Pulse Oximetry in Pediatric Practice

Abstract

The introduction of pulse oximetry in clinical practice has allowed for simple, noninvasive, and reasonably accurate estimation of arterial oxygen saturation. Pulse oximetry is routinely used in the emergency department, the pediatric ward, and in pediatric intensive and perioperative care. However, clinically relevant principles and inherent limitations of the method are not always well understood by health care professionals caring for children. The calculation of the percentage of arterial oxyhemoglobin is based on the distinct characteristics of light absorption in the red and infrared spectra by oxygenated versus deoxygenated hemoglobin and takes advantage of the variation in light absorption caused by the pulsatility of arterial blood. Computation of oxygen saturation is achieved with the use of calibration algorithms. Safe use of pulse oximetry requires knowledge of its limitations, which include motion artifacts, poor perfusion at the site of measurement, irregular rhythms, ambient light or electromagnetic interference, skin pigmentation, nail polish, calibration assumptions, probe positioning, time lag in detecting hypoxic events, venous pulsation, intravenous dyes, and presence of abnormal hemoglobin molecules. In this review we describe the physiologic principles and limitations of pulse oximetry, discuss normal values, and highlight its importance in common pediatric diseases, in which the principle mechanism of hypoxemia is ventilation/perfusion mismatch (eg, asthma exacerbation, acute bronchiolitis, pneumonia) versus hypoventilation (eg, laryngotracheitis, vocal cord dysfunction, foreign-body aspiration in the larynx or trachea). Additional technologic advancements in pulse oximetry and its incorporation into evidence-based clinical algorithms will improve the efficiency of the method in daily pediatric practice.

The Accuracy and Reliability of Non-Invasive Haemoglobin Measurements in the Emergency Room: a Small Prospective Observational Quality Control Study from a Swiss University Hospital ED

“…Non-invasive haemoglobin measurements not only depend on haemoglobin concentrations, but may be influenced by peripheral perfusion, hypothermia, cardiac output, shock -and drug-induced vasoconstriction, high bilirubin concentrations and severe anaemiawhich could play a role in the emergency room [5,33,34]. Recent studies have in fact shown that the correlation between SpHb and LHb is reduced in patients with significant haemorrhage or at risk of haemorrhage [4,25,35].…”

The Use of Pulse Oximetry in Pediatric Emergency Department: Review

“…Daha sonra SO 2 'yi hesaplamak için; oksi-Hb konsantrasyonunu, oksi-ve deoksi-Hb konsantasyonunun toplamına böler (yani; SO 2 =oksi-Hb/ Oksi-Hb+ deoksi-Hb) (Resim 1a-c, Şekil 1). 4,18 Cihazın doğru ölçüm yapabilmesi için, fotodedektör ile ışığı yayan diodların karşılıklı olması, dokunun bu iki prob arasında birbirine paralel uzanması gerekmektedir. Fotodiodlar, pulsatil veya nonpulsatil kan akımı sırasında, ışığın emilimini kaydetmek için saniyede birkaç yüz defa açılıp ka- panmaktadır.…”

“…Zayıf perfüzyon, hasta hareketi, yanlış prob kullanımı nedeni ile ortaya çıkan sinyal bozuklukları, takipne, metHb, COHb ve siyanotik kalp hastalıkları, nabız oksimetre sonuçlarını yanıltabilir. 4,18,19 Nabız oksimetre okumaları sırasında, ölçüm hatalarını ortadan kaldırmak için en önemli yol; şüpheci olmaktır. Yanlış veya hatalı okuma demeden önce, hastanın klinik durumu mutlaka değer- lendirilmelidir.…”

“…O Or rt ta am mı ın n a ay yd dı ın nl lı ığ ğı ı; ; Yoğun gün ışığı, floresan, parlak akkor lambalar, ksenon, fototerapi ve infrared ışık kaynaklarının nabzın okunması sıra-sında artefakta neden oldukları bildirilmiştir. 18,29 Sensörün fazla ışık almasını engelleyecek bir madde ile sarılması bu ölçüm hatasını azaltabilir.…”

Robust Design of Pulse Oximeter Using Dynamic Control and Motion Artifact Detection Algorithms

“…In case of jaundice treatment for the vast majority of neonates, the intense white light of phototherapy impinges the photo-detector and SpO 2 can be underestimated. This is one of the most common problems in the NICU [17]. When using pulse oximetry in the NICU under an extreme environment, it is necessary to deal with a wide dynamic range.…”