the study. We excluded 730 notifications due to events such as cardiac arrest, arrhythmia, death, resolution of EKG changes and/or symptoms, cardiologist decision not to perform PCI, arrival as a transfer after prior stabilization at a referring facility or arriving by an EMS agency other than New Castle County EMS (NCC*EMS). Sixty-four (64) sequential patients from each group comprised the study sample. The average DTB (SD) for the standard communication method was 57.6 minutes (17.9), while that for dispatcher-aided communication was 46.1 minutes (12.8), (mean difference 57.6-46.1 minutes=11.5 minutes with a 95% CI [6.06,16.94]) p=0.0001. In the dispatcher-aided group, 92% of patients (59/64) met standards of ≤60 minute DTB time. Only 64% (41/64) met this goal in the standard communication group (p=0.0001). Conclusion: Brief, early notification of STEMI by paramedics through 9-1-1 dispatchers achieves earlier CCL activation in a hospital system already using EMS-directed CCL activation. This practice significantly decreased DTB and yielded a higher percentage of patients meeting the DTB≤60 minutes quality metric. [West J Emerg Med. 2015;16(3):472–480.]

A study is conducted to examine whether complete diaphragm inactivity and mechanical ventilation for more than 18 hours that creates disuse atrophy of diaphragm fibers in animals would do the same in humans too. Results indicate that 18 to 69 hours of total diaphragm inactivity and mechanical ventilation does cause disuse atrophy in humans also.

Physicians should be cautious in interpreting the results of polymerase chain reaction (PCR) testing in newborn infants of mothers with HIV infection. PCR testing is used in newborn infants because it directly detects viral DNA rather than antibodies to the virus, which could have come from the mother. Researchers used meta-analysis to evaluate 32 studies of PCR testing for HIV infection in newborn infants. The sensitivity of the tests ranged from 31% to 100% and the specificity ranged from 50% to 100%. Some studies reported false-positive and false-negative rates as high as 6.7% in newborn infants. However, the rate of false positives and false negatives dropped to 1.8% in older infants. It may be necessary to delay the test until the infant is older than one month. Any tests done at birth can also be repeated at this time., Objective. - To evaluate the sensitivity and specificity of the polymerase chain reaction (PCR) for the diagnosis of infection with human immunodeficiency virus (HIV) in infants. Data Sources. - We used studies published between 1988 and 1994 identified in a literature search of 17 databases, including MEDLINE. Study Selection. - Studies were included if DNA amplification by PCR was performed on peripheral blood mononuclear cells from infants or children. Data Extraction. - Two investigators independently extracted data. The study design was assessed independently by 2 investgators who were blinded to study results. Data Synthesis. - Thirty-two studies met the inclusion criteria and were analyzed. The median reported sensitivity was 91.6% (range, 31%-100%), and the median specificity was 100% (range, 50%-100%). A summary receiver operating characteristic curve based on all 32 studies indicated that PCR has a maximum joint sensitivity and specificity between 93.2% and 94.9%. Subgroup analysis indicated that the joint sensitivity and specificity was significantly (P=.04) higher in older infants (98.2%) than in neonates (aged [less than or equal to] 30 days; 93.3%). For infants at low risk of perinatal transmission (probability of transmission, 8.3%), the positive predictive value for PCR is 55.8% in neonates and 83.2% in older infants. A negative PCR result reduces the probability of HIV infection to less than 3%. No studies met all criteria for study design. Conclusions. - Although PCR is of the of the best available tests for diagnosis of HIV infection in neonates and infants, it is not definitive. Therefore, PCR should be interpreted with the aid of careful clinical follow-up examinations. The sensitivity and specificity of PCR in neonates is lower than in older infants, which results in a low positive predictive value; however, negative tests are informative. Delaying the use of PCR until after the neonatal period or repeating PCR on independent samples obtained 30 to 60 days later will reduce test errors. (JAMA. 1996;275:1342-1348)