Learning outcome 1: Explain how pulse oximetry works and how it is used
CPP/PSP/CSC Norman, Thomas L. in Developing Practical Adult Nursing Skills, 2009
Have you seen pulse oximetry used in practice? If so, can you remember what the equipment looked like, and do you know how it works? What is a normal reading? ACTIVITY Pulse oximeters range from small hand-held devices displaying the percentage of oxygen saturation and the pulse rate, to more substantial devices that also show the pulsatile waveform (see Fig. 4.6). The box has a wire leading to the sensor or probe – a clip or sleeve which is placed on a finger, toe or earlobe. Probes can be disposable or reusable and are available in different sizes. The diagram in Fig. 4.7 shows how the sensor works.
Cyanides: Toxicology, Clinical Presentation, and Medical Management
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
This chapter discusses the experimental and human clinical toxicology of central nervous system with particular reference to their potential for application as chemical warfare weapons and use by terrorists. The most commonly available cyanides are hydrogen cyanide, a highly volatile liquid, and sodium, potassium, and calcium cyanides, which are solids. Some physicochemical properties are compared with those of the sodium, potassium, and calcium salts. As cyanides (CN) inhibit many enzyme systems, and since other biochemical and physiological functions may be adversely affected by CNs, the overall mechanism and presentation of CN intoxication may be complex. In general medical practice, acute CN intoxication is a rare, potentially fatal, but treatable condition. Confirmation of suspected acute CN poisoning should include the following investigations: ECG, plasma lactate, serum electrolytes, blood glucose, arterial ketone body ratio, pulse oximetry, arterial blood gas analysis, chest radiography, and blood CN analysis.
Common neonatal problems
David M. Luesley, Mark D. Kilby in Obstetrics & Gynaecology, 2016
This chapter introduces the reader to the most common problems encountered at or shortly after birth, concentrating in the main on those relating to the term fetus/neonate. It highlights some of the more common problems facing the newborn infant. Most babies are born healthy and remain so throughout their lives. However, they can develop a number of common problems which, while not necessarily life threatening, may nonetheless cause significant morbidity and parental anxiety. One of the most common problems that paediatricians review is acute respiratory embarrassment. The majority of neonatal fractures will heal uneventfully with conservative treatment. Increasingly, neonatal pulse oximetry is used as part of the examination to screen babies for both undiagnosed cardiac and non-cardiac anomalies. During the neonatal period, the main concern is one of feeding, and referral for specialist advice at an early stage is paramount. Most common neonatal problems are not life threatening.
Early screening for critical congenital heart defects in asymptomatic newborns in Bursa province
Published in The Journal of Maternal-Fetal & Neonatal Medicine, 2016
Elif Özalkaya, Arzu Akdağ, Ismail Şen, Erol Cömert, Hamide Melek Yaren
Objective: In this study, pulse oximetry screening results in the early diagnosis of critical congenital heart diseases (CCHD) will be evaluated. Methods: Eight-thousand two-hundred and eight of 10 200 newborns born between January 2014 and December 2014 were screened using pulse oximetry for the diagnosis of CCHD. Screening test was considered to be positive in the newborns whose saturation after 24 h from the birth with pulse oximetry was ≤95% and/or in the newborns who had a difference of ≥3% between the lower and right upper extremity. Results: Incidence of CCHD was 1 per 1000 live births. Coarctation of the aorta was the most commonly determined CCHD. Sensitivity, specificity, false negative rate and false positive rate of pulse oximetry in the diagnosis of CCHD were 60%, 99.8%, 40% and 0.12%, respectively. Seventy-five percent of the newborns who had a false negative diagnosis with pulse oximetry had coarctation of the aorta. Coarctation of the aorta was determined at a rate of 20% using CCHD screening. Conclusions: The diagnosis of coarctation of the aorta is missed in the newborns screened with pulse oximetry in the first 24–48 h after birth. Screening with pulse oximetry should be repeated for early diagnosis of coarctation of the aorta.
Latency and Loss of Pulse Oximetry Signal with the Use of Digital Probes during Prehospital Rapid-Sequence Intubation
Published in Prehospital Emergency Care, 2011
Daniel P. Davis, Steve Aguilar, Catherine Sonnleitner, Maya Cohen, Michelle Jennings
Background. Prehospital personnel rely on timely and accurate pulse oximetry data when performing critical skills, such as rapid-sequence intubation (RSI). However, loss of signal may be a frequent occurrence in patients with poor peripheral perfusion. In addition, a delay or latency period in the timeliness of pulse oximetry data may exist with probes placed on the fingers. Objective. To define the incidence of pulse oximetry signal loss or a latent period during prehospital RSI. Methods. Patients with severe traumatic brain injury (TBI) (Glasgow Coma Scale score [[GCS]] 3–8) undergoing prehospital RSI by air medical crews were enrolled. Data from hand-held oximetry–capnometry units were analyzed for either the loss of a pulse oximetry tracing (≥ 30 seconds) during the RSI procedure or the presence of a latent period, defined by the saturation of peripheral oxygen (SpO2) nadir occurring after intubation in patients undergoing desaturation (SpO2 ≤ 93%%) during the procedure. Results. A total of 98 of 124 patients (79%%, 95%% confidence interval [[CI]] 71–85%%) had pulse oximetry failure during critical points in the RSI procedure. In the 49 patients with a desaturation during RSI, a latent period was observed in 27 patients (55%%, 95%% CI 41–68%%). Conclusions. A high incidence of pulse oximetry failure was observed with the use of a digital pulse oximetry probe during prehospital RSI. In addition, a latent period appears to exist in the majority of patients undergoing desaturation.
Accuracy of fetal pulse oximetry
Published in Acta Obstetricia et Gynecologica Scandinavica, 2002
Andreas K. Luttkus, Marion Lübke, Ulrich Büscher, Martina Porath, Joachim W. Dudenhausen
1Financial disclosure: Nellcor Puritan Bennett, Pleasanton, CA provided the technical equipmentBackground. The goal of this investigation was to evaluate the agreement of fetal pulse oximetry to saturation readings from hemoximetry at low oxygen saturation. Methods. Fetal oxygen saturation measurements obtained by pulse oximetry were compared with those obtained by hemoximetry in fetal scalp blood samplings. The prospective observational trial included fetuses with non-reassuring fetal heart rate tracings suggestive of hypoxia and requiring fetal scalp blood samplings. Arterial oxygen saturation was determined by a blinded pulse oximeter (N400, FS14; Nellcor Puritan Bennett, Pleasanton, CA, USA) and continuously stored on a notebook computer. Saturation from fetal scalp blood samples was measured by hemoximetry (Bayer Diagnostics 865; ABL 625, Radiometer). Data analysis focussed on the absolute and relative difference between hemoximetry and pulse oximetry of fetuses, showing the most distinct difference in neonatal outcome. Normal outcome was defined as spontaneous delivery and umbilical artery pH ≥ 7.20 + Apgar 5 ≥ 7(n = 42). In contrast, a group of neonates with combined respiratory and metabolic acidemia at birth wasdefined by pH ≤ 7.16 and an additional base excess≤ -9.4mmol/l in the umbilical artery (n = 18). Results. The correlation coefficient between hemoximetry and pulse oximetry measurements was r = 0.72; p = 0.002 in the acidemic group. The median of absolute differences in saturation was + 5.2% (95%CI 2.5–10.3) saturation. The absolute differences ranged from− 21% to+ 36% saturation. The median of relative differences amounted to 23% (95%CI 15.1–55.0). The relative differences ranged from -30% to+ 217%. Observing the saturation distribution in the two groups (hemoximetry and pulse oximetry, respectively) presented a median hemoximetry pulse oximetry of 38% (42%) in the normal and 26% (39%) in the acidemic group. In this small group of cases, the correlation coefficient between pH and saturation from pulse oximetry in fetal scalp blood from the samplings was r = 0.19. Conclusion. Fetal pulse oximetry tends to overestimate arterial oxygen saturation compared with hemoximeter values.