Peripheral Oxygenation In Term Neonates With In Utero Exposure To Smoking

Question: Aim of the present study was to analyse the influence of in utero exposure to smoking on peripheral oxygenation in healthy term neonates.

Method used: 12 term healthy neonates with in utero exposure to smoking were compared 12 term healthy neonates without in utero exposure to smoking. Measurements were performed during first week of life. Neonates were matched for gestational age, actual weight and postnatal age at time of measurement.

Peripheral oxygenation was measured by means of near infrared spectroscopy (NIRS) in combination with the venous occlusion method. NIRS optodes were placed on the left forearm. Venous occlusion was obtained using a pneumatic cuff around the left upper arm. Oxygen delivery (DO2), oxygen consumption (VO2), fractional oxygen extraction (FOE), and tissue oxygenation index (TOI) were analysed.

Central and peripheral temperatures were measured continuously. By means of pulsoximetry heart rate and peripheral arterial oxygen saturation were measured continuously. Arterial blood pressure was measured before and after venous occlusions.

Results: There was no significant difference between the two groups – in addition to those parameters used for matching – in birth weight, arm circumferences, arterial blood pressure, arterial oxygen saturation and heart rate.

FOE was significantly higher in the group with in utero exposure to smoking (0,40) compared to the group without in utero exposure (0,31). There was no significant difference between the two groups in DO2 (10,0µmol/100ml/minute versus 12,6µmol/100ml/minute) and TOI (63,9% versus 65,6), whereby both parameters tended to be lower in the group with in utero exposure to smoking. VO2 was nearly the same in both groups (3,8µmol/100ml/minute versus 3,9µmol/100ml/minute).

CONCLUSION: In these preliminary results healthy term neonates demonstrated influence of in utero exposure to smoking on peripheral oxygenation in the first week of life.