Masimo Radical-7 Research Articles

Oxygen Saturation Readouts Generated by the i-STAT Point-of-Care Analyzer Are More Accurate Than Those Generated by the Masimo Radical-7 Pulse Oximeter During Profound Alkalemia

SESSION TITLE: Miscellaneous Critical Care SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: The oxygen saturation readouts from a pulse oximeter (Radical-7®; Masimo, Inc., Irvine, CA) and a Point-of-Care analyzer (i-STAT®; Abbott Laboratories, Princeton, NJ) were observed to disagree appreciably on a patient who presented with severe alkalemia. This prompted us to undertake an accuracy analysis of these two instruments. METHODS: We consulted the specification sheet of the Radical-7 to determine the accuracy of that device. Then, we generated an SaO2 figure for paO2 values that were allowed to vary between forty and one hundred torr, in one-torr increments, for this alkalemic data set using a polynomial equation originally described by G. Richard Kelman (Kelman GR. Digital computer subroutine for the conversion of oxygen tension into saturation. J Appl Physiol 1966; 21: 1375-1376). Next, we implemented the on-board algorithm incorporated within the i-STAT for this profoundly alkalemic blood gas data set, reasoning that the device and its’ algorithm would be maximally challenged by ABGs that elicit appreciable shifts in the oxyhemoglobin dissociation curve (OHDC). The OHDC for the Kelman algorithm and the i-STAT algorithm were plotted on the same grid, using Numbers® spreadsheet software (Apple, Inc., Cupertino, CA), providing us with a digital and a diagrammatic comparison of their respective results. Finally, we determined the upper and lower limits of the uncertainty intervals for both the pulse oximeter and the Point-of-Care analyzer and scribed these elements on the single composite image. RESULTS: The Radical-7 specifications indicate that this device can be expected to be within +/- 4% of the actual SaO2, to the 95% level of confidence (+/- two standard deviations). The results generated by the i-STAT were remarkably similar to those generated by Kelman’s methodology, being well within one percent of each other throughout most of the clinically relevant range. The i-STAT’s algorithm operates on the prevailing paO2, which the device determines in real-time, but that paO2 figure is itself subject to error. Consequently, the i-STAT’s uncertainty interval was altered accordingly when that datum was varied by +/- 2 SD. The digital results allow observers to determine the differences in performance of the two instruments precisely for any given paO2, while the presentation of the same data in diagrammatic form confers a global sense of the relative performance of the two devices throughout the clinically relevant range of paO2s. CONCLUSIONS: In this mathematical modeling study, the accuracy of the oxygen saturation readout from the Point-of-Care analyzer was found to compare quite favorably to the accuracy displayed by the pulse oximeter. In addition, the OHDC generated by the i-STAT was strikingly similar to the corresponding curve generated by a methodology that has long been considered “the Gold Standard”. CLINICAL IMPLICATIONS: The current-day ICU abounds with electronic instruments, some of which display the same parameters. Becaue they base their clinical decisions, at least in part, on the readouts supplied by these devices, it behooves ICU Team members to be aware of which of these instruments tend to be more accurate than others. DISCLOSURE: The following authors have nothing to disclose: Bob Demers, Joshua Cosa, Melvin Welch No Product/Research Disclosure Information

Oxygen Saturation Readouts Generated by the i-STAT Point-of-Care Analyzer Are More Accurate Than Those Generated by the Masimo Radical-7 Pulse Oximeter During Profound Acidemia

Oxygen Saturation Readouts Generated by the i-STAT Point-of-Care Analyzer Are More Accurate Than Those Generated by the Masimo Radical-7 Pulse Oximeter During Profound Acidemia

Evaluation of perfusion index as a tool for pain assessment in critically ill patients.

Pain is a common and undertreated problem in critically ill patients. Pain assessment in critically ill patients is challenging and relies on complex scoring systems. The aim of this work was to find out the possible role of the perfusion index (PI) measured by a pulse oximeter (Masimo Radical 7; Masimo Corp., Irvine, CA, USA) in pain assessment in critically ill patients. A prospective observational study was carried out on 87 sedated non-intubated patients in a surgical intensive care unit. In addition to routine monitoring, a Masimo pulse oximeter probe was used for PI measurement. The sedation level of the patients was assessed by using the Richmond Agitation-Sedation Scale (RASS). The pain intensity was determined by applying the behavioral pain scale for non-intubated (BPS-NI) patients. The PI, arterial blood pressure, heart rate, RASS, and BPS-NI values before and after the application of a standard painful stimulus (changing the patient position) were reported. Correlation between the PI and other variables was carried out at the two measurements. Correlation between changes in the PI (delta PI) and in the hemodynamic variables, RASS, and BPS-NI was also done. Changing the patient position resulted in a significant increase in SBP (128±20 vs 120.4±20.6, P=0.009), DBP (71.3±11.2 vs 68.7±11.3, P=0.021), heart rate (99.5±19 vs 92.7±18.2, P=0.013), and BPS-NI (7[6-8] vs 3[3-3], P<0.001) values and a significant decrease in the PI (1[0.5-1.9] vs 2.2[0.97-3.6], P<0.001) value compared to the baseline readings. There was no correlation between the values of the PI and the ABP, BPS-NI, and RASS at the two measurements. A good correlation was found between the delta PI and delta BPS-NI (r=-0.616, P<0.001). A weak correlation was observed between the PI and heart rate after the patient positioning (r=-0.249, P<0.02). In surgical critically ill non-intubated patients, the application of a painful stimulus was associated with decreased PI. There was a good correlation between the change in the PI and the change in BPS-NI values after the application of painful stimulus.

Predicting stroke volume and arterial pressure fluid responsiveness in liver cirrhosis patients using dynamic preload variables: A prospective study of diagnostic accuracy.

Predicting whether a fluid challenge will elicit 'fluid responsiveness' in stroke volume (SV) and arterial pressure is crucial for managing hypovolaemia and hypotension. Pulse pressure variation (PPV), SV variation (SVV) and the plethysmographic variability index (PVI) have been shown to predict SV fluid responsiveness, and the PPV/SVV ratio has been shown to predict arterial pressure fluid responsiveness under various conditions. However, these variables have not been investigated in liver cirrhosis patients. The objective was to evaluate SV and arterial pressure fluid responsiveness in liver cirrhosis patients by using dynamic preload and vascular tone variables. A prospective study of diagnostic accuracy. A single-centre trial conducted from November 2013 to April 2015. Thirty-one adult patients, recipients of a living donor liver transplantat. An intraoperative fluid challenge with 10 ml kg of 0.9% normal saline. PPV, SVV, cardiac index and systemic vascular resistance index were measured using the Pulse index Continuous cardiac system. The PVI and perfusion index were measured using the Masimo Radical 7 co-oximeter. The PPV, SVV and PVI were measured to investigate SV fluid responsiveness, and the PPV/SVV ratio, perfusion index and systemic vascular resistance index were measured to investigate arterial pressure fluid responsiveness. The areas under the receiver operating characteristic curves for PPV, SVV and PVI were 0.794, 0.754 and 0.800, respectively (all P < 0.001). The cut-off values for PPV, SVV and PVI were 10% (sensitivity 78.3%, specificity 79.5%), 12% (sensitivity 69.6%, specificity 71.8%) and 11% (sensitivity 95.7%, specificity 59.0%), respectively. However, all investigated vascular tone variables failed to predict arterial pressure and fluid responsiveness. Dynamic preload variables predicted SV fluid responsiveness. Therefore, these variables can be used for fluid management in liver cirrhosis patients receiving mechanical ventilation. In contrast, vascular tone variables did not predict arterial pressure fluid responsiveness in liver cirrhosis patients. Clinicaltrials.gov identifier: NCT01971333.

Adaptation to Life in the High Andes: Nocturnal Oxyhemoglobin Saturation in Early Development.

Physiological adaptation to high altitude hypoxia may be impaired in Andeans with significant European ancestry. The respiratory 'burden' of sleep may challenge adaptation, leading to relative nocturnal hypoxia. Developmental aspects of sleep-related breathing in high-altitude native children have not previously been reported. We aimed to determine the influence of development on diurnal-nocturnal oxyhemoglobin differences in children living at high altitude. This was a cross-sectional, observational study. Seventy-five healthy Bolivian children aged 6 mo to 17 y, native to low altitude (500 m), moderate high altitude (2,500 m), and high altitude (3,700 m) were recruited. Daytime resting pulse oximetry was compared to overnight recordings using Masimo radical oximeters. Genetic ancestry was determined from DNA samples. Children had mixed European/Amerindian ancestry, with no significant differences between altitudes. Sixty-two participants had ≥ 5 h of nocturnal, artifact-free data. As predicted, diurnal mean oxyhemoglobin saturation decreased across altitudes (infants and children, both P < 0.001), with lowest diurnal values at high altitude in infants. At high altitude, there was a greater drop in nocturnal mean oxyhemoglobin saturation (infants, P < 0.001; children, P = 0.039) and an increase in variability (all P ≤ 0.001) compared to low altitude. Importantly, diurnal to nocturnal altitude differences diminished (P = 0.036), from infancy to childhood, with no further change during adolescence. Physiological adaptation to high-altitude living in native Andeans is unlikely to compensate for the significant differences we observed between diurnal and nocturnal oxyhemoglobin saturation, most marked in infancy. This vulnerability to sleep-related hypoxia in early childhood has potential lifespan implications. Future studies should characterize the sleep- related respiratory physiology underpinning our observations.

Accuracy of non-invasive continuous total hemoglobin measurement by Pulse CO-Oximetry in severe traumatized and surgical bleeding patients.

The Masimo Radical-7 Pulse CO-Oximeter (Masimo Corp., USA) non-invasively computes hemoglobin concentration (SpHb). SpHb was compared to Co-Oximeter readings (CoOxHb) of arterial samples in surgery patients of the emergency department. Forty-six patients were enrolled. The Masimo R1 25L (revision F and G) adult adhesive sensor was attached to the ring finger of the arterially cannulated hand. Before start, every 30min during surgery and in the case of severe bleeding SpHb and CoOxHb values were documented. SpHb and post hoc adjusted SpHb (AdSpHb) values were analyzed. Linear regression analysis and Bland-Altman plot for agreement were performed. The detection failure rate of SpHb was 24.5%. CoOxHb and SpHb showed a strong correlation (r=+0.81), but agreement was moderate [bias (LOA) of -0.6 (-3.0; +1.9)] g/dl. Positive and negative predicted value was 0.49 and 0.69. Exclusion of changes of CoOxHb values ≤1g/dl resulted in a positive and negative predictive value of 0.66 and 1.00. Post hoc adjustment of the SpHb (AdSpHb) improved linear correlation of CoOxHb and AdSpHb [r=+0.90 (p<0.001)] but less the agreement [bias (LOA) of CoOxHb and AdSpHb=-0.1 (-2.1/+1.9)g/dl]. SpHb agreed only moderately with CoOxHb values and predicted decreases of CoOxHb only if changes of SpHb≤1.0g/dl were excluded. The detection failure rate of SpHb was high. At present, additional refinements of the current technology are necessary to further improve performance of non-invasive hemoglobin measurement in the clinical setting.

Trending, Accuracy, and Precision of Noninvasive Hemoglobin Monitoring During Human Hemorrhage and Fixed Crystalloid Bolus.

Automated critical care systems for en route care will rely heavily on noninvasive continuous monitoring. It has been reported that noninvasive assessment of blood hemoglobin via CO-oximetry (SpHb) assessed by spot measurements lacks sufficient accuracy for clinical decision making in trauma patients. However, the precision and utility of trending of continuous hemoglobin have not been evaluated in hemorrhaging humans. This study measured the trending and concordance of SpHb changes during dynamic variations resulting from controlled hemorrhage with concomitant fluid infusion. With institutional review board approval and informed consent, 12 healthy volunteers under general anesthesia were subjected to hemorrhage (10 mL/kg for 15 min) accompanied by Ringer's lactate solution infusion (30 mL/kg for 20 min). The SpHb was measured continuously by the Masimo Radical-7, whereas total blood hemoglobin was measured by arterial blood sampling. Trend analysis, assessed by plots of SpHb against time of 12 subjects, shows consistent falls in SpHb during hemodilution without exception. Four-quadrant concordance analysis was 95.4% with an exclusion zone of 1 g/dL. Spot comparisons of 106 data pairs (SpHb and total blood hemoglobin) showed that 50% exhibited an error of more than 1 g/dL with bias of 1.08 ± 0.82 g/dL and 95% limits of agreement of -0.5 to 2.6. Both trend analysis and concordance analysis suggest high precision of pulse CO-oximetry during hemodilution by hemorrhage and fluid bolus in human volunteers. However, accuracy was similar to other studies and therefore the use of pulse CO-oximetry alone is likely insufficient to make transfusion decisions.

Accuracy of pulse oximeters in detecting hypoxemia in patients with chronic thromboembolic pulmonary hypertension.

PurposePulse oximetry is routinely used to continuously and non-invasively monitor arterial oxygen saturation (SaO2). When oxygen saturation by pulse oximeter (SpO2) overestimates SaO2, hypoxemia may be overlooked. We compared the SpO2 - SaO2 differences among three pulse oximeters in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who spent their daily lives in a poor oxygen state.Material and MethodThis prospective observational study recruited 32 patients with CTEPH undergoing elective cardiac catheterization. As we collected arterial blood samples in the catheter laboratory, SpO2 values were simultaneously recorded. Three pulse oximeters were used on each patient, and SpO2 values were compared with oximetry readings using a blood gas analyzer. To determine the optimal SpO2 value by which to detect hypoxemia (SaO2≦90%), we generated receiver operating characteristic (ROC) curves for each pulse oximeter.ResultThe root mean square of each pulse oximeter was 1.79 (OLV-3100), 1.64 (N-BS), and 2.50 (Masimo Radical). The mean bias (SpO2 - SaO2) for the 90%–95% saturation range was significantly higher for Masimo Radical (0.19 +/- 1.78% [OLV-3100], 0.18 +/- 1.63% [N-BS], and 1.61 +/- 1.91% [Masimo Radical]; p<0.0001). The optimal SpO2 value to detect hypoxemia (SaO2≦90%) was 89% for OLV-3100, 90% for N-BS, and 92% for Masimo Radical.ConclusionWe found that the biases and precision with which to detect hypoxemia differed among the three pulse oximeters. To avoid hypoxemia, the optimal SpO2 should be determined for each pulse oximeter.

Accuracy of continuous noninvasive hemoglobin monitoring for the prediction of blood transfusions in trauma patients.

Early detection of hemorrhagic shock is required to facilitate prompt coordination of blood component therapy delivery to the bedside and to expedite performance of lifesaving interventions. Standard physical findings and vital signs are difficult to measure during the acute resuscitation stage, and these measures are often inaccurate until patients deteriorate to a state of decompensated shock. The aim of this study is to examine a severely injured trauma patient population to determine whether a noninvasive SpHb monitor can predict the need for urgent blood transfusion (universal donor or additional urgent blood transfusion) during the first 12 h of trauma patient resuscitation. We hypothesize that trends in continuous SpHb, combined with easily derived patient-specific factors, can identify the immediate need for transfusion in trauma patients. Subjects were enrolled if directly admitted to the trauma center, >17 years of age, and with a shock index (heart rate/systolic blood pressure) >0.62. Upon admission, a Masimo Radical-7 co-oximeter sensor (Masimo Corporation, Irvine, CA) was applied, providing measurement of continuous non-invasive hemoglobin (SpHb) levels. Blood was drawn and hemoglobin concentration analyzed and conventional pulse oximetry photopletysmograph signals were continuously recorded. Demographic information and both prehospital and admission vital signs were collected. The primary outcome was transfusion of at least one unit of packed red blood cells within 24 h of admission. Eight regression models (C1-C8) were evaluated for the prediction of blood use by comparing area under receiver operating curve (AUROC) at different time intervals after admission. 711 subjects had continuous vital signs waveforms available, to include heart rate (HR), SpHb and SpO2 trends. When SpHb was monitored for 15 min, SpHb did not increase AUROC for prediction of transfusion. The highest ROC was recorded for model C8 (age, sex, prehospital shock index, admission HR, SpHb and SpO2) for the prediction of blood products within the first 3 h of admission. When data from 15 min of continuous monitoring were analyzed, significant improvement in AUROC occurred as more variables were added to the model; however, the addition of SpHb to any of the models did not improve AUROC significantly for prediction of blood use within the first 3 h of admission in comparison to analysis of conventional oximetry features. The results demonstrate that SpHb monitoring, accompanied by continuous vital signs data and adjusted for age and sex, has good accuracy for the prediction of need for transfusion; however, as an independent variable, SpHb did not enhance predictive models in comparison to use of features extracted from conventional pulse oximetry. Nor was shock index better than conventional oximetry at discriminating hemorrhaging and prediction of casualties receiving blood. In this population of trauma patients, noninvasive SpHb monitoring, including both trends and absolute values, did not enhance the ability to predict the need for blood transfusion.

Validation of noninvasive hemoglobin measurement by pulse co-oximeter in newborn infants.

To describe the accuracy of noninvasive hemoglobin (Hb) obtained with pulse co-oximeter (SpHb) compared with total Hb (tHb) from laboratory co-oximeter in neonates. Neonates with birth weight (BW) <3000 g admitted to LAC+USC Medical Center neonatal intensive care unit were included. SpHb was recorded using Masimo Radical-7 and compared with tHb. A total of three data sets were obtained for each patient. Regression analysis and Bland-Altman analysis were performed. Sixty-one patients (mean±s.d., BW 1177±610 g and gestational age 28.7±3.9 weeks) were enrolled. The mean tHb value was 13.9±2.0 g dl(-1) and the mean SpHb was 14.0±2.0 g dl(-1). There was a moderately positive correlation between SpHb and tHb (r=0.66, P<0.001) with a bias and precision of -0.09±1.67 g dl(-1). Data from a subgroup of infants with gestational age ⩽32 weeks (52/61 patients) were analyzed, and the correlation coefficient was moderately positive (r=0.69, P<0.001) with a bias and precision of -0.23±1.60 g dl(-1). Our results suggest that noninvasive SpHb may be considered as an adjunct to invasive tHb measurements in newborn infants <3000 g especially in preterm infants ⩽32 weeks of gestation.

The impact of intra-abdominal pressure on the stroke volume variation and plethysmographic variability index in patients undergoing laparoscopic cholecystectomy.

The purpose of the present study was to evaluate the effect of increasing intra-abdominal pressure (IAP) on stroke volume variation (SVV) and plethysmographic variability index (PVI) in patients undergoing laparoscopic cholecystectomy. PVI examined by Masimo Radical 7 pulse oximeter and SVV determined using FloTrac/Vigileo were monitored simultaneously in forty-five patients undergoing laparoscopic cholecystectomy (LC). Mean arterial blood pressure (MAP), heart rate (HR), cardiac index (CI), perfusion index (PI), airway pressures (P), SVV, and PVI were also recorded at the following predetermined time: 5 min after endotracheal intubation (T1), 5 min after pneumoperitoneum at 5 mmHg (T2), 5 min after pneumoperitoneum at 10 mmHg (T3), 5 min after pneumoperitoneum at 15 mmHg (T4), and 5 min after the termination of pneumoperitoneum (T5). Forty-five patients with a total of 225 pairs of measurements were included in the analysis. Compared with the values at T1, both SVV and PVI showed significant progressive increases as the IAP was adjusted from 5 to 10, 15 mmHg at T2, T3, and T4, respectively. No significant difference was found when the pneumoperitoneum was terminated at T5. Further regressive analysis indicated strong relationships between SVV and IAP (r = 0.8118, p < 0.001), PVI and IAP(r = 0.8876, p < 0.001) respectively. Both PVI and SVV showed rapid and IAP correlative changes with increasing intra-abdominal pressure in patients undergoing laparoscopic cholecystectomy.

The changes of non-invasive hemoglobin and perfusion index of Pulse CO-Oximetry during induction of general anesthesia.

BackgroundWe hypothesized that induction of general anesthesia using sevoflurane improves the accuracy of non-invasive hemoglobin (SpHb) measurement of Masimo Radical-7® Pulse CO-Oximetry by inducing peripheral vasodilation and increasing the perfusion index (PI). The aim of this study is to investigate the change in the SpHb and the PI measured by Rad7 during induction of general anesthesia using sevoflurane.MethodsThe laboratory hemoglobin (Hblab) was measured before surgery by venous blood sampling. The SpHb and the PI was measured twice; before and after the induction of general anesthesia using sevoflurane. The changes of SpHb, Hbbias (Hbbias = SpHb - Hblab), and PI before and after the induction of general anesthesia were analyzed using a paired t-test. Also, a Pearson correlation coefficient analysis was used to analyze the correlation between the Hbbias and the PI.ResultsThe SpHb and the PI were increased after the induction of general anesthesia using sevoflurane. There was a statistically significant change in the Hbbias from -2.8 to -0.7 after the induction of general anesthesia. However, the limit of agreement (2 SD) of the Hbbias did not change after the induction of general anesthesia. The Pearson correlation coefficient between the Hbbias and the PI was not statistically significant.ConclusionsDuring induction of general anesthesia using sevoflurane, the accuracy of SpHb measurement was improved and precision was not changed. The correlation between Hbbias and PI was not significant.

Low perfusion index affects the difference in glucose level between capillary and venous blood.

AimIn emergency cases, finger stick testing is primarily used to check the blood glucose value of patients since it takes longer to obtain the venous value. In critical patients, under conditions that cause an increase in metabolic state and level of stress, there occurs considerable difference in glucose levels between capillary and venous measurements. This study aimed to investigate the comparability of capillary and venous glucose values, according to the perfusion index level obtained with the Masimo Radical-7® device, in critical patients aged 18 years and over.MethodWe conducted this prospective and observational study in the emergency department of the Eskisehir Osmangazi University hospital between November 3, 2008 and February 2, 2009.ResultsThe blood glucose of 300 critical patients was checked by finger stick in the emergency unit. The participants with normal vital signs had perfusion index between 0 and 5; the results obtained by the two methods were more consistent for perfusion index values of 6 and over. The results were most consistent in aged participants with normal vital sign findings and low perfusion index and in young patients with high perfusion index. In the cases where at least one of the vital signs was abnormal, the glucose values obtained by the two methods were more consistent when the perfusion index was 6 or over. In this group, independently from the perfusion index value, the consistency was higher in younger patients compared with aged patients.ConclusionIn the emergency department, perfusion index value measured by Masimo Radical-7 and capillary blood glucose levels can serve in blood sugar management in critically ill patients.

Does a non-invasive hemoglobin monitor correlate with a venous blood sample in the acutely ill?

Non-invasive hemoglobin measuring technology has potential for rapid, portable, and accurate way of providing identification of blood loss or anemia. Our objective is to determine if this technology is reliable in critically ill patients presenting to the Emergency Department. Prospective cross-sectional observational study was done at an urban level-one trauma center, 135 subjects were conveniently sampled, suspected of having active bleeding, sepsis, or other critically ill condition. Non-invasive measurements with Masimo (Irvine, CA, USA) Radical-7 and Rad-57 hemoglobin monitors were compared with the Beckman-Coulter LH-550 (Brea, CA, USA) clinical laboratory blood cell analyzer. The primary outcome was the relationship of the non-invasive device to the clinical laboratory results. Secondary evaluations included the effect of pulse rate, systolic BP, respiratory rate, temperature, capillary refill, skin color, nail condition, extremity movement. The Radical-7 was able to capture reading in 78% (88/113) of subjects, and the Rad-57 in 65% (71/110) of subjects. The correlation (R(2)) of the device Hb was 0.69 and 0.67 (p < 00.01) for the Radical-7 and Rad-57, respectively. The coefficient of variation for the Radical-7 was 18%, and for the Rad57 it was 13%. Univariate analysis shows none of the observed factors is associated with the difference values between the device Hb and laboratory Hb. Our results show that Radical-7 and Rad-57 devices do not report readings in 29% of patients and accuracy is significantly lower than reported by the manufacturer with over 50% of readings falling outside of ± 1 g/dL. We determined that none of the several potential factors examined are associated with the degree of device accuracy.

O-027 Microcirculation Within The First Minutes And First 24 Hours Of Life In Healthy Term Newborns

Background and aims Microcirculation is important to ensure adequate tissue oxygenation and nutrient delivery. Clinical findings, perfusion index (PI) measurements are used to assess microcirculation. Side stream dark field (SDF) imaging is a noninvasive method of assessing microcirculation by means of a videomicroscope. This study aimed to assess microcirculation in healthy term newborns born either by spontaneous vaginal delivery (SVD) or caesarean section (C/S). Methods The assessments were done within the first 30 min of life (T0) and repeated at the 24th hour of life (T1). Microcirculation was assessed from axillary skin by using SDF technique with Microscan device where total and perfused vessel density (TVD, PVD) and microvascular flow index (MFI) were calculated, as well as by using microcirculation score (MS) based on capillary refill time, skin colour and warmth and PI measured by Masimo Radical7 pulse oxymeter. Vital signs were also recorded. Nonparametric tests were used for statistical analysis. Results Twelve newborns born by SVD and 25 newborns born C/S were included. The mean, SD, median values for temperature, TVD, PVD, MFI, MS, and PI at T0 and T1 are as follows; T0: Temp:36 ± 0,44(36,1), TVD: 18,79 ± 1,49(18,81), PVD: 18,73 ± 1,5(18,81), MFI: 3,07 ± 0,25(3), MS: 2,14 ± 1,36(2), PI: 1,84 ± 0,97(1,75). T1: Temp:37,1 ± 0,26(37,1), TVD: 18,93 ± 2,1(18,73), PVD: 18,9 ± 2,13(18,73), MFI: 3,17 ± 0,32(3,1), MS:1,65 ± 0,48(2), PI: 1,9 ± 0,8(2). Temperature was significantly and MFI was slightly higher at T1 compared to T0 (p = 0,001 and p = 0, 04). No difference was observed between SVD or C/S groups or at different times within the same group. Conclusions Peripheral microcirculation in general is not affected by mode of delivery in term healthy newborns and doesn’t seem to change significantly within the first 24 h of life.

Nocturnal oxygen saturation profiles of healthy term infants

ObjectivePulse oximetry is used extensively in hospital and home settings to measure arterial oxygen saturation (SpO2). Interpretation of the trend and range of SpO2 values observed in infants is currently...

Accuracy of noninvasive hemoglobin measurement by Masimo Radical-7 Pulse CO-Oximeter in adult patients; comparison between revision C and revision K

Accuracy of noninvasive hemoglobin measurement by Masimo Radical-7 Pulse CO-Oximeter in adult patients; comparison between revision C and revision K

Continuous Noninvasive Hemoglobin Measurement Is Useful in Patients Undergoing Double-Jaw Surgery

Continuous measurement of hemoglobin by pulse CO-oximetry (SpHb; Masimo Radical 7 device, Masimo Corp, Irvine, CA) may be helpful during double-jaw surgery when massive hemorrhage is anticipated. Given the possible influence of low blood pressure on the detection of hemoglobin levels, the agreement of the SpHb was evaluated in patients undergoing orthognathic surgery when using hypotensive anesthesia. Patients who underwent elective Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSO) were enrolled in this observational prospective cohort study. SpHb was compared with time-matched arterial total hemoglobin (tHb) before incision, at Le Fort I osteotomy, at BSSO, and at skin closure. The correlation between simultaneous SpHb and tHb measurement pairs was evaluated. Agreement was assessed by a comparison of SpHb with tHb using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. The average age of 51 patients was 23 ± 5 years and 32 patients were male. The correlations of SpHb and tHb measurements were 0.72, 0.85, 0.89, and 0.78 before incision, at Le Fort I osteotomy, at BSSO, and at closure, respectively. Bland-Altman analysis for SpHb and tHb showed respective bias values of 0.12, 0.07, -0.09, and -0.90 g/dL. ICC values between SpHb and tHb were 0.82, 0.90, 0.91, and 0.87, respectively. Continuous monitoring of hemoglobin may help to determine the appropriate time to perform an invasive measurement of hemoglobin in patients who undergo double-jaw surgery.

Evaluation of noninvasive hemoglobin measurements in trauma patients

BackgroundReliable, accurate, noninvasive, and continuous determination of hemoglobin would be an important advance in the care of trauma patients. The aim of this study was to evaluate the utility of the Masimo Radical 7 device in severely injured trauma patients. MethodsHighest level trauma activation patients were enrolled over a 1-year period. Laboratory hemoglobin values were compared with Masimo hemoglobin values using Bland-Altman analysis. ResultsA total of 525 patients were enrolled in the study. Comparison of 861 paired values from 418 patients showed a variance of 3.89 to −3.84 g/dL, showing a nonsignificant correlation between Masimo hemoglobin and laboratory hemoglobin values. ConclusionsThe Masimo Radical 7 system evaluated in this study holds promise, but it is not ready to be used as an initial noninvasive evaluation tool in the acute treatment of severely injured trauma patients. There was a poor correlation between Masimo hemoglobin and laboratory hemoglobin and large numbers of missing data. On the basis of the poor correlation, the Masimo Radical 7 device cannot currently be used to guide transfusion therapy.

Noninvasive Hemoglobin Monitoring

Evaluating the accuracy of medical devices has traditionally been a blend of statistical analyses, at times without contextualizing the clinical application. There have been a number of recent publications on the accuracy of a continuous noninvasive hemoglobin measurement device, the Masimo Radical-7 Pulse Co-oximeter, focusing on the traditional statistical metrics of bias and precision. In this review, which contains material presented at the Innovations and Applications of Monitoring Perfusion, Oxygenation, and Ventilation (IAMPOV) Symposium at Yale University in 2012, we critically investigated these metrics as applied to the new technology, exploring what is required of a noninvasive hemoglobin monitor and whether the conventional statistics adequately answer our questions about clinical accuracy. We discuss the glucose error grid, well known in the glucose monitoring literature, and describe an analogous version for hemoglobin monitoring. This hemoglobin error grid can be used to evaluate the required clinical accuracy (±g/dL) of a hemoglobin measurement device to provide more conclusive evidence on whether to transfuse an individual patient. The important decision to transfuse a patient usually requires both an accurate hemoglobin measurement and a physiologic reason to elect transfusion. It is our opinion that the published accuracy data of the Masimo Radical-7 is not good enough to make the transfusion decision.