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Biomedical subjects

D J Dries

Publications and source records attributed to D J Dries.

At least 19 recordsLinked to original sources
PubMed1992

Aggressive hydration during continuous positive-pressure ventilation restores atrial transmural pressure, plasma atrial natriuretic peptide concentrations, and renal function.

BACKGROUND AND METHODS: The correlations between continuous positive-pressure ventilation-induced antidiuresis/antinatriuresis, atrial transmural pressure, and atrial natriuretic peptide concentrations have not been clarified. The purpose of the present study was to use aggressive hydration to restore atrial transmural pressure during continuous positive-pressure ventilation and to test for correlations of atrial transmural pressure, atrial natriuretic peptide concentration, diuresis, and natriuresis during this intervention. An intrapleural catheter was used to measure atrial transmural pressure in three ways: a) right atrial pressure minus intrapleural pressure, b) left ventricular end-diastolic pressure minus intrapleural pressure, and c) pulmonary artery occlusion pressure minus intrapleural pressure. Hemodynamic, atrial natriuretic peptide concentrations, and renal measurements were made in 12 anesthetized closed-chest dogs during baseline (intermittent positive-pressure ventilation), during continuous positive-pressure ventilation), during continuous positive-pressure ventilation with 10 cm H2O end-expiratory pressure, and during continuous positive-pressure ventilation plus aggressive hydration (approximately 60 mL/kg lactated Ringer's solution). Pearson's correlation matrix was used to generate all possible correlation coefficients between the three atrial transmural pressures, atrial natriuretic peptide concentrations, urine output, and urine sodium excretion. RESULTS: Application of continuous positive-pressure ventilation resulted in a 60% decrease in right atrial transmural pressure (p less than .05), a 51% decrease in left ventricular end-diastolic transmural pressure (p less than .05), and a 26% decrease in pulmonary artery occlusion transmural pressure (p less than .05) from baseline. Plasma atrial natriuretic peptide concentration decreased from 80 +/- 12 (SEM) pg/mL at baseline to 49 +/- 8 pg/mL during continuous positive-pressure ventilation (p less than .05). Both urine output and sodium excretion decreased by 81% (p less than .05). After aggressive hydration with lactated Ringer's solution during continuous positive-pressure ventilation, to restore atrial transmural pressure to baseline, plasma atrial natriuretic peptide concentration returned to baseline values (81 +/- 12 pg/mL) as did urine output and sodium excretion. Correlation indices (r2 values) between transmural pressure, atrial natriuretic peptide concentration, urine output, and sodium excretion ranged from .835 to .994. Multivariate analysis of covariance demonstrated significant (p less than .05) temporal dependence between the three transmural pressures, atrial natriuretic peptide concentration, urine output, and sodium excretion. CONCLUSIONS: The results demonstrate that aggressive hydration during continuous positive-pressure ventilation will restore diuresis and natriuresis and that this response correlates significantly with atrial transmural filling pressure and plasma atrial natriuretic peptide concentration.

Animals↗
PubMed1992

Myocardial metabolism and adaptation during extreme hemodilution in humans after coronary revascularization.

OBJECTIVE: This study was designed to evaluate the oxygen transport adjustments and myocardial metabolic adaptation that occurs with different levels of hemodilution during normothermia after cardiopulmonary bypass. DESIGN: Prospective, nonrandomized study. SETTING: Operating room in a university hospital. PATIENTS: Eight patients with ejection fractions (> 40%) undergoing elective coronary artery bypass grafting. METHODS: Before the institution of cardiopulmonary bypass, blood was withdrawn from patients to a target hematocrit of 15%. After coronary artery bypass grafting, a catheter was inserted directly into the coronary sinus. After the patients were rewarmed to 37 degrees C, they were weaned from cardiopulmonary bypass. Hemodynamic indices were measured, as well as measurements of myocardial oxygen consumption (VO2) and myocardial metabolism (lactate extraction and coronary sinus hypoxanthine). Measurements were made at three different hematocrit values: 15%, 20%, and 25%. Hematocrit was increased by autologous blood transfusion. MEASUREMENTS AND MAIN RESULTS: The three levels of hemodilution (hematocrit: 17.4 +/- 3.4%; 23.0 +/- 3.7%; 27.8 +/- 4.8%) were significantly different from baseline (hematocrit 37 +/- 2.6%; p < .05). Oxygen delivery, which increased with autologous transfusion, exceeded 350 mL/min/m2 at each level of dilution. The myocardial VO2 increased significantly after autologous transfusion compared with the most dilute condition (7.0 +/- 3.7 mL/min at hematocrit 17.4% vs. 11.2 +/- 4.8 mL/min at hematocrit 23.0% and 12.4 +/- 4.0 mL/min at hematocrit 27.8%). This transfusion-induced increase was also true of myocardial oxygen extraction. Lactate extraction and hypoxanthine release were normal and unchanged at each level of hemodilution. Systemic oxygen extraction ratio increased with hemodilution and decreased with autologous transfusion. CONCLUSIONS: Hemodilution to a hematocrit of approximately 15% is tolerated in anesthetized humans after coronary artery bypass surgery. There was no evidence of myocardial ischemia, as demonstrated by absence of S-T depression on the electrocardiogram, lactate extraction, or hypoxanthine release. In selected patients, postoperative transfusion may be based on systemic physiologic end-points, such as oxygen extraction ratio, rather than set hematocrit values.

Blood Transfusion, Autologous↗
PubMed1992

Predictors of blinding or serious eye injury in blunt trauma.

Multivariate analysis was used to identify factors predicting injury and visual outcome in 94 blunt trauma patients evaluated for eye injuries among 6700 admissions to a level I trauma center over a 29-month period. Patients with penetrating eye injuries were excluded from this review. Eye injury was detected in 93% or 87 of the patients evaluated. Seven percent of eye injuries resulted in blindness, 22% were serious (visual acuity between 20/40 and 20/200 or eye injury requiring surgery), and 71% were temporary (final visual acuity of 20/40 or better). The presence of an afferent pupillary defect or a nonreactive pupil was the most important factor in predicting the severity of eye injury (p = 0.0023), followed by facial fractures (p = 0.0084), and no eye opening or eye opening to pain within the Glasgow Coma Scale (p = 0.02). Eye injury is an infrequent complication of blunt trauma. Appropriate consultation for evaluation of this problem can be obtained based on findings from the initial history and screening physical examination.

Adolescent↗
PubMed1992

Atrial natriuretic peptide may not play a role in diuresis and natriuresis after cardiac operations.

Human atria through release of atrial natriuretic peptide play an important role in extracellular fluid homeostasis. This study investigates the perioperative role of atrial natriuretic peptide, renin, angiotensin, aldosterone, and vasopressin in patient response to cardiopulmonary bypass after coronary artery bypass operations. Serum levels of these hormones were measured, along with hemodynamic profiles, urine output, and urine electrolytes, before induction of anesthesia, after discontinuation of cardiopulmonary bypass, 1 hour postoperatively, and 3 hours postoperatively. Serum levels of atrial natriuretic peptide were found to be significantly elevated immediately after discontinuation of cardiopulmonary bypass. These elevations did not correspond temporally to elevated central venous pressure or tachycardia. Significant natriuresis and diuresis were observed during the first postoperative hour. This diuresis failed to correspond temporally with alterations noted in serum levels of atrial natriuretic peptide, renin, angiotensin, aldosterone, and vasopressin. The mechanism responsible for the increases in serum atrial natriuretic peptide and the postoperative natriuresis and diuresis after cardiopulmonary bypass remain unknown.

Aged↗
PubMed1991

Adequate resuscitation of burn patients may not be measured by urine output and vital signs.

OBJECTIVE: To compare vital sign and urine output monitoring of seriously burned patients with invasive monitoring during early resuscitation. DESIGN: Retrospective review. SETTING: A university hospital burn unit. PATIENTS: Fourteen seriously burned patients who had pulmonary arterial monitoring. Monitoring data were compared at baseline and after fluid challenges. RESULTS: There was no correlation between invasively derived physiologic variables and vital signs and urine output. Vital signs and urine output changed little after fluid challenge, while variables from invasive monitoring demonstrated significant change. In half of the patients, oxygen consumption increased after fluid challenge; vital signs and urine output did not distinguish these patients. CONCLUSIONS: The use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive cardiorespiratory monitoring may be necessary to optimize resuscitation of seriously burned patients.

Adolescent↗
PubMed1991

Transoral crossbow injury to the cervical spine: an unusual case of penetrating cervical spine injury.

The complexity of missile injuries to the cervical spine has increased as the technology that causes these injuries has become more sophisticated. Management requires adaptation of conventional neurosurgical approaches to the cervical spine in an effort to limit neurological deficit and establish stability. We report an unusual case of a 19-year-old man who suffered transoral penetration of the cervical spine by an arrow released by a crossbow at close range.

Adult↗
PubMed1991

Pressure support. Changes in ventilatory pattern and components of the work of breathing.

To evaluate the interaction between patient and ventilator during widely varying levels of pressure support (PS) ventilation, we studied 33 patients who had undergone aortocoronary bypass. All patients were without preoperative evidence of lung disease and had left ventricular ejection fractions greater than 45 percent. We assessed both changes in ventilatory pattern and the use of an extension of the Campbell technique to determine the components of the mechanical work of breathing (WOB). Patients were placed on 0, 10, 20, and 30 cm H2O of PS. We found that increasing the pressure support level (PSL) did not change minute ventilation, PCO2, or pH despite large changes in both rate and depth of breathing. The inspiratory time fraction was consistently and progressively reduced as PS increased. Although mean inspiratory flow (MIF) increased by 75 +/- 9 (SE) percent as the PSL increased to 30 cm H2O, mean airway pressure rose only 3.5 +/- 0.1 cm H2O. Observed changes in the resistive and elastic components of WOB at PSL greater than 0 were consistent with values predicted from baseline observations and changes in VT and MIF demonstrating that the Campbell technique of separating resistive and elastic components of the patient's WOB during unassisted ventilation can be extended to the analysis of WOB during mechanical ventilation. We were surprised to observe that although inspiratory WOB fell 67 +/- 13 percent as the PSL increased to 30 cm H2O, postinspiratory work by the inspiratory muscles (WOBPIIM) did not show significant change. The persistence and substantial values of WOBPIIM in some patients suggested the presence of significant patient-ventilator dyssynchrony, especially at higher levels of PS. Total inspiratory WOB per minute, including both patient WOB and WOB by the ventilator, increased by 186 +/- 29 percent, demonstrating that PS results in a respiratory pattern requiring substantially greater total mechanical work.

Aged↗
PubMed1991

Effect of fast vs slow intralipid infusion on gas exchange, pulmonary hemodynamics, and prostaglandin metabolism.

Intralipid (20 percent, 500 ml) was infused fast (5 h) or slow (10 h) randomly in patients with lung injury to relate changes in plasma prostaglandin (PG) concentrations to gas exchange and pulmonary hemodynamics. Data were collected at baseline, midpoint of infusion, and 2 h following infusion. Vasodilator and vasoconstrictor PG metabolites, 6-keto-PGF1 alpha, and thromboxane B2, respectively, were measured in radial arterial blood samples. Slow Intralipid infusion increased shunt fraction (QS/QT) without changing mean pulmonary artery pressure (MPAP), whereas fast Intralipid infusion increased MPAP without changing QS/QT. Prostaglandin levels did not change significantly during either infusion. However, in both groups when the PG substrate was removed, hemodynamic and metabolite values decreased in parallel. In conclusion, we were unable to demonstrate a cause and effect relationship between plasma levels of 6-keto-PGF1 alpha and thromboxane B2 and the observed pulmonary hemodynamic response to slow or fast Intralipid infusion.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Hemodynamic effects of pressure support ventilation in cardiac surgery patients.

Hemodynamic consequences of pressure support ventilation (PSV) were compared with intermittent mandatory ventilation (IMV) in 20 patients following aortocoronary bypass. On the morning following surgery, all patients were weaned by IMV to a rate of eight breaths per minute, tidal volume of 12 ml/kg and inspired oxygen concentration of 40 per cent. With patients awake and able to breath spontaneously, PSV was begun at 20 cm of water. In patients with static lung compliance, less than 0.06 l/cm H2O, 30 cm H2O of PSV was used. Subsequently, all patients were weaned to PSV 10 cm of water, continuous positive airway pressure (CPAP) at 5 cm water and extubated. Hemodynamic data including oxygen transport were obtained at each level of PSV and at IMV prior to weaning. Analysis using ANOVA showed comparable hemodynamic and oxygen transport parameters for PSV of 30 cm H2O in comparison with IMV. PSV at levels of 20 and 10 cm H2O produced statistically significant increases in heart rate, mean arterial pressure, central venous pressure, and pulmonary capillary wedge pressure. Cardiac output was stable, and these increases were not clinically significant. In awake patients following cardiac surgery, PSV up to 30 cm H2O can be safely applied without hemodynamic embarrassment in patients with good left ventricular ejection fractions.

Blood Gas Analysis↗
PubMed1990

Hemodynamic compromise associated with air trapping following coronary artery bypass surgery.

Cardiovascular collapse due to pulmonary hyperinflation was noted in a patient with chronic obstructive pulmonary disease following median sternotomy for cardiac surgery. Treatment included bronchodilator therapy to reduce airway obstruction, limitation of minute ventilation, and increasing time available for exhalation. High inspiratory flow rates and expiratory retard may be beneficial.

Acute Disease↗
PubMed1990

Effect of cardiac output on gas exchange in one-lung atelectasis.

To evaluate the effect of administration of dobutamine on gas exchange in patients with one-lung atelectasis during pneumonectomy, ten patients with normal pulmonary function and localized carcinoma of the lung were studied during pulmonary resection. With each patient in the lateral decubitus position, hemodynamic profiles and oxygen transport data were recorded before and after administration of dobutamine at 5 micrograms/kg/min. Patients were ventilated with one-lung anesthesia and administration of 100 percent oxygen. With infusion of dobutamine, the heart rate, cardiac index, and LVSWI significantly increased. Mean arterial pressure increased while PAP fell. Systemic and pulmonary vascular resistance also declined. Arterial oxygenization and delivery improved, while oxygen uptake was unchanged. Pulmonary shunt fraction was significantly reduced. While the mechanism for shunt reduction in our patients is unclear, operative factors may include pulmonary vasodilation with dobutamine inhibition of HPV. The negative impact of reduced HPV may have been lessened by gravitational distribution of blood flow and dobutamine-mediated reduction in PAP in our patients.

Aged↗
PubMed1990

Effect of opening the pericardium on right ventricular hemodynamics during cardiac surgery.

The impact of the pericardium on right ventricular performance in the presence of normal filling pressures was evaluated using a rapid response RVEF thermodilution pulmonary artery catheter and TEE. In eight patients with normal right coronary arteries undergoing coronary artery bypass surgery, hemodynamic measurements revealed increased right ventricular end-diastolic and end-systolic volumes with diminished RVEF after opening the pericardium. In eight additional patients with right coronary artery disease, directionally similar changes in right ventricular volume were seen. Ejection fraction, however, was unchanged possibly due to altered right ventricular compliance. Echocardiogram evaluation of right ventricular area changes in patients with compromised right coronary systems corresponded to ejection fraction determinations obtained with thermodilution technique.

Cardiac Surgical Procedures↗
PubMed1990

Permeability pulmonary edema following lung resection.

The etiology of edema associated with pulmonary resection was investigated in five patients during the immediate postoperative period. Three patients received pneumonectomy while two patients had one lobe resected. All patients suffered from severe respiratory distress and had x-ray evidence of diffuse interstitial pulmonary edema within 12 hours of surgery. Hemodynamic data were obtained with radial and pulmonary artery catheters. Edema fluid was obtained along with blood samples for simultaneous determination of protein and albumin content. All patients studied had normal or high cardiac output, normal cardiac filling pressures, and edema fluid protein to serum protein ratio of 0.6 or greater suggestive of permeability changes contributing to edema fluid accumulation. Calculated shunt fraction exceeded 25 percent in all patients. Pulmonary edema has been noted in patients following pulmonary resection in the early postoperative period. In patients reviewed here, two factors appeared to be significant. First is an increase in pulmonary capillary pressure associated with passage of a normal to high cardiac output in a reduced volume pulmonary vascular bed. The second factor, as demonstrated by protein content in the edema fluid, is injury to the alveolar capillary membrane.

Blood Proteins↗
PubMed1990

Calcitonin gene-related peptide levels are elevated in patients with sepsis.

Calcitonin gene-related peptide (CGRP), an endogenous vasoactive peptide encoded by the calcitonin gene in nerve cells, is distributed throughout the cardiovascular system and is a potent vasodilator. Plasma levels of CGRP have been elevated in animal models with sepsis. This study was designed to determine whether plasma CGRP levels are elevated in patients with sepsis and perhaps contribute to the hyperdynamic cardiovascular state in sepsis. Plasma CGRP levels were obtained from normal healthy volunteers and from patients with sepsis. Volunteers were afebrile and had normal pulse and blood pressure. Patients with sepsis were selected according to the following criteria: (1) temperature higher than 38.5 degrees C, (2) white blood count greater than 14,000/ml, (3) positive blood culture of bacterial organisms, (4) hemodynamic parameters consistent with hyperdynamic sepsis, and (5) negative history of thyroid or other endocrine abnormalities. CGRP was extracted and assayed by radioimmunoassay for iodine 125-labeled human CGRP. In patients with sepsis, the cardiac index was 5.4 +/- 0.5 L/min/m2 (normal, 3.0); systemic vascular resistance was 7.1 +/- 0.5 mm Hg/L/min (normal, 16); oxygen delivery was 1496 +/- 137 ml/min (normal, 1000). Plasma CGRP levels were significantly elevated in the patients with sepsis, 14.9 +/- 3.2 pg/ml, compared to plasma CGRP levels in control volunteers, 2.0 +/- 0.3 pg/ml (p less than 0.0005). These elevated levels of CGRP may contribute to the decreased vascular resistance and increased cardiac output in the hyperdynamic septic state.

Adult↗
PubMed1987

Endoscopic laser resection of atherosclerotic plaque in a live animal model. A preliminary report on some technical difficulties.

This study was designed to determine whether laser energy could be used effectively to resect atherosclerotic plaque through an endoscope in a live animal model. Twelve adult Yorkshire swine with infrarenal aortic atherosclerosis had a 2.5 mm and/or 3.2 mm diameter fiberscope passed into the aorta from the femoral artery after proximal aortic balloon occlusion. Endoscopic argon laser resection of the atherosclerotic plaque was then attempted in eight pigs with an argon laser fiber (60 to 400 microns). We were able to visualize the raised atherosclerotic plaque in all 12 pigs with the larger 3.2 mm diameter fiberscope, which was easily passed into the aortoiliac system from the 4 mm diameter femoral vessel. The articulating end feature enhanced maneuverability within the lumen and allowed laser fiber direction. The 2.5 mm endoscope did not allow adequate visualization in any pig since the vessel could not be cleared of blood. The 2.5 mm endoscope was also passed from the femoral artery distally into the hind limb and still did not allow adequate visualization of the vessel wall because of persistent luminal blood. The 3.2 mm endoscope enabled vessel wall visualization distal to the femoral artery when the proximal artery was occluded. No aortas were grossly perforated by the laser energy. In all pigs undergoing endoscopic laser resection, raised plaques were removed both grossly and histologically, although the plaque edges were carbonized and frayed as well as vaporized. With the small spot size of the argon fiber, channels were drilled through plaque, frequently with incomplete recanalization of the lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

The economic implications of infection in cardiac surgery.

To assess the economic impact of infection, the records of 496 patients aged 18 to 82 years (mean, 61 years) undergoing open-heart operations in 1981 and 1982 were reviewed, and the costs (length of stay, hospital charges, pharmacy charges) were compared for matched pairs of patients with and without infection who had coronary artery bypass grafting (CABG) procedures. Patients received a 5-day regimen of prophylactic cephalosporin. Operative site infections occurred within 6 months of operation in 17 patients (3.4%), urinary tract infections in 9 (1.8%), and pulmonary infections in 6 (1.2%). Early and late mortality was each 2%. No deaths were infection related, and no postoperative bacterial endocarditis occurred (minimum one-year follow-up). For the matched CABG patient in whom a postoperative wound infection developed, the average length of hospital stay was 16.7 days longer and the average hospital bill was $8,118 greater, with the average cost to the hospital $6,605 greater.

Adolescent↗
PubMed1985

Responses of atherosclerotic aorta to argon laser.

Lasers have been advocated to resect atherosclerotic plaques in the cardiovascular system, yet little information is available regarding the effects of laser on the range of occlusive lesions seen in the peripheral arterial tree. This study was conducted to assess the risk of perforation in human cadaveric aorta involved with variable degrees of atherosclerosis. Ten fresh segments of atherosclerotic human aorta were graded for extent of atherosclerosis, then subjected to argon laser energy within 48 hours. Using air as the conduction medium and with the fiber tip 2 or 5 mm from the vessel wall, the argon laser was applied to matched calcified and non-calcified arteries at 3.0-7.0 W and 10.0-13.5 W with energy density identical for matched pairs. Results were compared among segments which were normal in appearance or had only fatty streaks grossly with those with gross regional wall calcification. The mean penetration time (T) for calcified and non-calcified lesions at low and high power outputs was compared. (table; see text) Mean time to perforation and range of time necessary to produce perforation were greater in calcified than non-calcified segments at all power levels employed. These data suggest that atherosclerotic lesions vary in their response to argon laser. The presence of calcium may preclude resection of some plaques and protect against wall perforation.

Aortic Diseases↗