Pulsioximetría: papel en el paciente COVID-19 domiciliario / Pulse oximetry: Role in the COVID-19 patient at home

La COVID-19 se comporta como una enfermedad heterogénea. Algunos pacientes pueden presentar hipoxemia sin disnea durante su evolución (hipoxemia silente). La pulsioximetría juega un papel crucial en la detección de la hipoxemia en estos pacientes, especialmente cuando permanecen en su domicilio. Pacientes con niveles de SpO2 ≤ 92% o desaturaciónes ≥ 3% tras el ejercicio precisan de ingreso hospitalario. Los descensos progresivos de la saturación que alcancen niveles SpO2 < 96% precisan de valoración clínica estricta (estudio radiológico, analítica sanguínea) para lo que será enviado a un centro sanitario (AU)

COVID-19 behaves like a heterogeneous disease. Some patients may develop dyspnea-free hypoxemia during its evolution (silent hypoxemia). Pulse oximetry plays a crucial role in detecting hypoxemia in these patients, especially when they remain at home. Patients with SpO2 levels ≤ 92% or desaturations ≥ 3% after exercise test require hospital admission. Progressive saturation declines reaching SpO2 levels < 96% require strict clinical assessment (radiological study, blood test) for which it will be sent to a health center (AU)

[Pulse oximetry: Role in the COVID-19 patient at home]. / Pulsioximetría: papel en el paciente COVID-19 domiciliario.

COVID-19 behaves like a heterogeneous disease. Some patients may develop dyspnea-free hypoxemia during its evolution (silent hypoxemia). Pulse oximetry plays a crucial role in detecting hypoxemia in these patients, especially when they remain at home. Patients with SpO2 levels ≤ 92% or desaturations ≥ 3% after exercise test require hospital admission. Progressive saturation declines reaching SpO2 levels < 96% require strict clinical assessment (radiological study, blood test) for which it will be sent to a health center.

[Pulse oximetry screening of critical congenital heart defects in the neonatal period. The Spanish National Neonatal Society recommendation]. / Cribado de cardiopatías congénitas críticas en el periodo neonatal. Recomendación de la Sociedad Española de Neonatología.

Due to its severity, as well as the consequences of a late diagnosis, critical congenital heart defects (CCHD) represent a challenging situation, making an early diagnosis necessary and ideally before symptoms appear when circulatory collapse or death of the newborn can occur. Due to this, a prenatal and very early postnatal diagnosis is very important. Prenatal ultrasound screening and physical examination of the newborn can miss a considerable number of CCHD cases. Pulse oximetry screening has been demonstrated to be an effective, non-invasive, inexpensive, and well accepted tool in the early diagnosis of CCHD. The Spanish National Society of Neonatology, through its Standards Committee, and based on the current evidence, recommend the implementation of pulse oximetry screening of CCHD in Spain, and then to offer the best therapy possible to these newborn infants.

Correlation between oxyhaemoglobin saturation by pulse oximetry and partial pressure of oxygen in patients with acute respiratory failure. / Correlación entre la saturación de oxihemoglobina por pulsioximetría y la presión arterial de oxígeno en pacientes con insuficiencia respiratoria aguda.

OBJECTIVES: To ascertain the correlation between the partial pressure of oxygen (PaO2) and oxyhaemoglobin saturation by pulse oximetry (SpO2) in patients who were admitted to the emergency department with suspected acute respiratory failure. MATERIAL AND METHODS: A prospective, observational multicentre study was conducted in the emergency departments of 3 Spanish hospitals. RESULTS: The study included 166 patients who presented mean±standard deviation PaO2, SpO2 and fraction of inspired oxygen (FiO2) values of 61.64±17.3mmHg, 87.61±8.8% and 0.28±0.15%, respectively. The median PaO2/FiO2 and SpO2/FiO2 ratios were 256.6 and 359.2, respectively. The correlation between PaO2/FiO2 and the SpO2/FiO2 was 0.745 (P<.001). CONCLUSIONS: The SpO2/FiO2 ratio can be used to calculate PaO2/FiO2 and determine the oxygenation state of patients with acute respiratory failure.

[Estimation of arterial oxygen saturation in relation to altitude]. / Estimación de la saturación arterial de oxígeno en función de la altitud.

BACKGROUND AND OBJECTIVES: Arterial Oxygen Saturation (AOS) predicts altitude sickness. OBJECTIVES: To estimate the AOS values with relation to altitude. Furthermore, make a graph to use during activity which assesses the AOS for each altitude and the normal range. PATIENTS AND METHOD: Values of AOS were assessed during eight high mountain activities in the Alps, Himalaya, Caucasus and Andes; 53 mountaineers participated, 17 of them in more than one activity; 761 measurements of AOS were registered. RESULTS: A Logistic Regression Model was made to estimate the AOS values dependent on altitude, adjusted to possible related factors. A strong lineal relationship exists between altitude and AOS (R2=.83, P<.001); .7 points more in women. The AOS in a particular altitude is not related to age, weight, height, smoking, heart rate, or even with previous experiences in mountains. The calculation of the AOS responds to the follow equation: Blood Oxygen Saturation=103.3-(altitude × .0047)+(Z), being Z=.7 in men and 1.4 in women. A scatter plot was made to relate the estimated altitude with the AOS, with their normal limits values: percentiles 2.5 and 97.5. CONCLUSIONS: The simple calculation of the AOS estimated for a particular altitude with the proposed graphic can help in the early decision-making onsite.

[Pulse oximetry versus electrocardiogram for heart rate assessment during resuscitation of the preterm infant]. / Pulsioximetría frente al monitor de electrocardiograma para la determinación de la frecuencia cardíaca durante la reanimación del recién nacido pretérmino.

BACKGROUND: Heart rate (HR) assessment is essential during neonatal resuscitation, and it is usually done by auscultation or pulse oximetry (PO). The aim of the present study was to determine whether HR assessment with ECG is as fast and reliable as PO during preterm resuscitation. MATERIAL AND METHODS: Thirty-nine preterm (<32 weeks of gestational age and/or<1.500g of birth weight) newborn resuscitations were video-recorded. Simultaneous determinations of HR using ECG and PO were registered every 5s for the first 10min after birth. Time needed to place both devices and to obtain reliable readings, as well as total time of signal loss was registered. The proportion of reliable HR readings available at the beginning of different resuscitation manoeuvres was also determined. RESULTS: Time needed to connect the ECG was shorter compared with the PO (26.64±3.01 vs. 17.10±1.28 s, for PO and ECG, respectively, P<.05). Similarly, time to obtain reliable readings was shorter for the ECG (87.28±12.11 vs. 26.38±3.41 s, for PO and ECG, respectively, P<.05). Availability of reliable HR readings at initiation of different resuscitation manoeuvres was lower with the PO (PO vs. ECG for positive pressure ventilation: 10.52 vs. 57.89% P<.05; intubation: 33.33 vs. 91.66%, P<.05). PO displayed lower HR values during the first 6min after birth (P<.05, between 150 and 300s). CONCLUSIONS: Reliable HR is obtained later with the PO than with the ECG during preterm resuscitation. PO underestimates HR in the first minutes of resuscitation.

SISTEMA DE PULSIOXIMETRÍA Y CAPNOGRAFÍA PARA DISPOSITIVOS MÓVILES ANDROID / A PULSE-OXIMETRIC AND CAPNOGRAPHIC SYSTEM FOR ANDROID MOBILE DEVICES / SISTEMA DE OXIMETRIA DE PULSO E CAPNOGRAFIA PARA DISPOSITIVOS MÓVEIS ANDROID

El monitoreo constante del nivel de saturación de oxígeno y la producción de CO2 es de vital importancia para la supervisión del estado respiratorio del paciente. Este artículo presenta el diseño de un sistema de oximetría de pulso y capnografía que tiene como unidad de procesamiento un chip programable de señales mixtas denominado PSoC (Programable-System-On-Chip), el cual incorpora bloques análogos y digitales configurables, permitiendo que la adecuación de las señales suministradas por los sensores y el procesamiento digital de señales se lleve a cabo en el mismo chip. Se realizó una aplicación en Android para la visualización y registro de las señales biomédicas en una base de datos local, compatible con dispositivos móviles con conectividad wifi. El sistema fue verificado usando un simulador de SpO2 (Saturación parcial de oxígeno), que permitió la calibración de frecuencias cardiacas desde 55 BPM (Beats per Minute) a 145 BPM, así como la curva R con valores de 75% a 100% de SpO2. Se encontró que el error de medición de la frecuencia cardiaca es 1,81%, y 1.33% para la SpO2.

Constant monitoring of oxygen saturation level and CO2 production is vital for monitoring the patient's respiratory status. This paper presents the design of a pulse-oximetric and capnographic system, which core consists of a mixed signal programmable chip, PSoC (Programmable-System-On-Chip), which incorporates a whole analog and digital configurable block system, in order to adequate and process the signals from the sensors all in a single chip. An Android application was also developed, which can display biomedical signals in mobile devices with wireless connectivity, as well as to store information from these signals in a local user database. The microsystem was verified using a SpO2 (oxygen partial saturation) simulator, and heart rates of 55 BPM to 145 BPM were calibrated, as well as the R curve with values of 75% to 100% SpO2. The heart rate measurement error found is 1,81% and 1,33% for the SpO2.

O monitoramento constante do nível de saturação de oxigênio e produção de CO2 é fundamental para monitorar o estado respiratório do paciente. Este artigo apresenta o projeto de um sistema de oximetria de pulso e capnografia cuja unidade de processamento um chips de sinal misto programável chamado PSoC (Programmable-System-On-Chip), o qual incorpora blocos analógicos e digitais configuráveis, permitindo a adaptação dos sinais fornecidos pelos sensores e o processamento digital de sinais será executada no mesmo chip. Foi realizada una aplicação Android para visualização e gravação de sinais biomédicos em um banco de dados local, compatível com dispositivos móveis com conectividade sem fio. O sistema foi testado usando um simulador de SpO2 (saturação de oxigênio parcial), permitindo a calibração da freqüência cardíaca de 55 BPM (batidas por minuto) a 145 BPM, assim como a curva R com valores de 75% a 100% SpO2 . Verificou-se que o erro de medição do ritmo cardíaco é 1,81% e 1,33% para o SpO2.

[Extreme leucocytosis can lead to an erroneous diagnosis of severe hypoxaemia. Description of a case]. / La leucocitosis extrema puede inducir a un diagnóstico erróneo de hipoxemia severa. Descripción de un caso.

The diagnosis and treatment of respiratory failure is a part of the anaesthesist's daily practice, as well as the hypoxaemia that is one of its physiological and analytical consequences. Patients with an extreme leucocytosis secondary to leukaemia can suffer an incorrect diagnosis of hypoxemia, called "pseudohypoxaemia". This is basically due to the rapid in vitro oxygen consumption, and is characterized by a low partial pressure of oxygen in arterial blood (PaO2) despite a normal oxygen saturation (SpO2) measured by pulse oximetry. Pseudohypoxaemia appears in patients with thrombocytosis or hyper-leucocytosis occurring during blastic crisis of a leukaemia. It must be suspected in patients with a discrepancy between the SpO2 measured by oximetry and the PaO2. In this context, pulse oximetry is the most accurate way to establish the diagnosis and to avoid unnecessary actions. We report the case of a patient with chronic myeloid leukaemia and extreme leucocytosis requiring emergency surgery, and diagnosed with pseudohypoxaemia during the perioperative period that led to a delay in the extubation of the patient.

Anestésicos locales en odontología: valoración mediante pulsioximetría / Local anesthetics in dentistry: valuation by means of pulseoxymetry

Objetivos: Conocer la respuesta en el campo de la odontología de dos anestésicos locales que se utilizan habitualmente, como son la articaína y la lidocaína, así como los efectos adversos que se pudieran generar sobre el SNC, sobre los controles cardiocirculatorios y estructuras de la zona de infiltración. Pacientes: Se incluyeron en el estudio 264 pacientes distribuidos de forma aleatoria en dos grupos de 198 y 66 pacientes, que recibieron articaína y lidocaína respectivamente, cuyas edades estaban comprendidas entre los 19 y 56 años. Métodos: Los pacientes fueron controlados mediante un pulsioxímetro BPM 200 antes de iniciar el procedimiento, después de la anestesia, al comenzar la extracción y finalizada esta. La presión arterial se controló mediante tensiómetro digital OMRON M4-I. Los anestésicos utilizados fueron la lidocaína al 2 % con epinefrina y articaína al 4 % con epinefrina, ambos a una concentración de 1: 100.000. El análisis estadístico se realizó mediante el análisis de la varianza. Se analizó mediante el paquete estadístico SPSS versión 11 implementado para PC. El nivel de confianza fue del 80 % en la detección del riesgo relativo, con un rango de 1,84 o mayor, y de 0,54 o menor, para un nivel de significación de 0,05. Conclusión: La lidocaína como la articaína asociadas a epinefrina, pueden considerarse como anestésicos locales, adecuados y seguros en la práctica odontoestomatológica. Hay que tener singular cuidado en la utilización de estos anestésicos locales en pacientes hipertensos o con problemas cardiocirculatorios, por lo que sería conveniente el control con pulsioxímetro.

Objetives To know the answer in the field the odontolgy the two anesthetic premises that are used habitually, like are articaine and lidocaine, as well as the adverse effects that could be generated on the SNC, the cardiovascular controls and structures of the infiltration area. Patients: They were included in the study 264 distributed patients in a random way in two groups of 198 and 66 patients that received articaína and lidocaína respectively whose ages were between the 19 and 56 years. Methods: The patients were controlled by means of oximeter BPM 200 before beginning the procedure, after the anesthesia, when beginning the extraction and concluded this. The blood pressure was controlled by means of digital sphygmomanometer OMRON M4-I. The anesthetic ones used went lidocaine to the 2 % with epinephrine and articaine to 4 % with epinephrine, both to a concentration of 1: 100.000. The statistical analysis was made by means of the analysis of the variance. It was analyzed by means of the statistical package SPSS version 11 implemented for PC. The level of trust was of 80 % in the detection of the relative risk, with a range of the 1.84 or greater, one and of 0.54 or minor, for a level of significance of 0,05. Conclusión: Lidocaine like articaine associated to epinephrine, they can be considered as the local, adecuated and safe anesthetics in the dental practice. It is necessary to have singular taken care of in the use of these local anesthetics in hypertense patients or with cardiovascular problems, reason why the control with pulsioxymetry would be adecuated.

Resumo Objetivos: Para saber a resposta no campo o odontologia as duas premisoes anestésicas que são usadas habitualmente, como estão o articaine e o lidocaine, os efeitos adversos que poderiam ser gerados no SNC, os controles e as estruturas cardiovascular da área da infiltração. Pacientes: Foram incluídos nos pacientes distribuídos do estudo 264 em uma maneira aleatória em dois grupos de 198 e 66 pacientes que receberam o articaína e o lidocaína respectivamente cujas idades se realizavam entre os 19 e 56 anos. Métodos: Os pacientes eram controlados por meio do oxímetro BPM 200 antes de começar o procedimento, após o anestesia, ao começar a extração e concluído isto. A pressão de sangue era controlada por meio do sphygmomanometer digital OMRON M4-I. Anestésicos usados foram lidocaine aos 2 % com epinephrine e articaine a 4 % com epinephrine, ambos a uma concentração de 1: 100.000. A análise estatística foi feita por meio da análise da variação. Foi analisado por meio da versão estatística 11 do pacote SPSS executada para o PC. O nível da confiança era de 80 % na deteção do risco relativo, com uma escala do 1.84 ou mais grande, um e de 0.54 ou menor, para um nível de um significado de 0.05. conclusão conclusão: O lidocaine gosta do articaine associado ao epinephrine, podem ser considerados como anestésicos locais adequados e seguros na prática dental. É necessário ter cuidado tomado singular no uso destes anestésicos locais em pacientes da hipertensão ou com problemas cardiovasculares, raciocine porque o controle com pulsioximetria seria adequada.