Correlation of Perfusion Index with Superior Vena Caval flow and Utility of Plethysmography Variability Index as Early Predictor of fluid responsive Shock in sick newborn of less than 72 hrs age in a Tertiary Care Neonatal Unit

METHODOLOGY

STUDY DESIGN = Prospective observational study (diagnostic test)

MATERIAL & METHODS

Inclusion Criteria: Sick neonates  less than 72 hours of age  admitted in the  department of neonatology who need hemodynamic monitoring

Exclusion Criteria: Major Congenital Anomaly, Congenital Heart disease.

Sample Size : Convenient sample for 1 year according to the nicu admission rate of sick newborn less than 72 hours of age

PROCEDURE :

All  neonates less than 72 hours of age   admitted in the NICU  will be analyzed by SNAPPE II score.  Neonate with  Score ≥ 38 will be enrolled for study after obtaining consent  from parents. After recruitment, baseline data will be  entered in data entry form.

.Hemodynamic monitoring will be  done by investigators for the recruited neonates for 48 hours from the time of enrollment.

The monitoring will include the following clinical parameters: Heart Rate, Pulse rate, capillary refill time, cold extremities. SVC flow will be  measured by echocardiography. Recording of PI and PVI will be done by  pulse oximeter.

TIME SCHEDULE FOR MONITORING:

For all recruited babies, every 8th  hourly, from the time of recruitment till 48 hrs. In  babies with shock , every 20 minutes till perfusion is normal and thereafter as scheduled.

Heart rate monitoring: Done by investigator uses stethoscope when baby is not agitated Extremities cold to touch: Using dorsum of the hand to feel temperature on abdomen and feet. If both are warm, then the baby is normothermic and if the abdomen is warm and the foot is cold, then the baby is in cold stress or shock.

Pulse volume measurement:

Central pulse- The volume of brachial pulse and femoral pulse

Peripheral pulse-The volume of radial pulse and posterior tibial pulse

Capillary refill time: After application of pressure on chest for 3-5 seconds,time taken for return of colour would be assessed.

Blood pressure measurement: It is measured in a supine position with appropriate size cuff in a quiet environment in the right upper limb,when the baby is not agitated[14]. The width of the cuff being 60-70% of the arm length.

PI recording: It will be  obtained from recording of pulse oximeter having  signal extraction technology.Measurement will be  taken from the right upper limb after application of pulse oximeter probe, when limb is at rest and without agitation. Masimo Monitor would be  used.

PVI : Using PI, PVI is calculated according to equation

PVI = PI max – PI min / PI max     X  100 %

  SVC flow measurement: By following formula : SVC flow(ml/kg/min)=[{pi*(mean SVC D/2)2 (cm)2}*VTI(cm)*HR(BPM)]/BODY WEIGHT(KG) SVC internal diameter  measured in 2d mode echocardiography at the point the SVC starts to open up into RA and a mean of maximum and minimum diameter within the cardiac cycle would be  used for calculation of the flow[[i]].

SVC VTI will be measured with pulse doppler tracing in subcostal view with box positioned at the junction of SVC and RA[18]with an angle <15 degree. The mean velocity of blood flow will be averaged from 5 consecutive cardiac cycles. GE Vivid S60N Echocardiographic machine will be used.

 Clinical criteria to define shock or poor perfusion:

Weak and fast pulse( >180 bpm)

Capillary refill time >3 sec

Cold extremities with or without following :  pale, lethargy, not arousable on stimulation

STATISTICAL ANALYSIS : We plan to compute the linear dependency among two variables using Pearson product movement correlation and use a statistical test to check the significance of the linear correlation .We then fit a linear regression model to predict the response variable for a given covariate. .To identify the effect of covariate on the different quantiles of the response variable,we also plan to use “linear quantile regression”for predicting different quantiles of the response variable .All the computed results will be reported by the function of statistical software ‘R’.

 Ethical Consideration :

The project will be started after obtaining permission from Scientific and Ethical committee.

Funding – No