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Biomedical subjects

C E Lucas

Publications and source records attributed to C E Lucas.

At least 109 records · Page 6Linked to original sources
PubMed1984

Infected venous pseudoaneurysm. A complication of drug addiction.

There has been an increase in the incidence of major vascular complications of intravenous drug addiction. We studied five patients who had infected venous pseudoaneurysms of the femoral vein. Patients may have cryptic sepsis or an infected hematoma from venous rupture. The vein containing pus may drain through a venipuncture site. Treatment is complete excision of the involved vein with packing of the wound. Complications due to septic embolization or metastatic infection from septicemia are common. Venous reconstruction is unwarranted.

Adult↗
PubMed1984

Mechanisms of impaired renal function with PEEP.

Deterioration in renal function associated with positive end-expiratory pressure (PEEP) has been attributed to renal hypoperfusion from the fall in cardiac output and mean arterial blood pressure. Using a canine in vivo model, renal function was measured during control, zero end-expiratory pressure (ZEEP), and PEEP (5, 10, and 15 cm H2O) ventilatory cycles, while renal blood flow was maintained constant with a pump. High PEEP (15 cm H2O) led to a rise in renal vein pressure (RVP) and a fall in mean arterial pressure (MAP). PEEP resulted in no change in glomerular filtration rate (GFR) or solute exertion; however, free-water clearance (FWC) became less negative in the 15-cm H2O PEEP group. Intrarenal autoregulation maintains GFR during ventilation with PEEP when renal blood flow is constant, supporting the view that altered filtration and solute excretion clinically is secondary to changes in aortic pressure and renal perfusion.

Animals↗
PubMed1984

Parathyroid response to hypocalcemia after treatment of hemorrhagic shock.

Hypocalcemia often follows resuscitation from hemorrhagic shock. The role of calcium supplementation is controversial, whereas, little data are available regarding the parathyroid (PTH) response. Therefore this response was studied in 41 injured patients who required 15 blood transfusions and 11.7 L balanced electrolyte solution during emergency room and operating room therapy. Postoperative reduced total calcium (7.5 +/- 0.8 mg/dl SD) and ionized calcium 1.85 +/- 0.2 mEq/SD) paralleled a rise in PTH (69.7 +/- 37 microliters Eq/ml SD) and the severity of insult as reflected by shock time and hypoalbuminemia. Renal function was normal. Increased PTH is probably homeostatic and belies the theoretical merits of calcium channel blocker administration after hemorrhagic shock. Calcium supplements may be of benefit during resuscitation when bone flow is low and calcium release from bone in response to PTH is reduced.

Adult↗
PubMed1984

Assessment of pancreatic ductal penetration of antibiotics.

Pancreatic ductal penetration of antibiotics is not uniform. Antibiotic therapy for pancreatic and pancreatic related infections, theoretically, is enhanced by drugs that reach the ductal system. The pancreatic ductal penetrance of Cefamandol (1 gm), Amikacin (7.5 mg/kg), and Chloramphenicol (1 gm) given as a single intravenous dose prior to endoscopic retrograde cholangiopancreatography was studied in ten patients. Serum and pancreatic juice were collected simultaneously, frozen, and later assayed for antibiotic concentration. Each antibiotic achieved its expected therapeutic serum level. In contrast, pancreatic ductal levels of Cefamandol and Amikacin were subtherapeutic, whereas Chloramphenicol levels were therapeutic. Further studies are needed to identify other antibiotics with good pancreatic ductal penetrance.

Amikacin↗
PubMed1983

Mycotic aneurysm. New concepts in therapy.

Fifty patients were treated for 52 mycotic aneurysms secondary to intravenous drug abuse. An initial misdiagnosis of cellulitis or abscess in 17% of the patients was corrected after arteriography or bleeding following operative drainage. There was no ischemia following ligation and excision of aneurysms of the radial, brachial, external iliac, deep femoral, and superficial femoral arteries. Excision of the common femoral artery in four patients and femoral bifurcation in 25 led to marked morbidity in 28 patients without simultaneous revascularization. Ischemia occurred in 53% of these patients; it was mild in 21% with claudication only. Severe, limb-threatening ischemia occurred in 32% and led to amputation in 21%. Six patients underwent artificial bypass, including one for absent back-bleeding at the time of ligation, four for immediate severe ischemia, and one for late ischemia. Two infected grafts were removed; another became thrombotic. Cultures were positive for 73% of aneurysms and blood of 46% of the patients.

Adult↗
PubMed1983

Impaired renal concentrating ability during resuscitation from shock.

Renal concentrating ability was tested in 20 severely injured patients who received an average of 21 blood transfusions. Timed measurements were made of urine output (UO), and the clearance of creatinine glomerular filtration rate (GFR), sodium (CNa), osmols (COsm), and free water (CH2O) during operation and were repeated at 12 and 18 hours postoperatively, and on postoperative days 2 and 4. During operation the GFR was markedly reduced (36 mL/min), while UO, CNa, and COsm were all markedly increased (8.5, 5.9, and 8.1 mL/min, respectively). The CH2O was positive (0.4 mL/min). Following operation the rate of renal excretion of water and solutes was still high: UO, 4.0 mL/min; CNa, 4.3 mL/min; and COsm, 6.0 mL/min. Five hours postoperatively the CH2O had returned to normal. By day 2 the excretion rate of water had returned closer to normal: UO, 2.1 mL/min; CNa, 2.6 mL/min; COsm, 4.0 mL/min; the CH2O was normal. Subsequent study results were normal. These data demonstrate a renal concentrating impairment during and following operation. An osmotic diuresis, transient tubular ischemia, a washout of interstitial inner medullary osmoles, or some cryptic factor may be causative.

Glomerular Filtration Rate↗
PubMed1983

The fluid problem in the critically ill.

Fluid therapy in the critically ill patient must be adjusted to accommodate continuing changes in the plasma volume, interstitial space, and intracellular space. During and after hemorrhagic shock, replacement of crystalloid is needed to replenish the plasma and interstitial spaces during operation and then interstitial and intracellular spaces after operation. Severe sepsis leads to a more pronounced expansion of the interstitial space than that of hemorrhagic shock. Continuing therapy after both hemorrhage and sepsis should be directed toward maintaining effective plasma volume and levels of hemoglobin while the interstitial and intracellular spaces return to normal. Concomitantly, effective circulatory volume must be guided by continuing changes in cardiac, pulmonary, and renal function.

Aged↗
PubMed1983

Effect of albumin resuscitation on canine coagulation activity and content.

Prior work showed that albumin resuscitation in man leads to decreased coagulation activity and coagulation protein content. These observations were tested in 20 splenectomized dogs shocked by control hemorrhage and resuscitated with the sequential infusion of: (1) 20 ml/kg balanced electrolyte solution (BES) or 5% albumin/BES; (2) shed blood; (3) 30 ml/kg BES or 5% albumin/BES; (4) 250 ml blood stored from the time of splenectomy. Either BES or 5% albumin/BES was given for the next 3 days. Coagulation activity (fibrinogen, plasminogen, factor VIII, and prothrombin) and coagulation protein content (factor VIII by specific canine antigen) were measured preshock, post resuscitation, and daily for 3 days. Albumin resuscitation significantly (p = greater than 0.05) reduced coagulation activity of fibrinogen (423 +/- 145 vs. 274 +/- 80 mg/dl SD), factor VIII:C (64 +/- 24 vs 42 +/- 16% SD), prothrombin (195 +/- 44 vs. 141 +/- 22% SD) but did not alter CPC of factor VIII:RAg (142 +/- 83 vs. 156 +/- 141% SD). Lower coagulation activity after 5% albumin/BES resuscitation in conjunction with no change in factor VIII:RAg content which is produced by the vascular endothelium suggest that impaired hepatic synthesis may lead to the reduced coagulation activity after albumin resuscitation.

Albumins↗
PubMed1983

Significance of hypocalcemia following hypovolemic shock.

Changes in calcium levels during and after resuscitation from severe shock were studied in 22 seriously injured patients who received an average of 21 blood transfusions and 26 mEq supplemental calcium. Total serum proteins (TSP), serum albumin (SA), total calcium (TC), and ionized calcium (CA++), were studied intraoperatively after the tenth transfusion and postoperatively at 5 hours, 15 hours, day 2, day 4, and during convalescence (day 25). The intraoperative TSP fell to 3.7 gm%; the TC and Ca++ fell to 7.2 mg% and 1.4 mEq/L. The TSP and SA remained low throughout day 4 (4.8 and 2.6 gm%); the TC was also low on day 4 (7.5 mg%), whereas the Ca++ rose to normal (2.1 mEq/L) by day 2. The severity of hypocalcemia paralleled the hypoproteinemia, the number of transfusions given during resuscitation, and the duration of shock; paradoxically, hypocalcemia correlated inversely with Ca++ supplementation of blood transfusions during resuscitation, suggesting increased extravascular Ca++ flux with more severe shock. Further studies in comparably injured patients are needed to identify the concomitant responses of the calcium homeostatic factors such as parathormone in order to help identify the optimal role of calcium manipulation during resuscitation from hypovolemic shock.

Blood Proteins↗
PubMed1983

Role of Roux-en-Y feeding jejunostomy for patients with acute head injury.

The total care of a patient with severe head injury is challenging and may extend for weeks, months, or even years. A major challenge of this care includes nutritional support: swallowing is impaired, aspiration accompanies gastric tube feeding, parenteral nutrition is limited to short term in hospital care, and needle jejunostomy or transabdominal jejunostomy are prone to inadvertent removal. The role of Roux-en-Y feeding jejunostomy was evaluated in 13 patients with acute head injury. Procedure related complications include prolapse of the ostomy (1 patient) and stoma-ischemia requiring revision (1 patient). The effect of ostomy tube feedings on gastric acid secretions was studied in five patients, and no significant change was noted when saline feeding was compared to blenderized diet feeding. Blenderized diet feedings were advanced gradually, and antidiarrheals were added as needed once gastrointestinal function returned. In conclusion, Roux-en-Y feeding jejunostomy provides an attractive, safe method for long-term enteral nutrition in the head injury patient. Easy replacement of the feeding tube facilitates nursing care, and the threat of acid-induced stress gastric bleeding is not enhanced.

Adult↗
PubMed1983

Effect of calcium infusion on heart function.

The effects of calcium on heart function were studied in ten critically ill hypocalcemic patients (Ca++ = 1.93 +/- 0.08 mEq/L SD). Total calcium (TC), Ca++, blood pressure (MAP), venous pressure (CVP), pulmonary wedge pressure (PWP), cardiac output (CO), heart work (LVSW), systemic resistance (SPR), and pulmonary resistance (PVR) were measured before, during (15 and 30 minutes), and after (60 minutes) a 30-minute infusion of 1 gm CaCl2 (13.7 mEq). Calcium chloride infusion increased Ca++ significantly at 15 and 30 minutes (2.2 +/- 0.25 mEq/L) and remained elevated at 60 minutes (2.12 +/- 0.24). Cardiac output and LVSW rose at 15 minutes (9.4 leads to 10.6 L/min; 98 leads to 115 gm-m) but fell to below preinfusion levels by 60 minutes (8.9 +/- 2.0 L/min and 92 +/- 30 gm-m, respectively). These data show that calcium infusion for hypocalcemia does not provide meaningful improvement in cardiovascular function and is best avoided unless left heart function is closely monitored.

Calcium Chloride↗
PubMed1983

Effect of end-expiratory pressure on total oxygen dynamics.

The role of altered end-expiratory pressure on total oxygen dynamics was studied prospectively in 18 patients with injuries and sepsis. Eight patients received high tidal volumes (12 to 18 ml/kg), continuous positive airway pressure, and intermittent mandatory ventilation (CPAP/IMV); 10 patients received low tidal volumes (8 to 10 ml/kg) with zero end-expiratory pressure and assist control mode of ventilation (ZEEP/A-CM). CPAP/IMV patients had better oxygen tension, reduced physiologic shunting in the lung (24% versus 18%), and an improved arterial tension: inspired oxygen concentration ratio. CPAP/IMV patients also had significantly higher central filling pressures that were associated with significant reductions in cardiac output (8.2 L/min versus 6.4 L/min). The reduced cardiac output appeared to be a result of a reduction in left ventricular stroke work index. Consequently, the total oxygen delivery was reduced for all 3 days following insult and for the cumulative data for all 3 days (266 versus 306 ml/min) in the CPAP/IMV patients. Oxygen consumption was also reduced in the CPAP/IMV patients; this reduction was not significant for each of the first 3 days but was significant when the data for the 3 days were added to the analysis (306 versus 272 ml/min). Future prospective randomized studies are needed to determine the most effective use of ventilatory support on total oxygen dynamics including oxygen delivery and oxygen consumption.

Adult↗
PubMed1982

Reduced oncotic pressure after shock: a proposed mechanism.

Hemorrhagic shock plus resuscitation leads to expansion of both interstitial fluid space (IFS) and intracellular fluid (ICF). THe IFS expansion is thought to reflect reduced serum colloid oncotic pressure (COP) from capillary leak of serum albumin (SA). This hypothesis was analyzed in 138 injured patients who received an average of 13.6 units of blood and 10.7 L of saline solution for correction of shock. Plasma volume (PV), extracellular fluid (ECF) by inulin space technique, SA level, percent albumin leak (PAL), total intravascular albumin content (TIAC), COP, IFS, weight gain, and time of injury were analyzed. Patients studied during the postoperative fluid sequestration phase had a low to normal PV (2.9 L) with a high IFS (15.2 L) and a low PV-ECF ratio (0.15). Although the SA level (2.8 g/dL), TIAC (81 g), and COP (11.9 mOsm/L) were low, the PAL was also low (6.0%/hr; normal, 7%/hr). Patients studied during the fluid mobilization phase had a high PV (3.2 L) and normal PV-ECF ratio (0.21), whereas the SA level (3.0 g/dL), TIAC (103 g), and COP (14.1 mOsm/L) remained low. Despite these findings, the PAL was high (8.0%/hr). The fall in the PV-ECF ratio during the postresuscitation fluid sequestration phas is associated with but not due to reduced TIAC and COP, both of which remained low after the PV-ECF ratio has normalized during the mobilization phase. Contrary to prior reports, albumin leak is not responsible for reduced COP, TIAC, and postresuscitation weight gain. Presumably, the low COP results from decreased reentry of albumin into the plasma volume due to entrapment within the IFS matrix.

Body Fluids↗
PubMed1982

Altered coagulation protein content after albumin resuscitation.

Previous studies showed that the random addition of supplemental albumin to a resuscitation regimen of blood, salt, and frozen plasma caused a significant (p = less than 0.05) fall in fibrinogen clotting activity (FC) and a rise in prothrombin times (PT) in seriously injured patients; the partial thromboplastin times (PTT) were insignificantly prolonged. Based upon these findings, frozen plasma samples, prospectively collected in 41 non-albumin patients and 35 albumin patients, were analyzed immunologically, in duplicate, for protein content of coagulation factor VIII (VIIIAg), prothrombin (IIAg), fibrinogen (FAg), antithrombin III (ATAg), and fibrin(ogen) split products (FSP). Supplemental albumin resuscitation was associated with a significant fall in FAg (83 +/- 9 versus 124 +/- 10 SE mg/dl), VIIIAg (97 +/- 13 versus 127 +/- 135 SE %), IIAg (54 +/- 3 versus 80 +/- 4 SE %), and ATAg (14 +/- 0.8 +/- 19 +/- 0.8 SE mg%) with no significant changes in FSP. FSP, however, were more than 20 micrograms/ml in 13 of 41 nonalbumin patients versus four of 35 albumin patients (X2 = 4.5, p less than 0.05). Reduced coagulation activity following albumin supplementation seems partly caused by a decrease of coagulation protein content; increased fibrinolysis in the albumin patients is not the cause. Decreased coagulation protein content parallels the fall in coagulation activity and the need for postresuscitation blood transfusions. The role of reduced coagulation synthesis in these changes needs further study.

Adult↗
PubMed1982

Immunoglobulin changes after varied resuscitation regimens.

Prior studies showed that albumin supplementation of the resuscitation for hypovolemic shock caused an increase in serum albumin but a fall in serum globulins; immunoglobulins were not measured. Using frozen sera, immunoglobulins (IgG, IgM, IgA, IgD) were measured in 184 severely injured patients including 40 patients prospectively randomized for supplemental steroid therapy and 46 patients prospectively randomized for supplemental albumin therapy. The remaining patients served as the control patients. Compared to normal, the control patients had a significant reduction in IgG, IgM, and IgA. This reduction was associated with a fall in total serum proteins and serum albumin concentrations. Supplemental albumin resulted in an increase in the serum albumin concentration but a reciprocal fall in the serum globulin fraction and in IgG, IgM, and IgA. The serum proteins and immunoglobulins in the steroid patients were significantly below normal but similar to that seen in the control patients. The reduction in serum proteins and immunoglobulins in the control and steroid patients paralleled the shock time (systolic pressure below 80 mm Hg) and the amount of plasma given during resuscitation. These correlations were not significant in the albumin- supplemented patients. These data indicate that albumin supplementation alters the normal immunoglobulin response to shock. These changes in the postinjury recovery period need further study.

Adult↗