Monitoring of extubated patients: are routine arterial blood gas measurements useful and how long should patients be monitored in the intensive care unit?

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.

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Practice guidelines for arterial blood gas measurement in the intensive care unit decreases numbers and increases appropriateness of tests

Journal of Cardiothoracic and Vascular Anesthesia ◽

10.1016/s1053-0770(98)90346-9 ◽

1998 ◽

Vol 12 (2) ◽

pp. 233-234

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Practice Guidelines ◽

Blood Gas ◽

Arterial Blood Gas ◽

Arterial Blood ◽

Gas Measurement

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Feasıbılıty of Transcutaneous Method for Carbon Dıoxıde Monıtorıng in an Intensive Care Unıt

Current Respiratory Medicine Reviews ◽

10.2174/1573398x18666220103113003 ◽

2022 ◽

Vol 18 ◽

Author(s):

Nazlıhan Boyacı ◽

Sariyya Mammadova ◽

Nurgül Naurizbay ◽

Merve Güleryüz ◽

Kamil İnci ◽

...

Keyword(s):

Carbon Dioxide ◽

Intensive Care Unit ◽

Intensive Care ◽

Partial Pressure ◽

Blood Gas ◽

Peripheral Oxygen Saturation ◽

Arterial Blood Gas ◽

Arterial Blood ◽

Randomized Controlled Studies ◽

Significant Difference

Background: Transcutaneous partial pressure of carbon dioxide (PtCO2) monitorization provides a continuous and non-invasive measurement of partial pressure of carbon dioxide (pCO2). In addition, peripheral oxygen saturation (SpO2) can also be measured and followed by this method. However, data regarding the correlation between PtCO2 and arterial pCO2 (PaCO2) measurements acquired from peripheric arterial blood gas is controversial. Objective: We aimed to determine the reliability of PtCO2 with PaCO2 based on its advantages, like non-invasiveness and continuous applicability. Methods: Thirty-five adult patients with hypercapnic respiratory failure admitted to our tertiary medical intensive care unit (ICU) were included. Then we compared PtCO2 and PaCO2 and both SpO2 measurements simultaneously. Thirty measurements from the deltoid zone and 26 measurements from the cheek zone were applied. Results: PtCO2 could not be measured from the deltoid region in 5 (14%) patients. SpO2 and pulse rate could not be detected at 8 (26.7%) of the deltoid zone measurements. Correlation coefficients between PtCO2 and PaCO2 from deltoid and the cheek region were r: 0,915 and r: 0,946 (p = 0,0001). In comparison with the Bland-Altman test, difference in deltoid measurements was -1,38 ± 1,18 mmHg (p = 0.252) and in cheek measurements it was -5,12 ± 0,92 mmHg (p = 0,0001). There was no statistically significant difference between SpO2 measurements in each region. Conclusion: Our results suggest that PtCO2 and SpO2 measurements from the deltoid region are reliable compared to the arterial blood gas analysis in hypercapnic ICU patients. More randomized controlled studies investigating the effects of different measurement areas, hemodynamic parameters, and hemoglobin levels are needed.

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Role of Arterial Blood Gas (ABG) as a valuable assessment tool of disease severity in SARS-CoV-2 patients

Journal of Medical Biochemistry ◽

10.5937/jomb0-30927 ◽

2021 ◽

Author(s):

Jyot Amrita

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Disease Severity ◽

Negative Correlation ◽

Assessment Tool ◽

Ionized Calcium ◽

Blood Gas ◽

Arterial Blood Gas ◽

Arterial Blood

Summary Background: COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus2 (SARS-CoV-2). The foremost predominant complication of SARS-CoV-2 is arterial hypoxemia thereby disturbing lung compliance, requiring mechanical ventilation. The aim of the current research study is to analyze role of ABG as a valuable assessment tool of disease severity in SARS-CoV-2 patients. Methods: 170 arterial blood samples were collected from patients admitted in Intensive Care Unit (ICU) of Sri Guru Ram Das Charitable Hospital, Amritsar. They were analyzed for arterial blood gas using ABG analyzer. Parameters of ABG such as pH, pCo2, HCO3, O2 saturation, ionized calcium (iCa) and calculated ionized calcium (at pH 7.4) was calculated for all the samples. Results: Continuous variables were described as medians with interquartile ranges (IQRs) and categorical variables as percentages and frequencies. Spearman correlation test was done for calculation of correlation between pH and other ABG parameters. Analysis of arterial blood gas revealed significant negative correlation (p<0.05) between pH and pCO2 and significant positive correlation (p<0.05) between pH and HCO3 and between pH and delta ionized calcium. Low levels (98.2%) of ionized calcium were observed while monitoring the ABG findings though weak negative correlation (p<0.05) was observed between pH and iCa. Conclusion: Our study suggests that ABG analysis acts as a momentous indicator for critically ill patients admitted in Intensive Care Unit (ICU). Estimation of iCa in this critical care setting acts as a distinctive biochemical feature of SARS-CoV-2 disease, as an initial assessment tool, for hypocalcemia. Keywords: Arterial Blood Gas, SARS-CoV-2, Ionized Calcium, Hypocalcemia

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