High altitude arterialised capillary earlobe blood gas measurement using the Abbott i-STAT

2018 ◽  
Vol 164 (5) ◽  
pp. 335-337 ◽  
Author(s):  
Christopher T Lewis ◽  
W L Malein ◽  
I Chesner ◽  
S Clarke
Keyword(s):  
Partial Pressure ◽  
High Altitude ◽  
Point Of Care ◽  
Extreme Environments ◽  
Blood Gases ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Clinical Environment ◽  
Gas Measurements

IntroductionMeasurement of physiological parameters in extreme environments is essential to advancing knowledge, prophylaxis and treatment of altitude sickness. Point-of-care testing facilitates investigation in non-specialist and remote settings, as well as becoming increasingly popular at the bedside for real-time results in the clinical environment. Arterialised capillary earlobe blood gases are recommended as a valid alternative to arterial sampling in research. This study aimed to test the feasibility of obtaining and analysing daily earlobe samples at high altitude.MethodsFrom 17 to 24 January 2016, 24 participants on a research expedition to Ecuador underwent daily earlobe blood gas measurements including pH, partial pressure of oxygen and partial pressure of carbon dioxide to 5043 m. Samples were analysed using an Abbott i-STAT blood gas analyser and G3+ cartridges.ResultsDaily measurements were successfully obtained and analysed at the point of care in 23/24 participants and were well tolerated with no adverse events. 12% (27/220) cartridges failed and required repeat sampling.ConclusionsDaily earlobe blood gas analysis using the Abbott i-STAT is feasible in a protected environment at high altitude. Participants and equipment should be kept warm before and during testing. Spare cartridges should be available. This methodology may be useful for both research and therapeutic measurements in remote, rural and wilderness medicine.

StatPal II pH and Blood Gas Analysis System evaluated

1994 ◽  
Vol 40 (1) ◽  
pp. 124-129 ◽  
Author(s):  
R J Wong ◽  
J J Mahoney ◽  
J A Harvey ◽  
A L Van Kessel
Keyword(s):  
Point Of Care ◽  
Blood Gases ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Portable Instrument ◽  
Blood Gas ◽  
Target Value ◽  
Analysis System

Abstract We evaluated a new portable instrument, the PPG StatPal II pH and Blood Gas Analysis System, designed for "point-of-care" measurements of blood gases and pH. Inaccuracy (% of target value) and imprecision (CV%) were assessed by blood tonometry and comparison with a Corning 178. Within-day results for PCO2 inaccuracy and imprecision ranged from 98.2% to 102.9% and 3.3% to 3.9%, respectively; for PO2, these were 95.5% to 102.3% and 2.3% to 3.0%, respectively. Between-day results for PCO2 inaccuracy and imprecision ranged from 99.2% to 99.3% and from 2.9% to 3.2%, respectively; for PO2, the ranges were 96.2% to 98.2% and 2.6% to 3.0%, respectively. Two PCO2 outliers (in 645 samples = 0.3%) were observed. In general, tonometry recovery, measurement stability, and pH bias results for the StatPal II and Corning 178 were comparable. We conclude that the StatPal II performs within acceptable ranges of inaccuracy and imprecision.

Blood gas measurements during exercise: errors due to temperature correction

1989 ◽  
Vol 67 (2) ◽  
pp. 879-884 ◽  
Author(s):  
J. H. Jones ◽  
C. R. Taylor ◽  
A. Lindholm ◽  
R. Straub ◽  
K. E. Longworth ◽  
...  
Keyword(s):  
Blood Gases ◽  
Blood Gas Analysis ◽  
Temperature Correction ◽  
Gas Analysis ◽  
Blood Gas ◽  
Degree Of Dissociation ◽  
Pulmonary Arterial ◽  
Gas Measurements ◽  
Body Compartments ◽  
Biased Estimates

This study assessed the degree to which correcting blood gas measurements to rectal temperature (Tre) rather than to the temperatures at which gas exchange occurs [pulmonary arterial (Tpa) or intramuscular (Tm)] introduces errors into blood gas analysis of exercising mammals. Horses and steers weighing 450 kg were run on a treadmill at speeds up to those eliciting maximal rates of O2 consumption (VO2max), and temperatures were measured in various body compartments. In both species Tpa rose faster than Tre during the run, the degree of dissociation being a function of exercise intensity and duration. Tm was measured only in horses, and it rose faster than Tpa during the run and decreased more slowly postrun. Correcting blood gas values measured at an analyzer temperature of 37 degrees C to Tre without accounting for transient increases during the run of Tpa and Tm that were never reflected in Tre significantly biased estimates of blood gases. The biased estimates erroneously indicated that both species experienced more severe hypoxemia than they actually did at VO2max and masked the hypercapnia experienced by the horses at VO2max.

scholarly journals Be cautious during the interpretation of arterial blood gas analysis performed outside the intensive care unit

2020 ◽  
Author(s):  
Lukasz Krzych ◽  
Olga Wojnarowicz ◽  
Paweł Ignacy ◽  
Julia Dorniak
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Point Of Care ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Acid Base Balance ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Impact

Introduction. Reliable results of an arterial blood gas (ABG) analysis are crucial for the implementation of appropriate diagnostics and therapy. We aimed to investigate the differences (Δ) between ABG parameters obtained from point-of-care testing (POCT) and central laboratory (CL) measurements, taking into account the turnaround time (TAT). Materials and methods. A number of 208 paired samples were collected from 54 intensive care unit (ICU) patients. Analyses were performed using Siemens RAPIDPoint 500 Blood Gas System on the samples just after blood retrieval at the ICU and after delivery to the CL. Results. The median TAT was 56 minutes (IQR 39-74). Differences were found for all ABG parameters. Median Δs for acid-base balance ere: ΔpH=0.006 (IQR –0.0070–0.0195), ΔBEef=–0.9 (IQR –2.0–0.4) and HCO3–act=–1.05 (IQR –2.25–0.35). For ventilatory parameters they were: ΔpO2=–8.3 mmHg (IQR –20.9–0.8) and ΔpCO2=–2.2 mmHg (IQR –4.2––0.4). For electrolytes balance the differences were: ΔNa+=1.55 mM/L (IQR 0.10–2.85), ΔK+=–0.120 mM/L (IQR –0.295–0.135) and ΔCl–=1.0 mM/L (IQR –1.0–3.0). Although the Δs might have caused misdiagnosis in 51 samples, Bland-Altman analysis revealed that only for pO2 the difference was of clinical significance (mean: –10.1 mmHg, ±1.96SD –58.5; +38.3). There was an important correlation between TAT and ΔpH (R=0.45, p<0.01) with the safest time delay for proper assessment being less than 39 minutes. Conclusions. Differences between POCT and CL results in ABG analysis may be clinically important and cause misdiagnosis, especially for pO2. POCT should be advised for ABG analysis due to the impact of TAT, which seems to be the most important for the analysis of pH.

scholarly journals A paradigmatic case of haemolysis and pseudohyperkalemia in blood gas analysis

2018 ◽  
Vol 29 (1) ◽  
pp. 169-172
Author(s):  
Gian Luca Salvagno ◽  
Davide Demonte ◽  
Giuseppe Lippi
Keyword(s):  
Reference Range ◽  
Point Of Care ◽  
Venous Blood ◽  
Blood Gas Analysis ◽  
Plasma Potassium ◽  
Gas Analysis ◽  
Blood Gas ◽  
High Potassium ◽  
Plastic Tube ◽  
History Of

A 51-year old male patient was admitted to the hospital with acute dyspnea and history of chronic asthma. Venous blood was drawn into a 3.0 mL heparinized syringe and delivered to the laboratory for blood gas analysis (GEM Premier 4000, Instrumentation Laboratory), which revealed high potassium value (5.2 mmol/L; reference range on whole blood, 3.5-4.5 mmol/L). This result was unexpected, so that a second venous blood sample was immediately drawn by direct venipuncture into a 3.5 mL lithium-heparin blood tube, and delivered to the laboratory for repeating potassium testing on Cobas 8000 (Roche Diagnostics). The analysis revealed normal plasma potassium (4.6 mmol/L; reference range in plasma, 3.5-5.0 mmol/L) and haemolysis index (5; 0.05 g/L). Due to suspicion of spurious haemolysis, heparinized blood was transferred from syringe into a plastic tube and centrifuged. Potassium and haemolysis index were then measured in this heparinized plasma, confirming high haemolysis index (50; 0.5 g/L) and pseudohyperkalemia (5.5 mmol/L). Investigation of this case revealed that spurious haemolysis was attributable to syringe delivery in direct ice contact for ~15 min. This case emphasizes the importance of avoiding sample transportation in ice and the need of developing point of care analysers equipped with interference indices assessment.

scholarly journals Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

Breathe ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Julie-Ann Collins ◽  
Aram Rudenski ◽  
John Gibson ◽  
Luke Howard ◽  
Ronan O’Driscoll
Keyword(s):  
Oxygen Saturation ◽  
Partial Pressure ◽  
Pulse Oximetry ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Oxygen Dissociation Curve ◽  
Blood Gas ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Relationship

Key PointsIn clinical practice, the level of arterial oxygenation can be measured either directly by blood gas sampling to measure partial pressure (PaO2) and percentage saturation (SaO2) or indirectly by pulse oximetry (SpO2).This review addresses the strengths and weaknesses of each of these tests and gives advice on their clinical use.The haemoglobin–oxygen dissociation curve describing the relationship between oxygen partial pressure and saturation can be modelled mathematically and routinely obtained clinical data support the accuracy of a historical equation used to describe this relationship.Educational AimsTo understand how oxygen is delivered to the tissues.To understand the relationships between oxygen saturation, partial pressure, content and tissue delivery.The clinical relevance of the haemoglobin–oxygen dissociation curve will be reviewed and we will show how a mathematical model of the curve, derived in the 1960s from limited laboratory data, accurately describes the relationship between oxygen saturation and partial pressure in a large number of routinely obtained clinical samples.To understand the role of pulse oximetry in clinical practice.To understand the differences between arterial, capillary and venous blood gas samples and the role of their measurement in clinical practice.The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (SO2) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

Blood Gas Analysis and the Fundamentals of Acid-Base Balance

2009 ◽  
Vol 28 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Mary Farmand
Keyword(s):  
Systematic Approach ◽  
Blood Gases ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Acid Base Balance ◽  
Bedside Nurse ◽  
Acid Base ◽  
Neonatal Nursing ◽  
Base Balance

UNDERSTANDING BLOOD GAS values and acid-base balance are fundamental skills of neonatal nursing. This is because, in the NICU, blood gases are probably ordered more than any other laboratory test. The bedside nurse not only obtains the specimen, but is also crucially involved in interpreting the results because blood gases cannot stand alone; they need to be evaluated in the context of the entire clinical picture. This article provides basic information on the components of a blood gas, acid-base balance, as well as a systematic approach to blood gas analysis.

scholarly journals Gestation in a Mare with Facial Deviation (Wry Nose)

2019 ◽  
Vol 47 ◽  
Author(s):  
Mariana Andrade Mousquer ◽  
Vitória Müller ◽  
Fernanda Maria Pazinato ◽  
Bruna Dos Santos Suñe Moraes ◽  
Leandro Américo Rafael ◽  
...  
Keyword(s):  
Fetal Development ◽  
Post Partum ◽  
Venous Blood ◽  
Respiratory Acidosis ◽  
Blood Gases ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Aorta Diameter ◽  
Uterine Body

Background: Wry nose is a congenital deformity that causes respiratory obstruction and decreased oxygenation rate. Gestation in a wry nose mare may be considered a risk to the neonate since it depends on the maternal environment for development. Compromised oxygenation during pregnancy can lead to fetal distress and cause consequences on fetal development. However, depending on the degree of the impairment, the fetus may still be able to adapt. The aim of the present study was to report the gestation in a mare with facial deviation until term and to assess blood gases in the mare and neonate, and to evaluate the histomorphometry of the placenta.Case: A Criollo breed mare presenting facial deviation (Wry Nose) was donated to Equine Medicine Research Group (ClinEq) of the Federal University of Pelotas (UFPel) due to the presence of the physical deformity. When the mare was five years old, it was inseminated and had a pregnancy confirmed. At the fifth month of gestation, evaluation of fetal aorta diameter, fetal orbital diameter and combined thickness of the uterus and placenta (CTUP) started to be performed monthly to assess gestation health. The assessment of the fetal orbit and aorta diameter revealed a linear increase of both variables with the progress of gestation indicating a normal fetal development.  CTUP remained in the normal reference range, presenting no alterations during the gestational length. The mare foaled at 324 days of gestation a coat showing no congenital deformities. The foaling was monitored until the complete passage of fetal membranes. A complete clinical and hematological evaluation of the foal was carried out after birth. The foal showed normal adaptive behavior, clinical and hematological parameters during the first hours of life, although presenting physical signs of immaturity. Venous blood samples were collected from the mare at 315 days of gestation, immediately after foaling and 24 h post-partum for lactate and blood gas analysis.  Mild changes were observed in the mare’s blood gas analysis at foaling that were compensated within 24 h post-partum. Venous blood samples were collected from the umbilical cord and from the foal after birth, at 12 and 24 h post-partum to measure blood gases and lactate. The newborn foal presented respiratory acidosis immediately after birth, which was metabolically compensated at 24 h post-partum. Both mare’s and foal’s lactate evaluation were within the normal reference ranges. After expulsion of the placenta, samples from the gravid horn, uterine body and non-gravid horn were collected for histological and histomorphometric evaluation. In the histological evaluation, avillous areas were detected in the gravid horn and uterine body and mild hypoplasia was found in the uterine body. Placental histomorphometry revealed larger total microcotiledonary and capillary areas on the non-gravid horn when compared to the remaining areas of the placenta (gravid horn and uterine body). No abnormalities on the placental vasculature were detected.  Discussion: To date, there are no reports of a pregnancy in a mare with facial deviation in the literature. This report showed that the wry nose mare gave birth to a viable foal showing no congenital abnormalities, which suggests that wry nose animals can be bred normally. The mare presented a healthy pregnancy, with mild changes in the blood gas analysis at foaling that were compensated at 24 h postpartum. Similarly, despite the foal showed physical signs of immaturity and respiratory acidosis at birth, these changes were compensated in the later assessments. Furthermore, no abnormalities on the placental vasculature were detected.

23 NEONATAL SUPPORT THERAPY AND BLOOD GAS EVALUATION IN CLONED AND ARTIFICIAL INSEMINATION-DERIVED NEWBORN CALVES

2015 ◽  
Vol 27 (1) ◽  
pp. 104
Author(s):  
P. Fantinato-Neto ◽  
A. T. Zanluchi ◽  
M. M. Yasuoka ◽  
F. J. M. Marchese ◽  
J. R. V. Pimentel ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Point Of Care ◽  
Respiratory Acidosis ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Oxygenation ◽  
Blood Gas ◽  
Acid Base Balance ◽  
Reproductive Techniques ◽  
Newborn Calves

Offspring derived from artificial reproductive techniques are already known to present several postnatal undesirable phenotypes and clinical disorders. Despite its benefits, cloning by somatic cell nuclear transfer (SCNT) is extremely inefficient. The birth rate in cattle is around 5% of the transferred blastocysts, and ~50% of delivered calves die in the first 48 h. Neonatal respiratory distress is reported to be one of the main causes of such deaths. Veterinary intervention is often needed to promote or improve blood oxygenation, avoiding respiratory acidosis and improving carbon dioxide delivery from blood/lungs to the environment. This study aimed to evaluate a neonatal support therapy over the blood gas and acid-base balance on newborn calves derived from SCNT or AI. Four cloned and 3 AI-derived calves delivered by Caesarean section were used for the experiment. Postnatal therapeutic procedures were comprised 4 doses of 400 mg of intratracheal surfactant every 15 min, 25 mg of oral sildenafil every 8 h for 3 days, and 5 L min–1 intranasal oxygen. Blood collections were performed within 30 min (T0), at 12 (T12), 24 (T24) and 48 (T48) hours after delivery. Blood samples were collected from the caudal auricular artery with a butterfly and a blood gas syringe. Oxygen saturation (sO2), arterial pressure of oxygen (PaO2) and carbon dioxide (PaCO2), pH, and bicarbonate (HCO3–) were evaluated with a portable blood gas analyzer (i-STAT, Abbott Point of Care Inc., Princeton, NJ, USA). Data obtained were submitted to ANOVA (Proc MIXED; SAS/STAT, version 9; SAS Institute Inc., Cary, NC, USA). There were significant differences between groups in blood pH (P = 0.0182) and between groups (P = 0.0281) and time of collection (P = 0.0303) in blood bicarbonate (HCO3–). The AI calves were born with normal pH (7.468 ± 0.033) and the cloned calves were born in acidosis (7.216 ± 0.166). These calves were stabilised in T48 (7.427 ± 0.017) using their own HCO3– that increased over time. Although there were no differences in sO2 (P = 0.4525), PaO2 (P = 0.3086), or PaCO2 (P = 0.2514), sO2 and PaO2 were numerically increased at the same time that PaCO2 decreased in both groups. In the cloned calves, the sO2, PaO2, and PaCO2 at T0 were 61.3 ± 28.6%, 39.8 ± 18.5 mmHg, and 65.8 ± 29.3 mmHg, respectively and reached 90.0 ± 3.4%, 57.7 ± 15.8 mmHg, and 42.0 ± 3.7 mmHg. In the AI calves, T0 blood gas analysis were 79.8 ± 19.4%, 56.1 ± 42.1 mmHg, and 39.1 ± 4.8 mmHg, and at T48 were 89.0 ± 2.6%, 82.3 ± 43.5 mmHg, and 43.0 ± 4.9 mmHg for sO2, PaO2, and PaCO2 respectively. The neonate support therapy improved calves' oxygenation and helped to eliminate the carbon dioxide from the blood. In our experience, the neonatal treatment was essential in supporting the lives of the cloned calves.Funding support was received from FAPESP 2011/19543–9.

scholarly journals Comparing the Liquid Heparin Syringe with Dry Bound Heparin Syringe for Blood Gas Analysis

2019 ◽  
Vol 3 (02) ◽  
pp. 059-067
Author(s):  
Manoj Kumar Sahu ◽  
Seshagiribabu Yagani ◽  
Dharmraj Singh ◽  
Umed Singh ◽  
Sarvesh Pal Singh ◽  
...  
Keyword(s):  
Intensive Care ◽  
Partial Pressure ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Surgical Patients ◽  
Arterial Oxygen ◽  
Surgical Intensive Care Unit ◽  
Blood Gas ◽  
Surgical Intensive Care ◽  
Accurate Analysis

Abstract Background Blood gas (BG) analysis is routine today for patient management in intensive care units. Accurate analysis of different parameters in the BG is essential for managing critical patients. Errors in BG analysis can happen at many levels, with one of them being at sampling and heparinization. We compared self-prepared heparinized syringes rinsed with liquid heparin (LH) and the standard commercially available syringes with dry bound heparin (DBH) for arterial BG analysis of postoperative cardiac surgical patients. Methods This prospective observational study was conducted in 100 consecutive adult cardiac surgical patients in the cardiac surgical intensive care unit. Paired samples were collected, analyzed immediately, and statistically compared for pH, partial pressure of arterial oxygen (pO2), partial pressure of arterial carbon dioxide (pCO2), oxyhemoglobin saturation (SaO2), HCO, Na+, K+, Cl–, Ca2+, Mg2+, base excess (BE), hemoglobin (Hb), hematocrit, glucose, and lactate. Paired parameters were compared and agreement was evaluated using Bland–Altman difference plots. The 95% limits of absolute agreement (LOA) were compared with total allowable error (TEa). Results The BG parameters analyzed by two types of heparinized (LH and DBH) syringes were found to be comparable with a negligible mean difference and had an agreement outside the TEa of 8% for pO2, pCO2, and hematocrit, 7% for BE, 6% for Mg2+, 5% for K+, Ca2+, and lactate, 4% for HCOand Na+, 3% for pH, Cl–, Hb, and glucose, and zero for SaO2. The two types of syringes did not show clinically relevant discrepancies among many different parameters as per LOA and TEa limits. Conclusion In this study, we found that the BG parameters—respiratory, metabolic, and electrolytes—were comparable between the two types of syringes used for sampling. Unlike some previous studies, we did not find statistically significant differences among these analytes, which might have been due to appropriate self-preparation of heparin syringes.

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