scholarly journals Peripheral microcirculatory alterations are associated with the severity of acute respiratory distress syndrome in COVID-19 patients admitted to intermediate respiratory and intensive care units

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Jaume Mesquida ◽  
A. Caballer ◽  
L. Cortese ◽  
C. Vila ◽  
U. Karadeniz ◽  
...  
Keyword(s):  
Intensive Care ◽  
Oxygen Saturation ◽  
Intensive Care Units ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Invasive Mechanical Ventilation ◽  
Endothelial Damage ◽  
Arterial Oxygen ◽  
Blood Oxygen Saturation

Abstract Background COVID-19 is primarily a respiratory disease; however, there is also evidence that it causes endothelial damage in the microvasculature of several organs. The aim of the present study is to characterize in vivo the microvascular reactivity in peripheral skeletal muscle of severe COVID-19 patients. Methods This is a prospective observational study carried out in Spain, Mexico and Brazil. Healthy subjects and severe COVID-19 patients admitted to the intermediate respiratory (IRCU) and intensive care units (ICU) due to hypoxemia were studied. Local tissue/blood oxygen saturation (StO2) and local hemoglobin concentration (THC) were non-invasively measured on the forearm by near-infrared spectroscopy (NIRS). A vascular occlusion test (VOT), a three-minute induced ischemia, was performed in order to obtain dynamic StO2 parameters: deoxygenation rate (DeO2), reoxygenation rate (ReO2), and hyperemic response (HAUC). In COVID-19 patients, the severity of ARDS was evaluated by the ratio between peripheral arterial oxygen saturation (SpO2) and the fraction of inspired oxygen (FiO2) (SF ratio). Results Healthy controls (32) and COVID-19 patients (73) were studied. Baseline StO2 and THC did not differ between the two groups. Dynamic VOT-derived parameters were significantly impaired in COVID-19 patients showing lower metabolic rate (DeO2) and diminished endothelial reactivity. At enrollment, most COVID-19 patients were receiving invasive mechanical ventilation (MV) (53%) or high-flow nasal cannula support (32%). Patients on MV were also receiving sedative agents (100%) and vasopressors (29%). Baseline StO2 and DeO2 negatively correlated with SF ratio, while ReO2 showed a positive correlation with SF ratio. There were significant differences in baseline StO2 and ReO2 among the different ARDS groups according to SF ratio, but not among different respiratory support therapies. Conclusion Patients with severe COVID-19 show systemic microcirculatory alterations suggestive of endothelial dysfunction, and these alterations are associated with the severity of ARDS. Further evaluation is needed to determine whether these observations have prognostic implications. These results represent interim findings of the ongoing HEMOCOVID-19 trial. Trial registration ClinicalTrials.gov NCT04689477. Retrospectively registered 30 December 2020.

scholarly journals Association between Regional Tissue Oxygenation and Body Temperature in Term and Preterm Infants Born by Caesarean Section

Children ◽  
2020 ◽  
Vol 7 (11) ◽  
pp. 205
Author(s):  
Marlies Bruckner ◽  
Lukas P. Mileder ◽  
Alisa Richter ◽  
Nariae Baik-Schneditz ◽  
Bernhard Schwaberger ◽  
...  
Keyword(s):  
Body Temperature ◽  
Caesarean Section ◽  
Oxygen Saturation ◽  
Preterm Infants ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Secondary Outcome ◽  
Tissue Oxygen Saturation ◽  
Preterm Neonates

Body temperature (BT) management remains a challenge in neonatal intensive care, especially during resuscitation after birth. Our aim is to analyze whether there is an association between the BT and cerebral and peripheral tissue oxygen saturation (crSO2/cTOI and prSO2), arterial oxygen saturation (SpO2), and heart rate (HR). The secondary outcome parameters of five prospective observational studies are analyzed. We include preterm and term neonates born by Caesarean section who received continuous pulse oximetry and near-infrared spectroscopy monitoring during the first 15 min, and a rectal BT measurement once in minute 15 after birth. Four-hundred seventeen term and 169 preterm neonates are included. The BT did not correlate with crSO2/cTOI and SpO2. The BT correlated with the HR in all neonates (ρ = 0.210, p < 0.001) and with prSO2 only in preterm neonates (ρ = −0.285, p = 0.020). The BT was lower in preterm compared to term infants (36.7 [36.4–37.0] vs. 36.8 [36.6–37.0], p = 0.001) and prevalence of hypothermia was higher in preterm neonates (29.5% vs. 12.0%, p < 0.001). To conclude, the BT did not correlate with SpO2 and crSO2/cTOI, however, there was a weak positive correlation between the BT and the HR in the whole cohort and a weak correlation between the BT and prSO2 only in preterm infants. Preterm neonates had a statistically lower BT and suffered significantly more often from hypothermia during postnatal transition.

Investigating spectroscopic measurement of sublingual veins and tissue to estimate central venous oxygen saturation

2021 ◽  
pp. 1-9
Author(s):  
Aslinur Sircan-Kucuksayan ◽  
Oktay Eray ◽  
Murat Buyukaksu ◽  
Birce Gumus ◽  
Oguz Dursun ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Central Venous Oxygen Saturation ◽  
Arterial Oxygen ◽  
Central Venous ◽  
Venous Oxygen Saturation ◽  
Oxygenation Status

BACKGROUND: Venous oxygen saturation reflects venous oxygenation status and can be used to assess treatment and prognosis in critically ill patients. A novel method that can measure central venous oxygen saturation (ScvO2) non-invasively may be beneficial and has the potential to change the management routine of critically ill patients. OBJECTIVE: The study aims to evaluate the potential of sublingual venous oxygen saturation (SsvO2) to be used in the estimation of ScvO2. METHODS: We have developed two different approaches to calculate SsvO2. In the first one, near-infrared spectroscopy (NIRS) measurements were performed directly on the sublingual veins. In the second approach, NIRS spectra were acquired from the sublingual tissue apart from the sublingual veins, and arterial oxygen saturation was measured using a pulse oximeter on the fingertip. RESULTS: Twenty-six healthy subjects were included in the study. In the first and second approaches, average SsvO2 values were 75.0% ± 1.8 and 75.8% ± 2.1, respectively. The results of the two different approaches were close to each other and similar to ScvO2 of healthy persons (> 70%). CONCLUSION: Oxygen saturation of sublingual veins has the potential to be used in intensive care units, non-invasively and in real-time, to estimate ScvO2.

Quantification of adult cerebral hemodynamics by near-infrared spectroscopy

1994 ◽  
Vol 77 (6) ◽  
pp. 2753-2760 ◽  
Author(s):  
C. E. Elwell ◽  
M. Cope ◽  
A. D. Edwards ◽  
J. S. Wyatt ◽  
D. T. Delpy ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Cerebral Hemodynamics ◽  
Arterial Oxygen ◽  
The Mean

Near-infrared spectroscopy was used to measure global cerebral blood flow and volume in 10 healthy adult volunteers. High- and low-cerebral blood flow compartments were detected with mean flows for all 10 subjects of 59 +/- 21 (SD) and 11 +/- 4 ml.100 g-1.min-1, respectively. The mean cerebral blood volume of the group was 2.85 +/- 0.97 ml/100 g. Analysis of spontaneous changes in the cerebral concentrations of oxyhemoglobin and deoxyhemoglobin demonstrated strong correlations between respiratory rate and the oscillation frequency of cerebral oxyhemoglobin concentration (r = 0.99) and arterial oxygen saturation (SaO2) (r = 0.99). An estimate of the mean cerebral oxygen saturation for all subjects averaged 59.4 +/- 12.4% when their mean SaO2 was 91.8 +/- 2.4% (equivalent to 67.6 +/- 13.8% at a normoxic SaO2 of 98%). These results demonstrate that near-infrared spectroscopy can be used as a noninvasive bedside technique for both qualitative and quantitative evaluation of cerebral hemodynamics and oxygenation in adults.

Pilot study of cerebral and somatic autoregulation using NIRS in preterm neonates

2021 ◽  
pp. 1-8
Author(s):  
T.M. Traub ◽  
R. Grabowski ◽  
K. Rais-Bahrami
Keyword(s):  
Pilot Study ◽  
Oxygen Saturation ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Severity Of Illness ◽  
Arterial Oxygen ◽  
Tissue Oxygen Saturation ◽  
Preterm Neonates ◽  
Arterial Access ◽  
Arterial Blood

Background: As neonates transition from a relatively hypoxic environment to extra-uterine life, arterial oxygen saturation dramatically increases. This transition occurs while most organs have not fully matured. The ability for immature tissue to adequately extract and utilize oxygen remains largely unknown. With the development of near-infrared spectroscopy (NIRS), measuring specific tissue oxygen saturation (StO2) noninvasively, clinicians can measure StO2 and determine if adequate tissue oxygenation is maintained. The objective of this study is to determine the relationships of NIRS brain and somatic autoregulation function to patients’ severity of illness. Methods: In this prospective cohort pilot study, after parental consent, neonates less than 34 weeks with arterial access, were enrolled. The FORE-SIGHT NIRS probe was placed on the forehead and abdominal wall for 24 hours. Continuous arterial blood pressure, SpO2 and cerebral and somatic NIRS were used to derive autoregulation function. Results: Data was obtained from 17 neonates (0.540 to 2.37 kg, gestation 23.0 to 33.2 weeks). The autoregulation function categorizes pressure passive index (PPI) values as good, borderline, or poor. For normal autoregulation function, PPI values tend to be low and fairly constant for a range of MAP. The PPI borderline zone is a hypothetical range of PPI values where autoregulation function transitions from good to poor. Conclusion: Our results show most premature neonates, as long as they maintained normal BP and systemic circulation can autoregulate cerebral perfusion. When BP are above or below the normal MAP for age, the neonate is at risk for losing brain and somatic autoregulation.

Arterial and Venous Contributions to Near-infrared Cerebral Oximetry

2000 ◽  
Vol 93 (4) ◽  
pp. 947-953 ◽  
Author(s):  
H. Marc Watzman ◽  
C. Dean Kurth ◽  
Lisa M. Montenegro ◽  
Jonathan Rome ◽  
James M. Steven ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Frequency Domain ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Fixed Ratio ◽  
Cerebral Oximetry ◽  
Infrared Light ◽  
Arterial Oxygen

Background Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. Methods Twenty anesthetized children aged &lt; 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. Results Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). Conclusions Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.

Sign in / Sign up

Export Citation Format

Share Document