Correlation of left phrenic arterial flow with regional diaphragmatic blood flow

Previous work has assumed that left phrenic arterial blood flow (Qpa) reflects diaphragmatic blood flow. We have tested this assumption in four anesthetized mechanically ventilated dogs by measuring Qpa with a Doppler flow probe and regional diaphragmatic blood flow with radiolabeled microspheres. Flows were examined during control 1 (diaphragm at rest), pacing (phrenic pacing: rate 20/min, duty cycle 0.33), control 2, hypotension (rest with mean arterial pressure reduced by 45% of the control 1 value), and hypotension and pacing. As a percent of the control 1 value, Qpa was 511 +/- 107% during pacing, 139 +/- 12% during control 2, 40 +/- 13% during hypotension, and finally 347 +/- 31% during hypotension and pacing. Similarly, percent left hemidiaphragmatic blood flow (Qlh) was 362 +/- 91% during pacing, 91 +/- 10% during control 2, 14 +/- 2% during hypotension, and finally 213 +/- 50% during hypotension and pacing. The changes in flow to the left costal and crural diaphragm were similar to those recorded for Qlh. We conclude that Qpa correlates with total and regional diaphragmatic blood flow (r = 0.77–0.81, P less than 0.001) under conditions of supramaximal phrenic nerve stimulation in which the metabolic demands of the region perfused by the phrenic artery are presumed to be similar to the metabolic demands of the rest of the diaphragm.

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Increased vascular resistance in paralyzed legs after spinal cord injury is reversible by training

Journal of Applied Physiology ◽

10.1152/japplphysiol.00897.2001 ◽

2002 ◽

Vol 93 (6) ◽

pp. 1966-1972 ◽

Cited By ~ 64

Author(s):

Maria T. E. Hopman ◽

Jan T. Groothuis ◽

Marcel Flendrie ◽

Karin H. L. Gerrits ◽

Sibrand Houtman

Keyword(s):

Blood Pressure ◽

Spinal Cord ◽

Spinal Cord Injury ◽

Blood Flow ◽

Mean Arterial Pressure ◽

Arterial Pressure ◽

Vascular Resistance ◽

Arterial Blood Flow ◽

Arterial Blood ◽

Cord Injury

The purpose of the present study was to determine the effect of a spinal cord injury (SCI) on resting vascular resistance in paralyzed legs in humans. To accomplish this goal, we measured blood pressure and resting flow above and below the lesion (by using venous occlusion plethysmography) in 11 patients with SCI and in 10 healthy controls (C). Relative vascular resistance was calculated as mean arterial pressure in millimeters of mercury divided by the arterial blood flow in milliliters per minute per 100 milliliters of tissue. Arterial blood flow in the sympathetically deprived and paralyzed legs of SCI was significantly lower than leg blood flow in C. Because mean arterial pressure showed no differences between both groups, leg vascular resistance in SCI was significantly higher than in C. Within the SCI group, arterial blood flow was significantly higher and vascular resistance significantly lower in the arms than in the legs. To distinguish between the effect of loss of central neural control vs. deconditioning, a group of nine SCI patients was trained for 6 wk and showed a 30% increase in leg blood flow with unchanged blood pressure levels, indicating a marked reduction in vascular resistance. In conclusion, vascular resistance is increased in the paralyzed legs of individuals with SCI and is reversible by training.

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Changes in bronchial and pulmonary arterial blood flow with progressive tension pneumothorax

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.4.1664 ◽

1996 ◽

Vol 81 (4) ◽

pp. 1664-1669 ◽

Cited By ~ 15

Author(s):

Paula Carvalho ◽

Jacob Hildebrandt ◽

Nirmal B. Charan

Keyword(s):

Blood Flow ◽

Gas Exchange ◽

Tension Pneumothorax ◽

Blood Gases ◽

Left Pulmonary Artery ◽

Arterial Blood Flow ◽

Mechanically Ventilated ◽

Arterial Blood ◽

Flow Through ◽

Pulmonary Arterial

Carvalho, Paula, Jacob Hildebrandt, and Nirmal B. Charan.Changes in bronchial and pulmonary arterial blood flow with progressive tension pneumothorax. J. Appl. Physiol. 81(4): 1664–1669, 1996.—We studied the effects of unilateral tension pneumothorax and its release on bronchial and pulmonary arterial blood flow and gas exchange in 10 adult anesthetized and mechanically ventilated sheep with chronically implanted ultrasonic flow probes. Right pleural pressure (Ppl) was increased in two steps from −5 to 10 and 25 cmH2O and then decreased to 10 and −5 cmH2O. Each level of Ppl was maintained for 5 min. Bronchial blood flow, right and left pulmonary arterial flows, cardiac output (Q˙t), hemodynamic measurements, and arterial blood gases were obtained at the end of each period. Pneumothorax resulted in a 66% decrease inQ˙t, bronchial blood flow decreased by 84%, and right pulmonary arterial flow decreased by 80% at Ppl of 25 cmH2O ( P < 0.001). At peak Ppl, the majority ofQ˙t was due to blood flow through the left pulmonary artery. With resolution of pneumothorax, hemodynamic parameters normalized, although abnormalities in gas exchange persisted for 60–90 min after recovery and were associated with a decrease in total respiratory compliance.

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Effect of separate hemidiaphragm contraction on left phrenic artery flow and O2 consumption

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.1.86 ◽

1990 ◽

Vol 69 (1) ◽

pp. 86-90 ◽

Cited By ~ 7

Author(s):

F. Hu ◽

A. Comtois ◽

E. Shadram ◽

A. Grassino

Keyword(s):

Blood Flow ◽

Nerve Stimulation ◽

Phrenic Nerve ◽

Arterial Blood Flow ◽

O2 Consumption ◽

Phrenic Nerve Stimulation ◽

Diaphragm Pacing ◽

Transdiaphragmatic Pressure ◽

Arterial Blood ◽

Significant Difference

Phrenic arterial blood flow has been shown to increase during bilateral phrenic nerve stimulation (BPNS). However, the role of unilateral phrenic nerve stimulation [left (LPNS) or right (RPNS)] on the blood flow and O2 consumption of the contralateral hemidiaphragm is not known and is explored here. In six anesthetized, mechanically hyperventilated dogs, left phrenic arterial blood flow (Qlpha) was measured (Doppler technique). Supramaximal (10 V, 30 Hz, 0.25-ms duration) LPNS, RPNS, and BPNS at a pacing frequency 15/min and duty cycle of 0.50 were delivered in separate runs. Left hemidiaphragmatic blood samples for gas analyses were obtained by left phrenic venous cannulation. During RPNS, Qlpha and left hemidiaphragmatic O2 consumption (VO2ldi) did not change significantly compared with control. During LPNS and BPNS, there was a significant increase in Qlpha and VO2ldi (P less than 0.01). There was no significant difference in Qlpha and VO2ldi between LPNS and BPNS (P greater than 0.05). We conclude 1) that there is a complete independence of left-right hemidiaphragmatic circulation both at rest and during diaphragm pacing and 2) that during unilateral stimulation transdiaphragmatic pressure is not related to diaphragmatic blood flow.

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Real Time Monitoring of Peripheral Arterial Blood Flow Velocity and Volume During Aneurysm Clipping Using Doppler Flow Meter

Surgery for Cerebral Stroke ◽

10.2335/scs1987.22.5_379 ◽

1994 ◽

Vol 22 (5) ◽

pp. 379-383

Author(s):

Hiroshi UENOHARA ◽

Tomoko KOBAYASHI ◽

Akiko NISHINO ◽

Shinsuke SUZUKI ◽

Hiroaki ARAI ◽

...

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Real Time ◽

Blood Flow Velocity ◽

Arterial Blood Flow ◽

Flow Meter ◽

Doppler Flow ◽

Aneurysm Clipping ◽

Arterial Blood ◽

Peripheral Arterial

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Changes in Umbilical Arterial Blood Flow by an Intraamniotic Distilled Water Infusion

Yearbook of Obstetrics Gynecology and Women s Health ◽

10.1016/s1090-798x(08)70024-9 ◽

2007 ◽

Vol 2007 ◽

pp. 30-31

Author(s):

S.H. Ural

Keyword(s):

Blood Flow ◽

Arterial Blood Flow ◽

Distilled Water ◽

Arterial Blood ◽

Water Infusion

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Impact of Pre Transplant Transarterial Chemoembolization on Hepatic Arterial Blood Flow and Outcomes in Liver Transplantation

10.26226/morressier.58eb975dd462b80290b50084 ◽

2017 ◽

Author(s):

Siddharth Jain

Keyword(s):

Liver Transplantation ◽

Blood Flow ◽

Transarterial Chemoembolization ◽

Arterial Blood Flow ◽

Hepatic Arterial Blood Flow ◽

Arterial Blood

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Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

SNE Simulation Notes Europe ◽

10.11128/sne.23.tn.10189 ◽

2013 ◽

Vol 23 (2) ◽

Author(s):

Xenia Descovich ◽

Giuseppe Pontrelli ◽

Sauro Succi ◽

Simone Melchionna ◽

Manfred Bammer

Keyword(s):

Blood Flow ◽

Lattice Boltzmann ◽

Arterial Blood Flow ◽

Arterial Blood ◽

Lattice Boltzmann Simulations ◽

Elastic Walls

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Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽

10.3390/children8050353 ◽

2021 ◽

Vol 8 (5) ◽

pp. 353

Author(s):

Jayasree Nair ◽

Lauren Davidson ◽

Sylvia Gugino ◽

Carmon Koenigsknecht ◽

Justin Helman ◽

...

Keyword(s):

Blood Flow ◽

Perinatal Asphyxia ◽

Arterial Blood Flow ◽

Positive Pressure ◽

Optimal Timing ◽

Delayed Cord Clamping ◽

Arterial Blood ◽

Cord Clamping ◽

Sustained Inflation ◽

Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

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