Dr. Subash ArunGuide

Dr. Srinivas Murki

Changes in Blood Pressure and Echocardiographic Parameters in

Neonates with Shock – An Observational Study

Hyderabad, INDIAwww.fernandezhospital.foundation

Introduction

▪ Diagnosis and Management of shock is challenging

▪ Routine clinical parameters - very low diagnostic utility

▪ Bedside ECHO: Routine practice for managing shock in NICU

Existing Evidence

▪ Only few studies evaluated the role of fECHO in neonatal Shock (e.g. Saini et al and Baske et al)

▪ These studies evaluated Hemodynamics at onset of shock

▪ Comparison with control is missing

▪ Enrolled newborns with only septic shock

Study Objective

To evaluate the changes in

▪ Blood pressure (systole, diastole, mean arterial pressure i.e. MAP) and

▪ Echocardiographic markers of

Preload

Diastolic function

Systolic function

Onset of Shock Complete Resolution of shock

Patients

▪ All neonates with shock included in study

Exclusions

▪ Received fluid boluses or inotropes prior to enrollment

▪ Neonates having major congenital anomalies

▪ Neonates undergoing therapeutic hypothermia

Methods

▪ Prospective observational study

▪ October 2017 to May 2019

▪ Fernandez Hospital, Hyderabad – Tertiary care hospital

▪ Consent : At admission to NICU for possible enrollment

▪ All newborns were screened for features of shock hourly

▪ Newborns diagnosed with shock were monitored for

Clinical parameters

ECHO parameters

Shock defined as

Any 2 of following 6 parameters*

▪ HR>180/min

▪ CRT>3 sec

▪ Core to periphery difference >30C

▪ Base Excess >-5 in blood gas/ Lactate > 2 times normal

▪ Hypotension:

▪ Oliguria* International paediatric sepsis consensus conference, Goldstein B et al

Echocardiographic Evaluation

Echo imaging was done only by PI who was trained by pediatric cardiologist.

▪ IVC collapsibility index

▪ Left ventricular end diastolic volume (LVEDV)

▪ Mitral E/A ratio

▪ Isovolumetric relaxation time (IVRT)

▪ Left ventricular output

▪ Ejection Fraction

▪ Right ventricular output

Preload

Diastolic function

Systolic function

Shock Resolution

All of the following should be present-

▪ Heart rate 120 to 160 per min

▪ Capillary refill time < 3 seconds

▪ Blood pressure : >30 mm of Hg/ >5th GA

> 5th Centile for GA or systolic BP >2SD

▪ Urine output : >1 ml/kg/hour

▪ Normal peripheries Core to peripheral temperature < 3°C

▪ Not on inotropes

▪ No acidosis and normal lactate

Primary Outcome

▪ Median Change in

– Clinical Parameters

– Echo Parameters

At Onset of shock and at complete resolution of shock

Secondary Outcome

▪ Comparison of Clinical diagnosis versus echo diagnosis of Shock

Protocol

▪ For logistic and ethical reasons, only feasible parameters were recorded before giving bolus and rest either before or during saline bolus infusion / starting of inotropes

▪ Echo images - reviewed by pediatric cardiologist blinded to clinical findings

▪ Shock Management - as per standard unit protocol

▪ Clinical and echo parameters -repeated after resolution

Sample Size and Statistics

▪ No a-priori sample estimation done

▪ Median changes in clinical and Echo parameters at onset and after resolution of shock done by Wilcoxon signed rank test

▪ All the analysis was done using statistical software packages SPSS version 23 (IBM, New York)

Results

Infants admitted to NICU (N=1416)

Infants Diagnosed with shock

(N= 59)

Infants enrolled for study (N= 37)

Infants for paired analysis (N=31)

Excluded cases before

enrollement(N=22)

Excluded cases after enrollment

from paired analysis (N=6)

Study flow chart

Characteristics/ Variables Baseline data

Gestational Age (weeks) 30±3

Maternal age (years) 28.5±3.8

Birth weight (grams) 1213±448

Male gender (%) 20 (54)

Small for date (%) 9 (24.3)

Age at shock (days) 3.5 (2.5,6)

Weight loss at shock (%) 7.9±4

Blood pH at shock 7.20 (± 0.07)

Base Excess at shock 9.87 (± 2.5)

Blood culture +ve sepsis (%) 21 (56.8)

Probable sepsis (%) 6 (16.2)

HsPDA (%) 6 (16.2)

Baseline Characteristics

Indicator of shock Number(percent)N=37

HR>180/min 35(94.5)

CRT>3 sec 26(70)

Core to periphery difference >30C 30(81)

Base Excess >-5 in blood gas 33(89.18)

Elevated Lactate > 2 times 35(94.5)

Hypotension 0(00)

Oliguria 0(00)

Diagnosis of Shock

Parameters Medians (IQR) P value

At shock After resolution

HR(per min) 186(183,190) 140(138,146) <0.001

SBP(mm Hg) 61(56,68) 65(62,68) 0.75

DBP(mm Hg) 32(30,38) 39(36,42) 0.001

MAP(mm Hg) 46(40,50) 48(46,51) 0.007

Changes in Clinical Parameter at Onset and Resolution of Shock

Parameters Medians (IQR) P value

At shock After resolution

IVC Collapsibility Index % 42(23,48) 25(18,33) <0.001

LVEDV(ml) 5.8(2.9,9.6) 8(5,13) 0.003

Changes in Preload Parameters at Onset and Resolution of Shock

Parameters Medians (IQR) P value

At shock After resolution

IVRT(milliseconds) 42(39,47) 39(34,44) 0.002

E/A ratio 0.77(0.7,0.8) 0.75(0.66,0.8) 0.25

Changes in Diastolic cardiac function at onset and resolution of Shock

Parameters Medians (IQR) P value

At shock After resolution

LVO(ml/kg/min) 165(115,213) 179(141,241) 0.15

RVO(ml/kg/min) 246(181,298) 213(171,314) 1.0

Left Ventricular stroke volume(ml)

1(0.7,1.3) 1.47(1.3,1.8) <0.001

Right Ventricular stroke volume(ml)

1.4(1.2,1.8) 2(1.4,2.6) <0.001

EF (%) 69(62,74) 75(71,79) <0.001

Changes in Systolic Cardiac Function at onset and Resolution of Shock

Parameters Medians (IQR) P value

At shock After resolution

SVR Index(mmHg/ml/kg/min)

0.27(0.22,0.38) 0.26(0.17,0.33) 0.4

Systemic Vascular resistance (SVR) Index : MAP/LVO

Changes in SVR Index at Onset and Resolution of Shock

Time of resolution of shock Number (%)

12 to 24 hours 4(13%)

24 to 48 hours 17(55%)

48 to 72 hours 9(29%)

>72 hours 1(3.2%)

Time for Resolution of Shock

Secondary Outcomes ▪ Clinical Diagnosis of Shock

Hypovolemic shock- 5 (14%)

Cardiogenic shock - 3 (8%)

Clear classification not possible - 29 (78%)

▪ Echo Diagnosis of Shock

Hypovolemic shock- 3 (8%)

Cardiogenic shock – 8 (22%)

Clear classification not possible– 26 (70%)

Study Strengths▪ First study to Echo Parameters at onset and after

shock resolution

▪ Ideal study in which each infant acted as its own control

▪ Identified the median differences in Clinical and Echo parameters in newborns with shock

▪ Includes newborns with all types of shock (not only sepsis)

▪ Cardiologist blinded to the clinical details

Median Changes (Onset vs. Resolution)

▪ Preload PVI 12%

IVC CI 13%

LVEDV 2.3ml

▪ Diastolic Cardiac Function IVRT 4msMitral E/A 0.03

▪ Systolic Cardiac Function LVSV 0.3ml

RVSV 0.4ml

EF 7%

▪ Marker of Distributive shock SVR Index 0.04

Clinical Application of Study Findings

Clinical Implications

▪ Identify infants at risk for shock at admission to

NICU

▪ Evaluate IVC collapsibility index, MAP and Echo

parameters at admission or as early as possible

▪ Revaluate the same parameters at onset of shock to

– Classify pathophysiology of shock

– Manage shock from pathophysiology

Hypovolemic shock(median change)

Cardiogenic shock

Distributive shock(median change)

Diastolic dysfunction

(median change)

Systolic dysfunction

(median change)

1. IVC Collapsibility Index>13%

2. LVEDV < 2.3 ml

1. IVRT>4ms2. E/A

ratio>0.03

1. LSV<0.3ml2. RSV<0.4ml3. EF<7%

SVR Index < 0.04(mmHg/ml/kg/min)

Study Limitations

▪ Exclusively inborn neonates

▪ Sample size small

Conclusion

Our study highlights the need for baseline documentation of clinical and echo parameters and to observe their changes at onset of shock. Future validation is needed to manage infants with shock based on the changes observed in this study