1
|
Maiwald CA, Schwarz CE, Böckmann K, Springer L, Poets CF, Franz A. Randomised crossover study on pulse oximeter readings from different sensors in very preterm infants. Arch Dis Child Fetal Neonatal Ed 2024; 109:391-396. [PMID: 38129130 PMCID: PMC11228211 DOI: 10.1136/archdischild-2023-325961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE In extremely preterm infants, different target ranges for pulse oximeter saturation (SpO2) may affect mortality and morbidity. Thus, the impact of technical changes potentially affecting measurements should be assessed. We studied SpO2 readings from different sensors for systematic deviations. DESIGN Single-centre, randomised, triple crossover study. SETTING Tertiary neonatal intensive care unit. PATIENTS 24 infants, born at <32 weeks' gestation, with current weight <1500 g and without right-to-left shunt via a patent ductus arteriosus. INTERVENTIONS Simultaneous readings from three SpO2 sensors (Red Diamond (RD), Photoplethysmography (PPG), Low Noise Cabled Sensors (LNCS)) were logged at 0.5 Hz over 6 hour/infant and compared with LNCS as control using analysis of variance. Sensor position was randomly allocated and rotated every 2 hours. Seven different batches each were used. OUTCOMES Primary outcome was the difference in SpO2 readings. Secondary outcomes were differences between sensors in the proportion of time within the SpO2-target range (90-95 (100)%). RESULTS Mean gestational age at birth (±SD) was 274/7 (±23/7) weeks, postnatal age 20 (±20) days. 134 hours of recording were analysed. Mean SpO2 (±SD) was 94.0% (±3.8; LNCS) versus 92.2% (±4.0; RD; p<0.0001) and 94.5% (±3.9; PPG; p<0.0001), respectively. Mean SpO2 difference (95% CI) was -1.8% (-1.9 to -1.8; RD) and 0.5% (0.4 to 0.5; PPG). Proportion of time in target was significantly lower with RD sensors (84.8% vs 91.7%; p=0.0001) and similar with PPG sensors (91.1% vs 91.7%; p=0.63). CONCLUSION There were systematic differences in SpO2 readings between RD sensors versus LNCS. These findings may impact mortality and morbidity of preterm infants, particularly when aiming for higher SpO2-target ranges (eg, 90-95%). TRIAL REGISTRATION NUMBER DRKS00027285.
Collapse
Affiliation(s)
- Christian Achim Maiwald
- Department of Pediatrics, Center for Pediatric Clinical Studies (CPCS), University Hospital Tübingen, Tübingen, Germany
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
| | - Christoph E Schwarz
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
- Department of Neonatology, University of Heidelberg, Heidelberg, Germany
| | - Katrin Böckmann
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
| | - Laila Springer
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
| | - Christian F Poets
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
| | - Axel Franz
- Department of Pediatrics, Center for Pediatric Clinical Studies (CPCS), University Hospital Tübingen, Tübingen, Germany
- Department of Neonatology, Tübingen University Hospital, Tübingen, Germany
| |
Collapse
|
2
|
Sola A, Leslie Altimier, Teresa Montes Bueno M, Muñoz CE. Monitoring SpO 2: The Basics of Retinopathy of Prematurity (Back to Basics) and Targeting Oxygen Saturation. Crit Care Nurs Clin North Am 2024; 36:69-98. [PMID: 38296377 DOI: 10.1016/j.cnc.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024]
Abstract
Oxygen (O2) is a drug frequently used in newborn care. Adverse effects of hypoxia are well known but the damaging effects of excess oxygen administration and oxidative stress have only been studied in the last 2 decades. Many negative effects have been described, including retinopathy of prematurity . Noninvasive pulse oximetry (SpO2) is useful to detect hypoxemia but requires careful evaluation and understanding of the frequently changing relationship between O2 and hemoglobin to prevent hyperoxemia. Intention to treat SpO2 ranges should be individualized for every newborn receiving supplemental O2, according to gestational age, post-natal age, and clinical condition.
Collapse
Affiliation(s)
- Augusto Sola
- Iberoamerican Society of Neonatology (SIBEN), 2244 Newbury Drive, Wellington, FL 3341, USA.
| | - Leslie Altimier
- Cardinal Glennon Children's Hospital, 1465 South Grand Avenue, St. Louis, MO 63104, USA
| | | | | |
Collapse
|
3
|
Ambrisko TD, Dantino SC, Keating SCJ, Strahl-Heldreth DE, Sage AM, Martins FDC, Harper TAM, Wilkins PA. Repeatability and accuracy of fingertip pulse oximeters for measurement of hemoglobin oxygen saturation in arterial blood and pulse rate in anesthetized dogs breathing 100% oxygen. Am J Vet Res 2021; 82:268-273. [PMID: 33764836 DOI: 10.2460/ajvr.82.4.268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the repeatability and accuracy of fingertip pulse oximeters (FPO) for measurement of hemoglobin oxygen saturation in arterial blood and pulse rate (PR) in anesthetized dogs breathing 100% O2. ANIMALS 29 healthy client-owned anesthetized dogs undergoing various surgical procedures. PROCEDURES In randomized order, each of 7 FPOs or a reference pulse oximeter (PO) was applied to the tongue of each intubated anesthetized dog breathing 100% O2. Duplicate measurements of oxygen saturation (Spo2) and PR were obtained within 60 seconds of applying an FPO or PO. A nonparametric version of Bland-Altman analysis was used. Coefficient of repeatability was the interval between the 5th and 95th percentiles of the differences between duplicate measurements. Bias was the median difference, and the limits of agreement were the 5th and 95th percentiles of the differences between each FPO and the PO. Acceptable values for the coefficient of repeatability of Spo2 were ≤ 6%. Agreements were accepted if the limits of agreement had an absolute difference of ≤ ± 3% in Spo2 and relative difference of ≤ ± 10% in PR. RESULTS Coefficient of repeatability for Spo2 was acceptable for 5 FPOs, but the limits of agreement for Spo2 were unacceptable for all FPOs. The limits of agreement for PR were acceptable for 2 FPOs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that some FPOs may be suitable for accurately monitoring PRs of healthy anesthetized dogs breathing 100% O2, but mild underestimation of Spo2 was common.
Collapse
|
4
|
|
5
|
Evans NA, Walker JM, Manchester AC, Bach JF. Acute respiratory distress syndrome and septic shock in a cat with disseminated toxoplasmosis. J Vet Emerg Crit Care (San Antonio) 2017; 27:472-478. [DOI: 10.1111/vec.12621] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 07/14/2015] [Accepted: 08/27/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Natashia A. Evans
- Department of Medical Sciences, School of Veterinary Medicine; University of Wisconsin; Madison WI 53706
| | - Julie M. Walker
- Department of Medical Sciences, School of Veterinary Medicine; University of Wisconsin; Madison WI 53706
| | - Alison C. Manchester
- Department of Medical Sciences, School of Veterinary Medicine; University of Wisconsin; Madison WI 53706
| | - Jonathan F. Bach
- Department of Medical Sciences, School of Veterinary Medicine; University of Wisconsin; Madison WI 53706
| |
Collapse
|
6
|
Hassan MA, Weber C, Waitz M, Huang L, Hummler HD, Mendler MR. Reliability of Pulse Oximetry during Progressive Hypoxia, Cardiopulmonary Resuscitation, and Recovery in a Piglet Model of Neonatal Hypoxic Cardiac Arrest. Neonatology 2017; 112:40-46. [PMID: 28253519 DOI: 10.1159/000456648] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/16/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pulse oximetry is widely used in intensive care and emergency conditions to monitor arterial oxygenation and to guide oxygen therapy. OBJECTIVE To study the reliability of pulse oximetry in comparison with CO-oximetry in newborn piglets during progressive hypoxia, cardiac arrest, cardiopulmonary resuscitation (CPR), and after return of spontaneous circulation (ROSC). METHODS Thirty-three newborn piglets were exposed to hypoxia until asystole occurred and then resuscitated until ROSC. Arterial oxygen saturation was monitored continuously by pulse oximetry (SpO2) with one sensor applied to the wrist of the right forelimb (FL) and another to the thigh of the left hind limb (HL). Arterial functional oxygen saturation (SaO2) was measured at baseline and at predefined intervals during each phase of the experiment. SpO2 was compared with coinciding SaO2 values and bias considered whenever the difference (SpO2 - SaO2) was beyond ±5%. RESULTS Bias values were lower at the baseline measurements (-3.7 ± 2.3% in FL and -4.1 ± 3.4% in HL) as well as after ROSC (1.5 ± 4.2% in FL and 0.2 ± 4.6% in HL) with higher precision and accuracy than during other experiment phases. During hypoxia induction, cardiac arrest, and CPR, there was a marked decrease in precision and accuracy as well as an increase in bias up to 43 ± 26 and 56 ± 27% in FL and HL, respectively, over a range of SaO2 from 13 to 51%. CONCLUSION Pulse oximetry showed increased bias and decreased accuracy and precision during marked hypoxemia in a model of neonatal hypoxic cardiac arrest.
Collapse
|
7
|
Hassan MA, Mendler M, Maurer M, Waitz M, Huang L, Hummler HD. Reliability of pulse oximetry during cardiopulmonary resuscitation in a piglet model of neonatal cardiac arrest. Neonatology 2015; 107:113-9. [PMID: 25471619 DOI: 10.1159/000368178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 09/04/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pulse oximetry is widely used in intensive care and emergency conditions to monitor arterial oxygenation and to guide oxygen therapy. OBJECTIVE To study the reliability of pulse oximetry in comparison with CO-oximetry in newborn piglets during cardiopulmonary resuscitation (CPR). METHODOLOGY In a prospective cohort study in 30 healthy newborn piglets, cardiac arrest was induced, and thereafter each piglet received CPR for 20 min. Arterial oxygen saturation was monitored continuously by pulse oximetry (SpO2). Arterial blood was analyzed for functional oxygenation (SaO2) every 2 min. SpO2 was compared with coinciding SaO2 values and bias considered whenever the difference (SpO2 - SaO2) was beyond ±5%. RESULTS Bias values were decreased at the baseline measurements (mean: 2.5 ± 4.6%) with higher precision and accuracy compared with values across the experiment. Two minutes after cardiac arrest, there was a marked decrease in precision and accuracy as well as an increase in bias up to 13 ± 34%, reaching a maximum of 45.6 ± 28.3% after 10 min over a mean SaO2 range of 29-58%. CONCLUSION Pulse oximetry showed increased bias and decreased accuracy and precision during CPR in a model of neonatal cardiac arrest. We recommend further studies to clarify the exact mechanisms of these false readings to improve reliability of pulse oximetry during the marked desaturation and hypoperfusion found during CPR.
Collapse
Affiliation(s)
- Mohammad Ahmad Hassan
- Division of Neonatology and Pediatric Critical Care, Department of Pediatrics and Adolescent Medicine, Ulm University, Ulm, Germany
| | | | | | | | | | | |
Collapse
|
8
|
Kong L, Zhao Y, Dong L, Jian Y, Jin X, Li B, Feng Y, Liu M, Liu X, Wu H. Non-contact detection of oxygen saturation based on visible light imaging device using ambient light. OPTICS EXPRESS 2013; 21:17464-71. [PMID: 23938616 DOI: 10.1364/oe.21.017464] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A method that remotely measures blood oxygen saturation through two cameras under regular lighting is proposed and experimentally demonstrated. Two narrow-band filters with their visible wavelength of 660nm and 520nm are mounted to two cameras respectively, which are then used to capture two photoplethysmographic (PPG) from the subject simultaneously. The data gathered from this system, including both blood oxygen saturation and heart rate, is compared to the output of a traditional figure blood volume pulse (BVP) senor that was employed on the subject at the same time. Result of the comparison showed that the data from the new, non-contact system is consistent and comparable with the BVP senor. Compared to other camera-based measuring method, which requires additional close-up lighting, this new method is achievable under regular lighting condition, therefore more stable and easier to implement. This is the first demonstration of an accurate video-based method for non-contact oxygen saturation measurements by using ambient light with their respective visible wavelength of 660nm and 520nm which is free from interference of the light in other bands.
Collapse
Affiliation(s)
- Lingqin Kong
- Beijing Key Lab for Precision Optoelectronic Measurement Instrument and Technology, School of Optoelectronics, Beijing Institute of Technology, Beijing, 100081, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Quinn CT, Raisis AL, Musk GC. Evaluation of Masimo signal extraction technology pulse oximetry in anaesthetized pregnant sheep. Vet Anaesth Analg 2012; 40:149-56. [PMID: 22978823 DOI: 10.1111/j.1467-2995.2012.00772.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Evaluation of the accuracy of Masimo signal extraction technology (SET) pulse oximetry in anaesthetized late gestational pregnant sheep. STUDY DESIGN Prospective experimental study. ANIMALS Seventeen pregnant Merino ewes. METHODS Animals included in study were late gestation ewes undergoing general anaesthesia for Caesarean delivery or foetal surgery in a medical research laboratory. Masimo Radical-7 pulse oximetry (SpO(2) ) measurements were compared to co-oximetry (SaO(2) ) measurements from arterial blood gas analyses. The failure rate of the pulse oximeter was calculated. Accuracy was assessed by Bland & Altman's (2007) limits of agreement method. The effect of mean arterial blood pressure (MAP), perfusion index (PI) and haemoglobin (Hb) concentration on accuracy were assessed by regression analysis. RESULTS Forty arterial blood samples paired with SpO(2) and blood pressure measurements were obtained. SpO(2) ranged from 42 to 99% and SaO(2) from 43.7 to 99.9%. MAP ranged from 24 to 82 mmHg, PI from 0.1 to 1.56 and Hb concentration from 71 to 114 g L(-1) . Masimo pulse oximetry measurements tended to underestimate oxyhaemoglobin saturation compared to co-oximetry with a bias (mean difference) of -2% and precision (standard deviation of the differences) of 6%. Accuracy appeared to decrease when SpO(2) was <75%, however numbers were too small for statistical comparisons. Hb concentration and PI had no significant effect on accuracy, whereas MAP was negatively correlated with SpO(2) bias. CONCLUSIONS AND CLINICAL RELEVANCE Masimo SET pulse oximetry can provide reliable and continuous monitoring of arterial oxyhaemoglobin saturation in anaesthetized pregnant sheep during clinically relevant levels of cardiopulmonary dysfunction. Further work is needed to assess pulse oximeter function during extreme hypotension and hypoxaemia.
Collapse
Affiliation(s)
- Christopher T Quinn
- Division of Veterinary and Biomedical Sciences, Murdoch University, Perth, WA, Australia.
| | | | | |
Collapse
|
10
|
Abstract
OBJECTIVE To explore if regional cerebral tissue oxygen saturation monitoring by near-infrared spectroscopy (NIRS) is feasible during neonatal resuscitation of very low birth weight (VLBW) infants after birth. STUDY DESIGN Cerebral tissue oxygen saturation was measured by NIRS in 51 VLBW infants (mean gestational age: 27.8 weeks) during the first 10 min after delivery. RESULT A regional cerebral tissue oxygen saturation signal was available after a median (interquartile range) age of 52 (44 to 68) s. In three infants the signal was obtained after 10 min of age. After delivery cerebral tissue oxygen saturation rose continuously from 37 (31 to 49) % at 1 minute of age and reached a steady state in the range of 61 to 84% ∼7 min after birth. Percentiles of cerebral tissue oxygen saturation of this cohort of preterm infants are given. CONCLUSION Cerebral tissue oxygen saturation monitoring is feasible during neonatal resuscitation of VLBW infants within the first minutes of life.
Collapse
|
11
|
Wilson BJ, Cowan HJ, Lord JA, Zuege DJ, Zygun DA. The accuracy of pulse oximetry in emergency department patients with severe sepsis and septic shock: a retrospective cohort study. BMC Emerg Med 2010; 10:9. [PMID: 20444248 PMCID: PMC2876142 DOI: 10.1186/1471-227x-10-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 05/05/2010] [Indexed: 11/10/2022] Open
Abstract
Background Pulse oximetry is routinely used to continuously and noninvasively monitor arterial oxygen saturation (SaO2) in critically ill patients. Although pulse oximeter oxygen saturation (SpO2) has been studied in several patient populations, including the critically ill, its accuracy has never been studied in emergency department (ED) patients with severe sepsis and septic shock. Sepsis results in characteristic microcirculatory derangements that could theoretically affect pulse oximeter accuracy. The purposes of the present study were twofold: 1) to determine the accuracy of pulse oximetry relative to SaO2 obtained from ABG in ED patients with severe sepsis and septic shock, and 2) to assess the impact of specific physiologic factors on this accuracy. Methods This analysis consisted of a retrospective cohort of 88 consecutive ED patients with severe sepsis who had a simultaneous arterial blood gas and an SpO2 value recorded. Adult ICU patients that were admitted from any Calgary Health Region adult ED with a pre-specified, sepsis-related admission diagnosis between October 1, 2005 and September 30, 2006, were identified. Accuracy (SpO2 - SaO2) was analyzed by the method of Bland and Altman. The effects of hypoxemia, acidosis, hyperlactatemia, anemia, and the use of vasoactive drugs on bias were determined. Results The cohort consisted of 88 subjects, with a mean age of 57 years (19 - 89). The mean difference (SpO2 - SaO2) was 2.75% and the standard deviation of the differences was 3.1%. Subgroup analysis demonstrated that hypoxemia (SaO2 < 90) significantly affected pulse oximeter accuracy. The mean difference was 4.9% in hypoxemic patients and 1.89% in non-hypoxemic patients (p < 0.004). In 50% (11/22) of cases in which SpO2 was in the 90-93% range the SaO2 was <90%. Though pulse oximeter accuracy was not affected by acidoisis, hyperlactatementa, anemia or vasoactive drugs, these factors worsened precision. Conclusions Pulse oximetry overestimates ABG-determined SaO2 by a mean of 2.75% in emergency department patients with severe sepsis and septic shock. This overestimation is exacerbated by the presence of hypoxemia. When SaO2 needs to be determined with a high degree of accuracy arterial blood gases are recommended.
Collapse
Affiliation(s)
- Ben J Wilson
- Department of Medicine, University of Calgary, (1403 - 29th Street NW), Calgary, (T2N 2T9), Canada.
| | | | | | | | | |
Collapse
|
12
|
Biosignalverarbeitung. BIOMED ENG-BIOMED TE 2010. [DOI: 10.1515/bmt.2010.705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
13
|
Verkruysse W, Svaasand LO, Nelson JS. Remote plethysmographic imaging using ambient light. OPTICS EXPRESS 2008; 16:21434-45. [PMID: 19104573 PMCID: PMC2717852 DOI: 10.1364/oe.16.021434] [Citation(s) in RCA: 419] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plethysmographic signals were measured remotely (> 1m) using ambient light and a simple consumer level digital camera in movie mode. Heart and respiration rates could be quantified up to several harmonics. Although the green channel featuring the strongest plethysmographic signal, corresponding to an absorption peak by (oxy-) hemoglobin, the red and blue channels also contained plethysmographic information. The results show that ambient light photo-plethysmography may be useful for medical purposes such as characterization of vascular skin lesions (e.g., port wine stains) and remote sensing of vital signs (e.g., heart and respiration rates) for triage or sports purposes.
Collapse
Affiliation(s)
- Wim Verkruysse
- Beckman Laser Institue, University of California, Irvine, 1002 Health Sciences Rd. East, Irvine, CA 92612, USA.
| | | | | |
Collapse
|
14
|
Hawkins MG, Vernau W, Drazenovich TL, Griffey SM, Johnson LR. Results of cytologic and microbiologic analysis of bronchoalveolar lavage fluid in New Zealand White rabbits. Am J Vet Res 2008; 69:572-8. [DOI: 10.2460/ajvr.69.5.572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
15
|
Gehring H, Duembgen L, Peterlein M, Hagelberg S, Dibbelt L. Hemoximetry as the "gold standard"? Error assessment based on differences among identical blood gas analyzer devices of five manufacturers. Anesth Analg 2007; 105:S24-S30. [PMID: 18048894 DOI: 10.1213/01.ane.0000268713.58174.cc] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The calibration and testing procedures of a pulse oximeter with arterial blood samples from healthy subjects are based on reference values from the hemoximeter. There are no tests to identify the accuracy of the reference devices. Because of this limitation and since the true values of oxygen saturation (sO2 in %) in blood samples were not known, we used the differences between two identical devices, A and B, for error assessment. METHODS Two identical devices, A and B, from five leading manufacturers were investigated. Seventy-two arterial blood samples from 12 healthy volunteers at three different levels of saturation between 100% and 70% sO2 were randomly evaluated by the test systems. RESULTS The observed differences (Delta) between Devices A and B, as a measure for the error of the hemoximeters, increased significantly with all manufacturers from level 97 (Deltamin, -0.9%; Deltamax, 2.6%) to 85 (Deltamin, -2.4%; Deltamax, 4.3), this effect was even stronger between levels 97 and 75 (Deltamin, -4.6%; Deltamax, 4.3%). A variance proportion analysis revealed the concentration of the reduced hemoglobin as the main error source for sO2 measurements. Independent from the sO2 levels there were also significant differences for the carboxy hemoglobin concentration in the range of 0%-4% and for the methemoglobin concentration in the range of 0%-1%. CONCLUSIONS The variance of sO2 measurements between identical devices increased significantly when saturation decreased from the normal level of 97% to the hypoxemic levels of 85% and 75%.
Collapse
Affiliation(s)
- Hartmut Gehring
- From the *Department of Anesthesiology, University Clinic of Schleswig-Holstein, Campus Luebeck, Germany; †Institute of Mathematical Statistics and Actuarial Science, University of Bern, Switzerland; ‡Institute of Clinical Chemistry, University Clinic of Schleswig-Holstein, Campus Luebeck, Germany
| | | | | | | | | |
Collapse
|
16
|
Casati A, Squicciarini G, Baciarello M, Putzu M, Salvadori A, Fanelli G. Forehead reflectance oximetry: a clinical comparison with conventional digit sensors during laparotomic and laparoscopic abdominal surgery. J Clin Monit Comput 2007; 21:271-6. [PMID: 17701387 DOI: 10.1007/s10877-007-9084-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Accepted: 06/17/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE This study compared the performance of forehead reflectance and conventional pulse oximetry (SpO(2)) in mechanically ventilated, anesthetized patients undergoing major abdominal surgery with either laparoscopic or laparotomic techniques. METHODS SpO(2) was continuously measured both with a forehead reflectance and a conventional digit sensor in 20 ASA physical status I-III, anesthetized patients undergoing either a laparotomic (group Laparotomy, n = 10) or laparoscopic (group Laparoscopy, n = 10) major abdominal surgery. SpO(2) values measured with the two sensors were continuously recorded at 10-second intervals during the entire procedure, and then analyzed for consistency. RESULTS In group Laparotomy finger and forehead readings remained consistently similar during the study period; on the contrary, in group Laparoscopy forehead SpO(2) readings showed a much wider variability. The mean (95% Confidence Intervals) difference between finger and forehead SpO(2) readings was 2.0% (-1.3% to +6.0%) in group Laparotomy and 2.5% (-3.5% to +8.4%) in group Laparoscopy (p = 0.001); however, in group Laparoscopy the mean difference between digit and forehead SpO(2) values increased from 0.2% (CI(95): -2.1% to +2.5%) during the first hour to 4.5% (CI(95): -2.5% to +11-5%) in the second hour (p = 0.0005), and 3.1% (CI(95): -2.4% to + 8.6%) in the third hour of surgery (p = 0.0005). Clinically relevant desaturation (decrease of SpO(2) < 89% for > or =30 s) detected with the forehead sensor in the Laparoscopy group was significantly more frequent and longer lasting than with conventional digit sensor. No differences were observed in group Laparotomy. CONCLUSIONS Forehead reflectance oximetry is as accurate as conventional digit based oximetry in mechanically ventilated patients undergoing laparotomic surgery in the supine position, but is significantly influenced by patient positioning and pneumoperitoneum during laparoscopic surgery.
Collapse
Affiliation(s)
- Andrea Casati
- Department of Anesthesiology, Critical Care and Pain Medicine, University of Parma, Italy
| | | | | | | | | | | |
Collapse
|
17
|
Hagiwara H, Ohsawa Y, Asakura S, Murakami T, Teshima T, Sunada Y. Bone marrow transplantation improves outcome in a mouse model of congenital muscular dystrophy. FEBS Lett 2006; 580:4463-8. [PMID: 16859688 DOI: 10.1016/j.febslet.2006.07.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2006] [Revised: 06/10/2006] [Accepted: 07/03/2006] [Indexed: 11/24/2022]
Abstract
We examined whether pathogenesis in dystrophin-deficient (mdx) mice and laminin-alpha2-deficient (dy) mice is ameliorated by bone marrow transplantation (BMT). Green fluorescent protein (GFP) mice were used as donors. In mdx mice, BMT failed to produce any significant differences in muscle pathology, although some GFP-positive fibers with restored dystrophin expression were observed. In contrast, in the dy mice, BMT led to a significant increase in lifespan and an increase in growth rate, muscle strength, and respiratory function. We conclude that BMT improved outcome in dy mice but not mdx mice.
Collapse
Affiliation(s)
- Hiroki Hagiwara
- Division of Neurology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki-City, Okayama 701-0192, Japan
| | | | | | | | | | | |
Collapse
|
18
|
Hummler HD, Engelmann A, Pohlandt F, Högel J, Franz AR. Decreased accuracy of pulse oximetry measurements during low perfusion caused by sepsis: Is the perfusion index of any value? Intensive Care Med 2006; 32:1428-31. [PMID: 16810522 DOI: 10.1007/s00134-006-0254-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Accepted: 05/24/2006] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the effects of deteriorating perfusion caused by sepsis on the accuracy of pulse oximetry measurements using two more recently available techniques (Nellcor N-395 and Masimo Radical) and to evaluate the perfusion index as a marker of impaired peripheral perfusion to indicate that accuracy of pulse oximetry readings may be affected. DESIGN AND SETTING Interventional cohort study in a university animal research facility. SUBJECTS Thirty-seven adult anesthetized, ventilated rabbits. INTERVENTIONS Pneumonia/sepsis was induced by tracheal instillation of Escherichia coli. MEASUREMENTS AND RESULTS Oxygen saturation and perfusion index as a marker of peripheral perfusion were measured by pulse oximetry (SpO2) and recorded continuously for 8 h. Arterial oxygen saturation (SaO2) was measured every 30 min by CO oximetry, and bias (SpO2 - SaO2) was calculated at each time point for each device to assess time-dependent changes in bias. Bias increased significantly across time for both devices tested comparing the first with the second half of the experimental period. Bias measurements during the second half of the experimental time were beyond the +/-3% error limit in 21.4% of cases with Nellcor and in 22.6% with Masimo. A lower perfusion index was associated with increased bias, but sensitivity, specificity, and positive and negative predictive values of this marker for increased bias was very limited. CONCLUSIONS We conclude that accuracy of pulse oximetry measurements was considerably affected with both devices with progressively deteriorating hemodynamics in this animal model of severe sepsis. Perfusion index as a marker for increased risk of bias was not a useful tool.
Collapse
Affiliation(s)
- Helmut D Hummler
- Division of Neonatology and Pediatric Critical Care, Department of Pediatrics, Children's Hospital, University of Ulm, 89070 Ulm, Germany.
| | | | | | | | | |
Collapse
|
19
|
Jauchem JR, Sherry CJ, Fines DA, Cook MC. Acidosis, lactate, electrolytes, muscle enzymes, and other factors in the blood of Sus scrofa following repeated TASER exposures. Forensic Sci Int 2005; 161:20-30. [PMID: 16289999 DOI: 10.1016/j.forsciint.2005.10.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 10/05/2005] [Accepted: 10/18/2005] [Indexed: 11/25/2022]
Abstract
Repeated exposure to electro-muscular incapacitating devices could result in repetitive, sustained muscle contraction, with little or no muscle recovery period. Therefore, rhabdomyolysis and other physiological responses, including acidosis, hyperkalaemia, and altered levels of muscle enzymes in the blood, would be likely to occur. Experiments were performed to investigate effects of repeated exposures of TASER International's Advanced TASER X26 on muscle contraction and resultant changes in blood factors in an anaesthetized swine model. A total of 10 animals were used. Six swine were exposed for 5 s, followed by a 5-s period of no exposure, repeatedly for 3 min. (In five of the animals, after a 1-h delay, a second 3-min exposure period was added.) The remaining four animals were used for an additional pilot study. All four limbs of each animal exhibited contraction even though the electrodes were positioned in areas at some distances from the limbs. The degree of muscle contraction generated during the second exposure period was significantly lower than that in the first exposure series. This finding was consistent with previous studies showing that prolonged activity in skeletal muscle will eventually result in a decline of force production. There were some similarities in blood sample changes in the current experiments with previous studies of muscular exercise. Thus problems concerning biological effects of repeated TASER exposures may be related, not directly to the "electric output" per se, but rather to the resulting contraction of muscles (and related interruption of respiration) and subsequent sequelae. Transient increases in hematocrit, potassium, and sodium were consistent with previous reports in the literature dealing with studies of muscle stimulation or exercise. It is doubtful that these short-term elevations would have any serious health consequences in a healthy individual. Blood pH was significantly decreased for 1h following exposure, but subsequently returned toward a normal level. Leg muscle contractions and decreases in respiration each appeared to contribute to the acidosis. Lactate was highly elevated, with a slow return (time course greater than 1 h) to baseline. Other investigators have reported profound metabolic acidosis during restraint-associated cardiac arrest. Since restraint often occurs immediately after TASER exposure, this issue should be considered in further development of deployment concepts. On the basis of the results of the current studies, the repeated use of electro-muscular incapacitating devices in a short period of time is, at least, feasible, with the caveat that some medical monitoring of subjects may be required (to observe factors such as lactate and acidosis).
Collapse
Affiliation(s)
- James R Jauchem
- Air Force Research Laboratory, Human Effectiveness Directorate, Directed Energy Bioeffects Division, Brooks City-Base, Texas 78235, USA.
| | | | | | | |
Collapse
|
20
|
Sola A, Chow L, Rogido M. Oximetría de pulso en la asistencia neonatal en 2005. Revisión de los conocimientos actuales. An Pediatr (Barc) 2005; 62:266-81. [PMID: 15737290 DOI: 10.1157/13071843] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- A Sola
- Division of Neonatal Perinatal Medicine, Emory University, Atlanta, GA 30322, USA.
| | | | | |
Collapse
|