Advances and Challenges Associated with Low-Cost Pulse Oximeters in Home Care Programs: A Review.

Oximeters have significantly evolved since their invention and are essential for monitoring chronic diseases in home care. However, commercial models can present an economic barrier. Therefore, we conducted a review of the use of low-cost pulse oximeters in the home care of patients with respiratory diseases. Our review included studies addressing oxygen saturation and heart rate monitoring in adults, focusing on the use of portable devices. Our search identified advances in vital signs monitoring that could provide accessible solutions for non-clinical settings. Although there are challenges related to clinical validation and accuracy, these oximeters may improve medical care, particularly in resource-limited areas. As a result, the accessibility of these devices opens up new possibilities for patients with chronic respiratory diseases in home care, enabling regular self-monitoring and increasing control over their health.

Impact of Real-Time Assessment of Pulse Oximetry on the 6-Min Walk Distance in Patients With Chronic Respiratory Disease.

BACKGROUND: Continuous monitoring of pulse oximetry (SpO2 ) is recommended during the 6-min walk test (6MWT) to ensure that the lowest SpO2 is recorded. In this case, severe exercise-induced desaturation (EID; SpO2 < 80%) triggers walking interruption by the examiner. Our main objective was to assess the impact of this approach on 6MWT distance in patients with chronic respiratory diseases and, second, to evaluate the safety of the test without interruption due to severe EID. METHODS: 6MWTs with continuous monitoring of SpO2 were prospectively performed in subjects with chronic respiratory disease. The participants were randomly allocated to walk with or without SpO2 real-time assessment. SpO2 visualization during the test execution was available only in the first group, and walking interruption was requested by the examiner if SpO2 < 80%. RESULTS: One hundred forty-five participants were included in each group (68.6% females, 62 [52-69] y old) without differences in demographic and resting lung function parameters between them. The main respiratory conditions were COPD (n = 101), asthma (n = 73), pulmonary hypertension (n = 47), and interstitial lung disease (n = 39). The walked distance was similar comparing groups (349.5 ± 117.5 m vs 351.2 ± 105.4 m). Twenty-five subjects presented with severe EID in the group with real-time SpO2 assessment, and 20 subjects had severe EID in the group without real-time assessment respectively (overall prevalence of 15.5%). The 23 participants who had their test interrupted by the examiner due to severe EID in the first group (2 subjects stopped by themselves due to excessive symptoms) walked a shorter distance compared to the 11 subjects with severe EID without test interruption in the second group (9 subjects stopped by themselves due to excessive symptoms): 240.6 ± 100.2 m versus 345.9 ± 73.4 m. No exercise-related serious adverse events were observed. CONCLUSIONS: Interruption driven by severe EID reduced the walked distance during the 6MWT. No serious adverse event, in turn, was observed in subjects with severe desaturation without real-time SpO2 assessment.

Reference Ranges for Arterial Oxygen Saturation, Heart Rate, and Cerebral Oxygen Saturation during Immediate Postnatal Transition in Neonates Born Extremely or Very Preterm.

OBJECTIVE: To define percentile charts for arterial oxygen saturation (SpO2), heart rate (HR), and cerebral oxygen saturation (crSO2) during the first 15 minutes after birth in neonates born very or extremely preterm and with favorable outcome. STUDY DESIGN: We conducted a secondary-outcome analysis of neonates born preterm included in the Cerebral regional tissue Oxygen Saturation to Guide Oxygen Delivery in preterm neonates during immediate transition after birth III (COSGOD III) trial with visible cerebral oximetry measurements and with favorable outcome, defined as survival without cerebral injuries until term age. We excluded infants with inflammatory morbidities within the first week after birth. SpO2 was obtained by pulse oximetry, and electrocardiogram or pulse oximetry were used for measurement of HR. crSO2 was assessed with near-infrared spectroscopy. Measurements were performed during the first 15 minutes after birth. Percentile charts (10th to 90th centile) were defined for each minute. RESULTS: A total of 207 neonates born preterm with a gestational age of 29.7 (23.9-31.9) weeks and a birth weight of 1200 (378-2320) g were eligible for analyses. The 10th percentile of SpO2 at minute 2, 5, 10, and 15 was 32%, 52%, 83%, and 85%, respectively. The 10th percentile of HR at minute 2, 5, 10, and 15 was 70, 109, 126, and 134 beats/min, respectively. The 10th percentile of crSO2 at minute 2, 5, 20, and 15 was 15%, 27%, 59%, and 63%, respectively. CONCLUSIONS: This study provides new centile charts for SpO2, HR, and crSO2 for neonates born extremely or very preterm with favorable outcome. Implementing these centiles in guiding interventions during the stabilization process after birth might help to more accurately target oxygenation during postnatal transition period.

Finger photopletysmography detects early acute blood loss in compensated blood donors: a pilot study.

Objective.Diagnosis of incipient acute hypovolemia is challenging as vital signs are typically normal and patients remain asymptomatic at early stages. The early identification of this entity would affect patients' outcome if physicians were able to treat it precociously. Thus, the development of a noninvasive, continuous bedside monitoring tool to detect occult hypovolemia before patients become hemodynamically unstable is clinically relevant. We hypothesize that pulse oximeter's alternant (AC) and continuous (DC) components of the infrared light are sensitive to acute and small changes in patient's volemia. We aimed to test this hypothesis in a cohort of healthy blood donors as a model of slight hypovolemia.Approach.We planned to prospectively study blood donor volunteers removing 450 ml of blood in supine position. Noninvasive arterial blood pressure, heart rate, and finger pulse oximetry were recorded. Data was analyzed before donation, after donation and during blood auto-transfusion generated by the passive leg-rising (PLR) maneuver.Main results.Sixty-six volunteers (44% women) accomplished the protocol successfully. No clinical symptoms of hypovolemia, arterial hypotension (systolic pressure < 90 mmHg), brady-tachycardia (heart rate <60 and >100 beats-per-minute) or hypoxemia (SpO2< 90%) were observed during donation. The AC signal before donation (median 0.21 and interquartile range 0.17 a.u.) increased after donation [0.26(0.19) a.u;p< 0.001]. The DC signal before donation [94.05(3.63) a.u] increased after blood extraction [94.65(3.49) a.u;p< 0.001]. When the legs' blood was auto-transfused during the PLR, the AC [0.21(0.13) a.u.;p= 0.54] and the DC [94.25(3.94) a.u.;p= 0.19] returned to pre-donation levels.Significance.The AC and DC components of finger pulse oximetry changed during blood donation in asymptomatic volunteers. The continuous monitoring of these signals could be helpful in detecting occult acute hypovolemia. New pulse oximeters should be developed combining the AC/DC signals with a functional hemodynamic monitoring of fluid responsiveness to define which patient needs fluid administration.

Predicting Extubation Readiness in Preterm Infants Utilizing Machine Learning: A Diagnostic Utility Study.

OBJECTIVE: The objective of this study was to predict extubation readiness in preterm infants using machine learning analysis of bedside pulse oximeter and ventilator data. STUDY DESIGN: This is an observational study with prospective recordings of oxygen saturation (SpO2) and ventilator data from infants <30 weeks of gestation age. Research pulse oximeters collected SpO2 (1 Hz sampling rate) to quantify intermittent hypoxemia (IH). Continuous ventilator metrics were collected (4-5-minute sampling) from bedside ventilators. Data modeling was completed using unbiased machine learning algorithms. Three model sets were created using the following data source combinations: (1) IH and ventilator (IH + SIMV), (2) IH, and (3) ventilator (SIMV). Infants were also analyzed separated by postnatal age (infants <2 or ≥2 weeks of age). Models were compared by area under the receiver operating characteristic curve (AUC). RESULTS: A total of 110 extubation events from 110 preterm infants were analyzed. Infants had a median gestation age and birth weight of 26 weeks and 825 g, respectively. Of the 3 models presented, the IH + SIMV model achieved the highest AUC of 0.77 for all infants. Separating infants by postnatal age increased accuracy further achieving AUC of 0.94 for <2 weeks of age group and AUC of 0.83 for ≥2 weeks group. CONCLUSIONS: Machine learning analysis has the potential to enhance prediction accuracy of extubation readiness in preterm infants while utilizing readily available data streams from bedside pulse oximeters and ventilators.

Pulse oximetry test for screening congenital heart diseases: a systematic review.

OBJECTIVE: To determine the accuracy of the Pulse Oximetry Test (POT) in screening for Congenital Heart Diseases (CHD) in newborns in the first 48 hours of life. METHOD: Systematic review of diagnostic test accuracy with meta-analysis. The selection of studies was carried out in June 2021. Studies were selected with newborns, in a hospital or home environment, without a previous diagnosis of CHD, regardless of gestational age at birth, who underwent POT within the first 48 hours after birth. Registration on the PROSPERO platform - CRD42021256286. RESULTS: Twenty-nine studies were included, totaling a population of 388,491 newborns. POT demonstrated sensitivity of 47% (95% CI: 43% to 50%) and specificity of 98% (95% CI: 98% to 98%). Subgroup analyses were carried out according to the different testing period, inclusion of retests in protocols and population of premature newborns. CONCLUSION: POT is a test with moderate sensitivity and high specificity. It is more effective when carried out within 24h - 48h of birth; in protocols that present retests, within two hours after the first measurement. It does not show satisfactory effectiveness for premature newborns.

Exploring the Hidden Complexity: Entropy Analysis in Pulse Oximetry of Female Athletes.

This study examines the relationship between physiological complexity, as measured by Approximate Entropy (ApEn) and Sample Entropy (SampEn), and fitness levels in female athletes. Our focus is on their association with maximal oxygen consumption (VO2,max). Our findings reveal a complex relationship between entropy metrics and fitness levels, indicating that higher fitness typically, though not invariably, correlates with greater entropy in physiological time series data; however, this is not consistent for all individuals. For Heart Rate (HR), entropy measures suggest stable patterns across fitness categories, while pulse oximetry (SpO2) data shows greater variability. For instance, the medium fitness group displayed an ApEn(HR) = 0.57±0.13 with a coefficient of variation (CV) of 22.17 and ApEn(SpO2) = 0.96±0.49 with a CV of 46.08%, compared to the excellent fitness group with ApEn(HR) = 0.60±0.09 with a CV of 15.19% and ApEn(SpO2) =0.85±0.42 with a CV of 49.46%, suggesting broader physiological responses among more fit individuals. The larger standard deviations and CVs for SpO2 entropy may indicate the body's proficient oxygen utilization at higher levels of physical demand. Our findings advocate for combining entropy metrics with wearable sensor technology for improved biomedical analysis and personalized healthcare.

Is the time below 90% of SpO2 during sleep (T90%) a metric of good health? A longitudinal analysis of two cohorts.

BACKGROUND: Novel wireless-based technologies can easily record pulse oximetry at home. One of the main parameters that are recorded in sleep studies is the time under 90% of SpO2 (T90%) and the oxygen desaturation index 3% (ODI-3%). We assessed the association of T90% and/or ODI-3% in two different scenarios (a community-based study and a clinical setting) with all-cause mortality (primary outcome). METHODS: We included all individuals from the Sleep Heart Health Study (SHHS, community-based cohort) and Santiago Obstructive Sleep Apnea (SantOSA, clinical cohort) with complete data at baseline and follow-up. Two measures of hypoxemia (T90% and ODI-3%) were our primary exposures. The adjusted hazard ratios (HRs) per standard deviation (pSD) between T90% and incident all-cause mortality (primary outcome) were determined by adjusted Cox regression models. In the secondary analysis, to assess whether T90% varies across clinical factors, anthropometrics, abdominal obesity, metabolic rate, and SpO2, we conducted linear regression models. Incremental changes in R2 were conducted to test the hypothesis. RESULTS: A total of 4323 (56% male, median 64 years old, follow-up: 12 years, 23% events) and 1345 (77% male, median 55 years old, follow-up: 6 years, 11.6% events) patients were included in SHHS and SantOSA, respectively. Every 1 SD increase in T90% was associated with an adjusted HR of 1.18 [95% CI: 1.10-1.26] (p value < 0.001) in SHHS and HR 1.34 [95% CI: 1.04-1.71] (p value = 0.021) for all-cause mortality in SantOSA. Conversely, ODI-3% was not associated with worse outcomes. R2 explains 62% of the variability in T90%. The main contributors were baseline-mean change in SpO2, baseline SpO2, respiratory events, and age. CONCLUSION: The findings suggest that T90% may be an important marker of wellness in clinical and community-based scenarios. Although this nonspecific metric varies across the populations, ventilatory changes during sleep rather than other physiological or comorbidity variables explain their variability.

Advancements in Home-Based Devices for Detecting Obstructive Sleep Apnea: A Comprehensive Study.

Obstructive Sleep Apnea (OSA) is a respiratory disorder characterized by frequent breathing pauses during sleep. The apnea-hypopnea index is a measure used to assess the severity of sleep apnea and the hourly rate of respiratory events. Despite numerous commercial devices available for apnea diagnosis and early detection, accessibility remains challenging for the general population, leading to lengthy wait times in sleep clinics. Consequently, research on monitoring and predicting OSA has surged. This comprehensive paper reviews devices, emphasizing distinctions among representative apnea devices and technologies for home detection of OSA. The collected articles are analyzed to present a clear discussion. Each article is evaluated according to diagnostic elements, the implemented automation level, and the derived level of evidence and quality rating. The findings indicate that the critical variables for monitoring sleep behavior include oxygen saturation (oximetry), body position, respiratory effort, and respiratory flow. Also, the prevalent trend is the development of level IV devices, measuring one or two signals and supported by prediction software. Noteworthy methods showcasing optimal results involve neural networks, deep learning, and regression modeling, achieving an accuracy of approximately 99%.

Oximetria de pulso neonatal: capacitação de profissionais e estudantes da saúde no formato remoto e presencial / Neonatal pulse oximetry: training healthcare professionals and students in remote and on-site format / Pulsioximetría neonatal: formación de profesionales y estudiantes de la salud a distancia y presencial

Introdução:A oximetria de pulso neonatal compõe o Programa Nacional de Triagem Neonatal do Brasil desde 2014. Entretanto, existem poucos registros de sua efetiva implementação na rotina de cuidados materno-infantis no país.Objetivo:O objetivo deste trabalho foi relatar a experiência em ações de educação em saúde a profissionais e estudantes da área da saúde e à população em geral, em temas relacionados ao Teste do Coraçãozinho.Metodologia:Trata-se de um estudo descritivo, do tipo relato de experiência, executado entre julho de 2019 a julho de 2021, antes e durante a pandemia de Covid-19, por discentes vinculados ao projeto de extensão de serviço universitário de referência do Rio Grande do Norte. O público-alvo das capacitações foram estudantes e profissionais do curso de Medicina, Enfermagem e Técnico de Enfermagem dos municípios de Natal, Macaíba, Santa Cruz, Currais Novos, Mossoró e Caicó, do estado do Rio Grande do Norte. Foi realizada uma capacitação no formato presencial antes da pandemia causada pela COVID-19 ou no formato remoto como adaptação das atividades durante o período pandêmico. A metodologia dos treinamentos foi composta por um formulário de pré e pós teste visando avaliar a eficácia das capacitações, somado a fundamentação teórica, simulações teórico-práticas e discussão de casos clínicos. Além disso, foram promovidas ações educativas destinadas à população geral. Resultados:As capacitações ministradas a profissionais e estudantes da área da saúde totalizaram 1212 participantes. Os eventos direcionados ao meio externo, como transmissões ao vivo e conteúdos audiovisuais em redes sociais, atingiram 12.931 pessoas. O fomento à produção científica envolveu a elaboração de 95 trabalhos aprovados em congressos regionais, nacionais e internacionais, bem como a organização de um congresso internacional nas áreas de Pediatria e Cardiologia, contabilizando 29.007 inscritos.Conclusões:Evidenciou-se a importância de intervenções para melhoria da linha de cuidado à criança cardiopata (AU).

Introduction:Neonatal pulse oximetry has been part of the National Newborn Screening Program in Brazil since 2014. However, there are few reports of its effective implementation in routine maternal and child care in the country. Objective: This study reports on the experience of providing health education to health professionals, students and the general population on topics related to neonatal pulse oximetry.Methodology: This is a descriptive study, experience report type, carried out between July 2019 and July 2021,before and during the Covid-19 pandemic, by students linked to the extension project of a reference university service in Rio Grande do Norte. The target audience of the training were students and professionals from the Medicine, Nursing and Nursing Technician course in the municipalities of Natal, Macaíba, Santa Cruz, Currais Novos, Mossoró and Caicó, in the state of Rio Grande do Norte. Training was carried out in person before the COVID-19 pandemic or remotely as an adaptation of activities during the pandemic period. The training methodology consisted of a pre-and post-test form aimed at evaluating the effectiveness of the training, in addition to theoretical foundations, theoretical-practical simulations and discussion of clinical cases. In addition, educational activities were promoted for the general population.Results:Training given to health professionals and students totaled 1212 participants. Events directed to the external environment, such as live broadcasts and audiovisual content on socialnetworks, reached 12,931 people. Promotion of scientific production involved the preparation of 95 papers approved in regional, national, and international congresses, as well as the organization of an international congress in the areas of Pediatrics andCardiology, with 29,007 registered participants. Conclusions: The importance of interventions to improve the line of care for children with heart disease was evidenced (AU).

Introducción: La oximetría de pulso neonatal forma parte del Programa Nacional de Tamizaje Neonatal en Brasil desde 2014. Sin embargo, existen pocos registros de su implementación efectiva en la atención materno-infantil de rutina en el país. Objetivo: El objetivo de este trabajo fue relatar la experiencia en acciones de educación en salud para profesionales y estudiantes del área de la salud y la población en general, sobre temas relacionados con El Test del Corazoncito. Metodología:Se trata de un estudiodescriptivo, del tipo relato de experiencia, realizado entre julio de 2019 y julio de 2021, antes y durante la pandemia de la Covid-19, por estudiantes vinculados al proyecto de extensión de un servicio universitario de referencia en Rio Grande Norte. El público objetivo de la capacitación fueron estudiantes y profesionales de la carrera de Medicina, Enfermería y Técnico en Enfermería de los municipios de Natal, Macaíba, Santa Cruz, Currais Novos, Mossoró y Caicó, en el estado de Rio Grande do Norte. La formación se realizó en formato presencial antes de la pandemia causada por el COVID-19 o a distancia como adaptación de las actividades durante el periodo de pandemia. La metodología de capacitación consistió en un formulario de pre y post test dirigido a evaluar la efectividad de la capacitación, además de fundamentos teóricos, simulacros teórico-prácticos y discusión de casos clínicos. Además, se promovieron actividades educativas para la población en general. Resultados:La formación impartida a profesionales y estudiantes de la salud totalizó 1212 participantes. Los eventos dirigidos al entorno externo, como retransmisiones en directo y contenidos audiovisuales en redes sociales, llegaron a 12.931 personas. El fomento de la producción científica implicó la elaboración de 95 trabajos aprobados en congresos regionales, nacionales e internacionales, así como la organización de un congreso internacional en las áreas de Pediatría y Cardiología, con 29.007 inscritos. Conclusiones:Se destacó la importancia de las intervenciones para mejorar la línea de atención a los niños con cardiopatías (AU).

[Pulse Oximetry Values in Preterm infants at 34-36 weeks postmenstrual age]. / Valores de Oximetría de Pulso en Prematuros a las 34-36 semanas post-concepcional.

Pulse oximetry (SpO2) is essential for guiding oxygen therapy in preterm infants. Data on SpO2 values before discharge are limited. OBJECTIVE: To establish SpO2 values in asymptomatic premature infants at 34, 35, and 36 weeks of postmenstrual age (PMA). SUBJECTS AND METHOD: Longitudinal, multicen ter study carried out from May 2018 to May 2019 in three neonatal intensive care units in Santiago, Chile (altitude 579 m) which included premature infants born ≤ 32 weeks of gestational age, healthy, with clinical stability, and without respiratory morbidity at the moment of the study or until dis charge. The following parameters were analyzed: mean accumulated SpO2 and SD, minimum SpO2 value, SpO2 time percentage < 90%, SpO2 time percentage < 80%, DI4, and DI80. Continuous over night SpO2 was obtained with Masimo Radical-7 or Rad-8 (USA), mean artifact-free-recording-time (AFRT) ≥ 6 hours. RESULTS: 101 SpO2 recordings were registered in 44, 33, and 24 studies at 34, 35, and 36 weeks of PMA, respectively, from 62 preterm infants, twenty-eight (45%) were male, median gestational age at birth 30 weeks (range 26-32), and median birth weight 1480 g (range 785-2700g). Oximetry variables were mean AFRT (± SD) 8.6 (± 1.5) hours; median mean SpO2 96.9% (range 93.3-99.3%); median minimum SpO2 74% (range 51-89%); median time of SpO2 < 90% 2% (range 0-10.6%); median time of SpO2 < 80% 0.1% (range 0-1.3%); median desaturation event ≥ 4% (DI4) within ≥ 10 seconds per hour sampled 15 (range 3.5-62.5); and median desaturation event <80% (DI80) 0.58 (range 0-10.8). We found no differences in SpO2 values between the different PMA wee ks. CONCLUSIONS: We described SpO2 values in very preterm infants, asymptomatic at 34-36 PMA weeks. These values could be used as a reference for guiding oxygen therapy.

Hemoglobina Denver, una causa de desaturación en oximetría de pulso. Reporte de caso en un paciente pediátrico / Hemoglobin Denver, a cause of desaturated pulse oximetry. A pediatric case report

Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.

Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.

Arterial oxygen saturation in healthy Mexican full-term newborns at different altitudes above sea level.

BACKGROUND: Arterial oxygen saturation (SaO2) values are used to make clinical decisions that might change a patient's prognosis, and it has been proposed as the fifth vital sign. This study aimed to determine the variation of SaO2 at different altitudes above sea level (ASL) in healthy Mexican full-term newborns. METHODS: From July 2018 to June 2019, a cross-over study was conducted in six hospitals at different altitudes ASL in Mexico. SaO2 was measured in 4015 newborns after the first 24 h of birth and before leaving the hospital using pulse oximetry. We analyzed three groups: < 250 m ASL (group 1), 1500 m ASL (group 2), and 2250 m ASL (group 3). RESULTS: The mean SaO2 was 97.6 ± 1.8%. For group 1, mean oxygen saturation was 98.2 ± 1.9%; for group 2, 96.7 ± 1.9%, and for group 3, 96.0 ± 2.1%. A statistically significant difference was observed among the groups (p < 0.001), and this difference was higher between groups 1 and 2 (1.5%, p < 0.001). Linear regression analysis showed a decrease in oxygen saturation of 1.01% for every 1000 m ASL. CONCLUSIONS: We demonstrated a statistically significant reduction in SaO2 levels at higher altitudes. This observation can be relevant for clinical decision-making based on pulse oximetry such as critical congenital heart disease screening in Mexico, where more than half of the population lives above 1500 m ASL.

INTRODUCCIÓN: Los valores de SaO2 (saturación de oxígeno) se utilizan para la toma de decisiones clínicas que podrían cambiar el pronóstico del paciente. El objetivo de este estudio fue determinar la variación de la SaO2 en recién nacidos mexicanos a término sanos a diferentes altitudes en México. MÉTODOS: Se llevó a cabo un estudio transversal en seis hospitales situados a diferentes altitudes en México. Se determinó la SaO2 usando oximetría de pulso en 4015 recién nacidos después de las primeras 24 horas de vida, pero antes del egreso del hospital de nacimiento. Se formaron tres grupos para el análisis: grupo 1 con altitud < 250 m sobre el nivel del mar (SNM); grupo 2, altitud de 1500 m SNM y grupo 3, altitud de 2250 m SNM. RESULTADOS: El promedio de la SaO2 fue de 97.6 ± 1.8%. Para el grupo 1, la media fue 98.2 ± 1.9%, para el 2, 96.7 ± 1.9% y para el 3, 96.0 ± 2.1%. Se observó una diferencia estadísticamente significativa entre los grupos (p < 0.001), que fue mayor entre los grupos 1 y 2 (1.5%, p < 0.001). El análisis de regresión lineal mostró una reducción de 1.01% en la SaO2 por cada 1000 m SNM. CONCLUSIONES: Se demostró una disminución estadísticamente significativa de los valores de SaO2 conforme aumenta la altitud. Esto puede ser de particular relevancia en la toma de decisions clínicas basadas en la oximetría de pulso, como el tamiz neonatal cardiaco, sobre todo en México donde mas de la mitad de la población vive a una altitud superior a 1500 m SNM.

Can a Therapeutic Strategy for Hypotension Improve Cerebral Perfusion and Oxygenation in an Experimental Model of Hemorrhagic Shock and Severe Traumatic Brain Injury?

BACKGROUND: Restoration of brain tissue perfusion is a determining factor in the neurological evolution of patients with traumatic brain injury (TBI) and hemorrhagic shock (HS). In a porcine model of HS without neurological damage, it was observed that the use of fluids or vasoactive drugs was effective in restoring brain perfusion; however, only terlipressin promoted restoration of cerebral oxygenation and lower expression of edema and apoptosis markers. It is unclear whether the use of vasopressor drugs is effective and beneficial during situations of TBI. The objective of this study is to compare the effects of resuscitation with saline solution and terlipressin on cerebral perfusion and oxygenation in a model of TBI and HS. METHODS: Thirty-two pigs weighing 20-30 kg were randomly allocated into four groups: control (no treatment), saline (60 ml/kg of 0.9% NaCl), terlipressin (2 mg of terlipressin), and saline plus terlipressin (20 ml/kg of 0.9% NaCl + 2 mg of terlipressin). Brain injury was induced by lateral fluid percussion, and HS was induced through pressure-controlled bleeding, aiming at a mean arterial pressure (MAP) of 40 mmHg. After 30 min of circulatory shock, resuscitation strategies were initiated according to the group. The systemic and cerebral hemodynamic and oxygenation parameters, lactate levels, and hemoglobin levels were evaluated. The data were subjected to analysis of variance for repeated measures. The significance level established for statistical analysis was p < 0.05. RESULTS: The terlipressin and saline plus terlipressin groups showed an increase in MAP that lasted until the end of the experiment (p < 0.05). There was a notable increase in intracranial pressure in all groups after starting treatment for shock. Cerebral perfusion pressure and cerebral oximetry showed no improvement after hemodynamic recovery in any group. The groups that received saline at resuscitation had the lowest hemoglobin concentrations after treatment. CONCLUSIONS: The treatment of hypotension in HS with saline and/or terlipressin cannot restore cerebral perfusion or oxygenation in experimental models of HS and severe TBI. Elevated MAP raises intracranial pressure owing to brain autoregulation dysfunction caused by TBI.

Does radiotherapy treatment alter the pulp condition in patients with head and neck cancer? A systematic review.

The main purpose of this study was to answer the question: "Can radiotherapy cause changes in the dental pulp condition of patients treated with irradiation in the head and neck region?" Clinical observational studies in adults with head and neck cancer undergoing treatment with ionizing radiation, longitudinal or cross-sectional follow-up to measure oxygen saturation (SpO2), and/or pulp sensitivity test to cold stimulation, were considered eligible. A systematic literature search was performed in six different databases, including the gray literature, and in article references. Two independent evaluators selected the studies, extracted the data, recorded the data on electronic spreadsheets, and then evaluated the methodological quality using the Checklist for Quasi-Experimental Studies tool devised by JBI. The data were assessed qualitatively using the Synthesis Without Metanalysis (SWiM) guidelines. After removing the duplicate articles, carefully analyzing the titles and abstracts, and reading the papers in full, seven studies were included. Four of the studies evaluated applied the cold sensitivity test, two associated pulse oximetry and cold sensitivity, and only one used just pulse oximetry. Evaluation using the cold sensitivity test and pulse oximetry in the initial periods before radiotherapy showed a decrease in the sensitive response and in SpO2 levels during a maximum period of 1 year. However, analyses thereafter indicated a normal response in both tests from 5 to 6 years after the end of radiotherapy treatment. Radiotherapy causes changes in pulp behavior patterns in the short term; however, recovery and return to average values occurs after long periods.

Preterm Infants off Positive Pressure Respiratory Support Have a Higher Incidence of Occult Cerebral Hypoxia.

OBJECTIVE: To use cerebral near-infrared spectroscopy (NIRS) to quantify occult cerebral hypoxia across respiratory support modes in preterm infants. STUDY DESIGN: In this prospective, longitudinal, observational study, infants ≤32 weeks gestation underwent serial pulse oximetry (oxygen saturation [SpO2]) and cerebral NIRS monitoring (4-6 hours per session) following a standardized recording schedule (daily for 2 weeks, every other day for 2 weeks, then weekly until 35 weeks corrected gestational age). Four calculations were made: median cerebral saturation, median cerebral hypoxia burden (proportion of NIRS samples below the hypoxia threshold [<67%]), median systemic saturation, and median systemic hypoxia burden (proportion of SpO2 samples below the desaturation threshold [<85%]). During each recording session, respiratory support mode was noted (room air, low-flow nasal cannula, high-flow nasal cannula, noninvasive positive pressure ventilation, continuous positive airway pressure, and invasive ventilation). RESULTS: There were 1013 recording sessions made from 174 infants with a median length of 6.9 hours. Although the systemic (SpO2) hypoxia burden was significantly greater for infants on the highest respiratory support (invasive and noninvasive positive pressure ventilation), the cerebral hypoxia burden was significantly greater during recording sessions made on the lowest respiratory support (8% for room air; 29% for low-flow nasal cannula). CONCLUSIONS: Premature infants on the highest levels of respiratory support have less cerebral hypoxia than those on lower respiratory support. These results raise concern about unrecognized cerebral hypoxia during lower acuity periods of neonatal intensive care unit hospitalization and adverse outcomes.

Oximetry at admission as a predictor of tomographic and functional impairment after 3-6 months in hospitalized patients with COVID-19.

OBJECTIVE: To investigate characteristics that may be associated with radiologic and functional findings following discharge in patients with severe coronavirus disease 2019 (COVID-19). METHODS: This single-center, prospective, observational cohort study comprised patients aged >18 years who were hospitalized with COVID-19 pneumonia, between May and October 2020. After 3 to 6 months of discharge, patients were clinically evaluated and underwent spirometry, a 6-minute walk test (6MWT), and chest computed tomography (CT). Statistical analysis was performed using association and correlation tests. RESULTS: A total of 134 patients were included (25/114 [22%] were admitted with severe hypoxemia). On the follow-up chest CT, 29/92 (32%) had no abnormalities, regardless of the severity of the initial involvement, and the mean 6MWT distance was 447 m. Patients with desaturation on admission had an increased risk of remaining CT abnormalities: patients with SpO2 between 88 and 92% had a 4.0-fold risk, and those with SpO2 < 88% had a 6.2-fold risk. The group with SpO2 < 88% also walked shorter distances than patients with SpO2 between 88 and 92%. CONCLUSION: Initial hypoxemia was found to be a good predictor of persistent radiological abnormalities in follow-up and was associated with low performance in 6MWT.

Manejo de Disminución de Movimientos Fetales en pacientes del Área de Urgencias Obstétricas / Management of Decreased Fetal Movements in patients in the Obstetric Emergency Area

Los movimientos fetales son uno de los primeros signos de vitalidad fetal. Durante la gestación, éstos van apareciendo progresivamente. La adecuada adquisición y mantenimiento de los mismos durante la gestación indica un correcto desarrollo neuromuscular, así como de bienestar fetal1. La percepción materna de una Disminución de los Movimientos Fetales (DMF) constituye un motivo de consulta frecuente en los Servicios de Urgencias Obstétricas; toda paciente embarazada debe vigilar los movimientos fetales, mediante un conteo subjetivo de los movimientos del feto, a partir de las 24 semanas de gestación. La DMF constituye el 5 ­ 15% de motivos de consulta en los servicios de Urgencias en el tercer trimestre del embarazo. Hasta un 25% de fetos que presentan una DMF presentarán alguna complicación perinatal (malformaciones, retraso de crecimiento, parto prematuro, hemorragia fetomaterna, y éxitus fetal) incluso en población de bajo riesgo. El manejo inadecuado de la DMF representa un 10-15% de las muertes evitables a término1-3. Es por esto que ninguna paciente que consulte por Disminución de Movimientos Fetales debe ser dada de alta sin asegurarse del adecuado bienestar fetal.

Fetal movements are one of the first signs of fetal vitality. During gestation, they appear progressively. Adequate acquisition and maintenance of fetal movements during gestation indicates correct neuromuscular development, as well as fetal well-being1. Maternal perception of decreased fetal movements (DMP) is a frequent reason for consultation in Obstetric Emergency Departments; every pregnant patient should monitor fetal movements by subjectively counting fetal movements, starting at 24 weeks of gestation. FMD constitutes 5-15% of the reasons for consultation in the emergency department in the third trimester of pregnancy. Up to 25% of fetuses with FMD will present some perinatal complication (malformations, growth retardation, premature delivery, fetomaternal hemorrhage, and fetal death) even in low-risk populations. Inadequate management of FMD accounts for 10-15% of preventable deaths at term1-3. This is why no patient who consults for decreased fetal movements should be discharged without ensuring adequate fetal well-being.