COVID-19: Pulse oximeters in the spotlight.

From home to intensive care units, innovations in pulse oximetry are susceptible to improve the monitoring and management of patients developing acute respiratory failure, and particularly those with the coronavirus disease 2019 (COVID-19). They include self-monitoring of oxygen saturation (SpO2) from home, continuous wireless SpO2 monitoring on hospital wards, and the integration of SpO2 as the input variable for closed-loop oxygen administration systems. The analysis of the pulse oximetry waveform may help to quantify respiratory efforts and prevent intubation delays. Tracking changes in the peripheral perfusion index during a preload-modifying maneuver may be useful to predict preload responsiveness and rationalize fluid therapy.

Hipoxemia silenciosa y uso de oxímetro de pulso en el hogar para detección precoz de complicaciones por Covid-19: reporte de un caso y revisión de la literatura / Silent hypoxemia and use of pulse oximeter at home for early detection of complications from Covid-19: a case report and review of the literature

Silent hypoxemia is one of the clinical presentations caused by SARS-CoV-2. It is still considered a medical mystery, as there are inconsistencies between arterial oxygen saturation levels and respiratory symptoms; a clinical scenario that had not been seen before. Their main risk is that it delays medical assistance because they do not have breathing difficulties and, when they consult, the lung damage is quite advanced. The early detection of hypoxia can favor the premature diagnosis of COVID-19 pneumonia and start treatment without delay. The pulse oximeter is presented as a useful, inexpensive, and easy-to-use tool for monitoring oxygen saturation at home in mild illness and detecting silent hypoxemia. This work presents the case of a patient with COVID-19 who, thanks to the use of a pulse oximeter at home, was able to detect silent hypoxemia and favored the early diagnosis of SARS-CoV-2 pneumonia. (AU)

Factors responsible for cerebral hypoxia in hemodialysis population.

Brain tissue oxygenation (rSO(2)) measured by near-infrared spectroscopy (NIRS) is lower in hemodialysis patients than in the healthy population and is associated with cognitive dysfunction. The involved mechanisms are not known. We conducted this study to identify the factors that influence the rSO2 values in end-stage renal disease (ESRD) patients and to describe rSO2 changes during hemodialysis. We included a cohort of ESRD patients hemodialyzed in our institution. We recorded rSO2 using INVOS 5100C oximetry system (Medtronic, Essex, U.K.) and analyzed changes in basic laboratory values and hemodynamic fluctuations. Baseline rSO2 was lower in patients with heart failure (45.2±8.3 % vs. 54.1±7.8 %, p=0.006) and was significantly linked to higher red cell distribution width (RDW) (r=-0.53, p?0.001) and higher BNP level (r=-0.45, p=0.01). The rSO(2) value decreased in first 15 min of hemodialysis, this decrease correlated with drop in white blood count during the same period (r=0.43, p=0.02 in 10 min, r=0.43, p=0.02 in 20 min). Lower rSO(2) values in patients with heart failure and higher RDW suggest that hemodynamic instability combined with vascular changes probably leads to worse cerebral oxygenation in these patients. Decrease of rSO(2) in 15th minute of hemodialysis accompanied with a significant drop in leukocyte count could be explained by complement activation.

Decreasing SUDEP incidence in a tertiary epilepsy center between 1981 and 2016: Effects of better patient supervision.

OBJECTIVE: The objective of this study was to investigate the incidence of sudden unexpected death in epilepsy (SUDEP) in a tertiary epilepsy center in the years 1981-2016 with an emphasis on patient supervision and nursing intervention in different departments. METHODS: We identified 14 SUDEP cases (probable, definite, definite plus). Patient-years (PY) and incidence were calculated for the periods of six years for the general epileptology wards (adults and children) and, in addition, for the epilepsy monitoring unit (EMU) since 1990. RESULTS: The incidence of SUDEP showed a decreasing trend over time (r = -0.81; p = 0.053, two-sided; Pearson correlation coefficient). This is especially true in children (no SUDEP occurred in pediatric general epileptology since 1992). Additionally, in the EMU (314 PY since the start of 1990), no SUDEP occurred. Sudden unexpected death in epilepsy incidence was highest (6.8/1000 PY) in the early time periods (1981-1992) and lowest (1.7/1000 PY) in the later time periods (1999-2010). In the general epileptology wards (3579 PY), the overall incidence was 3.9 per 1000 PY (95% confidence interval (CI): 2.1-6.6). CONCLUSIONS: We assume that the decreased SUDEP incidence is an effect of better supervision by the use of technical means (e.g., video cameras, pulse oximeters, seizure detection systems) and rooming-in of parents or family.

Use of Oximetry to Determine Need for Adenotonsillectomy for Sleep-Disordered Breathing.

: media-1vid110.1542/5802711151001PEDS-VA_2017-3382Video Abstract OBJECTIVES: We evaluated the efficacy of adenotonsillectomy (T/A) in children with sleep-disordered breathing (SDB) in a controlled study using oximetry. We hypothesized that children with SDB and abnormal nocturnal oximetry in a community setting will have improved hypoxemia indices after T/A. METHODS: Children with snoring and tonsillar hypertrophy (4-10 years old) who were candidates for T/A were randomly assigned to 2 oximetry sequences (baseline and 3-month follow-up): (1) oximetry immediately before T/A and at the 3-month follow-up, which occurred postoperatively (T/A group); or (2) oximetry at the initial visit and at the end of the usual 3-month waiting period for surgery (control group). Outcomes were (1) proportion of subjects with McGill oximetry score (MOS) >1 at baseline acquiring MOS of 1 at follow-up and (2) proportion of subjects achieving oxygen desaturation (≥3%) of hemoglobin index (ODI3) <2 episodes per hour at follow-up if they had ODI3 ≥3.5 episodes per hour at baseline. RESULTS: One hundred and forty children had quality oximetry tracings. Twelve of 17 (70.6%) children with MOS >1 in the T/A group and 10 of 21 (47.6%) children with MOS >1 in the control group had MOS of 1 at follow-up (P = .14). More subjects in the T/A than in the control group achieved ODI3 <2 episodes per hour at follow-up (14 of 32 [43.8%] vs 2 of 38 [5.3%]; P < .001). Three children with elevated ODI3 were treated to prevent persistently abnormal ODI3 in 1 child at follow-up. CONCLUSIONS: An ODI3 ≥3.5 episodes per hour in nocturnal oximetry is related to increased resolution rate of nocturnal hypoxemia after T/A for SDB compared with no intervention.

Usefulness of the STOP-Bang Questionnaire in a Cardiac Surgical Population.

OBJECTIVE: The aim of this study was to assess the predictive accuracy of the STOP-Bang questionnaire in relation to obstructive sleep apnea (OSA) detected by nocturnal oximetry, as well as postoperative outcomes, in a population undergoing cardiac surgery. DESIGN: A prospective observational cohort study. SETTING: The specialist cardiothoracic center at the Royal Papworth Hospital, Cambridge University Health Partners, United Kingdom. PARTICIPANTS: All adult patients, undergoing elective coronary artery bypass grafting with or without cardiac valve surgery between March 2013 and July 2014 were included. The authors excluded patients participating in other interventional studies, those who had a tracheostomy before surgery, and those who required emergency surgery or were due to be admitted on the day of surgery. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Cardiac surgical patients were screened for the risk of OSA with the use of STOP-Bang questionnaire. The presence of OSA prior to surgery was assessed with overnight oximetry. The predictive performance of the STOP-Bang questionnaire was assessed by calculating sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC)-receiver operating characteristic curve (ROC). Multiple-logistic regression models were used to assess for associations between the STOP-Bang scores and postoperative outcomes. The STOP-Bang questionnaire discriminated poorly between mild OSA (AUC-ROC 0.57 [95% confidence interval (CI) 0.47-0.67]) and moderate/severe OSA (AUC-ROC 0.82 (95% CI 0.69-0.95)]. Accuracy was increased by modifying the cut-off value to 6 or greater, with sensitivity and specificity of 75% and 77%, respectively. A STOP-Bang score indicating the possibility of OSA was not significantly associated with prolonged intensive care unit lengths of stay (hazard ratio [HR] 1.1; 95% CI 0.99-1.19; p = 0.08) or postoperative complications (odds ratio [OR] 1.0; 95% CI 0.59-1.72; p = 0.98). CONCLUSIONS: In the study population, a STOP-Bang questionnaire score of 3 or greater had limited predictive value for identifying cardiac surgical patients at high risk of OSA. STOP-Bang scores were not significantly associated with worse postoperative outcomes. A STOP-Bang score of 6 or greater could help identify patients in need of a sleep study to confirm the presence of OSA as such patients may be at increased risk of postoperative complications.

Continuous Pulse Oximetry and Capnography Monitoring for Postoperative Respiratory Depression and Adverse Events: A Systematic Review and Meta-analysis.

BACKGROUND: Death and anoxic brain injury from unrecognized postoperative respiratory depression (PORD) is a serious concern for patient safety. The American Patient Safety Foundation has called for continuous electronic monitoring for all patients receiving opioids in the postoperative period. These recommendations are based largely on consensus opinion with currently limited evidence. The objective of this study is to review the current state of knowledge on the effectiveness of continuous pulse oximetry (CPOX) versus routine nursing care and the effectiveness of continuous capnography monitoring with or without pulse oximetry for detecting PORD and preventing postoperative adverse events in the surgical ward. METHODS: We performed a systematic search of the literature databases published between 1946 and May 2017. We selected the studies that included the following: (1) adult surgical patients (>18 years old); (2) prescribed opioids during the postoperative period; (3) monitored with CPOX and/or capnography; (4) primary outcome measures were oxygen desaturation, bradypnea, hypercarbia, rescue team activation, intensive care unit (ICU) admission, or mortality; and (5) studies published in the English language. Meta-analysis was performed using Cochrane Review Manager 5.3. RESULTS: In total, 9 studies (4 examining CPOX and 5 examining continuous capnography) were included in this systematic review. In the literature on CPOX, 1 randomized controlled trial showed no difference in ICU transfers (6.7% vs 8.5%; P = .33) or mortality (2.3% vs 2.2%). A prospective historical controlled trial demonstrated a significant reduction in ICU transfers (5.6-1.2 per 1000 patient days; P = .01) and rescue team activation (3.4-1.2 per 1000 patient days; P = .02) when CPOX was used. Overall, comparing the CPOX group versus the standard monitoring group, there was 34% risk reduction in ICU transfer (P = .06) and odds of recognizing desaturation (oxygen saturation [SpO2] <90% >1 hour) was 15 times higher (P < .00001). Pooled data from 3 capnography studies showed that continuous capnography group identified 8.6% more PORD events versus pulse oximetry monitoring group (CO2 group versus SpO2 group: 11.5% vs 2.8%; P < .00001). The odds of recognizing PORD was almost 6 times higher in the capnography versus the pulse oximetry group (odds ratio: 5.83, 95% confidence interval, 3.54-9.63; P < .00001). No studies examined the impact of continuous capnography on reducing rescue team activation, ICU transfers, or mortality. CONCLUSIONS: The use of CPOX on the surgical ward is associated with significant improvement in the detection of oxygen desaturation versus intermittent nursing spot-checks. There is a trend toward less ICU transfers with CPOX versus standard monitoring. The evidence on whether the detection of oxygen desaturation leads to less rescue team activation and mortality is inconclusive. Capnography provides an early warning of PORD before oxygen desaturation, especially when supplemental oxygen is administered. Improved education regarding monitoring and further research with high-quality randomized controlled trials is needed.

Brain Oxygen Supply Parameters in the Risk Assessment of Cerebral Complications During Carotid Endarterectomy.

OBJECTIVE: To determine whether preoperative regional cerebral oxygen saturation (rSO2) and the decrease in rSO2 during carotid clamping were predictive of the risk for neurologic complications in carotid endarterectomy and to determine the cutoff values of the studied parameters. DESIGN: Cohort, prospective, nonrandomized trial. SETTING: Research Institute of Circulation Pathology, Novosibirsk, Russia. PARTICIPANTS: The study comprised 466 adults who underwent carotid endarterectomy since 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patient characteristics, postoperative complications, and brain oxygen supply during carotid endarterectomy were analyzed. The primary endpoints were the perioperative and early postoperative neurologic complications. Ischemic stroke was diagnosed in 1.5% of patients, and cognitive disorders were reported in 2.6% of patients. Preoperative rSO2 of 50% was the cutoff value for the prediction of stroke outcome after carotid endarterectomy, with a sensitivity of 90.7% and specificity of 66.7%. A 20% decrease in rSO2 during temporary carotid clamping was the cutoff value for the prediction of stroke, with a sensitivity of 86.0% and specificity of 57.1%, and for the prediction of cognitive disorders, with a sensitivity of 88.1% and specificity of 58.3%. Preoperative rSO2 less than 50% and a decrease in rSO2 of at least 20% during temporary carotid artery clamping caused a significant increase in the hospitalization period. CONCLUSIONS: A 20% or more decrease in rSO2 during temporary internal carotid artery clamping during carotid endarterectomy caused a 10-fold increased risk of ischemic stroke and an 8-fold increased risk of cognitive disorders, whereas preoperative rSO2 less than 50% resulted in a 6-fold increased risk of ischemic stroke in the perioperative and early postoperative periods of carotid endarterectomy.

Impact of Left Heart Bypass on Arterial Oxygenation During One-Lung Ventilation for Thoracic Aortic Surgery.

OBJECTIVE: The aim of this study was to reveal the mechanism of improved arterial oxygenation by measuring the changes in oxygenation before and after initiation of left heart bypass (LHB) during one-lung ventilation (OLV) for thoracic aortic surgery. DESIGN: Prospective, observational study. SETTING: Single-institution, private hospital. PARTICIPANTS: The study comprised 50 patients who underwent aortic surgery via a left thoracotomy approach with LHB circulatory support. INTERVENTIONS: Patients were ventilated using pure oxygen during OLV, and the ventilator setting was left unchanged during the measurement period. MEASUREMENTS AND MAIN RESULTS: The measurement of partial pressure of arterial oxygen (PaO2) was made at the following 4 time points: 2 minutes after heparin infusion (point 1 [P1]), 2 minutes after inflow cannula insertion through the left pulmonary vein (P2), immediately before LHB initiation (P3), and 10 minutes after LHB initiation (P4). The mean±standard deviation (mmHg) of PaO2 measurements at the P1, P2, P3, and P4 time points were 244±121, 250±123, 419±122, and 430±109, respectively, with significant increases between P1 and P3, P1 and P4, P2 and P3, and P2 and P4 (p<0.0001, respectively). No significant increase in PaO2 was seen between P1 and P2 or between P3 and P4. CONCLUSIONS: The improved arterial oxygenation during OLV in patients who underwent thoracic aortic surgery using LHB can be attributed to the insertion of an inflow cannula via the left pulmonary vein into the left atrium before LHB.

Pulse Oximetry: Beyond SpO2.

Newer pulse oximetry technology is available that uses multiple wavelengths of light and is thereby able to measure more than 2 forms of hemoglobin, including carboxyhemoglobin (SpCO), methemoglobin (SpMet), and total hemoglobin (SpHb). Several studies have shown relatively low bias, but poor precision, for SpCO compared with HbCO. Evaluations of SpMet have been conducted primarily in normal subjects. Clinical evaluations of SpHb suggest that it might not yet be accurate enough to make transfusion decisions. Respiratory waveform variability of the pulse oximeter plethysmogram might be useful to assess pulsus paradoxus in patients with airway obstruction; it might also be used to measure the breathing frequency. The change in pulse pressure over the respiratory cycle has been used to assess fluid responsiveness in mechanically ventilated patients, and similarly, the pulse oximetry plethysmogram waveform amplitude variability might be used to assess fluid responsiveness. However, there are limitations to this approach, and it remains to be determined how well it can be applied clinically using existing pulse oximetry technology. The pulse oximeter signal is probably useful for applications beyond SpO2 However, the current technology is not mature, and improvements are necessary. With technology improvements, the use of pulse oximetry to detect SpCO, SpMet, SpHb, pulsus paradoxus, breathing frequency, and fluid responsiveness is likely to improve in the future.

Utility of overnight pulse oximeter as a screening tool for sleep apnea to assess the 8-year risk of cardiovascular disease: Data from a large-scale bus driver cohort study.

BACKGROUND: Professional drivers' work under conditions predisposes them for development of sleep-disordered breathing (SDB) and cardiovascular disease (CVD). However, the effect of SDB on CVD risk among professional drivers has never been investigated. A cohort study was used to evaluate the effectiveness of overnight pulse oximeter as a sleep apnea screening tool to assess the 8-year risk of CVD events. METHODS: The Taiwan Bus Driver Cohort Study (TBDCS) recruited 1014 professional drivers in Taiwan since 2005. The subjects completed questionnaire interview and overnight pulse oximeter survey. This cohort was linked to the National Health Insurance Research Dataset (NHIRD). Researchers found 192 CVD cases from 2005 to 2012. Cox proportional hazards model was performed to estimate the hazard ratio for CVD. The statistical analysis was performed using SAS software in 2015. RESULTS: ODI4 and ODI3 levels increased the 8-year CVD risk, even adjusting for CVD risk factors (HR: 1.36, 95% CI: 1.05 to 1.78; p=0.022, and HR: 1.40, 95% CI: 1.03 to 1.90; p=0.033). ODI4 and ODI3 thresholds of 6.5 and 10events/h revealed differences of CVD risks (HR: 1.72, 95% CI: 1.00 to 2.95; p=0.048, and HR: 1.76, 95% CI: 1.03 to 3.03; p=0.041). Moreover, the ODI levels had an increased risk for hypertensive disease (not including essential hypertension). CONCLUSIONS: This study concludes that ODI for a sign of SDB is an independent predictor of elevated risk of CVD. Further research should be conducted regarding measures to prevent against SDB in order to reduce CVD risk in professional drivers.

Journal of Clinical Monitoring and Computing 2015 end of year summary: tissue oxygenation and microcirculation.

Last year we started this series of end of year summaries of papers published in the 2014 issues of the Journal Of Clinical Monitoring And Computing with a review on near infrared spectroscopy (Scheeren et al. in J Clin Monit Comput 29(2):217-220, 2015). This year we will broaden the scope and include papers published in the field of tissue oxygenation and microcirculation, or a combination of both entities. We present some promising new technologies that might enable a deeper insight into the (patho)physiology of certain diseases such as sepsis, but also in healthy volunteers. These may help researchers and clinicians to evaluate both tissue oxygenation and microcirculation beyond macro-hemodynamic measurements usually available at the bedside.

Trends of Hemoglobin Oximetry: Do They Help Predict Blood Transfusion During Trauma Patient Resuscitation?

BACKGROUND: A noninvasive decision support tool for emergency transfusion would benefit triage and resuscitation. We tested whether 15 minutes of continuous pulse oximetry-derived hemoglobin measurements (SpHb) predict emergency blood transfusion better than conventional oximetry, vital signs, and invasive point-of-admission (POA) laboratory testing. We hypothesized that the trends in noninvasive SpHb features monitored for 15 minutes predict emergency transfusion better than pulse oximetry, shock index (SI = heart rate/systolic blood pressure), or routine POA laboratory measures. METHODS: We enrolled direct trauma patient admissions ≥18 years with prehospital SI ≥0.62, collected vital signs (continuous SpHb and conventional pulse oximetry, heart rate, and blood pressure) for 15 minutes after admission, and recorded transfusion (packed red blood cells [pRBCs]) within 1 to 3, 1 to 6, and 1 to 12 hours of admission. One blood sample was drawn during the first 15 minutes. The laboratory Hb was compared with its corresponding SpHb reading for numerical, clinical, and prediction difference. Ten prediction models for transfusion, including combinations of prehospital vital signs, SpHb, conventional oximetry, and routine POA, were selected by stepwise logistic regression. Predictions were compared via area under the receiver operating characteristic curve by the DeLong method. RESULTS: A total of 677 trauma patients were enrolled in the study. The prediction performance of the models, including POA laboratory values and SI (and the need for blood pressure), was better than those without POA values or SI. In predicting pRBC 1- to 3-hour transfusion, adding SpHb features (receiver operating characteristic curve [ROC] = 0.65; 95% confidence interval [CI], 0.53-0.77) does not improve ROC from the base model (ROC = 0.64; 95% CI, 0.52-0.76) with P = 0.48. Adding POA laboratory Hb features (ROC = 0.72; 95% CI, 0.60-0.84) also does not improve prediction performance (P = 0.18). Other POA laboratory testing predicted emergency blood use with ROC of 0.88 (95% CI, 0.81-0.96), significantly better than the use of SpHb (P = 0.00084) and laboratory Hb (P = 0.0068). CONCLUSIONS: SpHb added no benefit over conventional oximetry to predict urgent pRBC transfusion for trauma patients. Both models containing POA laboratory test features performed better at predicting pRBC use than prehospital SI, the current best noninvasive vital signs transfusion predictor.

Postoperative Hypoxemia Is Common and Persistent: A Prospective Blinded Observational Study.

BACKGROUND: The incidence, severity, and duration of postoperative oxygen desaturation in the general surgical population are poorly characterized. We therefore used continuous pulse oximetry to quantify arterial oxygen saturation (SpO2) in a cross-section of patients having noncardiac surgery. METHODS: Oxygen saturation, blinded to clinicians, was recorded at 1-minute intervals in patients >45 years old for up to 48 hours after noncardiac surgery in 1250 patients from Cleveland Clinic Main Campus and 250 patients from the Juravinski Hospital. We determined (1) the cumulative minutes of raw minute-by-minute values below various hypoxemic thresholds; and (2) the contiguous duration of kernel-smoothed (sliding window) values below various hypoxemic thresholds. Finally, we compared our blinded continuous values with saturations recorded during routine nursing care. RESULTS: Eight hundred thirty-three patients had sufficient data for analyses. Twenty-one percent had ≥10 min/h with raw SpO2 values <90% averaged over the entire recording duration; 8% averaged ≥20 min/h <90%; and 8% averaged ≥5 min/h <85%. Prolonged hypoxemic episodes were common, with 37% of patients having at least 1 (smoothed) SpO2 <90% for an hour or more; 11% experienced at least 1 episode lasting ≥6 hours; and 3% had saturations <80% for at least 30 minutes. Clinical hypoxemia, according to nursing records, measured only in Cleveland Clinic patients (n = 594), occurred in 5% of the monitored patients. The nurses missed 90% of smoothed hypoxemic episodes in which saturation was <90% for at least one hour. CONCLUSIONS: Hypoxemia was common and prolonged in hospitalized patients recovering from noncardiac surgery. The SpO2 values recorded in medical records seriously underestimated the severity of postoperative hypoxemia.

Pulse Oxygen Saturation Values in a Healthy School-Aged Population.

OBJECTIVES: The purpose of this study was to determine the normal values of oxygen saturation in a healthy school-aged pediatric population. METHODS: This study enrolled students in grades K-8 at an elementary and middle school in Los Angeles. Although all students were invited to participate, only pulse oximetry results among healthy students were included. Healthy students were defined as not having asthma, bronchitis, a recent cold or pneumonia within the past week, any chronic lung disease, or any heart condition. RESULTS: Two hundred forty-eight students participated in the study, and 246 students met the inclusion criteria. Pulse oxygen saturation values ranged from 97% to 100% with a mean of 98.7% (95% confidence interval [CI], 98.6%-99.8%) and median of 99%. The distribution of measured pulse oximetry values were 97%: 16 (95% CI, 6.5%), 98%: 45 (95% CI, 18.3%), 99%: 184 (95% CI, 74.8%), and 100%: 1 (95% CI, 0.4%). CONCLUSIONS: Although the conventional wisdom is that pulse oximetry values 95% or greater are normal, these data suggest that the normal oxygen saturation range should be between 97% and 100%. Values of 95% and 96% should increase clinical suspicion of underlying disease.

Intoxicaciones inadvertidas por monóxido de carbono: una epidemia oculta / Intoxications inadvertent carbon monoxide: an epidemic hidden

Diferentes autores afirman que existe un elevado volumen de intoxicaciones por monóxido de carbono que pasan inadvertidas para el personal sanitario, lo que representa un importante problema de salud. Para confirmar esta hipótesis en un área de salud determinada, sobre la que se dispone de reciente información en relación al volumen de intoxicaciones que sí son detectadas, se realizó este trabajo. Para ello, se seleccionó como población de estudio al conjunto de pacientes que acudieron al Servicio de Urgencias del Hospital do Salnes, por cualquier motivo, durante el mes de febrero de 2013. Se recogió una amplia muestra representativa de esta población por un sistema aleatorio sistemático, quedando constituida por 1501 pacientes. A todos ellos se les realizó una medición no invasiva de carboxihemoglobina mediante pulsicooximetría con el objetivo de detectar todas las intoxicaciones, tanto las sospechadas por el personal sanitario como las que pasarían inadvertidas. El número de intoxicaciones detectadas en la muestra fue de 10, lo que representa el 0,7% (± 0.34% p< 0.05) de las urgencias atendidas, siendo 18 (8,8-27,1) el número de casos esperados para la población de estudio. Esta cifra fue muy superior a la de intoxicados que se detectaron en el trabajo ordinario del personal sanitario durante los diez años previos, en el mismo mes de febrero y en el mismo centro sanitario, con una media anual de 1.3 casos (DS: 2.8), por lo que se concluye confirmando la hipótesis de que el número de intoxicaciones inadvertidas por monóxido de carbono es muy elevado (AU)

Different authors state that there is a high volume of carbon monoxide poisoning that go unnoticed for health workers, representing a major health problem. To confirm this hypothesis in a particular area of ​​health, on which recent information regarding the volume of poisonings that are detected itself, this work was performed. To do this, it was selected as study population to all patients presenting to the emergency department of Salnés Hospital, for any reason, during the month of February 2013. A broad cross-section of the population was collected by a systematic random system , it is composed of 1501 patients. All subjects underwent a noninvasive measurement of carboxyhemoglobin by pulsicooximetría in order to detect all poisonings, both suspected by medical personnel as they go unnoticed. The number of poisonings detected in the sample was 10, representing 0.7% (± 0.34% p <0.05) of emergencies attended, with 18 (8.8 to 27.1) for the number of expected cases the study population. This figure was much higher than that of intoxicated that were detected in the ordinary work of health workers during the previous ten years, in the month of February and at the same health center with an annual average of 1.3 cases (DS: 2.8) , so it is concluded confirming the hypothesis that the number of intoxications inadvertent carbon monoxide is very high

Trending and accuracy of noninvasive hemoglobin monitoring in pediatric perioperative patients.

BACKGROUND: Rainbow Pulse CO-Oximetry technology (Masimo Corporation, Irvine, CA) provides continuous and noninvasive measurement of arterial hemoglobin concentration (SpHb). We assessed the trending and accuracy of SpHb by this innovative monitoring compared with Hb concentration obtained with conventional laboratory techniques (Hb) in children undergoing surgical procedures with potential for substantial blood loss. METHODS: Hb concentrations were recorded from Pulse CO-Oximetry and a conventional hematology analyzer. Regression analysis and 4-quadrant plot were used to evaluate the trending for changes in SpHb and Hb measurements (ΔSpHb and ΔHb). Bias, precision, and limits of agreement of SpHb and of in vivo adjusted SpHb (SpHb - first bias to HB) compared with Hb were calculated. RESULTS: One hundred fifty-eight SpHb-Hb data pairs and 105 delta pairs (ΔSpHb and ΔHb) from 46 patients aged 2 months to 17 years with Hb ranging from 16.7 to 7.9 g/dL were collected. To evaluate trending, the delta pairs (ΔSpHb and ΔHb) were plotted, which revealed a positive correlation (ΔSpHb = 0.022 + 0.76ΔHb) with correlation coefficient r = 0.76, 95% CI [confidence interval] = 0.57-0.86. The bias and precision of SpHb to Hb and in vivo adjusted SpHb were 0.4 ± 1.3 g/dL and 0.1 ± 1.2 g/dL, respectively; the limits of agreement were -2.0 to 3.2 g/dL before in vivo adjustment and -2.4 to 2.2 g/dL after in vivo adjustment (P value = 0.04). The mean percent bias (from the reference Hb concentration) decreased from 4.1% ± 11.9% to 0.7% ± 11.3% (P value = 0.01). No drift in bias over time was observed during the study procedure. Of patient demographic and physiological factors tested for correlation with the SpHb, only perfusion index at sensor site showed a weak correlation. CONCLUSIONS: The accuracy of SpHb in children with normal Hb and mild anemia is similar to that previously reported in adults and is independent of patient demographic and physiological states except for a weak correlation with perfusion index. The trending of SpHb and Hb in children with normal Hb and mild anemia showed a positive correlation. Further studies are necessary in children with moderate and severe anemia.

Oximetría cerebral en endarterectomía pulmonar con parada circulatoria / Cerebral oximetry in pulmonary thromboendarterectomy with circulatory arrest

La tromboendarterectomía pulmonar es un procedimiento infrecuente que precisa parada circulatoria para su realización, por lo que uno de sus principales riesgos son las lesiones neurológicas postoperatorias. La monitorización cerebral intra- y postoperatoria sería, por tanto, conveniente en estos procedimientos para detectar precozmente episodios de hipoperfusión, su intensidad, así como otros episodios postoperatorios de desaturación cerebral que puedan empeorar el pronóstico neurológico (AU)

Pulmonary thromboendarterectomy is an uncommon procedure and should be performed with circulatory arrest. One of the major concerns is the postoperative central neurological injuries. Perioperative brain oxygen monitoring is advisable in this surgical procedure for the early detection of brain hypoperfusion episodes and their intensity as well as any other postoperative episodes that can deteriorate the neurological outcome (AU)