Minimally Invasive Surfactant Therapy: An Analytical Report of Our Prospective Dubai Cohort.

INTRODUCTION:  Type 2 pneumocytes of the respiratory epithelium secrete the endogenous surfactant, a detergent-like substance that lines the alveolar sacs of the lungs. The surfactant facilitates the gas exchange process across the alveolar membrane by preventing the collapse of the alveoli and thereby maintaining their distended state. Respiratory distress syndrome of the premature neonates is characterized by quantitative and/or qualitative defects of endogenous surfactant metabolic pathways. The advent of exogenous surfactant therapy is rightly hailed as the major milestone in advancement of the care of the babies with surfactant-deficient lung disease. The administration of exogenous surfactant traditionally involves endotracheal intubation and mechanical ventilation. Minimally invasive surfactant therapy (MIST) is the technique of delivering surfactant without intubation whilst continuing the baby on noninvasive respiratory support. This author introduced MIST as the default way of administering surfactant in his neonatal units in Dubai and has to his credit the first published report on MIST from the United Arab Emirates in this journal in 2018.  Objective: To analyze prospectively all our babies in Dubai who received surfactant by MIST.

DESIGN:  Prospective descriptive study of all babies receiving surfactant by MIST starting from January 2018.

SETTING:  Three tertiary care neonatal centers in Dubai.

PATIENTS AND METHODS:  Thirteen babies (gestation 27-36 weeks and birth weight 0.95-2.81 kg) were treated with MIST on 15 occasions. Catheterization techniques were by infant feeding tube in 10 babies, LISA (less invasive surfactant administration) catheter in one baby, and 2.0 size endotracheal tube (ETT) with surfactant filled syringe directly attached to its hub two times each in two babies. Curosurf the porcine surfactant at 200 mg/kg was used on nine occasions and Survanta the bovine surfactant at 4 mL/kg on six occasions.

MAIN OUTCOME MEASURES:  MIST success defined as the baby not needing intubation and ventilation within 72 hours post MIST. Outcome measures with respect to the different modalities of MIST procedure and surfactant preparations used in this prospective cohort.

RESULTS:  Only one of the 13 babies (7.7%) in this cohort needed escalation of support with mechanical ventilation and high frequency oscillation (HFO). MIST using semi-rigid catheters like the LISA catheter or the smallest size ETT was technically easier to perform. No differences were observed with regard to the surfactant preparation used. None had an abnormal neurosonogram and there were no instances of sepsis and necrotizing enterocolitis either. The baby that had an unsuccessful MIST had retinopathy of prematurity that was effectively treated with Laser post discharge from neonatal unit. All the babies in this cohort had age appropriate developmental milestones on subsequent follow up visits ranging from three months to two years.

CONCLUSIONS:  MIST can be easily mastered and adapted in our neonatal units. MIST by any of the three variations of techniques as described in our cohort at FiO2 thresholds not exceeding 0.4 results in quicker resolution of the surfactant deficient lung disease, reduces the oxygen days in these babies and perhaps thereby insures intact survival of these babies.