A unique valproic acid ingestion.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
S C Aldridge
Publications and source records attributed to S C Aldridge.
Open-chest cardiac massage without major thoracotomy: metabolic indicators of coronary and cerebral perfusion.
OBJECTIVE: To compare the coronary and cerebral perfusion achieved using a novel method of minimally-invasive, direct cardiac massage to that obtained using bimanual, open-chest cardiac massage. DESIGN: Prospective, controlled animal study with repeated measures. SETTING: University research laboratory. SUBJECTS: Large domestic swine. INTERVENTIONS: Aortic, coronary sinus, jugular venous and pulmonary artery catheters were placed. Following an equilibration period, ventricular fibrillation was induced. After 4 min of untreated ventricular fibrillation, animals underwent bimanual, open-chest cardiac massage (N = 6) or minimally-invasive, direct cardiac massage using a novel device for direct cardiac compression (N = 6). Adrenaline was administered at a dose of 1 mg intravenously every 5 min. MEASUREMENTS: Systemic metabolic parameters, (arterial PO2, PCO2 and lactate concentration) and coronary sinus and jugular venous metabolic parameters (pH, PVO2, SVO2, PVCO2 and lactate concentration) were measured and calculated (coronary sinus/jugular-arterial SVO2, coronary sinus/jugular-arterial PCO2 and lactate differences) at baseline and at 10, 20 and 30 min following induction of ventricular fibrillation. Animals were euthanised after 30 min with no attempt at defibrillation. MAIN RESULTS: Oxygen tension and oxygen saturation of coronary sinus blood declined significantly during the experimental period, but no differences were noted between treatment groups. The coronary sinus-arterial oxygen saturation difference increased during the study with no significant differences between groups. Coronary sinus PCO2 and the coronary sinus-arterial PCO2 difference increased significantly in both experimental groups during cardiac massage. No inter-group differences were noted. A similar relationship was noted in coronary sinus lactate values. The coronary sinus-arterial lactate difference displayed a positive balance at all intervals with no differences noted between group values. The oxygen tension and oxygen saturation of jugular venous blood, were reduced from baseline levels with both treatments. The jugular-arterial oxygen saturation difference increased in both groups compared to baseline values. Between group values were significantly different only at the 20 min interval. Both the jugular venous PCO2 and the jugular-arterial PCO2 gradient were elevated at all intervals, but no inter-group differences were noted. Jugular venous lactate concentration rose steadily with time in both groups. No significant increase in the jugular-arterial lactate gradient was noted at any time point. CONCLUSIONS: Minimally-invasive, direct cardiac massage provides coronary and cerebral perfusion similar to that achieved using standard open-chest cardiac massage. This method may provide a more effective substitute for standard, closed-chest cardiac massage in cases of refractory cardiac arrest.
Animals↗
Direct cardiac massage without major thoracotomy: feasibility and systemic blood flow.
BACKGROUND: Open-chest cardiac massage (OC-CM) provides higher blood pressure and flow than closed-chest compression and may improve the probability of successful resuscitation from cardiac arrest. Its clinical use has been limited by its requirement for a major thoracotomy. The present pilot study tested the technical feasibility of performing effective direct cardiac massage without a major thoracic incision, by using a simple, manually-powered plunger-like device, inserted through a small thoracic incision, to cyclically compress the cardiac ventricles. The method was termed minimally-invasive direct cardiac massage (MID-CM). Systemic blood flow using MID-CM was compared to that with OC-CM, by both direct systemic hemodynamic measurements, cumulative metabolic indicators of the ratio of whole body oxygen delivery and oxygen consumption, and a metabolic index of pulmonary blood flow. METHODS: In 12 large swine, baseline systemic and pulmonary hemodynamic measurements were performed. Arterial and mixed venous blood gases and metabolic indicators of systemic blood flow were measured. Ventricular fibrillation was induced and after 4 min, animals underwent either bimanual OC-CM (N = 6) or MID-CM (N = 6). At 10, 20 and 30 min, hemodynamic and metabolic measurements were repeated. RESULTS: Systemic Blood Pressure: Aortic systolic and diastolic blood pressures were reduced from baseline levels with both OC-CM and MID-CM. No difference in pressure was noted between OC-CM and MID-CM groups. Pulmonary Artery Pressure: Pulmonary artery systolic pressure was elevated from baseline during OC-CM and MID-CM. Pulmonary artery diastolic pressures remained constant throughout the resuscitation period in both groups. No differences in pulmonary systolic or diastolic pressure were noted between OC-CM and MID-CM groups. A trend towards higher pulmonary systolic pressures appeared with MID-CM. Thermodilution Blood Flow: Cardiac index fell from baseline levels with OC-CM and MID-CM. No difference in cardiac index was noted between OC-CM and MID-CM groups. Metabolic Indices: Mixed venous O2 saturation decreased from baseline levels during resuscitation in both experimental groups, with a further decrease at 30 min compared to 10- and 20-min levels. No difference was noted between OC-CM and MID-CM groups at any point. Arterial pH was reduced from baseline levels at 30 min in both groups compared to baseline but no difference was noted between groups.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
A strategy of aggressive regional therapy for acute iliofemoral venous thrombosis with contemporary venous thrombectomy or catheter-directed thrombolysis.
PURPOSE: Occlusive iliofemoral venous thrombosis is associated with morbid short- and long-term consequences. Having been disappointed with standard anticoagulant therapy and systemic fibrinolysis, we embarked on an aggressive multidisciplinary regional approach to treat these patients, with the goals of therapy being (1) to eliminate iliofemoral venous thrombus, (2) to provide unobstructed venous drainage from the affected limb, and (3) to prevent recurrent thrombosis. METHODS: Twelve consecutive patients were treated for extensive iliofemoral venous thrombosis. Each had thrombus from their infrapopliteal veins through their iliofemoral system, and four had vena caval involvement. The conditions of 11 patients failed to improve when the patients were given anticoagulants, and prior systemic fibrinolysis failed in five patients. The treatment strategy includes catheter-directed thrombolysis with intrathrombus infusion of the plasminogen activator or operative thrombectomy or venous bypass with a permanent 4 mm arteriovenous fistula (AVF). RESULTS: Nine of 12 patients had a good or excellent clinical outcome (mean follow-up 25 months), which correlated with restored unobstructed venous drainage from the affected limb. Seven patients had catheter-directed lytic therapy attempted. In five patients the catheters were appropriately positioned, and lysis was successful. Five of the eight patients who underwent operations had successful procedures. Two of the three patients with poor operative outcomes had residual thrombus in their iliac veins or vena cava after thrombectomy (without bypass). The third patient, in whom anticoagulation was contraindicated, had an initially successful thrombectomy and AVF; however, vena caval thrombosis developed 2 months after operation. No patient had symptomatic pulmonary emboli, and routine posttreatment ventilation/perfusion lung scanning was not performed. CONCLUSIONS: An aggressive multidisciplinary regional approach to patients with obliterative iliofemoral venous thrombosis, designed to remove thrombus and provide unobstructed venous drainage, offers substantially better clinical outcome compared with systemic fibrinolysis and standard anticoagulation. Catheter-directed thrombolysis is successful if the catheter is appropriately positioned within the thrombus. Contemporary venous thrombectomy, which includes thrombus removal, completion phlebography, AVF, and cross-pubic bypass when necessary, is associated with high success rates. Failures can be anticipated and avoided in most patients.
Acute Disease↗
Popliteal venous aneurysm: report of two cases and review of the world literature.
Two new cases of popliteal venous aneurysm are reported and added to the 22 other cases of popliteal venous aneurysm available for review. Both patients were first seen with acute pulmonary embolism and were treated with thrombolytic therapy followed by anticoagulation. Each had recurrent venous thromboembolism before discovery of the popliteal venous aneurysm. One popliteal venous aneurysm was diagnosed with phlebography and the second with venous duplex imaging, confirmed with phlebography. Both were surgically corrected with tangential aneurysmectomy and lateral venorrhaphy. Twenty-four cases of popliteal venous aneurysm are now available for review. Seventy-one percent (17 of 24) presented with pulmonary embolism, 88% (21 of 24) were saccular, and 96% (23 of 24) were located in the proximal popliteal vein. All but two were diagnosed by ascending phlebography. Three patients received no treatment: in two of these the outcome was not documented and the third had occasional pain. Two patients received anticoagulation without subsequent operative repair and both died of recurrent pulmonary emboli. Operative correction resulted in a 75% patency rate with 21% complications, most of which were related to postoperative anticoagulation. No patient who was operated on had subsequent pulmonary embolism, and there were no operative deaths. We suggest that all patients who have pulmonary embolism have lower-extremity venous duplex imaging. All popliteal venous aneurysms should be surgically repaired, inasmuch as nonoperative therapy results in recurrent thromboembolism and an unacceptably high mortality rate. Tangential aneurysmectomy with lateral venorrhaphy is the recommended procedure.
Adult↗
Quantitation of glycolysis and skeletal muscle glycogen synthesis in humans.
We measured the net rates of skeletal muscle glycogen synthesis and glycolysis (conversion of [3-3H]glucose to 3H2O) in healthy overnight-fasted volunteers. Two studies were performed. In study 1, seven subjects participated in two paired infusions under basal conditions of either [2-3H]glucose (H2) or [3-3H]glucose (H3). Total glucose uptake (Rd) and rates of whole body 3H2O formation (3H2O Ra) were measured. With H2, Rd and 3H2O Ra were similar. With H3, 3H2O Ra, equal to glycolysis, was 65% of Rd. In study 2, six different subjects underwent a 3-h, 40 mU.m-2 x min-1 euglycemic insulin clamp. [6,6-2H2]glucose was infused throughout and H3 was infused during the last hour of the study. Open muscle biopsies were obtained at 150 and 180 min. Glycogen synthesis was assessed by three independent means: 1) direct measurement, as 3H disintegrations per minute in isolated muscle glycogen per plasma H3 specific activity; 2) extrapolation from the activity of glycogen synthase assayed in the presence of the concentrations of glucose 6-phosphate and UDP-glucose measured in the biopsy; and 3) the difference between Rd and glycolysis. Despite a wide range in Rd [24.5-58.8 mumol.kg fat-free mass (FFM)-1 x min-1] and glycolysis (14.2-26.1), the three methods yielded similar results of 20.0 +/- 3.9, 22.5 +/- 3.7, and 20.6 +/- 3.7 mumol.kg FFM-1 x min-1 and correlated highly with each other (r2 = 0.92-0.96). Our results (study 1) indicate that the rate of plasma tritiated water formation reflects the intracellular detritiation of tritiated glucose. Under hyperinsulinemic conditions (study 2) the net rate of muscle glycogen synthesis can be accurately estimated from the glycogen synthase activity and from the difference between total glucose uptake and glycolysis. Thus, at high physiological plasma insulin concentrations resulting in submaximal stimulation of muscle glycogen synthesis, the latter can be accurately measured in humans.
Adult↗
Thrombolytic therapy for deep venous thrombosis: a clinical review.
Although anticoagulation is the treatment most commonly chosen for patients suffering from deep venous thrombosis (DVT), thrombolytic therapy offers the promise of dissolving the thrombus within the deep venous system, restoring patency and preserving valve function. If this is achieved, the incidence and severity of post-thrombotic syndrome can be reduced. Data from 13 studies comparing anticoagulant therapy with thrombolytic therapy for DVT in 591 patients have shown that, among those treated with heparin, 4% had significant or complete lysis, 14% had partial lysis and 82% failed to improve or worsened. Of those receiving lytic therapy, 45% had significant or complete lysis, 18% had partial lysis and 37% failed to improve or worsened. Long-term follow-up of randomized patients has shown that those with successful lysis had a lower incidence of post-thrombotic syndrome and improved long-term venous function. The failure rate of systemic lytic therapy among patients suffering iliofemoral venous thrombosis is high; therefore, catheter-directed thrombolysis has been adopted with increasing success. Thrombolytic therapy, delivered systemically using catheter-directed techniques, should be considered as an important alternative in the treatment of patients with DVT.
Anticoagulants↗
Temporary thoracotomy wound closure following penetrating thoracic aorta injury.
On rare occasions, thoracic injuries require resuscitative efforts including emergent thoracotomy that result in edematous changes to the lungs and heart. Hemodynamic compromise occurs when these organs are placed in their anatomic position and closure of the thoracotomy is attempted. Adaptation of a temporary abdominal closure to a thoracic injury is described.
Aorta, Thoracic↗
Hemodynamic deterioration in chronic venous disease.
Clinical deterioration of patients with chronic venous disease (CVD) has been well described and a standardized classification has been proposed. The progressive hemodynamic deterioration producing these clinical findings is less well appreciated. This study examines and correlates venous hemodynamics with clinical severity in patients with CVD. Two hundred seventy-four extremities from 149 patients with varying degrees of CVD and 56 extremities from 28 symptom-free volunteers were evaluated clinically and hemodynamically. Each limb was assessed for functional venous volume, degree of valvular insufficiency, efficiency of the calf muscle pump, and noninvasive estimate of ambulatory venous pressure. In addition, exercise venous pressures were recorded in 56 extremities from 36 patients and 9 extremities from 6 volunteers. As CVD progresses from class 0 to class 2, venous volume expands, valvular function deteriorates, the calf muscle pump becomes inefficient, and ambulatory venous hypertension develops. However, once extremities develop brawny edema or hyperpigmentation, further deterioration of limb hemodynamics does not occur. Patients with deep venous obstruction have more severe valvular insufficiency, calf muscle pump dysfunction, and ambulatory venous hypertension than have patients without evidence of obstruction. Residual volume fraction offers a reliable noninvasive estimate of ambulatory venous pressure (r = 0.76), although its correlation was significantly better for patients without venous obstruction (r = 0.86) than for those with obstruction (r = 0.40; p < 0.05). Deterioration in venous hemodynamics parallels clinical severity through class 2. Once brawny edema and hyperpigmentation occur, ulceration develops without additional deterioration of venous hemodynamics.
Adult↗
Experimental inhalation injury with concomitant surface burn: dextran resuscitation improves lung water and oxygenation.
UNLABELLED: The role of extravascular lung water (EVLW) in the pathogenesis of inhalation injury (INH) when associated with concomitant major burn (B) remains controversial. Previous experimental models have investigated isolated INH without surface burn. This study measured the effects of isolated and combined INH on EVLW and pO2 in a porcine experimental model. The beneficial effects of early resuscitation with dextran-40 (DEX) were assessed, using a control group receiving standard Parkland formula (LR). In the first part of the study (INH vs. INH + B), a group of animals with a standardized INH was compared to a group also receiving a standardized 40% BSA third-degree surface burn (n = 8, each group). With serial measurements for 5 hours, EVLW was only modestly increased unless INH was accompanied by surface burn: 20.3 +/- 4.2 vs. 32.0 +/- 4.1 ml/kg at 5 hours (p less than 0.01). Similarly, pO2 fell much more dramatically in the INH + B group, 61 +/- 5 vs. 37 +/- 5 torr (p less than 0.05). The second part of the study compared standard Parkland crystalloid resuscitation with dextran-40 resuscitation in animals receiving a combined INH + B injury (LR vs. DEX, n = 8, each group). DEX resuscitation resulted in substantially lower accumulation of EVLW out to 5 hours, 34.1 +/- 5.0 vs. 13.1 +/- 3.0 ml/kg (p less than 0.01), and significantly better pO2, 35 +/- 5 vs. 64 +/- 4 torr (p less than 0.01). CONCLUSIONS: Inhalation injury did not dramatically increase EVLW in this animal model unless accompanied by concomitant major surface burn. The deterioration in EVLW and pO2 seen in the combined injury was significantly improved with DEX resuscitation when compared to standard crystalloid resuscitation. Further study is indicated and clinical trials may be warranted.
Animals↗
Counselor intervention enhances life, reduces costs.
Explore the source record for details and available documents.
Aged↗