The effect of cardiopulmonary bypass on gastric and colonic mucosal perfusion: a tonometric assessment

Perfusion ◽  
1994 ◽  
Vol 9 (2) ◽  
pp. 101-108 ◽  
Author(s):  
S.K. Ohri ◽  
C.T. Bowles ◽  
A. Siddiqui ◽  
A. Khaghani ◽  
B.E. Keogh ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiopulmonary Bypass ◽  
Cardiac Index ◽  
Potential Effect ◽  
Strongly Correlated ◽  
Intramucosal Ph ◽  
Arterial Blood ◽  
Mucosal Perfusion ◽  
Haemodynamic Stress ◽  
The Difference

In a study to assess the potential effect of nonpulsatile hypothermic cardiopulmonary bypass (CPB), intramucosal pH (pHi) of the gastric and colonic mucosae was determined by tonometry ( n = 8). During the hypothermic phase of CPB, gastric and colonic pHi did not change significantly. Forty minutes after the start of rewarming, despite increases in the cardiac index and mean arterial blood pressure, gastric pHi fell from 7.53 ± 0.02 to 7.31 ± 0.03 ( p = 0.017) and colonic pHi fell from 7.50 ± 0.02 to 7.32 ± 0.03 ( p = 0.028). Forty minutes after the end of CPB both the colonic ( p = 0.017) and gastric ( p = 0.046) pHi remained depressed below pre-CPB values. The difference in the arterial (pHa) and the gastric mucosal pH changed from -0.097 before CPB to 0.016, 40 minutes after the end of CPB ( p = 0.027). This alteration in the pHa-pHi underlines the importance of measuring intramucosal pH by tonometry, since the pHa and pHi may move in opposite directions during episodes of haemodynamic stress. Both the gastric and colonic pHi were found to have a linear correlation with the pHa, although changes in the gastric pHi ( r = 0.41, p = 0.018) were more strongly correlated with the pHa than the colonic pHi ( r = 0.23, p = 0.19) in the rewarming phase of CPB and the immediate post-CPB period when there was a tendency towards intramucosal acidosis. The development of intramucosal acidosis in the rewarming and immediate post-CPB phases following hypothermic nonpulsatile CPB may impair the gut barrier and predispose patients to the absorption of luminal toxins.

scholarly journals Intramucosal pH as a criterion for the organism emergency from hepatospanchnic ischemia, or centralization of blood flow

2021 ◽  
Vol 17 (3) ◽  
pp. 10-14
Author(s):  
L.O. Maltseva ◽  
V.M. Lisnycha ◽  
I.A. Malsev ◽  
N.A. Kazimirova
Keyword(s):  
Blood Pressure ◽  
Intensive Care ◽  
Intensive Therapy ◽  
Tissue Perfusion ◽  
Regional Perfusion ◽  
Critical Conditions ◽  
Intramucosal Ph ◽  
Arterial Blood ◽  
The Difference ◽  
Splanchnic Hypoperfusion

In critical conditions, despite the restoration of systemic hemodynamics and overall oxygen delivery, tissue hypoxia and reduced oxygen extraction remain. One of the important tasks of intensive care for critical conditions is the early diagnosis of tissue perfusion disorders. In clinical circumstances, signs of hypoperfusion are arterial hypotension, tachycardia, oliguria, encephalopathy, low body temperature, the disappearance of skin capillary pattern, metabolic lactate acidosis. However, blood pressure is an insensitive indicator of tissue hypoperfusion itself. Experimental clinical trials have repeatedly documented that local perfusion pressure in critical conditions does not directly depend on systemic blood pressure. Lactate is not a specific marker of anaerobic metabolism, but rather impaired microcirculation seems to be one of the possible mechanisms of hyperlactatemia. Reliable markers of tissue perfusion and the effectiveness of early targeted therapy are regional capnometry (gastric intramucosal pH, sublingual pCO2), a saturation of mixed venous blood, etc. Intramucosal pH is of particular practical importance as a marker of regional capnometry. The aim of the study is the analysis of literature sources devoted to the effectiveness and diagnostic significance of intramucosal pH as a marker of regional perfusion. The value of intramucosal pH was evaluated: 1) during abdominal operations and the development of postoperative complications in comparison against IL-6 and IL-8; 2) during and after surgical interventions in conditions of prolonged cardiopulmonary bypass to assess the adequacy of blood supply to the abdominal organs; 3) in experimental septic shock compared to the values of lactate and hypoxanthine concentration in the liver and arterial blood; 4) the correlation between intramucosal pH va-lues, indices of the pediatric mortality risk scale, forming of great (cardiac arrest, shock) and minor (hypotension, hypovolemia, arrhythmia) hemodynamic complications and duration of staying in intensive care unit and intensive therapy; 5) during laparoscopic cholecystectomy in apparently healthy patients with the simultaneous calculation of the difference between arterial and intramucosal pH. Intramuscular pH-controlled intensive therapy is a separate fragment: an intramucosal pH of less than 7.3 reflects splanchnic hypoperfusion and is an indicator of the unfavorable outcomes; intramucousal pH of more than 7.3 is a criterion for the emergency of the organism from hepatosplanchic ischemia, i.e. centralization of blood circulation. Therefore, the intramucosal pH is valuable in the clinical picture of critical conditions as a marker of regional perfusion measured by capnometry, which allows monitoring that reflects the perfusion of the intestinal wall. The lower threshold is 7.35 (the sensitivity of the method is 67 %, specificity is 74 %). An intramucosal pH of < 7.3 reflects splanchnic hypoperfusion and is an indicator of an adverse outcome. An alternative measurement of intramucosal pCO2, pCO2 in arterial blood and the difference [P (1-a) CO2] is a more reliable index of intestinal oxygenation than single intramucosal pH, but rather pH (1-a) makes it possible to adequately assess the acid-base state of arterial blood. The improvement and widespread use of capnometry and capnography for monitoring during general anaesthesia and intensive care, on the one hand, and modern knowledge of the pathophysiology of gas exchange, on the other hand, stimulate the wider use of less invasive and more affordable methods of regional capnometry and aerial tonometry.

Vasomotor waves of arterial blood pressure after cessation of cardiopulmonary bypass in man

Perfusion ◽  
1990 ◽  
Vol 5 (4) ◽  
pp. 261-266
Author(s):  
V. Vainionpää ◽  
A. Hollme'n ◽  
J. Timisjärvi
Keyword(s):  
Blood Pressure ◽  
Cardiopulmonary Bypass ◽  
Arterial Pressure ◽  
Venous Pressure ◽  
Systemic Arterial Pressure ◽  
Heart Patients ◽  
Arterial Blood ◽  
Pulmonary Arterial ◽  
The Mean ◽  
Epicardial Pacing

The occurrence of vasomotor waves during cardiopulmonary bypass (CPB) is a recognized phenomenon. The lesser known oscillation of arterial pressure after cessation of CPB was observed in 18 open-heart patients. The duration of an oscillatory wave was 13.5±5.0 seconds, the amplitude 6.1 ±2.6mmNg and the mean arterial pressure 76.5± 10.7mmHg. Inter-and also intraindividual variations in frequency and amplitude of the oscillation, however, did occur. In 13 patients, this oscillation occurred during ventricular epicardial pacing. The oscillation continued until the end of the operation in eight patients; in others, the oscillation was of shorter duration. An oscillation of pulmonary arterial pressure (PAP) was simultaneously observed in nine patients (eight with pacemaker) and central venous pressure (CVP) oscillation in eight patients (all with pacemaker). The duration of a wave was the same as in systemic arterial pressure and the amplitudes were 1.5-3.0mmHg in PAP and 1.0-2.0mmHg in CVP. These arterial vasomotor waves, seen here after CPB, largely resemble those observed during perfusion in man and also the Mayerwaves explored in experimental animals. The pacing rhythm seems to favourthe appearance of those blood pressure oscillations.

Umbilical venous pressure and other cardiovascular responses of fetal lambs to epinephrine

1962 ◽  
Vol 203 (5) ◽  
pp. 955-960 ◽  
Author(s):  
S. R. M. Reynolds ◽  
John D. Mackie
Keyword(s):  
Blood Pressure ◽  
Umbilical Vein ◽  
Venous Pressure ◽  
Cardiovascular Responses ◽  
Ductus Venosus ◽  
Arterial Blood ◽  
Femoral Route ◽  
The Difference ◽  
Pregnant Ewe

Large fetuses in utero are more sensitive to infused epinephrine than smaller ones. The quality of response is the same. Increased arterial blood pressure and heart rate are associated with an increase in umbilical vein pressure. The large fetus is as sensitive as the pregnant ewe and the latter is more sensitive than the nonpregnant ewe. Single injections of epinephrine into umbilical or femoral veins have similar effects, except for the difference that the latent period is about twice as long when epinephrine is given by the femoral route as by the umbilical route. The sphincter of the ductus venosus is believed to constrict in response to epinephrine. It is shown to be adrenergically controlled. The import of the sphincter for maintenance of umbilical vein pressure is considered.

Evidence for Peripheral Vascular Involvement in Mild Elevation of Blood Pressure in Man

1976 ◽  
Vol 51 (s3) ◽  
pp. 65s-68s
Author(s):  
R. Sivertsson ◽  
R. Sannerstedt ◽  
Y. Lundgren
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Index ◽  
Structural Changes ◽  
Vascular Involvement ◽  
Control Group ◽  
Study Group ◽  
Blood Pressure Elevation ◽  
Pressure Elevation ◽  
Arterial Blood

1. Cardiac output at rest, intra-arterial blood pressure and hand blood flow at maximal vasodilatation were studied in two groups of 18–25-year-old men: forty-four with mild blood pressure elevation were referred from a military enlistment centre, and twenty-nine normotensive volunteers were mainly recruited from the same enlistment centre. 2. The study group was characterized by a significantly higher cardiac index at rest, and a significantly higher blood flow resistance in the hand at maximal vasodilatation than the control group, indicating the presence of structural modifications in the resistance vessels of patients with mild blood pressure elevation. 3. The tendency to increased vascular resistance in the blood vessels of the hand at maximal vasodilatation was more pronounced in patients with a normal cardiac index than in those with a high index. This suggests inclusion in the study group of tense, anxious individuals with an elevated cardiac index but otherwise normal circulation, but does not exclude the possibility that these patients may develop structural changes later on.

The pharmacodynamics of dexmedetomidine in elderly cardiac patients undergoing analgosedation in the ICU

2018 ◽  
Vol 86 (4) ◽  
pp. 265
Author(s):  
Justyna Alicja Ber ◽  
Mirosław Malec ◽  
Agnieszka Bienert ◽  
Małgorzata Nowicka ◽  
Łukasz Żurański ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Single Dose ◽  
Cardiac Index ◽  
Mean Arterial Blood Pressure ◽  
Bispectral Index ◽  
Cardiac Patients ◽  
Health Conditions ◽  
Arterial Blood ◽  
Dexmedetomidine Infusion

Aim. This study aimed to evaluate the pharmacodynamics of dexmedetomidine in elderly cardiac patients.Material and Methods. Twelve patients of 60 years or older and need for analgesia after surgery or as a result of critical health conditions were included into our study. Dexmedetomidine was administered intravenously as a continuous infusion without the initial dose. At the beginning the infusion was started at the rate of 0.7 μg/kg/h and then it was continued in the range of 0.17–1.39 μg/kg/h according to desired level of sedation. Information about heart rate, systolic, diastolic and mean arterial blood pressure, bispectral index and cardiac index were collected a few minutes before, during and in 12 hours after infusion of dexmedetomidine.Results. The hemodynamic data as well as BIS level were collected from 12 patients. The duration of dexmedetomidine infusion was less than 9 hours. For each patient the reduction in blood pressure and heart rate compared to the value before dexmedetomidine infusion was observed. We did not observe bradycardia in any patient. Appropriate sedation level was achieved using only dexmedetomidine and ranged from 60 to 80. In only 2 cases it was necessary to give a single dose of another sedative.Conclusions. To conclude, in the patients’ population involved in the study, which included older cardiac patients dexmedetomidne has been shown as a sedative agent which enabled to achieve desire level of sedation in the recommended ranges without episodes of bradycardia, however hypotension events were noted.

scholarly journals Seasonal changes in the cardiovascular, respiratory and metabolic responses to temperature and hypoxia in the bullfrog rana catesbeiana

1998 ◽  
Vol 201 (5) ◽  
pp. 761-768 ◽  
Author(s):  
P L Rocha ◽  
L G S Branco
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Arterial Blood Pressure ◽  
Plasma Glucose ◽  
Rana Catesbeiana ◽  
Breathing Frequency ◽  
Glucose Levels ◽  
Arterial Blood ◽  
The Difference

We assessed seasonal variations in the effects of temperature on hypoxia-induced alterations in the bullfrog Rana catesbeiana by measuring the heart rate, arterial blood pressure, breathing frequency, metabolic rate, blood gas levels, acid-base status and plasma glucose concentration. Regardless of the season, decreased body temperature was accompanied by a reduction in heart and breathing frequencies. Lower temperatures caused a significant decrease in arterial blood pressure during all four seasons. Hypoxia-induced changes in breathing frequency were proportional to body temperature and were more pronounced during winter, less so during spring and autumn and even smaller during summer. Season had no effect on the relationship between hypoxia and heart rate. At any temperature tested, the rate of oxygen consumption had a tendency to be highest during summer and lowest during winter, but the difference was significant only at 35 degrees C. The PaO2 and pH values showed no significant change during the year, but PaCO2 was almost twice as high during winter than in summer and spring, indicating increased plasma bicarbonate levels. Lower temperatures were accompanied by decreased plasma glucose levels, and this effect was greater during summer and smaller during autumn. Hypoxia-induced hyperglycaemia was influenced by temperature and season. During autumn and winter, plasma glucose level remained elevated regardless of temperature, probably to avoid dehydration and/or freezing. In winter, the bullfrog may be exposed not only to low temperatures but also to hypoxia. These animals show temperature-dependent responses that may be beneficial since at low body temperatures the set-points of most physiological responses to hypoxia are reduced, regardless of the season. &lt;P&gt;

scholarly journals Hypertensive effect of calcilytic NPS 2143 administration in rats

2006 ◽  
Vol 191 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Apolonia Rybczynska ◽  
Artur Lehmann ◽  
Anna Jurska-Jasko ◽  
Konrad Boblewski ◽  
Czeslawa Orlewska ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Group Performance ◽  
Parathyroid Glands ◽  
Control Group ◽  
Calcium Sensing Receptor ◽  
Spontaneously Hypertensive ◽  
Calcium Sensing ◽  
Arterial Blood ◽  
Male Wistar Rats ◽  
The Difference

Secretion of parathormone (PTH), the main parathyroid hormone, which is under the control of the calcium sensing receptor, might be inhibited by calcimimetics and stimulated by calcilytics. Parathyroid glands also secrete parathyroid hypertensive factor. Recently, it was shown that calcimimetic NPS R-568 induced decreased blood pressure in spontaneously hypertensive rats (SHR) in the presence of parathyroid glands. Therefore, the aim of this study was to determine whether administration of the calcilytic NPS 2143 provoked an increase of mean arterial blood pressure (MAP) in normotensive rats. We used male Wistar rats anaesthetized with thiopental. Clearance experiments were performed and the effect of bolus, 1 mg/kg body weight i.v. of NPS 2143 on MAP in the presence and absence of thyroparathyroidectomy (TPTX) was monitored continuously. Calcilytic properties of NPS 2143 were confirmed directly by a significant (P < 0.05) increase of plasma PTH concentration, and indirectly by a rise of plasma Ca2+ concentration and urinary fractional phosphate excretion (FE Pi). NPS 2143 administration markedly (P < 0.05) increased MAP, calculated as the difference ( Δ ) in MAP between sequential measurements and the time of bolus injection of calcilytic. The observed increase of blood pressure in the NPS 2143 group was also significant (P < 0.05) compared with the control group. Performance of TPTX prevented the hypertensive effect of NPS 2143. We conclude that NPS 2143 is responsible for increased blood pressure in rats in the presence of parathyroid glands.

Abstract 125: Elevated Muscle Sympathetic Nerve Activity is Associated With Higher Aortic and Carotid Stiffness Independent of Blood Pressure in Women

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Seth W Holwerda ◽  
Rachel E Luehrs ◽  
Nealy A Wooldridge ◽  
Lyndsey E DuBose ◽  
Jess G Fiedorowicz ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Arterial Stiffness ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Strongly Correlated ◽  
Nerve Activity ◽  
Arterial Blood ◽  
Age Related ◽  
Related Increase

Central arterial stiffness, a significant contributor to the development of hypertension and cardiovascular disease with aging, is linked to elevated muscle sympathetic nerve activity (MSNA) in men. However, the extent to which MSNA is associated with central arterial stiffness in women is unknown. Given that the age-related increase in MSNA and arterial blood pressure (BP) occurs at a steeper rate among women compared to men, we tested the hypothesis that resting MSNA is more strongly correlated with central arterial stiffness in women than in men. Also, because of the parallel age-related increase in MSNA, we further hypothesized that the relation between MSNA and central arterial stiffness would not be independent of age. MSNA (microneurography), aortic stiffness (carotid-femoral pulse wave velocity, CFPWV), and carotid β-stiffness (carotid tonometry and ultrasound) were assessed in 54 healthy men (n=29; 19-72 yrs; 30 ± 1 kg/m 2 ; systolic BP: 128 ± 3 mmHg) and women (n=26; 26-64 yrs; 29 ± 2 kg/m 2 ; systolic BP: 116 ± 3 mmHg). No differences between men and women were observed for CFPWV (Men: 7.0 ± 0.3 vs. Women: 6.8 ± 0.4 mmHg, P=0.747) and carotid β-stiffness (Men: 7.6 ± 0.8 vs. Women: 7.6 ± 0.5 mmHg, P=0.975). Mean BP was lower in women compared to men (Men: 93 ± 3 vs. Women: 85 ± 2 mmHg, P=0.021) and MSNA tended to be lower in women compared to men (Men: 25 ± 3 vs. Women: 20 ± 2 bursts/min, P=0.091). After adjusting for mean BP and HR (partial correlation), CFPWV was significantly correlated with MSNA in men (R=0.44, P=0.021) and women (R=0.58, P=0.004). Interestingly, further adjustment for age abolished the association between CFPWV and MSNA in men (R=0.01, P=0.968), but not in women (R=0.43, P=0.046). A moderate relation between carotid β-stiffness and MSNA was observed in men (R=0.37, P=0.063) and women (R=0.44, P=0.034), but was abolished after adjusting for age (Men: R=-0.001, P=0.995; Women: R=0.26, P=0.245). These preliminary data demonstrate that MSNA is positively correlated with central arterial stiffness in women and men independent of BP. Furthermore, abolishment of the relation between MSNA and CFPWV in men only when adjusting for age suggests that the association between MSNA and central arterial stiffness may be more robust in women.

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