Noninvasive Pulse Oximetry Research Articles

Short-term vital parameter forecasting in the intensive care unit: A benchmark study leveraging data from patients after cardiothoracic surgery.

Patients in an Intensive Care Unit (ICU) are closely and continuously monitored, and many machine learning (ML) solutions have been proposed to predict specific outcomes like death, bleeding, or organ failure. Forecasting of vital parameters is a more general approach to ML-based patient monitoring, but the literature on its feasibility and robust benchmarks of achievable accuracy are scarce. We implemented five univariate statistical models (the naïve model, the Theta method, exponential smoothing, the autoregressive integrated moving average model, and an autoregressive single-layer neural network), two univariate neural networks (N-BEATS and N-HiTS), and two multivariate neural networks designed for sequential data (a recurrent neural network with gated recurrent unit, GRU, and a Transformer network) to produce forecasts for six vital parameters recorded at five-minute intervals during intensive care monitoring. Vital parameters were the diastolic, systolic, and mean arterial blood pressure, central venous pressure, peripheral oxygen saturation (measured by non-invasive pulse oximetry) and heart rate, and forecasts were made for 5 through 120 minutes into the future. Patients used in this study recovered from cardiothoracic surgery in an ICU. The patient cohort used for model development (n = 22,348) and internal testing (n = 2,483) originated from a heart center in Germany, while a patient sub-set from the eICU collaborative research database, an American multicenter ICU cohort, was used for external testing (n = 7,477). The GRU was the predominant method in this study. Uni- and multivariate neural network models proved to be superior to univariate statistical models across vital parameters and forecast horizons, and their advantage steadily became more pronounced for increasing forecast horizons. With this study, we established an extensive set of benchmarks for forecast performance in the ICU. Our findings suggest that supplying physicians with short-term forecasts of vital parameters in the ICU is feasible, and that multivariate neural networks are most suited for the task due to their ability to learn patterns across thousands of patients.

A Built-In Guidance System to Monitor Vital Signs in Space and on Earth.

INTRODUCTION: Different types of remote expeditions often require an expedition crew to conduct medical emergency assessments without prior medical training. Modern technology offers new devices that support diagnosis with a simple guided user instructions interface. It is not yet clear how quickly medically untrained individuals can acquire the required skills with such a device. This study investigated the time and quality of obtained outcomes, as well as the mental workload when using a vital signs monitor and its guided procedure interface during a simulation of a medical emergency event.METHODS: There were 50 individuals (25 medically inexperienced, 25 medically trained) who participated in this study. In a randomized order subjects measured electrocardiography, noninvasive blood pressure, pulse oximetry, and body temperature. The procedure was repeated after a 20-min break. Completion time, data validity, and mental workload were analyzed.RESULTS: Average times to obtain stable and reliable signals of all recorded vital signs were significantly shorter for both groups during the second attempt and for medically experienced individuals in comparison to medically inexperienced individuals. The number of errors did not change between attempts for both groups. The mental workload was higher during the first attempt in both groups for most vital sign acquisitions.DISCUSSION: Automated devices could be easily and quickly used by members of a given expedition, even if the crew lacks advanced medical training. With relatively little training provided by a built-in guidance system, medically untrained individuals can achieve a basic level of proficiency in reliably obtaining valid vital signs.Huerta R, Kaduk SI, Fatai L, Rusch H, Weber T, Sammito S. A built-in guidance system to monitor vital signs in space and on Earth. Aerosp Med Hum Perform. 2024; 95(3):139-146.

Prospective clinical validation of the Empatica EmbracePlus wristband as a reflective pulse oximeter.

Respiratory diseases such as chronic obstructive pulmonary disease, obstructive sleep apnea syndrome, and COVID-19 may cause a decrease in arterial oxygen saturation (SaO2). The continuous monitoring of oxygen levels may be beneficial for the early detection of hypoxemia and timely intervention. Wearable non-invasive pulse oximetry devices measuring peripheral oxygen saturation (SpO2) have been garnering increasing popularity. However, there is still a strong need for extended and robust clinical validation of such devices, especially to address topical concerns about disparities in performances across racial groups. This prospective clinical validation aimed to assess the accuracy of the reflective pulse oximeter function of the EmbracePlus wristband during a controlled hypoxia study in accordance with the ISO 80601-2-61:2017 standard and the Food & Drug Administration (FDA) guidance. Healthy adult participants were recruited in a controlled desaturation protocol to reproduce mild, moderate, and severe hypoxic conditions with SaO2 ranging from 100% to 70% (ClinicalTrials.gov registration #NCT04964609). The SpO2 level was estimated with an EmbracePlus device placed on the participant's wrist and the reference SaO2 was obtained from blood samples analyzed with a multiwavelength co-oximeter. The controlled hypoxia study yielded 373 conclusive measurements on 15 subjects, including 30% of participants with dark skin pigmentation (V-VI on the Fitzpatrick scale). The accuracy root mean square (Arms) error was found to be 2.4%, within the 3.5% limit recommended by the FDA. A strong positive correlation between the wristband SpO2 and the reference SaO2 was observed (r = 0.96, P < 0.001), and a good concordance was found with Bland-Altman analysis (bias, 0.05%; standard deviation, 1.66; lower limit, -4.7%; and upper limit, 4.8%). Moreover, acceptable accuracy was observed when stratifying data points by skin pigmentation (Arms 2.2% in Fitzpatrick V-VI, 2.5% in Fitzpatrick I-IV), and sex (Arms 1.9% in females, and 2.9% in males). This study demonstrates that the EmbracePlus wristband could be used to assess SpO2 with clinically acceptable accuracy under no-motion and high perfusion conditions for individuals of different ethnicities across the claimed range. This study paves the way for further accuracy evaluations on unhealthy subjects and during prolonged use in ambulatory settings.

Role of Perfusion Index and Pulse Variability Index in the Assessment of Neonatal Hemodynamics: A Systematic Review.

Hemodynamic monitoring of neonates is crucial because neonates are easily and acutely susceptible to hemodynamic disturbances. As such, non-invasive monitoring of hemodynamics is preferable. It has been postulated that non-invasive pulse oximetry determines the perfusion index and pulse variability index and provides accurate measurements to predict hemodynamic changes in preterm or term infants. Equally, numerous studies have investigated the efficacy of perfusion and pulse variability indices in monitoring neonatal hemodynamics. The aim of this study was to systematically review studies that have delved into the role of perfusion and pulse variability indices in the assessment of neonatal hemodynamics. The study collected data from 2010-2023 using the patient, intervention, comparison, outcome (PICO) search strategy using the databases PubMed, Scopus, and Excerpta Medica database (Embase). A total of 616 articles were evaluated based on their appropriateness and relevance; we included seven studies. As per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic review. Our study concluded that these indices were effective in measuring hemodynamics.

Impact of Care Interventions on the Survival of Patients with Cardiac Chest Pain.

Chest pain is considered the second most frequent complaint among patients seeking emergency services. However, there is limited information in the literature about how the care provided to patients with chest pain, when being attended to in the emergency room, influences their clinical outcomes. To assess the relationship between care interventions performed on patients with cardiac chest pain and their immediate and late clinical outcomes and to identify which care interventions were essential to survival. In this retrospective study. We analyzed 153 medical records of patients presenting with chest pain at an emergency service center, São Paulo, Brazil. Participants were divided into two groups: (G1) remained hospitalized for a maximum of 24 h and (G2) remained hospitalized for between 25 h and 30 days. Most of the participants were male 99 (64.7%), with a mean age of 63.2 years. The interventions central venous catheter, non-invasive blood pressure monitoring, pulse oximetry, and monitoring peripheral perfusion were commonly associated with survival at 24 h and 30 days. Advanced cardiovascular life support and basic support life (p = 0.0145; OR = 8053; 95% CI = 1385-46,833), blood transfusion (p < 0.0077; OR = 34,367; 95% CI = 6489-182,106), central venous catheter (p < 0.0001; OR = 7.69: 95% CI 1853-31,905), and monitoring peripheral perfusion (p < 0.0001; OR = 6835; 95% CI 1349-34,634) were independently associated with survival at 30 days by Cox Regression. Even though there have been many technological advances over the past decades, this study demonstrated that immediate and long-term survival depended on interventions received in an emergency room for many patients.

A calibration method for smartphone camera photophlethysmography.

Smartphone camera photoplethysmography (cPPG) enables non-invasive pulse oximetry and hemoglobin concentration measurements. However, the aesthetic-driven non-linearity in default image capture and preprocessing pipelines poses challenges for consistency and transferability of cPPG across devices. This work identifies two key parameters-tone mapping and sensor threshold-that significantly impact cPPG measurements. We propose a novel calibration method to linearize camera measurements, thus enhancing consistency and transferability of cPPG across devices. A benchtop calibration system is also presented, leveraging a microcontroller and LED setup to characterize these parameters for each phone model. Our validation studies demonstrate that, with appropriate calibration and camera settings, cPPG applications can achieve 74% higher accuracy than with default settings. Moreover, our calibration method proves effective across different smartphone models (), and calibrations performed on one phone can be applied to other smartphones of the same model (), enhancing consistency and scalability of cPPG applications.

Challenges of Anesthetic Monitoring in Low- and Middle-Income Countries: Availability of Equipment in Major Referral Hospitals in Kenya.

Anesthetic monitoring within standards defined by various professional anesthesia organizations has been shown to reduce perioperative mortality. Given the scarce resources for anesthesia and surgery in low- to middle-income countries, we sought to determine the availability of recommended monitoring devices in major referral hospitals in Kenya. We purposely selected the 16 major referral hospitals in Kenya. A cross-sectional survey was conducted in 103 operating theaters, 96 postanesthesia care unit (PACU) beds, and 16 areas where procedural sedation was routinely administered. A checklist questionnaire based on the Association of Anaesthetists of Great Britain and Ireland (AAGBI) guidelines of 2015 was used to determine the availability of basic and functional monitoring devices. We determined that only 1 of 16 (6.25%) hospitals had all the monitoring devices recommended by the AAGBI. Automated noninvasive blood pressure (NIBP) monitoring and pulse oximetry were present in all operating theaters. Continuous electrocardiography (ECG) was available in 102 of 103 (99%) operating theaters, skin temperature monitoring probes in 73 of 103 (70.9%), and capnography in 49 (47.6%). A nerve stimulator was accessible in 5 of 16 (31.25%) hospitals. There were functional patient monitors in all operating theaters (100%). One of the regional referral hospitals did not have a PACU. We encountered 9 of 96 (9.4%) PACU beds without any monitoring devices. Pulse oximetry was the most common device (84.4%) in the PACU beds equipped with monitoring. In 5 of 16 (31.25%) procedural sedation areas, pulse oximetry was the only monitoring device, whereas there were no devices in 2 of 16 (12.5%) areas. Portable multiparameter devices used for patient transport were present in 5 of 16 (31.25%) hospitals. The availability of recommended monitoring devices in major referral hospitals in Kenya is inadequate. Thus, there are challenges to anesthetic monitoring in these hospitals, and perioperative patient safety is jeopardized. We recommend the universal provision of basic monitoring devices and suggest the use of the data collected in this study to affect policy change and safe anesthesia practice in our country.

Early detection model of normal and abnormal blood flow using pulse Oximetry non-invasive of pregnant heart rate

The heart is an important organ in humans as an identification of early examinations in pregnant women carried out by doctors to determine normal and abnormal pregnancies in the fetus. Heart rate or BPM (beats per minute) is a parameter that indicates the condition of a person's heart. The normal human heart rate ranges from 60-100 beats per minute. In pumping blood throughout the body, the heart then holds it back after being cleaned by the lungs and this is closely related to the level of oxygen flowing in the bloodstream. Humans need sufficient oxygen levels in the body to survive. One of the vital monitoring tools for oxygen levels in the human body is pulse oximetry. Pulse oximetry is usually in units or rooms with high and rapid action cases such as the ICU. From these problems, it is necessary to make a research on a diagnostic instrument model for early detection of normal and abnormal blood flow using non-invasive pulse oximetry, a case study of the heart rate of pregnant women which can be identified early through the max 30100 sensor reading in the form of detecting the heart rate and oximeter, then processed by Arduino uno R3 where arduino uno processes data in the form of heart rate and oxymeter readings so that it can be displayed via a 16x2 LCD, the output is the identification of the value of the heart rate and oximeter input so that the normal and abnormal heart rate conditions are known. The purpose of this study is to detect early pregnant women and fetuses with normal or abnormal blood flow using non-invasive pulse oximetry in which case studies are implemented on the heartbeat of pregnant women. The method used in this study uses the hardware programming method by starting with project planning, research, part testing, mechanical design, electrical design, software design, functional test, integration, overall testing and optimization. The measurement results from the MAX30100 sensor are processed on Arduino UNO R3 and displayed on the LCD screen. The system as a whole can work with energy supply from the power supply. After measuring with a comparator that has been calibrated, the average error value of the measurement is 3.32 %.

Acil Servise ST Segment Elevasyonlu Olmayan Miyokard Enfarktüsü ve Kararsız Angina Pektoris ile Başvuran Hastalarda Perfüzyon İndeksinin Klinik Değerlendirmesi

Background: We aimed to evaluate the perfusion index (PI) level at the 10th minute of admission to the emergency department in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina pectoris (USAP). In addition, we aimed to evaluate whether PI is useful in differentiating NSTEMI and USAP patients in the emergency department in the early stage.Materials and Methods: Eighty NSTEMI (Group 1) and 50 USAP (Group 2) patients who were consecutively admitted to our emergency department between November 2017 and May 2019 and diagnosed with acute coronary syndrome were included in the study. In both patient groups, PI measured with the Massimo-SET Root 7362A RDS7 non-invasive pulse oximetry probe and other routine laboratory measurements were measured and compared.Results: The mean PI was significantly lower in NSTEMI patients (p &amp;lt;0.001). At 30-day patient follow-up, the PI of the reduce was significantly lower (P &amp;lt;0.001). The area under the curve was significantly lower for PI in NSTEMI patients (area under the curve 0.313, p = 0.016). At 30-day patient follow-up, the level of PI was significantly lower in the died patients than the survived patients (P &amp;lt;0.001). The area under the curve was significantly lower for PI in NSTEMI patients (area under the curve 0.313, p = 0.016).Conclusions: Although our study shows that PI may be an early marker in the distinguish of NSTEMI and USAP patients and may be useful in predicting the mortality of these patients, more extensive studies will support our hypothesis.

Invasive And Non-invasive Assessment Of Arterial Blood Oxygen Saturation In Patients With Continuous Flow LVADs: Is There A Correlation?

<h3>Background</h3> Patients with continuous flow left ventricular assist devices (CF-LVAD) typically have a narrow pulse pressure. This may pose a challenge for transcutaneous automated pulse oximeter devices to accurately measure arterial blood saturation. This study aimed to assess their accuracy in a CF-LVAD population by comparing pulse oximetry readings to invasive arterial blood gas (ABG) measurements. <h3>Methods</h3> A total of eighteen patients with a CF-LVAD were identified using chart review at the University of Minnesota and Minneapolis Heart Institute. All, except one patient were implanted with a HeartMate III device (Abbott Laboratories, Minneapolis, MN). Non-invasively assessed oxygen saturation was compared to simultaneously obtained arterial blood oxygen saturation. Two patients were receiving mechanical ventilation, one received BiPAP support, and 15 patients were either breathing room air or receiving supplemental oxygen by nasal cannula. <h3>Results</h3> A non-invasive pulse oximeter read was obtained on every patient. There was a moderate correlation between the invasively and non-invasively obtained oxygen saturation values as shown in Figure 1 (R²=0.624). Waveform quality, as assessed by the treating physician, qualified as good or acceptable in 16 cases and as poor for 2 patients. Data points for these 2 patients are marked in red in Figure 1. <h3>Conclusion</h3> Despite a narrow pulse pressure in patients with CF-LVAD, non-invasive pulse oximetry provided a reliable assessment of arterial blood saturation when compared to the gold standard ABG measurement. This finding presents an opportunity to conduct future studies in this patient population in which continuous monitoring of oxygen saturation may be necessary, such as evaluation for obstructive sleep apnea.

A comparative study of the effect of dexamethasone versus its use with clonidine on postoperative sore throat and hoarseness of voice

Regardless of some preventive measures, postoperative sore throat (POST) and hoarseness of voice are most undesirable and most frequent complication in the post-operative period [1,2]. Postoperatively it seems reasonable that most of the signs and symptoms are the result of mucosal injury which leads to inflammation caused by the process of air way instrumentation, also its postulated etiology has been associated with mucosal dehydration or edema, tracheal ischemia secondary to the pressure of endotracheal tube cuffs, aggressive oropharyngeal suctioning and mucosal erosion from friction between delicate tissues and the endotracheal tube (ETT) [4,5]. Aim, the primary outcome was to compare between the effects of Dexamethasone alone versus its use with Clonidine on post-operative sore throat. The secondary outcome was to compare between the effects of Dexamethasone alone versus its use with Clonidine on post-operative hoarseness of voice. Method, this prospective controlled randomized double- blind study was carried on 126 patients divided into two groups the Dexa group 63 and Dexaclonidine group 63. Randomization were done by using closed envelop technique opened immediately before induction by an anaesthetist who was unaware of the study protocol and responsible for preparing the study drugs. Patient in Dexaclonidine group received oral 150 microgram Clonidine tablet one hour before induction, whereas patients in the Dexa group received placebo which is multivitamin tablet with the same shape and size of Clonidine. Both Clonidine and placebo were covered with nontransparent paper. Patients in both groups were received 5 ml of normal saline containing Dexamethasone (8 mg) iv at 30 min before anaesthetic induction. Sedation with midazolam was given (0.05 mg/kg) IV 15 minutes before surgery for the two groups. On arrival to operating room patients were cannulated and monitored with electrocardiography, non-invasive blood pressure, pulse oximetry and capnography. Anaesthesia was induced with intravenous propofol (2 mg/kg) and fentanyl (1–1.5 micro g/kg) after approximately 5 min of preoxygenation and face mask ventilation. Rocuronium (0.6–0.8 mg/ kg) was administered to facilitate endotracheal intubation after using of nerve stimulator (train of four) to ensure complete muscle relaxation before intubation, an endotracheal tube were inserted (ETTs) after Cormack-Lehane scoring (13) of internal diameter 7.0 and 7.5 were used for females and males, respectively by Direct laryngoscopy with either a Macintosh blade size 3 or 4. The ETTs were inserted so that the vocal cords were located between the two indicator marks on the proximal part of the tube shaft. Intubations were confirmed by capnography and chest auscultation for equality of air entry on both sides. None of the patients received topical lidocaine or lidocaine jelly during the intubation procedure. The lungs were ventilated with 50% air 50% oxygen; ventilation was adjusted to maintain an end tidal carbon dioxide of 35–45 mmHg. Anaesthesia was maintained with isoflurane and intermittent bolus dose of rocuronium. Isoflurane concentration was adjusted to minimal alveolar concentration (MAC) 1–1,5% according to haemodynamics. After the end of surgery, residual neuromuscular relaxation was reversed by Neostigmine (0.03_0.07 mg/ kg) and Atropine (0,02–0,1 mg/kg). Oropharyngeal suction was gently performed under direct vision by soft suction catheter with sideway port to avoid trauma to the tissues before extubation, one end of the catheter was attached to an aspirator or collection canister and the unattached end was placed directly into a tube to extract secretions safely without injury to the mucous membranes. Conclusion From this study including that addition of clonidine to dexamethasone was more superior in reducing POST &amp; hoarseness of voice than dexamethasone alone, resulted in more haemodynamic stability in both intra operative and early post-operative period. Result From this study, there was statistically significant difference between the two studied groups regarding the sore throat and hoarseness of voice incidence and grade (P value &lt; 0.05). so, Addition of clonidine to dexamethasone was more superior in reducing POST &amp; hoarseness of voice than dexamethasone alone.

Comparison of Levobupivacaine with dexmedetomidine in Infraumbilical surgeries

Introduction: Due to decreased cardiovascular and central nervous system toxicity, levobupivacaine is a good alternative for spinal anesthesia. Dexmedetomidine when used intrathecally is associated with prolonged motor and sensory block, hemodynamic stability, and less requirement of rescue analgesia in 24 h. Materials and Methods: We assumed that sevoflurane will provide clinically acceptable conditions for endotracheal intubation comparable to propofol-suxamethonium in children. All patients received diazepam 0.2 mg/kg orally, the night before surgery. The patients were preloaded with Lactated Ringer's solution 15 mL/kg. They were monitored with automated noninvasive blood pressure, pulse oximetry, and electrocardiogram. Results: In Group LD, increase in VAS was observed at 210 min and the first dose of rescue analgesia was given at 5th h postoperatively. The second dose of recue analgesia was given at 12th h and the third dose was given at 21st h. Postoperative VAS scores at different time intervals were significantly lower in Group LD than Group L, thus indicating superior analgesia. The time of request of the first dose of rescue analgesia was delayed in Group LD as it was demanded at 309.93 ± 23.19 min and in Group L was at 168.30 ± 12.32 min. The difference in the two groups was highly significant (P< 0.001). Conclusion: Sevoflurane provides clinically acceptable intubating conditions and can be a suitable alternative to propofol-suxamethonium for endotracheal intubation in children.

Correlation of Pao2/Fio2 Ratio with Spo2/Fio2 Ratio in Children on Mechanical Ventilation

Background: Mechanical ventilation is frequently used in pediatric patients to ensure adequate gas exchange, improve respiratory distress, and to resolve pulmonary or other disorders. Monitoring of various parameters which are invasive, while patient is on mechanical ventilation it is fundamental to observe the progress of patient’s condition. We conducted this study to observe if PaO2/FiO2 and the ratio of SPO2 /FiO2 can be used interchangeably, we can have option for lesser invasive parameter. Aim: To determine the correlation of PaO2/FiO2 with SPO2 /FiO2 ratio in children on mechanical ventilation. Methods: A Cross-sectional study, Non-probability and purposive sampling. The study conducted at The Children’s hospital and the Institute of Child Health, Lahore from 04-10-2017 to 03-06-2018. Informed consent was obtained. Arterial blood gas sampling for calculation of PaO2/FiO2 ratio and simultaneous recording of SPO2 for measurement of SPO2/FiO2 ratio was done. The data collected was analysed on S.P.S.S (Statistical Package for Social Sciences) version 22. Results: In this study 30 patients on mechanical ventilation were enrolled with mean age of 58.55±5 months. There was male predominance. (M: F ratio 2:1). This study showed a strong positive correlation of the PaO2/FiO2 with SPO2/FiO2 that is r=0.603. Conclusion: According to our study noninvasive SpO2/FiO2 ratio (PFr) can reliably be used in place of PaO2/FiO2 ratio(SFr) in children on mechanical ventilation as a strong correlation was observed between them. The advantage is invasive arterial sampling can be replaced by non-invasive pulse oximetry for oxygen saturation. Key words: Mechanical Ventilation, Pediatric ICU, SPO2/FiO2, PaO2/FiO2

Role of Erector Spine Plane Block for Postoperative Analgesia in Patients Undergoing Percutaneous Nephrolithotomy

Background and objective: The objective of the present study was to determine the effectiveness of erector spinae plane block (ESPB) for pain relief in patients undergoing percutaneous nephrolithotomy. Methods: Sixty-four patients of either sex, American Society of Anaesthesiology (ASA) Grade I/II for surgery were enrolled. After informed consent, all participants received subarachnoid block with 3 ml of 0.5% injection heavy bupivacaine. Participants in the block group received ultrasound-guided ESPB with 30 ml of 0.5% ropivacaine, whereas participants in the control group received routine analgesia as per our hospital's protocol for percutaneous nephrolithotomy procedure which is tramadol 100 mg intravenously. This prospective, single-blind, randomized, controlled study was conducted after approval from the institutional ethics committee (SRHU/HIMS/RC/2019/291) and written informed consent was obtained for surgery under spinal anesthesia. Pain score (visual analog scale, VAS) was evaluated by the anesthesiologist who was not involved in the study at 30 minutes and 2, 4, 6, 8, 12, 18, and 24 hours postoperatively and patient was monitored with electrocardiogram, noninvasive blood pressure, heart rate, and pulse oximetry. Unpaired t test was used for comparison between the groups. Results: Both the groups were appropriately matched for age, ASA physical status, weight, and duration of surgery. The total dosing of rescue analgesia, that is, tramadol was considerably more in the control group in comparison with the ESPB group in the first postoperative day (P = 0.000; 218.75 ± 82.06 mg vs. 103.12 ± 47.41 mg, respectively). Similar results were obtained in the VAS pain score. Conclusion: ESPB helped in providing considerable postoperative pain relief in patients undergoing percutaneous nephrolithotomy.

Repeatability of adaptive traits among ethnic Tibetan highlanders.

Connecting traits to biological pathways and genes relies on stable observations. Researchers typically determine traits once, expecting careful study protocols to yield measurements free of noise. This report examines that expectation with test-retest repeatability analyses for traits used regularly in research on adaptation to high-altitude hypoxia, often in settings without climate control. Two hundred ninety-one ethnic Tibetan women residing from 3500 to 4200 m in Upper Mustang District, Nepal, provided three observations of hemoglobin concentration, percent of oxygen saturation of hemoglobin, and pulse by noninvasive pulse oximetry under conditions designed to minimize environmental noise. High-intraclass correlation coefficients and low within-subject coefficients of variation reflected consistent measurements. Percent of oxygen saturation had the highest intraclass correlation coefficient and the smallest within-subject coefficient of variability; measurement noise occurred mainly in the lower values. Hemoglobin concentration and pulse presented slightly higher within-subject coefficients of variation; measurement noise occurred across the range of values. The women had performed the same measurements 7 years earlier using the same devices and protocol. The sample means and SD observed across 7 years differed little. Hemoglobin concentration increased substantially after menopause. Analyzing repeatability features of traits may improve our interpretation of statistical analyses and detection of variation from measurement or biology. The high levels of measurement repeatability and biological stability support the continued use of these robust traits for investigating human adaptation in this altitude range.

Pericapsular nerve group (PENG) block for hip fractures: Another weapon in the armamentarium of anesthesiologists.

Pericapsular nerve group (PENG) block for hip fractures: Another weapon in the armamentarium of anesthesiologists.

Correlation Between Monitoring Practices During Anesthesia and Patient Recovery

Anesthesia is used by healthcare professionals to induce loss of sensation in the body of the patient so that the surgical process of treatment is carried out effectively. Anesthesia doses that are given to patients have been classified into three types which are general anesthesia, sedation anesthesia, and regional or local anesthesia. These medications are given to patients as per the severity of the injury and treatment process. The provision of anesthesia includes monitoring processes such as Electrocardiography (ECG), Noninvasive Blood Pressure (NIBP), pulse oximetry, and others so that patient safety is ensured at all the levels of treatment. It also includes Depth of General Anesthesia (DGA) is an advanced monitoring process of anesthesia through which accurate drug administration in the individual patient is executed. The study introduces current prospects of anesthesia monitoring and mentions details about important methods and technologies in use and their both advantages and disadvantages. It also provides details about DGA and other latest upcoming methods for anesthesia monitoring.

Evaluation of perfusion index in pediatric trauma patients.

The aim of this study is to investigate the effectiveness of perfusion index (PI) measured by non-invasive pulse oximetry in the evaluation of pediatric trauma patients and to show its correlation with pediatric trauma score (PTS). Patients hospitalized in the pediatric intensive care unit due to trauma were examined between March 2017 and March 2018. Characteristic variables of the patients, Pediatric Index of Mortality 2 score, Pediatric Logistic Organ Dysfunction score, PTS, type of trauma, number of systems affected by trauma, mechanical ventilation, transfusion, hemoglobin, lactate, PI at admission, length of ICU stay, and prognosis were recorded. Ninety-one pediatric trauma patients were included in the study. The majority of the patients were male (64.8%), with a mean age of 99.47±71.27 months, the most common cause of trauma was an out of-vehicle traffic accident. There was a positive correlation between PI and PTS (p<0.05). In patients with PTS TS ≤8, the mean PI was 0.89, the standard deviation was 0.35; however, the mean PI was 1.77, the standard deviation was 0.95 in the group with PTS >8, and it was statistically significant (p=0.000). PI can be used for non-invasive and rapid assessment of unstable patients separately or in combination with PTS in pediatric trauma patients.

Ultrasound increases the success rate of spinal needle placement through the epidural needle during combined spinal-epidural anaesthesia: A randomised controlled study.

Combined spinal-epidural anaesthesia (CSEA) using a needle-through-needle technique is currently widely used. However, successful epidural needle placement does not mean a successful spinal needle placement during CSEA. Whether ultrasound assistance could increase the first-pass success rate of spinal needle placement for CSEA remains unknown. The aim of this study was to investigate if ultrasound assistance could increase the first-pass success rate of spinal needle placement through the epidural needle during CSEA performed by experienced anaesthesiologists in patients undergoing caesarean section. A prospective, randomised, double-blind study. Single centre, Department of Anaesthesiology, Shengjing Hospital, China Medical University, China, from June 2019 to September 2019. A total of 185 patients (aged 24 years to 52 years, American Society of Anesthesiologists grade (ASA) II-III, 38 to 40 weeks gestation) scheduled to undergo elective caesarean section under CSEA were enrolled. The patients were randomised to either an ultrasound group (patients received a preprocedural ultrasound scan, and the puncture site was identified by ultrasound imaging) and a palpation group (patients received a sham procedural ultrasound scan, and the puncture site was identified by conventional palpation). The primary outcome measure was the first-pass success rate for spinal needle placement through the epidural needle. Secondary outcome measures were total duration of CSEA, time required for successful epidural needle and spinal needle placement, number of epidural needle redirections and complications. Preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle compared with conventional palpation (93.8 vs. 68.8%, P < 0.001). Preprocedural ultrasound imaging also decreased the total duration of CSEA (186.9 ± 37.1 vs. 213 ± 60.4 s, P = 0.0015) and the time required for successful spinal needle placement (78.3 ± 22.9 vs. 100.1 ± 53.7 s, P < 0.01) compared with conventional palpation. Fewer patients in the ultrasound group needed epidural needle redirections during the spinal needle placement procedure than in the palpation group (four patients vs. 20 patients, P < 0.01). For experienced anaesthesiologists, preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle for obstetric patients undergoing caesarean section under CSEA. chictr.org.cn, identifier: ChiCTR1900024132.

How Do We Monitor Oxygenation during the Management of PPHN? Alveolar, Arterial, Mixed Venous Oxygen Tension or Peripheral Saturation?

Oxygen is a pulmonary vasodilator and plays an important role in mediating circulatory transition from fetal to postnatal period. Oxygen tension (PO2) in the alveolus (PAO2) and pulmonary artery (PaO2) are the main factors that influence hypoxic pulmonary vasoconstriction (HPV). Inability to achieve adequate pulmonary vasodilation at birth leads to persistent pulmonary hypertension of the newborn (PPHN). Supplemental oxygen therapy is the mainstay of PPHN management. However, optimal monitoring and targeting of oxygenation to achieve low pulmonary vascular resistance (PVR) and optimizing oxygen delivery to vital organs remains unknown. Noninvasive pulse oximetry measures peripheral saturations (SpO2) and a target range of 91–95% are recommended during acute PPHN management. However, for a given SpO2, there is wide variability in arterial PaO2, especially with variations in hemoglobin type (HbF or HbA due to transfusions), pH and body temperature. This review evaluates the role of alveolar, preductal, postductal, mixed venous PO2, and SpO2 in the management of PPHN. Translational and clinical studies suggest maintaining a PaO2 of 50–80 mmHg decreases PVR and augments pulmonary vasodilator management. Nevertheless, there are no randomized clinical trials evaluating outcomes in PPHN targeting SpO2 or PO2. Also, most critically ill patients have umbilical arterial catheters and postductal PaO2 may not be an accurate assessment of oxygen delivery to vital organs or factors influencing HPV. The mixed venous oxygen tension from umbilical venous catheter blood gas may assess pulmonary arterial PO2 and potentially predict HPV. It is crucial to conduct randomized controlled studies with different PO2/SpO2 target ranges for the management of PPHN and compare outcomes.