Cerebral hemodynamic effects of treatment with modified natural surfactant investigated by near infrared spectroscopy.

The purpose of this study was to investigate PAP, peak airway pressure the effects on cerebral hemodynamics of administering EEP, end expiratory pressure modified natural surfactant (Curosurf, 200 mg.kg-') to FiOz, inspired oxygen fraction infants requiring mechanical ventilation for hyaline mem- PVH, periventricular cerebral hemorrhage brane disease. Observations were made using near infrared Paoz, arterial oxygen tension spectroscopy on 20 infants for between 26 and 109 (median Pacoz, arterial carbon dioxide tension 57) min before and 22 to 112 (median 46) min after surfactant instillation. Changes in cerebral oxyhemoglobin concentration and cerebral blood volume (CBV) were mon- itored continuously; cerebral blood flow, oxygen delivery, and the response of CBV to changes in arterial carbon There is abundant evidence that surfactant replacement ther- dioxide tension were measured while the infants were apy improves pulmonary gas exchange and reduces mortality in stable shortly before and after surfactant was given. Cere- infants with hyaline membrane disease (surfactant-deficient res- bra1 oxyhemoglobin concentration fell transiently in all piratory distress syndrome) (1). The effects of this therapy on infants immediately after surfactant by a median of -0.21 intracerebral complications, such as PVH, that lead to later (range -0.46 to 0.05) mL 100 g-I, but quickly recovered morbidity are less certain. Most randomized trials show no so that the median change during the 10 min after surfac- evidence of a change in the incidence of PVH in infants treated tant was 0.01 (-0.46 to 0.46) mL.lOO g-I. Alterations in with either natural or artificial surfactant (1). However, in one CBV also occurred ranging from -0.44 to 0.40 (median 0) recent multicenter trial in which an enriched extract of bovine mL. 100 g-I, which represented -12 to 16% of total CBV; lung was used, a substantial increase in the incidence of PVH these changes rapidly resolved. When the infants were was found (2). Hemorrhages graded as severe occurred in 39% stable before and after surfactant, the values for mean (SD) of treated infants compared with 15% of controls. Concern about cerebral blood flow were 20.5 (7.5) and 23.1 (5.2) mL. 100 the high incidence of PVH in the treated infants prompted the g-' . min-I, respectively (n = 9); for mean cerebral oxygen U.S. Food and Drug Administration to terminate this trial before delivery, values were 2.71 (0.89) and 3.15 (0.73) mL. 100 planned enrollment was completed. g-' . min-' (n = 9); and for response of CBV to changes in Little information is available about intracerebral conse- arterial carbon dioxide tension, they were 0.14 (0.09) and quences of surfactant administration that might provoke PVH, 0.11 (0.11) mL 100 g-' . kPa-' (n = 16); these changes although abnormalities of EEG recordings (3) and falls in cerebral were not statistically significant. We conclude that (I) arterial blood velocity (4) have been demonstrated coincident surfactant administration caused small, transient pertur- with administration of a natural surfactant derived from porcine bations in cerebral oxyhemoglobin concentration and CBV, lung (Curosurf, Chiesi Farmaceutici, Parma, Italy). The purpose and (2) no important alterations in cerebral blood flow, of this study was to investigate with NIRS the extent of any cerebral oxygen delivery, or response of CBV to changes perturbations in cerebral hemodynamics associated with admin- in arterial carbon dioxide tension were detected. (Pediatr istration of surfactant. Res 32: 532-536,1992)