Influence of G-suit abdominal bladder inflation on gas exchange during +GZ stress

1985 ◽  
Vol 58 (2) ◽  
pp. 506-513
Author(s):  
H. I. Modell ◽  
P. Beeman ◽  
J. Mendenhall

Available data relating duration of +GZ stress to blood gas exchange status is limited. Furthermore, studies focusing on pulmonary gas exchange during +GZ stress when abdominal restriction is imposed have yielded conflicting results. To examine the time course of blood gas changes occurring during exposure to +GZ stress in dogs and the influence of G-suit abdominal bladder inflation on this time course, seven spontaneously breathing pentobarbital-anesthetized adult mongrel dogs were exposed to 60 s of up to +5 GZ stress with and without G-suit abdominal bladder inflation. Arterial and mixed venous blood were sampled for blood gas analysis during the first and last 20 s of the exposure and at 3 min postexposure. Little change in blood gas status was seen at +3 GZ regardless of G-suit status. However, with G-suit inflation, arterial PO2 fell by a mean of 14.7 Torr during the first 20 s at +4 Gz (P less than 0.01, t test) and 20.6 Torr at +5 GZ (P less than 0.01). It continued to fall an additional 10 Torr during the next 40 s at both +4 and +5 GZ. Arterial PO2 was still 5–10 Torr below control values (P less than 0.05) 3 min postexposure. A second series of experiments paralleling the first focused on blood gas status during repeated exposure to acceleration. Blood gas status was assessed in five dogs during the late 20 s of two 60-s exposures separated by 3 min at 0 GZ. No significant differences between the initial and repeated exposures were detected. The data indicate that G-suit abdominal bladder inflation promotes increased venous admixture.

1990 ◽  
Vol 70 (5) ◽  
pp. 523???529 ◽  
Author(s):  
Adrianus Trouwborst ◽  
Rob Tenbrinck ◽  
Elisabeth C.S.M. van Woerkens

1995 ◽  
Vol 79 (6) ◽  
pp. 1951-1957 ◽  
Author(s):  
S. Deem ◽  
M. J. Bishop ◽  
M. K. Alberts

To elucidate the effects of anemia on intrapulmonary shunt, we studied a model of left lung atelectasis in anesthetized rabbits. In 10 rabbits, isovolemic anemia was produced by sequential hemodilution. Seven control rabbits were followed over time, without hemodilution. Intrapulmonary shunt (Qs/QT) was measured by using blood gas analysis and by quantitation of the percentage of blood flow to the collapsed left lung (QLl/QT) using fluorescent microspheres. In control rabbits, Qs/QT and QLl/QT decreased over time, whereas arterial PO2 increased. In hemodiluted rabbits, there was a trend toward increased Qs/QT and QLl/QT. There were significant differences in the behavior of Qs/QT, QLl/QT, and arterial PO2 between control and hemodiluted rabbits. Hemodynamic parameters, including cardiac output and pulmonary artery pressure, were not different between groups. In a third group of rabbits with pharmacologically induced acidosis but no hemodilution, Qs/QT and QLl/QT decreased over time, and arterial PO2 increased. We conclude that acute isovolemic anemia has a deleterious effect on pulmonary gas exchange, possibly through attenuation of hypoxic pulmonary vasoconstriction.


2018 ◽  
Vol 29 (1) ◽  
pp. 169-172
Author(s):  
Gian Luca Salvagno ◽  
Davide Demonte ◽  
Giuseppe Lippi

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.


2019 ◽  
Vol 47 ◽  
Author(s):  
Mariana Andrade Mousquer ◽  
Vitória Müller ◽  
Fernanda Maria Pazinato ◽  
Bruna Dos Santos Suñe Moraes ◽  
Leandro Américo Rafael ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document