Integrated Evaluation of Neonatal Hemodynamics, Part 2: Systematic Bedside Assessment

2016 ◽  
Vol 35 (4) ◽  
pp. 192-203 ◽  
Author(s):  
Yasser N. Elsayed ◽  
Debbie Fraser
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Carrying Capacity ◽  
Clinical Markers ◽  
Organ Function ◽  
Term Infants ◽  
Routine Monitoring ◽  
Oxygen Carrying Capacity ◽  
Sufficient Oxygen

AbstractIntact hemodynamics results when there is adequate oxygen uptake by the respiratory system, normal cardiac output, sufficient oxygen-carrying capacity of blood, and intact autoregulatory mechanisms to maintain enough oxygenation for normal end-organ function. The current routine monitoring of cardiovascular dynamics in sick preterm and term infants has been based on incomplete evaluation and relies on nonspecific and sometimes misleading clinical markers such as blood pressure. A thorough understanding of perinatal and neonatal cardiovascular, respiratory, oxygen, and other specific end-organ physiology is also mandatory for proper targeted interpretation.

The Influence of Nutritional State on the Circulatory and Respiratory Physiology of the Shore Crab, Carcinus Maenas

1985 ◽  
Vol 65 (1) ◽  
pp. 69-78 ◽  
Author(s):  
M. H. Depledge
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Salinity Stress ◽  
Carrying Capacity ◽  
Carcinus Maenas ◽  
Nutritional State ◽  
Respiratory Physiology ◽  
Shore Crab ◽  
Decapod Crustaceans ◽  
Oxygen Carrying Capacity

The oxygen-carrying capacity of the blood of decapod crustaceans fluctuates widely. Salinity stress results in doubling of haemocyanin concentration within 24–48 h in Carcinus maenas (Boone & Schoeffeniels, 1979) while in the lobster, Homarus gammarus respiratory pigment levels are very low prior to and following moulting (Spoek, 1974). In general, however, the most important factor regulating haemocyanin concentration is nutritional state. Following starvation low values are recorded (Wieser, 1965; Uglow, 1969; Djangmah, 1970) and there are concomitant reductions in ventilation, oxygen consumption and cardiac output (Ansell, 1973; Marsden, Newell & Ahsanullah, 1973; Wallace, 1973). The interrelationships between these events are poorly understood.

scholarly journals Reduction of Oxygen-Carrying Capacity Weakens the Effects of Increased Plasma Viscosity on Cardiac Performance in Anesthetized Hemodilution Model

2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
Surapong Chatpun ◽  
Pedro Cabrales
Keyword(s):  
Cardiac Output ◽  
Carrying Capacity ◽  
Oxygen Delivery ◽  
Maximum Rate ◽  
Systolic Pressure ◽  
Pressure Change ◽  
Plasma Viscosity ◽  
Cardiac Performance ◽  
Dextran 70 ◽  
Oxygen Carrying Capacity

We investigated the effects of reduced oxygen-carrying capacity on cardiac function during acute hemodilution, while the plasma viscosity was increased in anesthetized animals. Two levels of oxygen-carrying capacity were created by 1-step and 2-step hemodilution in male golden Syrian hamsters. In the 1-step hemodilution (1-HD), 40% of the animals' blood volume (BV) was exchanged with 6% dextran 70 kDa (Dx70) or dextran 2000 kDa (Dx2M). In the 2-step hemodilution (2-HD), 25% of the animals' BV was exchanged with Dx70 followed by 40% BV exchanged with Dx70 or Dx2M after 30 minutes of first hemodilution. Oxygen delivery in the 2-HD group consequently decreased by 17% and 38% compared to that in the 1-HD group hemodiluted with Dx70 and Dx2M, respectively. End-systolic pressure and maximum rate of pressure change in the 2-HD group significantly lowered compared with that in the 1-HD group for both Dx70 and Dx2M. Cardiac output in the 2-HD group hemodiluted with Dx2M was significantly higher compared with that hemodiluted with Dx70. In conclusion, increasing plasma viscosity associated with lowering oxygen-carrying capacity should be considerably balanced to maintain the cardiac performance, especially in the state of anesthesia.

Ventilatory responses to cardiac output changes in patients with pacemakers

1981 ◽  
Vol 51 (5) ◽  
pp. 1103-1107 ◽  
Author(s):  
P. W. Jones ◽  
W. French ◽  
M. L. Weissman ◽  
K. Wasserman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Blood Gas ◽  
Cardiac Pacemakers ◽  
Ventilatory Responses ◽  
Mean Delay ◽  
Arterial Blood ◽  
End Tidal

Cardiac output changes were induced by step changes of heart rate (HR) in six patients with cardiac pacemakers during monitoring of ventilation and gas exchange, breath-by-breath. Mean low HR was 48 beats/min; mean high HR was 82 beats/min. The change of oxygen uptake immediately after the HR change was used as an index of altered cardiac output. After HR increase, oxygen uptake (V02) rose by 34 +/- 20% (SD), and after HR decrease, Vo2 fell by 24 +/- 11%. There was no change in arterial blood pressure. After HR increase, ventilation increased, after a mean delay of 19 +/- 4 s; after HR reduction, ventilation fell, after a mean delay of 29 +/- 7 s. In the period between HR increase and the resulting increase in ventilation, end-tidal PCO2 (PETCO2) rose by 2.6 +/- 2.0 Torr, and in the period between HR decreases and the fall in ventilation, PETCO2 dropped by 2.9 +/- 2.2 Torr. The response time and end-tidal gas tension changes implicate the chemoreceptors in the reflex correction of blood gas disturbances that may result from imbalances between cardiac output and ventilation.

Respiratory and Cardiac Performance in Lolliguncula Brevis (Cephalopoda, Myopsida): The Effects of Activity, Temperature and Hypoxia

1988 ◽  
Vol 138 (1) ◽  
pp. 17-36 ◽  
Author(s):  
M.J. WELLS ◽  
R. T. HANLON ◽  
P. G. LEE ◽  
F. P. DIMARCO
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Acute Hypoxia ◽  
Ventilation Rate ◽  
Necessary Condition ◽  
Jet Propulsion ◽  
Q10 Values ◽  
Oxygen Carrying Capacity ◽  
Lolliguncula Brevis

Lolliguncula brevis Blainville is a small euryhaline squid found at temperatures between 11 and 31 °C. Changes in VO2, heartbeat and ventilation frequencies were observed throughout this temperature range and under a variety of conditions, including acute hypoxia and swimming by jet propulsion in a tunnel respirometer. Resting VO2 showed a Q10 of 1.47, and heart rate and ventilation rate Q10 values of 1.92 and 1.73, respectively; oxygen uptake could exceed 1.01kg−1h−1 at 30°C even at rest. The squids regulated their oxygen uptake at all temperatures. Oxygen extraction rates were in the region of 5–10% in saturated water, increasing to 15–20% in hypoxic water or after exercise. One effect of this variability is that ventilation stroke volume can remain constant throughout the range of temperatures and oxygen concentrations that the animal is likely to encounter, a necessary condition since the ventilation stream is also the principal mode of locomotion by jet propulsion. Blood oxygen-carrying capacity (from the copper concentration) was 4.6 ± 1.8vols%. Cardiac output and stroke volume were estimated from the observed VO2 values and heartbeat frequencies. Resting at 25°C, the output was close to 11.51kg−1 body mass h−1. The systemic heart of Lolliguncula weighed only 2.06 ± 0.62 g kg−1. In exercise the cardiac output must exceed 14×103 1kg−1 heart mass h−1, pumping more than the heart's own mass of blood at each stroke.

Consultation with the Specialist

1992 ◽  
Vol 13 (10) ◽  
pp. 379-380
Author(s):  
William B. Strong
Keyword(s):  
Cardiac Output ◽  
Oxygen Saturation ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Cyanotic Congenital Heart Disease ◽  
Compensatory Mechanism ◽  
Peripheral Tissues ◽  
Arterial Blood ◽  
Infant And Young Child ◽  
Oxygen Carrying Capacity

What is the likely pathophysiology of this event? What are the more common complications of hypoxemia in the older infant and young child? This clinical scenario is uncommon, but it represents one of the two feared central nervous system complications of cyanotic congenital heart disease, (ie, cerebrovascular accident and brain abscess). A uniform response to hypoxemia of cardiac etiology is the production of erythropoietin to produce more red blood cells. This is a compensatory mechanism to maintain oxygen delivery to the peripheral tissues. Normally, hemoglobin is about 96% saturated with oxygen. Therefore, the oxygen-carrying capacity of blood with a normal hemoglobin concentration of 15 g/dL is approximately 20.3 mL of oxygen per 100 mL of blood (ie, 15 g of hemoglobin x 1.35 mL of O2 per g of hemoglobin = 20.3). The oxygen content of blood equals the oxygen-carrying capacity multiplied by the oxygen saturation. At a normal oxygen saturation of 96%, the O2 content of arterial blood (Hgb 15 g/dL) equals 19.5 mL/dL (96% x 20.3 mm3/dL) or 195 mL per liter of cardiac output. The arterial O2 content of this child, assuming an average arterial saturation of 85%, will be 11.1 mL/dL. Therefore, every liter (10 dL) of cardiac output will carry 111 mL of O2 or 84 mL of O2 less than the child with a 15 g/dL hemoglobin level.

Effects of acute prolonged hypoxia on cardiovascular dynamics in dogs

1977 ◽  
Vol 43 (5) ◽  
pp. 784-789 ◽  
Author(s):  
J. F. Borgia ◽  
S. M. Horvath
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cardiac Index ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Severe Hypoxia ◽  
Systemic Hypertension ◽  
Anesthetized Dogs ◽  
Oxygen Tensions ◽  
Oxygen Carrying Capacity

Intact anesthetized dogs were exposed for 75 min to either 5.75, 9.0, or 12.0% oxygen in nitrogen. Although pulmonary artery pressures were significantly elevated in all hypoxic exposures, systemic hypertension occurred only at the onset of severe hypoxia(5.75% O2). Coronary blood flow increased from an average of 130 during normoxia to a peak of 400 ml/100 g per min during inhalation of 5.75% O2, and coronary sinus oxygen tensions of 8 Torr and oxygen contents of 1.1 ml/100 ml were sustained for 75 min without biochemical, functional, or electrophysiological evidence of myocardial ischemia. Cardiac index (CI) increased significantly only during severe hypoxia (5.75% O2) with the greatest elevation after 30 min. Subsequently, CI decreased concomitantly with a 27% elevation in arterial hemoglobin concentration and oxygen-carrying capacity. It is concluded that the hypoxic threshold for significant elevations of cardiac output is between 6.0 and 9.0% O2.

CARDIOVASCULAR RESPONSES IN DOGS TO INTRAVENOUS INFUSIONS OF WHOLE BLOOD, PLASMA, AND PLASMA FOLLOWED BY PACKED ERYTHROCYTES

1955 ◽  
Vol 33 (3) ◽  
pp. 349-360 ◽  
Author(s):  
F. A. Sunahara ◽  
J. D. Hatcher ◽  
L. Beck ◽  
C. W. Gowdey
Keyword(s):  
Cardiac Output ◽  
Blood Plasma ◽  
Blood Volume ◽  
Carrying Capacity ◽  
Whole Blood ◽  
Cardiovascular Responses ◽  
Controlling Factors ◽  
Intravenous Infusions ◽  
Oxygen Carrying Capacity ◽  
The Right

The effects of intravenous infusions of large volumes of blood or of plasma followed by packed erythrocytes were studied in anesthetized normal dogs. During plasma infusion the right auricular pressure (RAP) and cardiac output increased as the hematocrit decreased. Blood infusion caused a rise in RAP but was, in most cases, not accompanied by an increased output. It is concluded that, although the blood volume and RAP may be important in the regulation of cardiac output, they are not under all conditions the controlling factors. The relative oxygen-carrying capacity of the blood appears to be more important in the cardiovascular adjustments to hypervolemia.

Circulatory response to prolonged severe exercise

1964 ◽  
Vol 19 (5) ◽  
pp. 833-838 ◽  
Author(s):  
Bengt Saltin ◽  
Jesper Stenberg
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Arterial Blood Pressure ◽  
Blood Volume ◽  
Major Change ◽  
Work Load ◽  
The Body ◽  
Arterial Blood

Four subjects worked on a treadmill or a bicycle ergometer for 180 min at oxygen uptakes of 75% of the individual's max Vo2; after 90 min rest, the exercise was resumed and a maximal work load was tried. Repeated circulatory studies were made. The body weight decreased 3.1 kg (3.2–5.2%), but the reduction in blood volume was less than 5%. During submaximal exercise the major change in the hemodynamic response was a decrease in stroke volume (from 126 to 107 ml). Oxygen uptake and cardiac output increased slightly. There was a decrease of about 10% in systolic, diastolic, and mean arterial blood pressure during the 180 min of exercise. When the work was performed in a supine position there was the same reduction in the stroke volume as in the sitting work position. At the maximal work oxygen uptake, cardiac output, heart rate, and blood pressure attained almost normal values but there was a marked decrease in both work time and blood lactates. dehydration; blood volume; arterial blood pressure; circulatory reaction Submitted on January 31, 1964

CARDIOVASCULAR RESPONSES IN DOGS TO INTRAVENOUS INFUSIONS OF WHOLE BLOOD, PLASMA, AND PLASMA FOLLOWED BY PACKED ERYTHROCYTES

1955 ◽  
Vol 33 (1) ◽  
pp. 349-360
Author(s):  
F. A. Sunahara ◽  
J. D. Hatcher ◽  
L. Beck ◽  
C. W. Gowdey
Keyword(s):  
Cardiac Output ◽  
Blood Plasma ◽  
Blood Volume ◽  
Carrying Capacity ◽  
Whole Blood ◽  
Cardiovascular Responses ◽  
Controlling Factors ◽  
Intravenous Infusions ◽  
Oxygen Carrying Capacity ◽  
The Right

The effects of intravenous infusions of large volumes of blood or of plasma followed by packed erythrocytes were studied in anesthetized normal dogs. During plasma infusion the right auricular pressure (RAP) and cardiac output increased as the hematocrit decreased. Blood infusion caused a rise in RAP but was, in most cases, not accompanied by an increased output. It is concluded that, although the blood volume and RAP may be important in the regulation of cardiac output, they are not under all conditions the controlling factors. The relative oxygen-carrying capacity of the blood appears to be more important in the cardiovascular adjustments to hypervolemia.

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