Normal baseline cardiac autonomic function and increased pupillary parasympathetic tone in patients with vasovagal syncope.

It is controversial whether people with vasovagal syncope (VVS) have abnormal autonomic responses at baseline and whether specific diagnostic manoeuvres have a diagnostic value. We investigated whether the pupillary light reflex and cardiac autonomic tests can be used to identify autonomic dysfunction in volunteers with a medical history of VVS. The study groups included 128 healthy volunteers, of whom 31 reported a history of typical VVS. The right pupil was evaluated using an automated, commercial infra-red pupillometer under strict conditions. In addition to miosis and mydriasis kinetics, pupil diameters were measured. Heart rate variability at rest and heart rate changes to standing were quantified with high-resolution electrocardiography and designated software. The demographic and clinical characteristics of both groups were statistically similar. Average constriction velocity (ACV) was significantly higher in VVS patients following a univariate analysis (3.83 ± 0.59 vs. 3.56 ± 0.73 mm/s, p = 0.042) and after correcting for potential confounders (p = 0.049). All other pupillometric and heart rate indices were comparable between groups. Patients with a history of VVS depict pupillary parasympathetic overactivity in response to light stimuli, manifested as increased ACV. The prognostic implications of this finding and the significance of using this simple clinical tool to identify patients who are at risk for developing frequent episodes of VVS or physical injuries following a syncope merits further study.

Diabetes without Overt Cardiac Disease Is Associated with Markers of Abnormal Repolarization: A Case-Control Study.

Patients with diabetes mellitus (DM) are prone to advanced atherosclerosis, microvascular disease, and tissue fibrosis. Despite the increased risk for arrhythmias, little is known about cardiac repolarization abnormalities in DM. We aimed to determine whether abnormal T-wave morphology markers are common among patients with DM and no known cardiac disease. Patients were recruited and classified as having DM or impaired fasting glucose (IFG) according to accepted guidelines. Total cosine R to T (TCRT) and T-wave morphology dispersion (TMD) were computed with custom-designed software for randomly selected and averaged beats. Among 124 patients recruited; 47 were diagnosed with DM and 3 IFG. DM patients and the control group had similar clinical characteristics, other than statins and anti-diabetic drugs, which were more common among DM patients. Patients with DM/IFG had decreased TCRT values computed from a random beat (0.06 ± 0.10 vs. 0.43 ± 0.07, p < 0.01) and an average beat (0.08 ± 0.09 vs. 0.44 ± 0.06, p < 0.01), when compared with the control group. TMD parameters did not differ. In conclusion, TCRT is reduced in patients with DM and no known cardiac diseases. Further research is required to investigate whether repolarization-associated changes in DM are the consequence of subclinical atherosclerosis, diabetic cardiomyopathy, or a combination of the two.

Venous capacitance and venous return in young adults with typical vasovagal syncope: a cross-sectional study.

Vasovagal syncope (VVS) has a high prevalence in the general population and is associated with potential complications. There is limited information on the possible association between venous capacitance (VC) and venous return (VR), important determinants of preload and VVS. Since the tilt test was reported to yield a high rate of false positive results, the aim of this study was to evaluate whether abnormal VC and VR at baseline could predispose individuals to VVS.To this end, 88 young, healthy volunteers were recruited and classified to 26 (29.5%) who experienced typical VVS and 62 (70.5%) who did not. VC and VR were evaluated with a commercial device and plethysmography applied to the elevated legs. Maximum venous outflow (MVO), segmental venous capacitance (SVC) and MVO/SVC ratio were calculated and averaged.No significant differences between MVO (5.0±0.5 vs 5.6±0.8, p>0.05), SVC (6.0±0.5 vs 6.3±0.8, p>0.05) or MVO/SVC ratio (0.83±0.02 vs 0.86±0.03, p>0.05) were observed for the non-VVS and VVS volunteers, respectively. There was a significant association between a higher MVO and SVC values and a larger decrease in diastolic blood pressure with standing, although correlations were weak (R2=0.0582 and 0.0681, respectively).In conclusion, at baseline, VC and VR are not impaired in healthy volunteers with a history of VVS. It remains unknown if similar results would be found in patients with cardiovascular comorbidities. Also, the sensitivity of VC and VR evaluations to identify a predisposition for VVS following physiological provocations merits further study.

Periprocedural analgesia and sedation in air enema reduction for intussusception: A retrospective Australian cohort study.

AIM: Periprocedural analgesia or sedation for air enema reduction (AER) of intussusception is a matter of debate. We set out to review Australian periprocedural pain management in AER. METHODS: Retrospective electronic medical record review of emergency department presentations of intussusception at an Australian children's hospital over 2 years for periprocedural analgesia and sedation and short-term outcomes. RESULTS: A total of 73 patients (mean age 23 months) had ultrasound-confirmed intussusception. Prior to AER, analgesia was administered to 61 of 73 (83.5%) patients. Opioids were administered in 48 of 73 (65.8%) and 8 of 73 (11.0%) received sedation. Thirteen of 73 (17.8%, 95% confidence interval 9.0-26.6) had spontaneously reduced; 60/73 that underwent primary AER had successful reduction in 54 (90.0%, 95% confidence interval 82.4-97.6). A total of seven patients required surgery. No AER attempts were complicated by bowel perforation. CONCLUSION: The use of periprocedural analgesia for AER in this Australian series was common, whilst sedation use was infrequent. No perforations occurred.

Neonatal acute kidney injury: recording rate, course, and outcome: one center experience.

Background: Neonates, and particularly preterm newborns, are at increased risk for acute kidney injury (AKI) due to immature kidney function. While specific criteria have been defined for AKI in this particular population, this diagnosis is frequently overlooked, and consequently, is often not recorded in patients' medical files. AKI-associated short- and long-term morbidity and mortality underline the importance of this diagnosis Objective: To assess the recording rate of AKI in the neonatal intensive care unit (NICU), and to identify clinical features that may promote awareness to this condition. Study design: The database of one medical center was searched for serum creatinine values above 1 mg% among all the newborns (more than 48 hours old) who were hospitalized in the neonatal intensive care unit (NICU) during the years 2010-2015, and who underwent at least two blood tests during their hospitalization. The files of patients who met acute kidney injury (AKI) diagnostic criteria were searched for AKI diagnosis, maternal, fetal, and postnatal course and outcome. Results: Of 59 newborns who met AKI criteria, 51 (86%) were preterm and 8 term newborns. The respective mean gestational weeks at birth were: 28 ± 3 and 38.5 ± 1, and mean birth weights: 1002 ± 57 and 3157 ± 375 grams. Mortality rates were 14/51 (27%) versus 1/8 (12.5%). Of the 44 survivors, AKI was recorded in the medical files of 9/37 (24%) preterm versus 5/7 (71%) term-newborns. AKI associated with twin pregnancy in preterm neonates: 22 (43%) versus 1 (12.5%) in term-newborn. Unexpected high frequencies of maternal obstetrical problems and cesarean section delivery: 62.5 and 78%, respectively, along with persistently depressed 5-min Apgar 6.6 ± 3.5 were found in term newborns with AKI. Congenital anomalies of the urinary tract (CAKUT) were suspected prenatally on fetal ultrasound in 3 (6%) and 1 (12.5%) of the respective groups, a 10-fold higher rate than that observed in the general population. AKI recurred in 18 (35%) of the preterm and none of the term neonates. Mild AKI episodes (Stage 1-2) occurred in 30/37 (81%) by contrast to severe events (Stage 3) in 4/7 (57%) preterm and term survivors, respectively. Ventilation duration associated significantly with AKI recurrence, and sepsis with mortality: OR 1.25 (95%CI = 1.09-1.43) (p < .001) and OR = 4.65 (95%CI = 1.26-17.2) (p = .014), respectively. Conclusions: We demonstrated underreporting of AKI, particularly among preterm newborns, a population at high risk of developing recurrent episodes. Our data suggest different clinical profiles of AKI among preterm and term neonates: with later onset, milder but recurrent episodes in the former. Increased alertness for AKI diagnosis is needed for neonates with prolonged respiratory support, treated with diuretics and after sepsis. Newborns suspected of CAKUT (Congenital Anomalies of Kidneys and Urinary Tract) as per fetal ultrasound might need closer observation for AKI occurrence.

Ethics of research in pediatric emergency medicine.

Clinical research in the pediatric emergency department (ED) has been rapidly growing in the past decade, and has resulted in some of the most important milestone studies in the pediatric medical literature. However, it presents a unique ethical goal and requires that additional challenges, such as the acute medical condition, fear and anxiety, unfamiliar physician(s), fatigue, and lack of time be addressed in addition to the standard ethical requirements. These may impair several fundamental elements of research, including the patient enrollment process, informed consent/assent, randomization, and others. Every possible attempt must be made to reduce or minimize the risks to which the children are exposed, and one must be cognizant of the special needs of children and their families in the ED. Nevertheless, we are also obliged to find ethical ways to include them in appropriate research endeavors that aim to improve treatments for conditions unique to the ED. This paper explores and overviews the most recent literature in order to characterize the nature of ethical challenges complicating clinical research in pediatric emergency medicine, and then suggests some ethically sound solutions such as deferred/waived consent, designated research staff, and alternative study designs. Finally, a few examples of prospective, blinded randomized trials involving drugs in pediatric emergency medicine are provided, with special emphasis on how the investigators are overcoming the obvious ethical challenges.

Supplemental oxygen compromises the use of pulse oximetry for detection of apnea and hypoventilation during sedation in simulated pediatric patients.

OBJECTIVE: The goal was to assess the time to recognition of apnea in a simulated pediatric sedation scenario, with and without supplemental oxygen. METHODS: A pediatric human patient simulator mannequin was used to simulate apnea in a 6-year-old patient who received sedation for resetting of a fractured leg. Thirty pediatricians participating in a credentialing course for sedation were randomly assigned to 2 groups. Those in group 1 (N = 15) used supplemental oxygen, and those in group 2 (N = 15) did not use supplemental oxygen. A third group (N = 10), consisting of anesthesiology residents (postgraduate years 2 and 3 equivalent), performed the scenario with oxygen supplementation, to ensure validity and reliability of the simulation. The time interval from simulated apnea to bag-mask ventilation was recorded. Oxygen saturation and Paco(2) values were recorded. All recorded variables and measurements were compared between the groups. RESULTS: The time interval for bag-mask ventilation to occur in group 1 (oxygen supplementation) was significantly longer than that in group 2 (without oxygen supplementation) (173 +/- 130 and 83 +/- 42 seconds, respectively). The time interval for bag-mask ventilation to occur was shorter in group 3 (anesthesiology residents) (24 +/- 6 seconds). Paco(2) reached a higher level in group 1 (75 +/- 26 mmHg), compared with groups 2 and 3 (48 +/- 10 and 42 +/- 3 mmHg, respectively). There was no significant difference between the groups in oxygen saturation values at the time of clinical detection of apnea (93 +/- 5%, 88 +/- 5%, and 94 +/- 7%, respectively). CONCLUSIONS: Hypoventilation and apnea are detected more quickly when patients undergoing sedation breathe only air. Supplemental oxygen not only does not prevent oxygen desaturation but also delays the recognition of apnea.