Pain-related changes in crSO₂ among premature infants undergoing PICC insertion

To evaluate the effectiveness of cerebral regional oxygen saturation (crSO₂) values, measured using near-infrared spectroscopy (NIRS), in assessing pain associated with the peripherally inserted central catheter (PICC) in premature infants.

NIRS was used to measure the crSO₂ levels of 48 premature infants with gestational age (GA) of < 32 weeks or a birth weight of < 1500 g. Premature infant pain profile (PIPP) scores, vital signs, transcutaneous oxygen tension (TcpO₂), transcutaneous carbon dioxide tension (TcpCO₂), and crSO₂ values were monitored. One-way repeated measure analysis of variance was used to compare heart rate (HR), respiratory rate (RR), blood pressure (BP), peripheral oxygen saturation (SpO₂), TcpO₂, TcpCO₂, and crSO₂ values before (Time 1), during (Time 2), and after (Time 3) PICC insertion. The correlation between the PIPP scores at Time 2 and the fluctuations (values detected at Time 2 minus those at Time 1) of SpO_2, TcpO_2, and crSO₂ were also analyzed.

The PIPP score at Time 2 was significantly higher than those at Times 1 and 3. HR, RR, and BP values increased (p < .05), and SpO₂ and crSO₂ levels decreased at Time 2 (p < .05) compared with those at Time 1. Stratified analysis based on GA revealed significant differences in HR, RR, and crSO₂ values between Times 1 and 2 in infants with a GA of ≥ 32 weeks. In infants with a GA < 32 weeks, significant differences were observed in HR, RR, SpO₂, BP, and crSO₂ values between Times 1 and 2. The fluctuation of the crSO₂ level was strongly correlated with the PIPP score at Time 2 (r = -0.829, p < .001). A weak correlation was observed between the PIPP score at Time 2 and TcpO₂ level fluctuation (r = 0.375, p = .009). No correlation was observed between the PIPP score at Time 2 and SpO₂ level fluctuation (r = 0.242, p = .097).

The fluctuation of crSO₂ levels strongly correlates with PICC procedural pain. Hence, crSO₂ levels measured using NIRS may be used as an indicator for pain assessment in premature infants.