atrial-natriuretic-factor and Respiratory-Insufficiency

To assess the influence of different positive end-expiratory pressure (PEEP) levels on plasma atrial natriuretic peptide concentrations.. Prospective, randomized study.. Intensive care unit of a university hospital.. Twenty-seven patients who were mechanically ventilated due to acute respiratory failure.. None.. The patients were randomized into three groups: in each group, a defined PEEP level (5, 10, or 15 cm H2O, respectively) was applied, alternating with zero PEEP (0 cm H2O) in consecutive order (reversal experiment). Blood samples for the determination of atrial natriuretic peptide concentrations were drawn from the pulmonary artery and the radial artery catheters. There were no decreases in atrial natriuretic peptide concentrations with a PEEP of 5 cm H2O, but significant decreases could be shown for PEEP values of 10 and 15 cm H2O. The patients of all groups were subjected to PEEP levels of 5, 10, 15, and 20 cm H2O in randomized order (step experiment). The data demonstrated a significant inverse correlation between changes in PEEP levels and changes in plasma atrial natriuretic peptide concentrations.. The data suggest that the release of atrial natriuretic peptide is influenced by a PEEP of > or = 10 cm H2O, while a PEEP of < or = 5 cm H2O does not disturb this cardiac endocrine function.

Topics: Adult; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Catecholamines; Female; Hemodynamics; Humans; Male; Middle Aged; Positive-Pressure Respiration; Pressure; Prospective Studies; Respiratory Insufficiency

Topics: Acute Disease; Atrial Natriuretic Factor; Diagnosis, Differential; Dyspnea; Heart Failure; Humans; Natriuretic Peptide, Brain; Respiratory Distress Syndrome; Respiratory Insufficiency

Plasma opioid peptides, norepinephrine, atrial natriuretic factor (ANF) and blood pressure (BP) were assessed in 24 chronic obstructive pulmonary disease patients with acute respiratory failure. Hypoxemic-hypercapnic patients had high BP, beta-endorphin, Met-enkephalin and dynorphin B, whereas hypoxemic-normocapnic and hypoxemic-hypocapnic patients showed normal BP, high beta-endorphin, and normal Met-enkephalin and dynorphin B. Norepinephrine and ANF were high in all patients, particularly in hypoxemic-hypercapnic patients. Infusion with the opioid antagonist naloxone hydrochloride significantly increased systolic blood pressure (SBP) in hypoxemic-hypercapnic (182.0 +/- 3.2 versus 205.1 +/- 3.0 mmHg; P < 0.01), hypoxemic-normocapnic (149.3 +/- 1.8 versus 169.1 +/- 2.2 mmHg; P < 0.01) and hypoxemic-hypocapnic (147.3 +/- 1.3 versus 166.8 +/- 2.2 mmHg; P < 0.01) patients, norepinephrine in hypoxemic-hypercapnic patients (3583.2 +/- 371.8 versus 5371.3 +/- 260.0 fmol/ml; P < 0.01), and reduced ANF in hypoxemic-normocapnic (18.3 +/- 0.8 versus 11.9 +/- 1.0 fmol/ml; P < 0.05) and hypoxemic-hypocapnic (18.1 +/- 1.2 versus 12.1 +/- 2.1 fmol/ml; P < 0.05) patients. These results indicate that the endogenous opioid system attenuates SBP responses in acute respiratory failure by affecting norepinephrine or ANF release.

Topics: Acute Disease; Adult; Aged; Atrial Natriuretic Factor; Blood Pressure; Female; Heart Rate; Humans; Male; Middle Aged; Naloxone; Norepinephrine; Opioid Peptides; Placebos; Respiratory Insufficiency

To investigate the effects of hypoxemia, hypercapnia, and cardiovascular hormones (norepinephrine, endothelin-1, and atrial natriuretic factor) on blood pressure during acute respiratory failure.. Patients with chronic obstructive pulmonary disease and acute respiratory failure were divided into four groups of 10 patients each: hypoxemia-normocapnia, hypoxemia-hypercapnia, hypoxemia-hypocapnia, and normoxemia-hypercapnia. Plasma norepinephrine levels were determined by high-performance liquid chromatography with electrochemical detection. Plasma endothelin-1 and atrial natriuretic factor levels were radioimmunoassayed after chromatographic preextraction.. Systolic blood pressure and cardiovascular hormone levels were greater in patients with hypercapnia (whether or not they also had hypoxemia) than in those with normocapnia and hypoxemia. For example, in patients with hypercapnia and normoxemia, the mean (+/- SD) systolic blood pressure was 183+/-31 mm Hg and the mean norepinephrine level was 494+/-107 pg/mL, as compared with 150+/- 6 mm Hg and 243+/-58 pg/mL in those with normocapnia and hypoxemia (both P<0.05). Similar results were seen for endothelin-1 and atrial natriuretic factor levels, and for the comparisons of hypoxemic patients who were hypercapnic with those who were normocapnic.. These results suggest that blood carbon dioxide levels, rather than oxygen levels, are responsible for hypertension during acute respiratory failure, perhaps as a result of enhanced sympatho-adrenergic activity.

Topics: Acute Disease; Adult; Aged; Atrial Natriuretic Factor; Blood Pressure; Carbon Dioxide; Endothelin-1; Female; Heart Rate; Humans; Hypercapnia; Hypertension; Hypocapnia; Hypoxia; Lung Diseases, Obstructive; Male; Middle Aged; Norepinephrine; Oxygen; Respiratory Insufficiency; Severity of Illness Index

Elevated plasma brain natriuretic peptide (BNP) levels have been described in patients with congestive heart failure and acute myocardial infarction. We measured plasma BNP levels in patients with chronic respiratory failure to evaluate the correlation between plasma BNP levels and pulmonary haemodynamics. Plasma BNP levels were measured in 28 patients with chronic respiratory failure accompanied by three underlying diseases [14 with chronic obstructive pulmonary disease (COPD), seven with sequelae of pulmonary tuberculosis (sequelae Tbc) and seven with diffuse panbronchiolitis (DPB)] by immunoradiometric assay methods (IRMA). Twenty-one of 28 patients had already received oxygen supplementation and 16 of 21 patients were treated as outpatients with home oxygen therapy. Plasma BNP levels were significantly elevated in patients with chronic respiratory failure complicated by cor pulmonale (81.5 +/- 13.1 pg ml-1) compared to patients without cor pulmonale (13.3 +/- 2.7 pg ml-1, P < 0.001). As controls, plasma BNP levels in 10 patients with primary lung cancer were studied, and the results (3.5 +/- 1.0 pg ml-1) were not significantly different from those of patients with chronic respiratory failure without cor pulmonale. Plasma BNP levels in 12 healthy subjects were also studied, and the results (7.2 +/- 1.0 pg ml-1) were not significantly different from those of the control subjects. Plasma BNP levels showed a weak linear correlation with systolic pulmonary arterial blood pressure, estimated by Doppler echocardiography (r = 0.43; P = 0.068), but there was no significant correlation between BNP levels and the degree of hypoxaemia (r = 0.30; P = 0.138). Plasma atrial natriuretic peptide (ANP) levels in patients with chronic respiratory failure were also measured using the same samples. Plasma ANP levels were also significantly elevated in patients with chronic respiratory failure complicated by cor pulmonale (80.8 +/- 12.1 pg ml-1) compared to patients without cor pulmonale (26.1 +/- 4.4 pg ml-1, P = 0.003). A significant correlation was found between plasma BNP and ANP levels (r = 0.68; P < 0.001). Our results suggest that the plasma BNP or ANP level may be a useful indicator for detecting the presence of cor pulmonale in patients with chronic respiratory failure.

Topics: Adult; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Female; Humans; Immunoradiometric Assay; Lung Diseases, Obstructive; Male; Middle Aged; Natriuretic Peptide, Brain; Pulmonary Heart Disease; Respiratory Insufficiency

The pituitary-thyroid axis and neurohumoral activation indexes were simultaneously investigated in 16 in-patients hospitalized for cardiac heart failure (CHF), New York Heart Association (NYHA), class II-IV, and Killip clinical scale, class II-III, to evaluate their relationship with CHF morbidity and the relative prognostic value. At entry the patients were divided into two subgroups (A and B), according to the severity of CHF. Patients were further classified into two subgroups, according to the subsequent clinical course (C, poor outcome and D, improved clinical course). Blood samples were obtained every day for the radioimmunoassay measurement of plasma alpha-atrial natriuretic peptide (alphaANP), arginine vasopressin (AVP), and thyroid hormones, and the results were compared with those of 12 control subjects. At admission, alphaANP and 3,3',5'-triiodothyronine (rT3) values were higher, while 3,3',5-triiodothyronine (T3) to rT3 (T3/rT3) ratio was lower in subgroups A and B than in controls (p<0.001), respectively, and in C than in D (p<0.001), respectively, according to the prognosis. Conversely, no differences in other thyroid indexes, nor a significant correlation between alphaANP and either rT3 or T3/rT3 ratio were present in any of the subgroups. AVP plasma levels in subgroup A were not statistically different from those of controls, whereas they were significantly decreased in subgroups B and C (p<0.05) and D (p<0.001). In conclusion, these results indicate that in CHF the pituitary-thyroid axis is not altered, that alphaANP and T3/rT3 ratio are non-invasive and reliable predictors of severity and prognosis, while AVP might be affected by the different pathological processes leading to CHF or by the concomitant use of drugs.

Topics: Acute Disease; Aged; Aged, 80 and over; Arginine Vasopressin; Atrial Natriuretic Factor; Female; Follow-Up Studies; Heart Failure; Hospitalization; Humans; Male; Middle Aged; Pituitary Gland; Prognosis; Respiratory Insufficiency; Thyroid Function Tests; Thyroid Gland

The aim of this study was to investigate the haemodynamic and endocrinological effects of noninvasive positive pressure ventilation (NIPPV). Eleven patients with oedema and recent hypercapnic and hypoxaemic worsening of a chronic respiratory insufficiency were included. Echocardiography, cardiac radionuclide assessment, blood catecholamines, salt and water handling hormones were measured at admission and discharge (long study (LS)). To discriminate between the action of NIPPV and other treatments, measurements were performed on the fourth day, for 4 h without NIPPV and 4 h with NIPPV (short study (SS)). NIPPV entailed a correction of P(a,CO2) and an increase of P(a,O2) in LS and SS. Oedema disappeared. Body weight decreased (from 85+/-42 to 81+/-40 kg) during LS. Systolic and mean pulmonary arterial pressure decreased in LS and SS. Right ventricular ejection fraction increased in LS. Left ventricular ejection fraction did not change. Cardiac index was normal on admission and then decreased. Natriuretic peptides and catecholamines were increased on admission, whereas plasma renin activity, aldosterone and vasopressin were normal. We suggest that in these patients, oedema can occur independently of renin-angiotensin-aldosterone-vasopressin and with a normal cardiac output. Noninvasive positive pressure ventilation allowed a correction of blood gases, associated with the resolution of oedema, a decrease in pulmonary arterial pressures and an increase in right ventricular ejection fraction.

Topics: Atrial Natriuretic Factor; Body Composition; Case-Control Studies; Edema; Female; Hemodynamics; Hormones; Humans; Hypercapnia; Intermittent Positive-Pressure Ventilation; Male; Middle Aged; Natriuretic Peptide, Brain; Nerve Tissue Proteins; Pulmonary Wedge Pressure; Respiratory Insufficiency; Ventricular Function, Right; Water-Electrolyte Balance

To quantify the hemodynamic effects of turning critically ill, mechanically ventilated patients to the extreme left and right lateral postures.. Prospective investigation.. Eight-bed intensive care unit in a university hospital.. Twelve consecutive patients presenting with severe respiratory failure and requiring continuous positive inotropic support.. All patients were mechanically ventilated and placed in a kinetic treatment system. They were positioned in the supine, left dependent, and right dependent postures, resting for 15 min in each position.. Hemodynamic measurements, assessments of right ventricular function, and determinations of intrathoracic blood volume were performed in three different positions. Concentrations of atrial natriuretic peptide in plasma were quantified. In three patients, the findings were controlled by transesophageal echocardiography. Cardiac index [median (range) 5.5 (3.2-8.1) vs 4.3 (3.2-7.5) l/min per m2, p < 0.01], intrathoracic blood volume [1125 (820-1394) vs 1037 (821-1267) ml/m2, p < 0.01], and right ventricular end-diastolic volume [130 (83-159) vs 114 (79-155) ml/m2, p < 0.05] increased significantly in the left dependent position compared to supine. Mean arterial pressure did not change. Atrial natriuretic peptide levels rose from 140 to 203 pg/ml. In the right dependent position, we found a marked decrease in the mean arterial pressure [85 mmHg (supine) to 72 mmHg (right dependent), p < 0.01]. Cardiac index and intrathoracic blood volume were unchanged, but right ventricular end-diastolic volume decreased from 114 to 102 ml/m2 (p < 0.05). Additionally, atrial natriuretic peptide levels decreased significantly (median delta value: 37 pg/ml). In echocardiographic controls we found an increase in right ventricular end-diastolic diameters in the left dependent position and shortened diameters in the right dependent position.. Extreme lateral posture affects the cardiovascular system in critically ill, mechanically ventilated patients: in the left dependent position a "hyperdynamic state" is reinforced, while the right decubitus position impairs right ventricular preload and predisposes to hypotension. Echocardiography and changes in plasma atrial natriuretic peptide values indicate that these findings are due to altered distensibility of the right ventricle caused by regional intrathoracic gravitational changes. We conclude that the duration and the angle of lateral posture should be restricted in hemodynamically unstable patients.

Topics: Acute Disease; Aged; Atrial Natriuretic Factor; Critical Illness; Echocardiography, Transesophageal; Female; Hemodynamics; Humans; Male; Middle Aged; Monitoring, Physiologic; Posture; Prospective Studies; Respiration, Artificial; Respiratory Insufficiency

To clarify which endocrine modifications can be observed in acute hypoxaemic respiratory failure, 15 severely ill male patients [PAT; median age: 61 (range: 48 years); median height: 173 (range: 12) cm; median mass: 73 (range 31) kg] were investigated immediately upon admission to an intensive care unit (ICU) for this clinical disorder. Before starting treatment, the blood gases were measured and a number of selected hormones with special relevance for an ICU setting were determined. These are known to be modified by acute hypoxaemia in healthy subjects and to possess glucoregulatory properties, or an influence upon cardiocirculation or the vascular volume regulation: insulin, cortisol, adrenaline, noradrenaline, atrial natriuretic peptide, renin, aldosterone, angiotensin converting enzyme, and endothelin-I (ET). To elucidate whether potential endocrine changes resulted from acute hypoxaemia alone, the underlying disease, or unspecific influences connected with the ICU setting, all measurements were compared to those of a completely healthy reference group (REF) with comparable acute experimental hypoxaemia. The latter state was achieved by having the REF breathe a gas mixture with the oxygen content reduced to 14% (H). In the REF, neither the medians nor the distribution of endocrinologic measurements were modified significantly by acute hypoxaemia. In the PAT, the medians were increased considerably, yet with a slight diminution of ET. The distribution of individual values was considerably broader than in the REF with H. In conclusion, considerable increases in the means of the above hormones, with the exception of ET, can be registered in severely ill patients admitted to ICUs with acute hypoxaemic failure. However, such modifications cannot be considered attributable exclusively to acute arterial hypoxaemia. The underlying clinical disorders, such as septicaemia or an unspecific endocrine epiphenomenon, including severe and not only hypoxaemic stress, seem to be predominant.

Topics: Acute Disease; Adult; Aged; Aldosterone; Atrial Natriuretic Factor; C-Peptide; Critical Care; Endocrine Glands; Endothelins; Epinephrine; Humans; Hydrocortisone; Hypoxia; Insulin; Male; Middle Aged; Norepinephrine; Peptidyl-Dipeptidase A; Pneumonia; Renin; Respiratory Insufficiency

We previously reported the clinical role of plasma immunoreactive atrial natriuretic polypeptide (ANP) and cyclic GMP in patients with respiratory diseases, bronchial asthma (BA), chronic pulmonary emphysema (CPE) and pulmonary insufficiency induced by pulmonary tuberculosis (TBC). In this study, moreover, we divided patients with respiratory failure induced by tuberculosis sequelae into two groups, patients with oxygen therapy group [O2 (+) group] or ordinary practical treatment group [O2 (-) group], and we evaluated the difference of the roles of ANP in two groups and the correlation of ANP and c-GMP with clinical findings, blood gas analysis, electrocardiogram, chest roentogen photography and spirogram in two groups. In conclusion, the respiratory failure in patients with tuberculosis sequelae is compensated by increased cardiac output, and that causes the rising of right atrial pressure. These results show, addition to the basic effects of ANP, the concentration of plasma ANP is released with relating the degree of respiratory failure.

Topics: Adult; Aged; Atrial Natriuretic Factor; Cyclic GMP; Humans; Middle Aged; Respiratory Insufficiency; Tuberculosis, Pulmonary

The purpose of this study was to evaluate the pathophysiologic role of atrial natriuretic peptide (ANP) as a pulmonary artery vasodilator in patients with acute respiratory failure receiving artificial ventilation. Twenty-one consecutive patients were studied, 12 without and 9 with preexisting cardiopulmonary disease. Pulmonary artery plasma ANP levels were significantly higher than the levels obtained in the superior vena cava and radial artery. Plasma ANP levels correlated significantly with the plasma levels of its second messenger, guanosine 3',5'-cyclic monophosphate (cGMP). In the 12 patients without prior cardiopulmonary disease, plasma ANP levels correlated significantly with mean pulmonary arterial pressure (MPAP). This correlation was not found in the nine patients with preexisting cardiopulmonary disease. The cGMP/ANP ratio, indicating the biologic effect of ANP, was also higher in the patients without preexisting cardiopulmonary disease. These results are compatible with clearance and vasodilator activity of ANP in the pulmonary vascular bed, but only in patients without preexisting cardiopulmonary disease.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Atrial Function, Right; Atrial Natriuretic Factor; Blood Pressure; Cyclic GMP; Female; Heart Failure; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Artery; Pulmonary Fibrosis; Radial Artery; Respiration, Artificial; Respiratory Insufficiency; Vena Cava, Superior

Plasma alpha-atrial natriuretic peptide (alpha-ANP) concentrations were measured during mechanical ventilation in nine patients with acute respiratory failure (ARF) associated with sepsis. The relationships between alpha-ANP and pulmonary hemodynamic variables were examined. A total of 22 measurements of alpha-ANP and other variables were obtained. The mean plasma alpha-ANP concentration of 22 measurements was 120.1 +/- 79.8 pg/ml (normal 31.7 +/- 12.0, mean +/- SD). Plasma alpha-ANP concentrations correlated with mean pulmonary artery pressure (MPAP) (r = .703, p less than .01) and pulmonary vascular resistance (PVR) (r = .606, p less than .01), but not with other variables. These findings suggest that alpha-ANP elevation may be related to the increases in MPAP and PVR in ARF associated with sepsis.

Topics: Aged; Aged, 80 and over; Atrial Natriuretic Factor; Blood Pressure; Humans; Middle Aged; Pulmonary Artery; Respiration, Artificial; Respiratory Insufficiency; Sepsis; Vascular Resistance

Mechanical ventilation with positive end-expiratory pressure (PEEP) decreases urine output and urinary sodium excretion. The influence of PEEP during controlled mechanical ventilation on the circulating concentrations of the N-terminus and C-terminus of the atrial natriuretic factor (ANF) prohormone which both contain natriuretic and diuretic peptides was investigated in 7 patients with acute respiratory failure. The 98 amino acid (aa) N-terminus, the midportion of the N-terminus consisting of aa 31-67 of the 126 aa ANF prohormone (i.e., pro ANF 31-67) and the C-terminus (aa 99-126; ANF) were found to be significantly (p less than 0.05; ANOVA) elevated compared to 54 healthy volunteers during acute respiratory failure prior to institution of PEEP. With institution of 10 cm of H2O of PEEP all 7 patients had a significant (p less than 0.05) decrease in the circulating concentrations of pro ANFs 1-98, 31-67 and ANF. These findings suggest that the increased thoracic pressure secondary to PEEP which reduces venous return and lowers atrial filling pressure results in a decreased release of the N-terminus and C-terminus of the ANF prohormone. This decrease in the N-terminus and C-terminus of the ANF prohormone appears to represent a physiologic mechanism for restoration of intravascular volume, secondary to decreased sodium excretion.

Topics: Acute Disease; Aged; Atrial Natriuretic Factor; Humans; Male; Middle Aged; Natriuresis; Peptide Fragments; Positive-Pressure Respiration; Protein Precursors; Respiration, Artificial; Respiratory Insufficiency

To investigate the potential role of natriuretic factor (ANF) on changes on renal excretory function in response to increased intrathoracic pressure, seven patients were studied during three successive 60-min periods of 1) mechanical ventilation (MV) and zero end-expiratory pressure (ZEEP), 2) MV with 12 cmH2O positive end-expiratory pressure (PEEP), and 3) MV with the same level of PEEP while lower-body positive pressure (LBPP) was applied to restore venous return and increase central blood volume without fluid loading. Hemodynamics, renal excretory function parameters, and plasma immunoreactive atrial natriuretic factor (irANF) levels were recorded at the end of each period. Compared with ZEEP, PEEP induced a significant reduction of diuresis (from 134 +/- 17 to 59 +/- 13 ml/h, P less than 0.01) and natriuresis (from 8.37 +/- 3.5 to 3.83 +/- 2 mmol/h, P less than 0.01), whereas plasma irANF fell from 520 +/- 292 to 155 +/- 40 pg/ml (P less than 0.01) and transmural right atrial pressure decreased from 3.9 +/- 0.5 to 2.4 +/- 0.3 mmHg (P less than 0.01). Opposite changes were observed during application of LBPP, which restored diuresis and plasma irANF to near control ZEEP values, despite continuation of PEEP. Changes in renal excretory function parameters thus paralleled changes in right atrial pressure and plasma irANF. We suggest that changes in plasma irANF in response to hemodynamic variations induced by changes in intrathoracic pressure may contribute to alterations of renal excretory function during PEEP.

Topics: Adult; Aged; Atrial Natriuretic Factor; Diuresis; Female; Hemodynamics; Hormones; Humans; Kidney; Male; Middle Aged; Oxygen; Positive-Pressure Respiration; Respiratory Insufficiency

Topics: Adult; Aged; Atrial Natriuretic Factor; Blood Pressure; Chronic Disease; Female; Humans; Male; Middle Aged; Pulmonary Circulation; Respiratory Insufficiency

Topics: Aged; Atrial Natriuretic Factor; Female; Humans; Male; Middle Aged; Respiratory Insufficiency