Effects of fetal-maternal exchange transfusion on fetal oxygenation and blood flow distribution

1984 ◽  
Vol 247 (4) ◽  
pp. H655-H660 ◽  
Author(s):  
J. Itskovitz ◽  
B. W. Goetzman ◽  
C. Roman ◽  
A. M. Rudolph
Keyword(s):  
Blood Flow ◽  
Exchange Transfusion ◽  
Venous Blood ◽  
Flow Distribution ◽  
Blood Gases ◽  
Maternal Blood ◽  
Organ Blood Flow ◽  
Fetal Life ◽  
Fetal Blood ◽  
Fetal Oxygenation

The effect of reducing hemoglobin affinity for O2 on fetal oxygenation was assessed in seven fetal lambs in which fetal blood was almost completely replaced by maternal blood 2-3 days postoperatively. Measurements of fetal blood gases and organ blood flow (radionuclide-labeled microsphere technique) were obtained before and 1 h after the exchange transfusion. Umbilical venous blood PO2 increased from 29 +/- 5 to 35 +/- 6 (SD) Torr (P less than 0.001) but hemoglobin O2 saturation decreased from 78.2 +/- 10.3 to 39.8 +/- 8.8% (P less than 0.001), resulting in a 46% decrease in umbilical venous blood O2 content. Since umbilical-placental blood flow also decreased (P less than 0.002), O2 delivery to the fetus decreased by 64% (P less than 0.002). Although O2 extraction increased from 32.5 +/- 6.8 to 50.9 +/- 9.0% (P less than 0.002), fetal O2 consumption fell from 7.28 +/- 1.97 to 4.10 +/- 1.20 ml X min-1 X kg-1 (P less than 0.02), and metabolic acidemia developed. No significant change in fetal cardiac output was observed. Blood flow increased significantly to the myocardium and adrenals but fell in the placenta, carcass, and lungs and was maintained in other organs. This resulted in a significant decrease in the amount of O2 delivered to all fetal organs except to the myocardium in which it was maintained. In the sheep the higher affinity of fetal blood hemoglobin for O2 helps maintain normal oxygenation during fetal life by facilitating O2 uptake at the placenta and unloading O2 in the tissues.

scholarly journals The Contribution of Arterial Blood Gases in Cerebral Blood Flow Regulation and Fuel Utilization in Man at High Altitude

2015 ◽  
Vol 35 (5) ◽  
pp. 873-881 ◽  
Author(s):  
Christopher K Willie ◽  
David B MacLeod ◽  
Kurt J Smith ◽  
Nia C Lewis ◽  
Glen E Foster ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
High Altitude ◽  
Cerebral Metabolism ◽  
Venous Blood ◽  
Blood Gases ◽  
Cerebrovascular Reactivity ◽  
Arterial Blood Gases ◽  
Arterial Blood ◽  
Cerebrovascular Function

The effects of partial acclimatization to high altitude (HA; 5,050 m) on cerebral metabolism and cerebrovascular function have not been characterized. We hypothesized (1) increased cerebrovascular reactivity (CVR) at HA; and (2) that CO2 would affect cerebral metabolism more than hypoxia. PaO2 and PaCO2 were manipulated at sea level (SL) to simulate HA exposure, and at HA, SL blood gases were simulated; CVR was assessed at both altitudes. Arterial–jugular venous differences were measured to calculate cerebral metabolic rates and cerebral blood flow (CBF). We observed that (1) partial acclimatization yields a steeper CO2-H+ relation in both arterial and jugular venous blood; yet (2) CVR did not change, despite (3) mean arterial pressure (MAP)-CO2 reactivity being doubled at HA, thus indicating effective cerebral autoregulation. (4) At SL hypoxia increased CBF, and restoration of oxygen at HA reduced CBF, but neither had any effect on cerebral metabolism. Acclimatization resets the cerebrovasculature to chronic hypocapnia.

Cardiovascular adjustments to laboratory diving in beavers and nutria

1982 ◽  
Vol 242 (5) ◽  
pp. R434-R440
Author(s):  
T. McKean
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Castor Canadensis ◽  
Venous Blood ◽  
Regional Distribution ◽  
Blood Gases ◽  
Myocastor Coypus ◽  
Recovery From Anesthesia ◽  
Rate Of Decline

Beavers (Castor canadensis) and nutria (Myocastor coypus) were anesthetized with halothane and catheters placed in the left ventricle, aorta and pulmonary artery, right ventricle or right atrium. The animals were strapped to a board and following recovery from anesthesia the following measurements were taken: regional distribution of blood flow, cardiac output, O2 consumption, arterial and venous blood gases, and pH. The animal was then immersed in 15-20 degrees C water for up to 2.75 min (nutria) or 4 min (beaver) and the measurements repeated. Heart rate and cardiac output decreased by 80 and 75%, respectively. Arterial and venous oxygen partial pressure and content fell as did pH whereas CO2 pressures rose during diving. Oxygen consumption at rest was 124 and 102% of that predicted on the basis of body mass for the beaver and nutria, respectively. Rate of decline of O2 stores during diving decreased by 93% in beavers and 89% in nutria compared to the predive value. Regional blood flow decreased to all organs except the adrenals, heart, and lungs. Blood flow to the brain increased during diving.

Segment stroke work and metabolism depend on coronary blood flow in the pig

1978 ◽  
Vol 234 (5) ◽  
pp. H597-H607 ◽  
Author(s):  
D. F. Stowe ◽  
D. G. Mathey ◽  
W. Y. Moores ◽  
S. A. Glantz ◽  
R. M. Townsend ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Myocardial Ischemia ◽  
Mechanical Performance ◽  
Venous Blood ◽  
Lactate Production ◽  
Blood Gases ◽  
Metabolic Effects ◽  
Stroke Work ◽  
Blood Flows

We determined the mechanical and metabolic effects of graded myocardial ischemia in 23 open-chest, anesthetized pigs. By connecting the midportion of the left anterior descending artery (LAD) to the carotid artery via a constant volume, calibrated pump, we reduced the flow in the LAD to 0, 25, 50, and 75% of control rates for periods of 1 h. Flows of 100% and 150% were also examined. Using pairs of ultrasonic crystals to measure segment dimensions, we calculated segment shortening and thickening, and total and systolic stroke work in the ischemic and normally perfused segments. Blood gases, pH, and lactate and inosine balances were determined from the regional coronary venous blood. At coronary blood flows of 0, 25, 50, and 75% of normal resting flow, total segment work was 8 +/- 8, 25 +/- 4, 51 +/- 5, and 80 +/- 6% of control, respectively, while systolic segment work was -2 +/- 5, -10 +/- 5, 40 +/- 5, and 86 +/- 7% of control, respectively (means +/- SE). Thus, the decrease in total segment stroke work is proportional to the decrease in flow over the range 0-100%. However, no useful work (i.e., systolic work) is done until flow exceeds 25%. Segment shortening and thickening are significantly depressed with flows diminished by only 25%. Segmental inosine production correlates with lactate production and parallels decreased mechanical performance.

Effect of Inverse I 

1998 ◽  
Vol 88 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Elizabeth Zavala ◽  
Miguel Ferrer ◽  
Guido Polese ◽  
Joan Ramon Masclans ◽  
Merce Planas ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Gases ◽  
Conventional Mechanical Ventilation ◽  
Inert Gases ◽  
Lung Mechanics ◽  
The Mean ◽  
The Right ◽  
Volume Controlled ◽  
Pressure Controlled

Background It is not known whether inverse I:E ratio ventilation (IRV) offers any real benefit over conventional mechanical ventilation with positive end-expiratory pressure (CMV-PEEP) at similar levels of end-expiratory pressure. Methods The effects of volume-controlled and pressure-controlled IRV (VC-IRV and PC-IRV, respectively) on VA/Q inequality were compared with those of CMV-PEEP at a similar level of end-expiratory pressure and with CMV without PEEP (CMV) in eight patients in the early stages of acute respiratory distress syndrome (ARDS). Respiratory blood gases, inert gases, lung mechanics, and hemodynamics were measured 30 min after the onset of each ventilatory mode. Results Recruitment of nonventilated, poorly ventilated (or both) but well-perfused alveoli increased the partial pressure of oxygen (PaO2) during CMV-PEEP (+13 mmHg) and IRV-VC (+10 mmHg; P < 0.05) compared with CMV. In contrast, PC-IRV did not affect PaO2 but caused a decrease in PaCO2 (-7 mmHg; P < 0.05). The latter was due to a concomitant decrease in dead space (P < 0.01) and shift to the right of VA/Q distributions. During PC-IRV, the increase in the mean of blood flow distribution (mean Q; P < 0.01) without a change in the dispersion (log SD Q) did not result in an increase in PaO2, probably because it reflected redistribution of blood flow within well-ventilated areas. Conclusions Short-term PC-IRV improved carbon dioxide clearance, but the lung became less efficient as an oxygen exchanger. Furthermore, based on mean airway and plateau pressures, the risk of barotrauma was not reduced with this type of ventilation.

WITHDRAWN: Venous Blood Gases of Varicocele Veins: Correlation With Testicular Blood Flow and Semen Quality in Varicocele Patients

Urology ◽  
2016 ◽  
Author(s):  
Khaleeq ur Rehman ◽  
Hafsa Zaneb ◽  
Ahsan Numan ◽  
Abdul Basit Qureshi ◽  
Imtiaz Rabbani ◽  
...  
Keyword(s):  
Blood Flow ◽  
Semen Quality ◽  
Venous Blood ◽  
Blood Gases ◽  
Testicular Blood Flow

scholarly journals OC135: Fetal blood flow distribution to the placenta

2003 ◽  
Vol 22 (S1) ◽  
pp. 37-37 ◽  
Author(s):  
T. Kiserud ◽  
S. Rasmussen ◽  
V. Sethi
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Fetal Blood

Indomethacin compromises hemodynamics during positive-pressure ventilation, independently of prostanoids

1993 ◽  
Vol 74 (4) ◽  
pp. 1672-1678 ◽  
Author(s):  
D. D. Malcolm ◽  
J. L. Segar ◽  
J. E. Robillard ◽  
S. Chemtob
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Airway Pressure ◽  
Regional Blood Flow ◽  
Blood Gases ◽  
Positive Pressure ◽  
Organ Blood Flow ◽  
Mean Airway Pressure ◽  
Airway Pressures

We examined whether prostanoids contribute to the impaired cardiac function and decrease in regional blood flow induced by increasing mean airway pressure. Using microspheres, we measured cardiac output and major organ blood flow and assayed prostaglandin E2, 6-ketoprostaglandin F1 alpha, and thromboxane B2 in blood at mean airway pressures of 5–25 cmH2O in mechanically ventilated newborn piglets treated with ibuprofen (40 mg/kg, n = 6), indomethacin (0.3 mg/kg, n = 6), or vehicle (n = 6). Blood gases and pH were stable throughout the experiments. Prostanoid levels remained constant with increasing mean airway pressure in vehicle-treated pigs and were unchanged by indomethacin. However, ibuprofen decreased the prostanoid levels at all mean airway pressures studied (P < 0.01). As ventilatory pressure was progressively increased, cardiac output decreased gradually and similarly by 42–45% (P < 0.05) in all groups. At the highest mean airway pressure, blood flow decreased to the kidneys by 37–57%, to the ileum by 58–74%, and to the colon by 53–71% (P < 0.05) in all groups. Cerebral blood flow remained constant at all ventilatory pressures regardless of the treatment. There was no difference in cardiac output and regional hemodynamics between ibuprofen- and vehicle-treated animals. However, after indomethacin, ileal blood flow at the higher ventilatory pressures was 41–46% lower and cerebral blood flow at all mean airway pressures was 14–25% lower than after the other treatments (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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