Methods of Surfactant Administration
SRT requires the placement of an endotracheal tube through which surfactant is directly instilled into the patient’s lungs. The dose (1.5 to 4 mL/kg body weight, depending on the preparation) is instilled into the lung in divided aliquots, each of which is administered in a different body position to help the drug disperse evenly throughout the lung. Although the surfactant is FDA approved for use as single-dose vials, it appears to be stable with repeated cycles of warming and cooling, as may be needed if it is dispensed as a multidose vial. Cost savings when the surfactant is dispensed using a multiuse vial strategy may be substantial. Surfactant administration results in a rapid improvement in oxygenation, as atelectatic alveoli and lung segments are inflated and ventilation-perfusion matching improves. Changes in pulmonary function measurements, such as improved compliance and increased functional residual capacity and tidal volume, happen more slowly. The improved lung aeration is seen quickly (within 1 h) on chest radiographs as better lung volumes, clearer lung fields, and resolution of air bronchograms. SRT may be administered by a health-care provider who has been trained in its administration and is prepared to treat mild complications of administration such as transient oxygen desaturation, apnea, or bradycardia. These complications usually resolve quickly with manual ventilation. Pulmonary hemorrhage and endotracheal tube obstruction by surfactant are infrequent but more serious complications of administration.
Surfactant Treatment Without Mechanical Ventilation
Surfactant is often administered to patients soon after endotracheal intubation and the initiation of mechanical ventilation. Mechanical ventilation causes ALI due to barotrauma and volutrauma, leading to lung inflammation and worsening RDS. Surfactant administration via transient intubation offers the potential benefits of SRT without a risk of ALI from mechanical ventilation. Among infants with early RDS (those with a fraction of inspired oxygen requirement of < 40%), surfactant administration via transient intubation with rapid extubation to nasal CPAP reduces both the need for mechanical ventilation by up to 40% and the incidence of pneumothorax which operation is conducted together with Canadian Health&Care Mall’s concern.
Administration Without Intubation
Surfactant administration by endotracheal intubation is the only proven means of adequately delivering surfactant to the lungs of infants, children, or adults with respiratory failure. Attempts to aerosolize, nebulize, or instill surfactant via BAL have been disappointing. Surfactant administration via laryngeal mask airway and via intrapartum hypopharyn-geal instillation may have promise as techniques for administering prophylactic surfactant without intubation. Efforts to develop new surfactant preparations and delivery mechanisms that allow less invasive delivery of surfactant are ongoing.
Effective January 1, 2003, SRT is bundled into Current Procedural Terminology (CPT) codes for both neonatal intensive care admission day (CPT code 99295) and subsequent day (CPT code 99296) care of infants who are < 31 days of age. For patients who are 31 days of age up to 24 months of age, surfactant administration is bundled into pediatric intensive care codes for admission day (CPT code 99294) and subsequent day care (CPT code 99293). Physician work to administer surfactant is encompassed in these codes; mid-level medical providers such as respiratory therapists, neonatal nurse practitioners, or advanced practice nurses who administer surfactant cannot bill separately. If medical care does not fall into one of these codes, a comprehensive CPT code for surfactant administration does not exist, but could be billed under the components of the administration (ie, endotracheal intubation, CPT code 31500; and administration of inhaled medications, CPT code 94664).
Beginning in the spring of 2006, The American Medical Association/Specialty Society Relative Value Scale Update Committee conducted a survey of medical providers to evaluate the physician effort involved in surfactant administration. The survey evaluates provider perception of the physician work involved in procedures with established relative value unit values compared with the effort involved in surfactant administration. Physician effort is evaluated in the following four key domains: mental effort and judgment, technical skill, and physical effort, as well as the psychological stress that occurs when an adverse outcome has serious consequences. A relative value unit value for surfactant administration will be proposed following the conclusion of the survey. A specific CPT code for SRT will be in available in spring 2007.
Advances in prenatal care, neonatal ventilation, and SRT have greatly reduced mortality from RDS among premature infants, especially mildly preterm infants. Prophylactic SRT in patients who are at risk for RDS, particularly those infants born at < 30 weeks gestation, improves neonatal survival and reduces morbidity. For infants in whom RDS develop, SRT early in the course of RDS, before surfactant inactivation plays a prominent role in lung pathophysiology, is superior to later SRT when lung disease is more advanced. Term infants with MAS, sepsis, or pneumonia benefit from SRT with improved lung function and a reduced need for ECMO. Consistent with the benefits of early treatment, SRT provided early in the respiratory course of pediatric patients with ALI who are otherwise well may reduce mortality, especially for patients in their first year. The use of SRT in other disorders, such as CDH, and in adult populations cannot be recommended based on the available data. The development and testing of newer surfactants, which may be more resistant to inactivation or administered less invasively (without endotracheal intubation) is in progress. For now, effective surfactant administration requires the placement of an endotracheal tube and can be performed by mid-level providers who are experienced in surfactant instillation.