Ravi Shankar Samraj

709: INHERENT FACTORS AFFECTING THERAPEUTIC VANCOMYCIN LEVELS IN THE PEDIATRIC POPULATION

www.ccmjournal.org Critical Care Medicine • Volume 46 • Number 1 (Supplement) Learning Objectives: Vancomycin remains one of the commonly used antibiotics in the empiric treatment of pediatric infections. In 2011, The Infectious Disease Society of America (IDSA) recommended to increase the therapeutic drug goals for Vancomycin troughs to 15–20 mg/L for the treatment of suspected MRSA. It is unclear if the commonly used initial vancomycin regimen of 45 mg/kg/day is effective in achieving this higher therapeutic goal in a timely manner and whether the underlying patient’s condition has any effect on the dose and the time required to reach the therapeutic goal. Methods: We performed a retrospective chart review of all pediatric patients that received at least three days of intravenous (IV) Vancomycin therapy over a three-year period in a large, singlecenter children’s hospital. We compared and contrasted patient demographics, suspected site of infection, side effects, and outcomes that may have directly affected the attainment of therapeutic drug concentrations. Results: Ninety-two patients were included in our study. Mean patient age was 13.1 years while the mean body weight was 49.5 kg and the mean Body Mass Index (BMI) was 22.7 kg/m2. Initial trough levels were significantly lower than the therapeutic goal (median 9.15mg/L, p < 0.05) and a median of 7 doses were required to reach the therapeutic goal. Using correlation analysis, we found that patients with higher BMI required more dose changes to achieve goal of 15–20 mcg/L (p=0.004) while patients with a higher body weight needed more doses to attain therapeutic trough (p = 0.0001). Patients with cystic fibrosis required a significantly higher dose to attain a vancomycin therapeutic trough. (p = 0.02). Moreover, cystic fibrosis patients took a longer time to reach the therapeutic trough (p = 0.04). Conclusions: Results of our study suggest that the current commonly followed vancomycin regimen may be inadequate for patients with higher BMI, higher body weight and in patients with cystic fibrosis. Consideration should be given to starting these patients on a higher vancomycin dose based on the urgency of the patient’s clinical condition.

256: CEREBRAL REGIONAL OXYGEN SATURATION (RSO2) HAS BETTER ACCURACY COMPARED TO RENAL RSO2 IN CHILDREN

www.ccmjournal.org Critical Care Medicine • Volume 46 • Number 1 (Supplement) Learning Objectives: Pulmonary artery catheter (PAC) with thermodilution serves as a reference standard for measurement of hemodynamic parameters. Nevertheless, the technique is difficult in children. Transthoracic echocardiography (TTE) has been widely used instead. Nonetheless, the process is time consuming and requiring expertise. Noninvasive cardiac output monitoring, such as ultrasonic cardiac output monitor (USCOM®) and impedance cardiography (electrical velocimetry; EV) can be done rapidly and requiring less expertise. With current studies, there were inconsistent evidences and variable precision and reproducibility of EV, USCOM® and TTE measurements. The main objective is to compare USCOM®, EV and TTE in measurements of hemodynamic in critically ill children aged from 1 month to 18 years old admitted to pediatric intensive care unit (PICU) and intermediate ward (IW) of Ramathibodi Hospital, Mahidol University, Thailand from the period of September 2016 to June 2017. Methods: This study was conducted as single center, prospective observational study. Children with congenital heart diseases and unstable hemodynamics were excluded. Simultaneous measurements of hemodynamic parameters were conducted using USCOM® (Sydney, Australia), ICON® (EV; Osypka Medical, Germany) and TTE (Philips iE33). Interrater reliability was determined. Bland-Altman plots were used to analyze agreement of assessed parameters. A percentage of error > 30% would be considered as significant. Results: A total of 121 patients (age 4.99 + 4.55 years old; male 56.2%) were analyzed. Interrater reliability showed acceptable agreement in all measured parameters (stroke volume (SV), cardiac output (CO), cardiac index (CI), velocity time integral (VTI), inotropy (INO), flow time corrected (FTC), aortic valve diameter (AV), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI) and stroke volume variation (SVV);(Crochbach’s alpha 0.53–1). BlandAltman analysis showed acceptable percentage of error in all parameters (9.2–28.8%) except SVR (30.8%) and SVV (257.1%). Conclusions: It might be possible to use these three noninvasive methods interchangeably in pediatric critical care settings. Prudence must be employed in interpretation of SVV and SVR measurements.

The Impact of Antithrombin III Use in Achieving Anticoagulant Goals in Pediatric Patients

OBJECTIVESnTo determine the percentage of patients with >10% reduction in heparin infusion rate within 48 hours of antithrombin III (ATIII) administration. Secondary objectives include the achievement of therapeutic anticoagulation and determining the days of subtherapeutic infusion prior to supplementation.nnnMETHODSnRetrospective chart review of 12 patients younger than 18 years of age who received ATIII concentrate supplementation while on continuous heparin infusion. Specific indications for heparin infusion therapy included extracorporeal membrane oxygenation (ECMO), treatment of thrombus, and post implantation of ventricular assist device(s).nnnRESULTSnFrom time of heparin initiation to ATIII supplementation, patients spent a mean 4.9 ± 2.6 days of subtherapeutic infusion and required uptitration from a mean of 15.3 ± 4.4 units/kg/hr to a mean rate of 40.7 ± 9.5 units/kg/hr. 58.3% of the patients (n = 7) had a ≥10% reduction from the baseline heparin infusion rate within 48 hours of ATIII administration. Those patients considered responders (≥10% reduction from baseline rate) had a slightly higher mean baseline antithrombin level (76.3% ± 22.0% vs. 58.6% ± 2.7% in non-responders, p = 0.1) and were administered comparable doses of ATIII. ATIII supplementation did appear to increase the time of therapeutic anticoagulation within the 48 hours.nnnCONCLUSIONSnAdministration of ATIII is associated with >10% decrease in heparin requirements in more than half of the patients identified. In those patients deemed non-responders, there was a trend towards lower baseline antithrombin serum levels. Further studies are warranted to determine if the lack of response in some patients is due to inadequate dosing of ATIII or any patient-related factors.

Severe Neonatal Purpura Fulminans Caused by Staphylococcus aureus.

An 8-day-old term male patient presented to an outside hospital for vomiting and lethargy for 1 day. He was noted to be lethargic, poorly perfused and had erythematous ecchymotic lesions on the lower back. He was endotracheally intubated, aggressively fluid resuscitated, started on inotropic and antibiotic therapy (ampicillin, cefotaxime). Over the next 48 hours, there was deterioration in his clinical condition. He developed worsening respiratory failure and refractory shock. His skin lesions rapidly increased, extending to the upper back, pelvis, and abdominal wall. In addition, he developed severe ischemia of fingers and toes and had evidence of disseminated intravascular coagulation (DIC). Antibiotic coverage was expanded to include vancomycin, gentamicin and acyclovir. Endotracheal cultures grew methicillin-resistant Staphylococcus aureus (MRSA), blood/urine cultures/viral respiratory polymerase chain reaction panel were negative. After 48 hours, the patient was transferred to our institution. On arrival he was noted to have severe anasarca and poor perfusion. His skin examination revealed hemorrhagic bullae with ecchymoses and erythema on back/buttocks (Figure 1) and digital ischemia of multiple fingers/toes. Laboratory investigations revealed arterial pH 7.17, arterial lactate 5.3 mmol/L, white cell count 1400/mm, hemoglobin 11 g/dL, platelet count 10 000/mm, creatinine 0.6 mg/dL, alanine transaminase 86 U/L, international normalized ratio 1.5, and fibrinogen 270 mg/dL. Renal replacement therapy was initiated for severe anasarca. Over the next 48 hours, there was progression of septic shock with rising serum lactate levels and worsening of DIC, renal and hepatic failure. His echocardiogram demonstrated good cardiac function. He was initiated on venoarterial extracorporeal membrane oxygenation (ECMO) on day 3 of admission for refractory septic shock and worsening hyperlactemia (peak lactate = 16 mmol/L). His tissue perfusion and organ dysfunction improved subsequently and he was weaned from ECMO after 7 days. However, his skin lesions progressed and he developed full thickness necrosis of the skin over the whole back and buttocks (Figure 2). Culture of the skin lesion grew MRSA, blood and urine cultures were negative. Molecular characteristics of MRSA were not studied. Patient had low adenovirus serum titers (1904 copies/mL). Infectious disease experts opined that the load was too low to cause clinically significant disease. However, he was treated empirically with cidofovir (2 doses) and immunoglobulin. Repeat titers were negative and cidofovir was discontinued. Other infectious diseases work-up, including 660693 CPJXXX10.1177/0009922816660693Clinical PediatricsNicolas et al brief-report2016

Septic arthritis and hemarthroses caused by Haemophilus influenzae serotype A in children

Invasive disease caused by Haemophilus influenzae serotype A (Hia) is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

1604: MRSA INFECTIVE ENDOCARDITIS INVOLVING THE INTRAVENTRICULAR SEPTUM

Crit Care Med 2016 • Volume 44 • Number 12 (Suppl.) hypoxic requiring oxygen and high dose methylprednisolone. He later developed bilateral pneumothoraces requiring chest tubes. High flow nasal cannula, N-acetylcysteine, and broad spectrum antibiotics were added. Intubation, paralytics, and VV ECMO were needed for refractory hypoxemia. He subsequently developed septic shock. A bronchoscopy was negative for infection. He was transferred to an ICU at a transplant center for consideration of emergent lung transplantation. His hypoxemia worsened, an ECHO showed right ventricular (RV) failure and VA ECMO was added. His oxygenation deteriorated, he was deemed too unstable for transplantation, and he ultimately died. Results: We believe that his hypoxemia resulted from limited left ventricular (LV) preload and cardiac output (CO) due to severe RV dilation from pressure and volume overload. While VA ECMO was necessary for cardiogenic shock, his otherwise healthy left ventricle became severely hyperdynamic. VA ECMO could not sufficiently oxygenate his 10 L/min CO, which passed through essentially non-functional lungs. Beta blockers and continuous dialysis could not overcome the shunt, and both ECMO circuits were needed to achieve effective oxygenation. Refractory hypoxemia from severe right to left shunt is a feared complication of VA ECMO in young individuals without underlying cardiac pathophysiology, and a parallel VV circuit should be maintained to relieve the oxygen deficit.