Orthostatic intolerance in post-concussion patients.

Orthostatic intolerance (OI) following pediatric concussion is not well understood. Assessing the prevalence of concussion-related OI and how it compares to non-concussion-related OI will improve care for patients suffering with these symptoms. OBJECTIVE: We set out to describe concussion-related OI in adolescence, with particular emphasis on time to recovery and differences from non-concussion-related OI (including male vs. female prevalence). Retrospective chart reviews were completed on post-concussion patients endorsing symptoms of OI. The patients' sex, sport history, previous concussions, time since injury, and recovery time were analyzed and compared between males and females as well as against general OI statistics. Thirty-nine pediatric patients, representing 8.7% of all new patients referred to a specialized concussion clinic over a 13-month interval, were included in the chart review. Mean age of onset was 15.0 ± 2.5 years and 18 (46%) were males. The median times from evaluation to symptom resolution were 120 days. Of 18 patients who completed head-up tilt table testing, 17 (94%) had orthostatic tachycardic response (>40 bpm heart rate increment). Post-concussive OI differs from other orthostatic intolerance etiologies, lacking a strong female predominance and exhibiting a shorter time course to recovery compared to other etiologies of OI (but longer recovery time compared to concussion patients in general). Clinical orthostatic vital signs may not be sensitive for diagnosing orthostatic intolerance in athletes, likely due to higher vagal tone and more efficient skeletal muscle pump.

Pediatric dysautonomia: Much-maligned, often overmedicated, but not as complex as you think.

Dysautonomia is an increasingly recognized yet still poorly understood disease within the field of pediatrics. Symptoms, including dizziness, headaches, fatigue, joint pain, anxiety, and intolerance of heat or cold, are often significant and difficult to sort, especially in terms of their relation to each other. This often leads to referral to multiple subspecialists, who then proceed to treat seemingly familiar symptoms in kind. In the authors' experience, this leads to more frustration on the part of the patients and their physicians when symptom improvement does not follow (or can even worsen). On the other hand, by understanding the pathophysiology, treatment success is possible by directing therapies toward the root causes and just as importantly, enlisting the patient in a daily treatment plan. In the text that follows, we hope to convey these viewpoints by highlighting an involved case, discussing the pathophysiology, outlining the usual evaluation, and finally describing our approach to treatment.

Hemodynamic phenotype of the failing Fontan in an adult population.

Fontan failure can occur even with normal systolic ventricular function and often in the context of significant liver disease. We hypothesized that Fontan failure is hemodynamically distinct from traditional heart failure and characterized by low systemic vascular resistance (SVR) index and preserved cardiac index. Twenty-seven symptomatic adult Fontan (SAF) patients who underwent catheterization from 2001 to 2011 constituted our study group. Fifty-four predominantly asymptomatic pediatric Fontan (PF) patients who underwent catheterization during the same period were randomly selected to perform a control:case cohort analysis. Clinical comparisons were made between the 2 groups. The adults were more symptomatic than the PF cohort (New York Heart Association classes I and II or III and IV: 48% or 52% [SAF] vs 94% or 6% [PF], respectively, p <0.01). SAF versus PF mean catheterization findings were central venous pressure 18 ± 6 versus 14 ± 3 mm Hg (p <0.01), SVR index 1,680 ± 368 versus 1,960 ± 550 dyn s/cm(5)/m(2) (p = 0.02), and cardiac index 2.7 ± 0.8 versus 2.8 ± 0.7 L/min/m(2) (p = 0.25). By imaging, the SAF cohort demonstrated a greater incidence of abnormal liver texture changes (96% vs 75%, p = 0.04) and nodularity (77% vs 42%, p = 0.02). In conclusion, adult patients with failing Fontan circulation had a lower SVR index and similar cardiac index compared with the pediatric cohort. Liver disease in the adults was more advanced. Our data suggest that Fontan failure is a distinct circulatory derangement with hemodynamic features similar to portal hypertension, albeit with limited ability to augment cardiac output.

Safe and effective use of a glycemic control protocol for neonates in a cardiac ICU.

OBJECTIVE: To investigate the safety and efficacy of a hyperglycemia protocol in neonates with critical cardiac illness. Neonates are often regarded as high risk for hypoglycemia while receiving continuous insulin infusions and thus have been excluded from some clinical trials. DESIGN: A retrospective review. SETTING: A pediatric cardiac ICU in a tertiary academic center. INTERVENTIONS: Neonates with critical cardiac illness who developed hyperglycemia were placed on an insulin-hyperglycemia protocol at the attending physician's discretion. Insulin infusions were titrated based on frequent blood glucose monitoring. MEASUREMENTS: Critical illness hyperglycemia was defined as a blood glucose less than 140 mg/dL. Hypoglycemia was defined as moderate (≤ 60 mg/dL) or severe (≤ 40 mg/dL). Initiating blood glucose, lowest blood glucose during insulin infusion, doses of insulin, duration of insulin, and time to blood glucose greater than 140 mg/dL were evaluated. MAIN RESULTS: A total of 44 patients were placed on the protocol between January 2009 and October 2011. The majority of insulin infusions were initiated in the early postoperative period (33 of 44, 75%). Moderate hypoglycemia occurred in two patients (4.5%), with blood glucose levels of 49 and 53 mg/dL. No episodes of severe hypoglycemia occurred. A total of 345 discrete blood glucose levels were analyzed; two of these being greater than 60 mg/dL (0.58%). Mean blood glucose prior to starting insulin was 252 ± 45 mg/dL and time until euglycemia was 6.1 ± 3.9 hours. The mean duration of insulin infusion was 24.6 ± 38.7 hours, mean peak dose was 0.10 ± 0.05 units/kg/hour, and mean insulin dose was 0.06 ± 0.02 units/kg/hour. For postoperative patients, mean time after bypass until onset of hyperglycemia was 2.2 ± 2.6 hours. CONCLUSIONS: A glycemic control protocol can safely and effectively be applied to neonates with critical cardiac disease. Neonates with critical cardiac illness should be included in clinical trials evaluating the benefits of glycemic control.

Association of feeding modality with interstage mortality after single-ventricle palliation.

OBJECTIVE: Interstage mortality has been reported in 10% to 25% of hospital survivors after single-ventricle palliation. The purpose of this study was to examine the impact of feeding modality at discharge after single-ventricle palliation on interstage mortality. METHODS: We conducted a retrospective review of all neonates undergoing single-ventricle palliation from January 2003 to January 2010. A total of 334 patients (90%) survived to hospital discharge, comprising the study group. Preoperative, operative, and postoperative variables were examined, including feeding method at discharge. Multivariate Poisson regression models were constructed to estimate the relative risk of interstage mortality. RESULTS: Of 334 patients, 56 (17%) underwent gastrostomy tube ± Nissen. There was a statistically significant increase in interstage mortality for patients who underwent gastrostomy tube ± Nissen compared with patients who did not (relative risk, 2.38; 95% confidence interval, 1.05-5.40; P = .04]). Of the 278 patients who were not fed via a gastrostomy tube ± Nissen, 190 (68%) were fed with nasogastric feedings and 88 (32%) were fed entirely by mouth. There was no difference in interstage mortality between these 2 groups (relative risk, 0.92; 95% confidence interval, 0.31-2.73; P = .89). CONCLUSIONS: Neonates undergoing single-ventricle palliation who require gastrostomy tube ± Nissen are at an increased risk of interstage mortality. The need for gastrostomy tube ± Nissen in this population may be a marker for other unmeasured comorbidities that place them at an increased risk of interstage mortality. Discharge with nasogastric feeds does not increase the risk of interstage mortality.