Early norepinephrine decreases fluid and ventilatory requirements in pediatric vasodilatory septic shock.
OBJECTIVE
We previously reported that vasodilatation was common in pediatric septic shock, regardless of whether they were warm or cold, providing a rationale for early norepinephrine (NE) to increase venous return (VR) and arterial tone. Our primary aim was to evaluate the effect of smaller fluid bolus plus early-NE versus the American College of Critical Care Medicine (ACCM) approach to more liberal fluid boluses and vasoactive-inotropic agents on fluid balance, shock resolution, ventilator support and mortality in children with septic shock. Secondly, the impact of early NE on hemodynamic parameters, urine output and lactate levels was assessed using multimodality-monitoring.


METHODS
In keeping with the primary aim, the early NE group (N-27) received NE after 30ml/kg fluid, while the ACCM group (N-41) were a historical cohort managed as per the ACCM Guidelines, where after 40-60ml/kg fluid, patients received first line vasoactive-inotropic agents. The effect of early-NE was characterized by measuring stroke volume variation(SVV), systemic vascular resistance index (SVRI) and cardiac function before and after NE, which were monitored using ECHO + Ultrasound-Cardiac-Output-Monitor (USCOM) and lactates.


RESULTS
The 6-hr fluid requirement in the early-NE group (88.9+31.3 to 37.4+15.1ml/kg), and ventilated days [median 4 days (IQR 2.5-5.25) to 1day (IQR 1-1.7)] were significantly less as compared to the ACCM group. However, shock resolution and mortality rates were similar. In the early NE group, the overall SVRI was low (mean 679.7dynes/sec/cm5/m2, SD 204.5), and SVV decreased from 23.8±8.2 to 18.5±9.7, p=0.005 with NE infusion suggesting improved preload even without further fluid loading. Furthermore, lactate levels decreased and urine-output improved.


CONCLUSIONS
Early-NE and fluid restriction may be of benefit in resolving shock with less fluid and ventilator support as compared to the ACCM approach.
Pediatric Intensive Care Unit, Apollo Children's Hospital, Chennai, Tamil Nadu, India.
Suchitra
S
Ranjit
Pediatric Intensive Care Unit, Apollo Children's Hospital, Chennai, Tamil Nadu, India.
Rajeswari
R
Natraj
Pediatric Intensive Care Unit, Apollo Children's Hospital, Chennai, Tamil Nadu, India.
Sathish Kumar
SK
Kandath
Department of Pediatrics and Emergency Medicine, BC Children's Hospital, Sunny Hill Health Centre for Children, University of British Columbia, BC V6H 3V4, Canada.
Niranjan
N
Kissoon
Department of Medical Education, Apollo Hospitals, Chennai, Tamil Nadu, India.
Balasubramaniam
B
Ramakrishnan
Department of Pulmonary and Critical Care Medicine, Eastern Virginia Medical School, VA 23507, USA.
Paul E
PE
Marik
Critical illness; fluid infusion; morbidity; mortality; norepinephrine; pediatrics; sepsis; septic shock; vasodilatory; venous return