Cardiac Output and Organ Blood Flow in Young Rabbits during Intermittent Positive-Pressure Ventilation

Neonatology ◽  
1983 ◽  
Vol 44 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Elizabeth John ◽  
Michael McDevitt ◽  
George Cassady
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Organ Blood Flow

Regional Organ Blood Flow during High-frequency Positive-pressure Ventilation (HFPPV) and Intermittent Positive-pressure Ventilation (IPPV)

1984 ◽  
Vol 61 (4) ◽  
pp. 416-419 ◽  
Author(s):  
Leonid Bunegin ◽  
R. Brian Smith ◽  
Ulf H. Sjostrand ◽  
Maurice S. Albin ◽  
Maciej F. Babinski ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Frequency ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Organ Blood Flow

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)

scholarly journals Influence of Cimetidine on Cardiovascular Parameters in Man

1979 ◽  
Vol 72 (12) ◽  
pp. 898-901 ◽  
Author(s):  
I O Samuel ◽  
J W Dundee
Keyword(s):  
Blood Pressure ◽  
Intensive Care Unit ◽  
Cardiac Output ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Dilution Method ◽  
Depressant Effect ◽  
Average Blood Pressure ◽  
Before And After

Cardiac output was measured in 10 patients using the dye dilution method, before and after the intravenous injection of 400 mg cimetidine. The subjects were in the intensive care unit and required intermittent positive pressure ventilation. There was no change in the average blood pressure, heart rate and cardiac output during the 60 minutes following the cimetidine, although one patient showed a marked fall in cardiac output. The results suggest that cimetidine is without a marked depressant effect on cardiovascular system.

Ventilation with external high frequency oscillation around a negative baseline increases pulmonary blood flow after the Fontan operation

1992 ◽  
Vol 2 (3) ◽  
pp. 277-280 ◽  
Author(s):  
Daniel J. Penny ◽  
Zamir Hayek ◽  
Peter Rawle ◽  
Michael L. Rigby ◽  
Andrew N. Redington
Keyword(s):  
Blood Flow ◽  
Negative Pressure ◽  
High Frequency ◽  
Pulmonary Blood Flow ◽  
Positive Pressure Ventilation ◽  
Fontan Operation ◽  
Intermittent Positive Pressure Ventilation ◽  
High Frequency Oscillation ◽  
Positive Pressure ◽  
Frequency Oscillation

AbstractIn this prospective study, pulmonary blood flow was measured using transesophageal Doppler echocardiography to assess whether ventilation by means of external high frequency oscillation around a negative pressure baseline can increase pulmonary blood flow, compared to intermittent positive pressure ventilation, in five patients after the Fontan operation. Pulmonary blood flow was measured when patients were ventilated by means of intermittent positive pressure ventilation and again during equivalent negative pressure ventilation using the external oscillatory technique. When compared to that with intermittent positive pressure ventilation, ventilation using external high frequency oscillation increased pulmonary blood flow by 116 ±61.5% (p=0.013). These results show that ventilation using an external oscillatory device with a mean negative chamber pressure may provide hemodynamic advantages in patients requiring assisted ventilation after the Fontan operation.

Effects of intermittent positive-pressure ventilation on cardiac output measurements by thermodilution

1986 ◽  
Vol 14 (11) ◽  
pp. 977-980 ◽  
Author(s):  
KAZUFUMI OKAMOTO ◽  
TORU KOMATSU ◽  
VIJAYA KUMAR ◽  
VAJUBHAI SANCHALA ◽  
KESHAV KUBAL ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Cardiac Output Measurements

Gas density dependence of regional VA/V and VA/Q inequality during constant-flow ventilation

1989 ◽  
Vol 66 (4) ◽  
pp. 1722-1729 ◽  
Author(s):  
P. T. Schumacker ◽  
R. W. Samsel ◽  
J. I. Sznajder ◽  
L. D. Wood ◽  
J. Solway
Keyword(s):  
Blood Flow ◽  
Regional Differences ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Constant Flow ◽  
Alveolar Pressure ◽  
Lung Inflation ◽  
Arterial Pco2 ◽  
Lung Motion

Constant-flow ventilation (CFV) is achieved by delivering a constant stream of inspiratory gas through cannulas aimed down the main stem bronchi at flow rates totaling 1–3 l.kg-1.min-1 in the absence of tidal lung motion. Previous studies have shown that CFV can maintain a normal arterial PCO2, although significant ventilation-perfusion (VA/Q) inequality appears. This VA/Q mismatch could be due to regional differences in lung inflation that occur during CFV secondary to momentum transfer from the inflowing stream to resident gas in the lung. We tested the hypothesis that substitution of a gas with lower density might attenuate regional differences in alveolar pressure and reduce the VA/Q inequality during CFV. Gas exchange was studied in seven anesthetized dogs by the multiple inert gas elimination technique during ventilation with intermittent positive-pressure ventilation, CFV with O2-enriched nitrogen (CFV-N2), or CFV with O2-enriched helium (CFV-He). As an index of VA/Q inequality independent of shunt, the log SD blood flow increased from 0.757 +/- 0.272 during intermittent positive-pressure ventilation to 1.54 +/- 0.36 (P less than 0.001) during CFV-N2. Switching from CFV-N2 to CFV-He at the same flow rate did not improve log SD blood flow (1.45 +/- 0.21) (P greater than 0.05) but tended to increase arterial PCO2. In excised lungs with alveolar capsules attached to the pleural surface, CFV-He significantly reduced alveolar pressure differences among lobes compared with CFV-N2 as predicted. Regional alveolar washout of Ar after a stap change of inspired concentration was slower during CFV--He than during CFV-N2.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of negative-pressure ventilation on lung water in permeability pulmonary edema

1989 ◽  
Vol 66 (5) ◽  
pp. 2223-2230 ◽  
Author(s):  
M. Skaburskis ◽  
R. P. Michel ◽  
A. Gatensby ◽  
A. Zidulka
Keyword(s):  
Cardiac Output ◽  
Pulmonary Edema ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Lung Water ◽  
Anesthetized Dogs ◽  
Water Accumulation ◽  
Permeability Pulmonary Edema ◽  
Continuous Positive Pressure

We have previously shown (Am. Rev. Respir. Dis. 136: 886–891, 1987) improved cardiac output in dogs with pulmonary edema ventilated with external continuous negative chest pressure ventilation (CNPV) using negative end-expiratory pressure (NEEP), compared with continuous positive-pressure ventilation (CPPV) using equivalent positive end-expiratory pressure (PEEP). The present study examined the effect on lung water of CNPV compared with CPPV to determine whether the increased venous return created by NEEP worsened pulmonary edema in dogs with acute lung injury. Oleic acid (0.06 ml/kg) was administered to 27 anesthetized dogs. Supine animals were then divided into three groups and ventilated for 6 h. The first group (n = 10) was treated with intermittent positive-pressure ventilation (IPPV) alone; the second (n = 9) received CNPV with 10 cmH2O NEEP; the third (n = 8) received CPPV with 10 cmH2O PEEP. CNPV and CPPV produced similar improvements in oxygenation over IPPV. However, cardiac output was significantly depressed by CPPV, but not by CNPV, when compared with IPPV. Although there were no differences in extravascular lung water (Qwl/dQl) between CNPV and CPPV, both significantly increased Qwl/dQl compared with IPPV (7.81 +/- 0.21 and 7.87 +/- 0.31 vs. 6.71 +/- 0.25, respectively, P less than 0.01 in both instances). CNPV and CPPV, but not IPPV, enhanced lung water accumulation in the perihilar areas where interstitial pressures may be most negative at higher lung volumes.

Effects of positive end-expiratory pressure on hepatic blood flow and performance

1987 ◽  
Vol 62 (4) ◽  
pp. 1377-1383 ◽  
Author(s):  
G. M. Matuschak ◽  
M. R. Pinsky ◽  
R. M. Rogers
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Hepatic Blood Flow ◽  
Positive Pressure Ventilation ◽  
Hepatic Function ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Intravascular Volume ◽  
Positive End Expiratory Pressure ◽  
Group I

Positive end-expiratory pressure (PEEP) may impair extrapulmonary organ function. However, the effects of PEEP on the liver are unclear. We tested the hypothesis that at a constant cardiac output (CO), PEEP does not induce changes in hepatic blood flow (QL) and parenchymal performance. In splenectomized, close-chested canine preparations (group I, n = 6), QL was derived as hepatic outflow using electromagnetic flow probes (QLemf), and hepatic performance was defined by extraction and clearance of indocyanine green (ICG). In a noninvasive model (group II, n = 7), the effects of PEEP on hepatic performance alone were similarly analyzed. Measurements were taken during intermittent positive-pressure ventilation (IPPV1), after addition of 10 cmH2O PEEP to IPPV (PEEP1), during continued PEEP but after return of CO to IPPV1 levels by intravascular volume infusions (PEEP2), and after removal of both PEEP and excess blood volume (IPPV2). Phasic inspiratory decreases in QLemf present during positive-pressure ventilation were not increased during either PEEP1 or PEEP2. Mean QLemf decreased proportionately with CO during PEEP1 (P less than 0.05), but was restored to IPPV1 levels in a parallel fashion with CO during PEEP2. The ICG pharmacokinetic responses to PEEP were complex, with differential effects on extraction and clearance. Despite this, hepatic performance was not imparied in either group. we conclude that global QL reductions during PEEP are proportional to PEEP-induced decreases in CO and are preventable by returning CO to pre-PEEP levels by intravascular volume infusions. However, covarying changes in blood volume and hepatic outflow resistance may independently modulate hepatic function.

Nasal Intermittent Positive Pressure Ventilation versus Continuous Positive Airway Pressure and Apnea of Prematurity: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Bayane Sabsabi ◽  
Ava Harrison ◽  
Laura Banfield ◽  
Amit Mukerji
Keyword(s):  
Systematic Review ◽  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Primary Outcome ◽  
Positive Pressure Ventilation ◽  
Positive Airway Pressure ◽  
Meta Analysis ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Apnea Of Prematurity

Objective The study aimed to systematically review and analyze the impact of nasal intermittent positive pressure ventilation (NIPPV) versus continuous positive airway pressure (CPAP) on apnea of prematurity (AOP) in preterm neonates. Study Design In this systematic review and meta-analysis, experimental studies enrolling preterm infants comparing NIPPV (synchronized, nonsynchronized, and bi-level) and CPAP (all types) were searched in multiple databases and screened for the assessment of AOP. Primary outcome was AOP frequency per hour (as defined by authors of included studies). Results Out of 4,980 articles identified, 18 studies were included with eight studies contributing to the primary outcome. All studies had a high risk of bias, with significant heterogeneity in definition and measurement of AOP. There was no difference in AOPs per hour between NIPPV versus CPAP (weighted mean difference = −0.19; 95% confidence interval [CI]: −0.76 to 0.37; eight studies, 456 patients). However, in a post hoc analysis evaluating the presence of any AOP (over varying time periods), the pooled odds ratio (OR) was lower with NIPPV (OR: 0.46; 95% CI: 0.32–0.67; 10 studies, 872 patients). Conclusion NIPPV was not associated with decrease in AOP frequency, although demonstrated lower odds of developing any AOP. However, definite recommendations cannot be made based on the quality of the published evidence. Key Points

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