Comparison Of Surfactant Lung Lavage With Standard Care In The Treatment Of Meconium Aspiration Syndrome (Sur-Lu-Lav)

• duration of oxygen therapy in hours [ Time Frame: till discharge or death ] [ Designated as safety issue: No ]
  The duration of oxygen therapy, mode of delivery, FiO2 and flow rate will be documented hourly within first 2 hours before lavage and in post lavage- hourly up to first 24 hours, 2 hourly up to 72 hours and 4 hourly thereafter till the cessation of oxygen therapy
  
  
• Severity of respiratory distress [ Time Frame: till discharge or death ] [ Designated as safety issue: No ]
  The severity of respiratory distress will be assessed using Downe's Score. These parameters will be documented hourly within first 2 hours before lavage and in post lavage hourly up to first 24 hours, 2 hourly up to 72 hours and 4 hourly thereafter till the cessation of respiratory distress
  
  
• need for mechanical ventilation [ Time Frame: till discharge or death ] [ Designated as safety issue: No ]
  The babies will be assessed for the need for mechanical ventilation as per standard unit protocols.
  
  

• Duration of mechanical ventilation [ Time Frame: till discharge or death ] [ Designated as safety issue: No ]
  Total duration of mechanical ventilation, mode and ventilator parameters are noted till the baby is on mechanical ventilation.
  
  
• Complications [ Time Frame: till discharge ] [ Designated as safety issue: No ]
  Incidence of PPHN by Echocardiography and Pneumothorax by transillumination confirmed by chest x-ray.
  
  
• Incidence of sepsis [ Time Frame: till discharge ] [ Designated as safety issue: No ]

  Incidence of sepsis defined as -

  1. SUSPECTED SEPSIS - Sepsis Screen > 2 parameters positive and/or
  2. CONFIRMED SEPSIS - Sepsis Screen positive + Blood or CSF culture positive for bacteria.

  Sepsis Screen

  1. Total leukocyte count < 5000/mm3
  2. Absolute neutrophil count < 1800/cu.mm.(Low counts as per Manroe chart for term neonates)
  3. Immature/total neutrophil ratio > 0.2
  4. Micro-ESR > 15mm in 1st hour
  5. C Reactive Protein (CRP) > 1 mg/dl
  
  
• Mortality [ Time Frame: till discharge ] [ Designated as safety issue: No ]
  
• Duration of Hospital stay [ Time Frame: till discharge ] [ Designated as safety issue: No ]
  

Meconium is an odourless, thick, blackish green material first demonstrable in the foetal intestinal tract during the third month of gestation. Approximately 10-15% of deliveries are complicated by the passage of meconium around the time of delivery. The risk of meconium stained amniotic fluid (MSAF) is strongly correlated with gestational age. An adverse intrauterine environment with resultant foetal asphyxia is proposed as the most common explanation for MSAF.

Aspiration of meconium into the tracheo-bronchial tree with the onset of respiration results in meconium aspiration syndrome (MAS). MAS is defined as respiratory distress with compatible chest x-ray finding in an infant born through MSAF whose symptoms cannot be otherwise explained. Despite current interventions such as intubation with tracheal suction, it is estimated that 5-20 % of infants born through MSAF develop MAS. It represents a leading cause of perinatal morbidity. Approximately 50% of the infants with MAS require mechanical ventilation; 15%-30% develop pulmonary air leaks and 5%-12% die.

The pathophysiology of meconium aspiration syndrome includes airway obstruction, surfactant inactivation, inflammation and pulmonary hypertension. Meconium itself inactivates the surfactant in the alveoli and its presence also causes secondary surfactant deficiency as meconium is toxic to type 2 alveolar cells which secrete surfactant. There is no specific treatment recommended for meconium aspiration syndrome .Treatment for MAS is generally supportive and includes supplemental oxygen as needed, assisted ventilation to maintain lung volume and improve gas exchange, and circulatory support with volume resuscitation and vasopressor infusions to maintain adequate perfusion. Successful treatment of meconium aspiration relies on effective meconium removal without inactivating or washing out surfactant, followed by appropriate ventilator care.

Surfactant replacement in neonates with severe meconium aspiration syndrome has been shown to improve oxygenation and reduce the severity of respiratory failure, air leaks and need for extracorporeal membrane oxygenation.

Surfactant replacement alone does not remove the meconium present in the airways and hence multiple doses may be required. Therefore an effective strategy to improve outcome in neonates with MAS needs to not only remove meconium but also retain the surfactant for adequate lung expansion and function.

Lung lavage using diluted surfactant has recently been shown to be an alternative to bolus therapy in treating MAS. This has advantage of removing surfactant inhibitors from alveolar space, in addition to augmenting surfactant concentration in alveolar space. Initial pilot case series using surfactant lung lavage have shown promise and there is a need to systematically study this in a RCT. The same has also been expressed in the literature on this subject. Hence the purpose of this prospective randomized controlled trial is to compare the efficacy of surfactant lung lavage over standard therapy in the treatment of meconium aspiration syndrome.