Does Targeted Neonatal Echocardiography(TnECHO) can help prevent Postoperative Cardiorespiratory instability following PDA ligation? Amish Jain, Mohit Sahni, Afif El Khuffash, Arvind Sehgal, Patrick J McNamara. Division of Neonatology, Hospital for Sick Children, Toronto, Ontario, Canada.
Post Ligation Cardiac Syndrome (PLCS) Cardiorespiratory deterioration occuring 6 12 hours post surgery characterized by Systolic hypotension Need of inotropes Oxygenation failure Incidence: 25 3% Teixeira et al. J Perinat 28 Associated with increased mortality (OR 3.1; 95% CI: 1. 9.5) Harting et al. J Invest Surg 28 PDA ligation associated with adverse neurosensory outcome Schmidt et al. Pediatrics 27
Pathophysiology I Taylor et al. J Surg Res 199
Pathophysiology II McNamara et al. J Thorac Cardiovasc Surg 21
coronary artery perfusion HSDA Ligation LVE VR preload diastolic function systolic function SV & LVO PCLS Risk factors
Early prediction of PLCS Left Ventricular Index LVI - t8 [mls/kg/min] 7 6 5 4 3 2 1 2 4 6 8 1 LVI - t1 [mls/kg/min] Left ventricular index - 1 hour (mls/min/kg) 4 3 2 1 # None Cardiotropes p =.3 Threshold of LVO < 2 mls/min/kg at 1 hour will identify 1% neonates who required cardiotropes Sahni et al. E PAS 29.274.5
Targeted neonatal ECHO directed therapy program introduced in January 29
Modifications since January 29: ACTH stimulation test pre-operatively TnECHO at 1 hour post surgery LVO < 2 mls/min/kg MILRINONE infusion at.33 mics/kg/min LVO > 2 ml/min/kg continue observation Guideline for cardiovascular intervention: SAP < 3 rd centile & DAP > 3 rd centile iv. DOBUTAMINE SAP < 3 rd centile & DAP < 3 rd centile VOLUME or DOPAMINE If failed ACTH stimulation test and refractory hypotension consider HYDROCORTISONE
Study Objective To compare the rate and components of PLCS in infants who have undergone PDA ligation before and after the introduction of targeted neonatal echocardiography (TnECHO) directed therapy program
Methods I Design: Matched case control study of data collected prospectively in two epochs Site: Quaternary out born NICU Epoch I: July 25 to January 27 Epoch II: January 29 to July 21 Patients in epoch I were matched 1:1 for gestational age and one hour post ligation LVO
Methods II Inclusion criteria: 1. Prematurity < 32 weeks gestational age 2. LVO < 2 mls /kg/min on echocardiogram one hour following PDA ligation Exclusion criteria: 1. Other major cardiac anomaly (except for small ASD/VSD) 2. Any known chromosomal or major congenital defect Data Collection: Neonatal demographics, TnECHO results, details of pre and post operative stability (arterial pressure, lactate, ABG, ventilator parameters) and details of all perioperative cardiovascular interventions were compared.
Methods III Primary outcome PLCS defined by the composite outcome of oxygenation failure or post operative need of cardiotropes Secondary outcomes: Need for cardiotropes oxygenation failure combination of both Definitions
Statistical Analysis Continuous variables: T test for parametric Mann Whitney test for non parametric Categorical variables: chi square test Two way repeated analysis of variance (ANOVA) used for multiple time point analysis Data presented as mean ± SD, median (IQR) or frequency
Results
Baseline Characteristics Characteristics Epoch I (N=25) Epoch II (N=27) P Value Birth weight (grams) 69 (643-795) 662 (595-85) ns Gestational age (weeks) 25 (24-26) 25 (24-26) ns Apgar score at 5 minutes 7 (6-8) 7 (6-8) ns Age at surgery (days) 23 ± 8 23 ± 7.4 ns Weight at surgery (grams) 88 (797-975) 943 (774-13) ns IVH (n) 17 14 ns NEC (n) 1 5 ns Sepsis (n) 3 9 ns Echocardiography characteristics PDA diameter (mm) 2.9 ±.5 2.7 ±.5 ns La:Ao ratio 1.6 ±.2 2. ±.4.4 LVO at one hour (mls/min/kg) 15 (138-188) 168 (149-185) ns Fractional shortening at one hour (%) 37 ±1 34 ±1 ns
Systolic arterial pressure Diastolic arterial pressure did not differ between groups with a mean of 3 ± 7 mmhg (epoch I) and 3 ± 8 mmhg (epoch II) at 8 hours.
Outcomes Outcome Epoch I (N=25) Epoch II (N=27) P Value PCLS (n) 64% 37%.5 Oxygenation failure (n) 56% 29%.9 Need for cardiotropes (n) 36% 14%.14 Oxygenation failure & need for cardiotropes (n) 28% 7.4%.7
Annual Incidence of PLCS
Conclusion Targeted prophylactic milrinone therapy after PDA ligation for babies with LVO <2 ml/min/kg at 1 hour was associated with improved hemodynamic stability and reduced need for cardiotropes
Small sample size Limitations Learning curve for new guidelines (in 21 only 1 out 2 babies required inotropes) Delays in initiation of milrinone: median of 4 hrs after surgery Impact of ACTH stimulation test [Only 1/12 (8%) babies with LVO< 2 in epoch II had ACTH stimulation test and received milrinone]
Evolution of post operative care TnECHO, dobutamine Use of pressors, PLCS 2 5 2 6 2 7 2 8 2 9 2 1 ECHO Research/analysis TnECHO Directed Therapy ACTH
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