A modified collection and rapid infusion system for shed whole blood autotransfusion during aortic aneurysm surgery

We describe our experience in 10 patients (5 males) undergoing resection of a descending thoracic aortic aneurysm or a thoracoabdominal aortic aneurysm in which a modified shed whole blood collection and autotransfusion system was used. This modification allows several options for the processing and autotransfusion of shed blood: use of the cell saving device or the ultrafiltration of collected blood, and the autotransfusion of unprocessed shed whole blood. Either low dose heparin or sodium citrate was used for anticoagulation. All 10 patients underwent autotransfusion and volume resuscitation with the modified rapid infusion device. Total autotransfusion ranged from 1400 ml to 7843 ml. Ultrafiltration volumes ranged from 600 ml to 1100 ml. There were no intraoperative deaths and no patient reoperations for bleeding. Arterial blood gases, potassium, and platelet counts were all within the normal laboratory ranges. This modification enables the clinician to process poor quality shed blood and reinfuse whole blood, in an attempt to decrease the need for homologous blood products.     

Up & comers 1995

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Hypermanganesemia in patients receiving total parenteral nutrition

BACKGROUND: Manganese is one of the trace elements that is routinely administered to total parenteral nutrition (TPN) patients. The recommended daily IV dosage ranges from 100 to 800 MICROg. We have used 500 microg daily. Recent reports have suggested neurologic symptoms seen in some patients receiving home parenteral nutrition (HPN) may be due to hypermanganesemia. Therefore, HPN patients and some short-term inpatients receiving TPN were studied to ascertain the relationship between dose and blood levels. METHODS: Red blood cell manganese levels were obtained by atomic absorptiometry. RESULTS: The levels in 36 hospitalized, short-term patients obtained within 48 hours of initiating TPN were all normal. The 30 patients receiving TPN from 3 to 30 days had levels that ranged from 4.8 to 28 microg/L (normal, 11 to 23 microg/L). Two patients had abnormal levels, at days 14 and 18. Fifteen of the 21 patients receiving inpatient TPN or HPN for 36 to 5075 days had elevated Mn levels. Only one patient with hypermanganesemia, an inpatient, had abnormal biochemical liver tests (bilirubin and alkaline phosphatase). One of the patients with a high level had some vestibular symptoms attributed to aminoglycoside use and had increased signal density in the globus pallidus on T1-weighted images on magnetic resonance imaging (MRI). A second patient with Mn levels twice normal had no neurologic symptoms, but had similar MRI findings. A third had some basal ganglia symptoms, confirmed by a neurologic evaluation, seizures, and very high Mn levels. The MRI showed no signal enhancement, but motion artifacts limited the study technically. CONCLUSIONS: Hypermanganesemia is seen in HPN patients receiving 500 microg manganese daily and may have resulted in some neurologic damage in three patients. Hypermanganesemia is sometimes seen after a short course of TPN in inpatients, as early as 14 days. Patients should be monitored for hypermanganesemia if they receive Mn in their TPN for >30 days. A 500 microg/d dose of Mn is probably excessive, and 100 microg/d should probably never be exceeded. Mn should be eliminated from the solution if the Mn level is elevated and should not be readministered unless the level returns to normal or subnormal. Mn should not be supplemented if the patient has liver disease with an elevated bilirubin.     

Optimization of an enzyme immunoassay for 11-dehydro-thromboxane B(2) in urine: comparison with GC-MS

The urinary excretion of stable metabolites of thromboxane A2, such as 11-dehydro-thromboxane B2, reflects platelet activity in vivo. Efficient sample purification is required before analysis of thromboxane metabolites, due to the presence of large amounts of interfering material in urine. Analysis by gas chromatography-mass spectrometry after extensive sample work-up procedures provides the most reliable data, but detection by enzyme immunoassay may be reliable if sample cleanup is adequate. We describe an improved immunoassay procedure for 11-dehydro-thromboxane B2, which is based on a simple one-step solid phase extraction, by using Bond-Elut Certify II columns, followed by enzyme immunoassay by using commercially available reagents. 11-Dehydro-thromboxane B2 exists in two forms, with different chemical and immunological characteristics, which are in pH-dependent equilibrium. We kept 11-dehydrothromboxane B2 in its open ring form throughout the assay, by incubating and handling samples at pH 8.6. The extraction step achieved a recovery of 83% (95% confidence interval 74-92%), the sensitivity of the enzyme immunoassay was doubled, and the reproducibility of the assay improved under these conditions. Intra- and interassay coefficients of variation were 3 and 13.8%, respectively. A single 500-mg dose of aspirin reduced the excretion of 11-dehydro-thromboxane B2 by 77+/-14%, suggesting good specificity. Comparison with gas chromatography-mass spectrometry in 28 urine samples showed excellent agreement between the two methods (r2 = 0.94; p<0.0001), and a regression line with a slope close to 1.0. The presently modified enzyme immunoassay for 11-dehydro-thromboxane B2 is suitable for clinical studies evaluating platelet function in vivo and has the advantage of being simpler and less expensive to use than gas chromatography-mass spectrometry.     

Synthesis, corticotropin-releasing factor receptor binding affinity, and pharmacokinetic properties of triazolo-, imidazo-, and pyrrolopyrimidines and -pyridines

The synthesis and CRF receptor binding affinities of several new series of N-aryltriazolo- and -imidazopyrimidines and -pyridines are described. These cyclized systems were prepared from appropriately substituted diaminopyrimidines or -pyridines by nitrous acid, orthoester, or acyl halide treatment. Variations of amino (ether) pendants and aromatic substituents have defined the structure-activity relationships of these series and resulted in the identification of a variety of high-affinity agents (Ki's < 10 nM). On the basis of this property and lipophilicity differences, six of these compounds (4d,i,n,x, 8k, 9a) were initially chosen for rat pharmacokinetic (PK) studies. Good oral bioavailability, high plasma levels, and duration of four of these compounds (4d,i,n,x) prompted further PK studies in the dog following both iv and oral routes of administration. Results from this work indicated 4i,x had properties we believe necessary for a potential therapeutic agent, and 4i1 has been selected for further pharmacological studies that will be reported in due course.     

Renal hemodynamic responses to intrarenal infusion of ligands for the putative angiotensin IV receptor in anesthetized rats.

Angiotensin IV, a hexapeptide fragment (3-8) of angiotensin II metabolism, has been reported to produce vasodilatation within the renal vasculature by activation of the putative AT4 receptor. However, there are conflicting findings, with previous in vivo studies providing evidence for and against a renal vasodilator action of angiotensin IV. In this study, the renal hemodynamic responses to activation of the putative AT4 receptor were studied in anesthetized rats by left renal arterial infusion of two endogenous ligands, angiotensin IV and LVV-hemorphin-7. Angiotensin IV (10, 100, and 1,000 pmol/min) infusion caused dose-dependent reductions in blood flow to the infused kidney, which were abolished by pretreatment with losartan. In respect to this effect, angiotensin IV was approximately 300-fold less potent than angiotensin II. There were no significant effects of angiotensin IV on mean arterial pressure, heart rate, or blood flow to the noninfused kidney. Intrarenal infusion of LVV-hemorphin-7 (10, 100, and 1,000 pmol/min) had no significant effect on renal blood flow in the infused and noninfused kidneys, or on mean arterial pressure or heart rate. These results provide no evidence for a renal vasodilatory action of angiotensin IV or LVV-hemorphin-7. On the contrary, intrarenal angiotensin IV infusion produced vasoconstriction of the renal vasculature, mediated by activation of AT1 receptors. These observations provide evidence against a vasodilatory role of putative AT4 receptors in the rat kidney.     

Development and validation of the Diabetes Care Profile

To determine the reliability and the validity of the Diabetes Care Profile (DCP), an instrument that assesses the social and psychological factors related to diabetes and its treatment, two studies with separate populations and methodologies were conducted. In the first study, the DCP was administered to, and physiologic measures collected from, individuals with diabetes being cared for in a community setting (n = 440). In the second study, the DCP and several previously validated scales were administered to individuals with diabetes receiving care at a university medical center (n = 352). Cronbach's alphas of individual DCP scales ranged from .60 to .95 (Study 1) and from .66 to .94 (Study 2). Glycohemoglobin levels correlated with three DCP scales (Study 1). Several DCP scales discriminated among patients with different levels of disease severity. The results of the studies indicate that the DCP is a reliable and valid instrument for measuring the psychosocial factors related to diabetes and its treatment.