Can pulse oxymetry be used as a routine screening tool in early diagnosis of critical congenital heart diseases in newborns?

Background: Unrecognition or delayed diagnosis of severe congenital cardiac diseases (CCD) can lead to cardiac failure, cardiovascular collapse and death. Pulse oximetry can be used as a screening tool for detection of critical CCD (CCCD) in newborns. We conducted this study to correlate pulse oximetry findings in asymptomatic newborns to detect CCCD and coarctation of aorta.Methods: All babies delivered in our hospital were included; after clinical evaluation, pulse oximetry screening was done 12 hours after delivery, taken in three extremities (Right thumb, left thumb and left great toe). If the readings were <95% in any of the limbs, they were further evaluated to detect cardiac defects.Results: Of 800 babies, 54.4% were males and 66.1% were delivered by normal vaginal delivery. Antenatal scan of all were normal. Mean±SD birth weight was 2.92 kg ±.29 ranging 2.14 Kgs-3.80 kgs. Oxygen saturation was >95% in 799 babies, there was no significant clinical findings, and were negative for pulse oxymetry screening; one baby had positive pulse oximetry screening (<95%) with ‘ejection systolic murmur’ over left 2nd and 3rd intercostal space. There was no evidence of cyanosis, oedema or tachypnoea. Pulse oximetry reading was 88% in right thumb, 90% in left thumb and 92% in left great great toe. Echocardiography showed Atrial Septal Defect, Ventricular Septal Defect with Pulmonary Stenosis.Conclusions: Pulse oximetry is a non-invasive, reliable, and useful screening tool for an early detection of CCCD in newborns. The combination of pulse oximetry and clinical judgement is needed.

Cardiovascular changes during underwater static and dynamic breath-hold dives in trained divers

Limited information exists concerning arterial blood pressure (BP) changes in underwater breath-hold diving. Simulated chamber dives to 50 m of freshwater (mfw) reported very high levels of invasive BP in two divers during static apnea (SA), whereas a recent study using a noninvasive subaquatic sphygmomanometer reported unchanged or mildly increased values at 10 m SA dive. In this study we investigated underwater BP changes during not only SA but, for the first time, dynamic apnea (DA) and shortened (SHT) DA in 16 trained breath-hold divers. Measurements included BP (subaquatic sphygmomanometer), ECG, and pulse oxymetry (arterial oxygen saturation, SpO2, and heart rate). BP was measured during dry conditions, at surface fully immersed (SA), and at 2 mfw (DA and SHT DA), whereas ECG and pulse oxymetry were measured continuously. We have found significantly higher mean arterial pressure (MAP) values in SA (∼40%) vs. SHT DA (∼30%). Postapneic recovery of BP was slightly slower after SHT DA. Significantly higher BP gain (mmHg/duration of apnea in s) was found in SHT DA vs. SA. Furthermore, DA attempts resulted in faster desaturation vs. SA. In conclusion, we have found moderate increases in BP during SA, DA, and SHT DA. These cardiovascular changes during immersed SA and DA are in agreement with those reported for dry SA and DA.