Showing papers on "Phlebotomy published in 1995"

Laboratory methods and quality assurance in the Cardiovascular Health Study.

Abstract: The Cardiovascular Health Study is an observational cohort study of risk factors for cardiovascular disease in 5201 participants, ages > or = 65 years. We report the methods and quality-assurance results for blood procurement, processing, shipping, storage, and sample analysis used during the first examination period (May 1989-June 1990). The most frequent difficulty in phlebotomy and processing was the requirement of more than one venipuncture (in 2.6% of the participants). The CVs for control materials ranged from 0.93% for glucose to 10.7% for insulin; most were < 4%. In addition to standard quality-assurance methods, we applied two other methods: technical error calculation for replicates, and weighted linear regression to assess time trend in results of control materials. After outliers were excluded, technical error values ranged from 1.7 for uric acid to 18.8 for insulin. Factor VII and factor VIII had slight trends over the 12-month analysis period. Results of quality-assurance analyses used to resolve problems were successful, thereby improving the second laboratory examination.

Role of interferon alpha-2a in the treatment of polycythemia vera.

Abstract: We studied the effects of recombinant interferon alpha-2a (IFN-alpha) in 36 patients with polycythemia vera (PV) previously treated with phlebotomy and/or conventional cytostatic agents. In each patient, after at least 2 months of discontinuation of any cytotoxic therapy, the hematocrit (Hmt) was first brought to normal value by phlebotomy; IFN-alpha treatment was then begun at a starting dose of 3,000,000 IU s.c. three times a week. Response to treatment, which was assessed monthly, was defined as persistent normalization of Hmt without concomitant phlebotomy; in non-responsive patients the initial IFN-alpha weekly dosage was progressively increased. Twenty patients were responsive with a median duration of response of 7 months (range 2-25+ months); out of these, 7 patients are still under treatment and responsive at 13+, 17+, 20+, 22+, 23+, 25+, 25+ months. These findings indicate that a cohort, although small, of patients with PV (19.4%) are persistently sensitive to IFN-alpha; in this subset of patients, this cytokine can therefore provide a useful treatment option, since, contrary to conventional therapeutic approaches such as radioactive phosphorus, cytostatic agents, or phlebotomy, IFN-alpha is devoid of harmful side effects.

Flow cytometric analysis of punctate and aggregate reticulocyte responses in phlebotomized cats

Abstract: Five cats were made anemic by one-time phlebotomy, and their reticulocyte responses were monitored daily for 20 days, using manual enumeration and a standardized feline reticulocyte protocol developed and validated in our laboratory. The reticulocyte responses of 38 clinically normal client-owned cats also were analyzed manually and cytometrically to determine clinical reference ranges. Increases in the percentage of aggregate reticulocytes over the reference range were detected in 5 of 5 phlebotomized cats, using the cytometric protocol. Only 4 of the 5 cats had an increase by results of manual enumeration. Manual aggregate counts had considerable daily variation and often fluctuated in and out of reference range, whereas cytometric aggregate counts remained consistently increased for distinct periods. Increased numbers of aggregate cells could also be detected for longer periods when evaluated by flow cytometry. Increased numbers of punctate reticulocytes were detected in 4 of 5 cats, using the cytometric protocol. None of the cats had increased numbers of punctate cells when evaluated by use of the manual technique. Aggregate reticulocytes in the 38 clinically normal cats ranged from 0.1 to 0.5%, which corresponded to 8,487 to 42,120 cells/microliter. Punctate reticulocytes ranged from 2 to 17%, which corresponded to 225,400 to 1,268,584 cells/microliter. Flow cytometry, using a standardized analysis protocol, was a more reliable and sensitive technique for detection and evaluation of feline reticulocytosis than was manual enumeration. The sensitivity of the flow cytometer to small amounts of intracellular nucleoprotein makes this assay especially valuable for detection of punctate reticulocytosis and low degrees of aggregate reticulocytosis in cats.

A computer model comparing normovolemic hemodilution, hypervolemic hemodilution, and neither on intraoperative blood loss and final hematocrit.

Abstract: Homologous blood transfusion, while frequently life-saving, is attended by risks and complications. Autologous blood transfusions have become an increasingly common alternative. Volume expansion, which is simpler, also is used. This study was designed to construct computer models of hypervolemic hemodilution and normovolemic hemodilution to compare them with each other and with normal (neither hypervolemic nor normovolemic hemodilution). Each model started with blood volume (BV) equal to 5,000 mL. Initial hematocrits (HCTs) were varied from 25% to 50%. Following phlebotomy and hemodilution or volume expansion, which ranged from 0 to 2,500 mL (50% of initial BV), the models were then bled 250 to 2,500 mL (5% to 50% of initial BV). In the phlebotomy model, the autologous blood was then returned. Final HCTs were then calculated. Preoperative phlebotomy of 500 to 1,000 mL, an amount commonly withdrawn, provides a minimally higher final HTC. Volume expansion by hypervolemic hemodilution provides almost the same low level of benefit. Benefits (3% higher HCT) are not seen until larger volumes are phlebotomized or hemodiluted and accompanied by large intraoperative blood losses. Autologous blood drawn by preoperative phlebotomy for intraoperative transfusion should not be used until studies show that these large volumes are safe and actually save blood.

Asymptomatic Erythrocyte Disorder Presenting as Increased Porphobilinogen Deaminase and Uroporphyrinogen Decarboxylase

Abstract: Hematocrit,% Reticulocytes, % Erythrocyte porphobilinogen deaminase and uroporphyrinogen decarboxylase were measured as previously described (5, 6) by using porphobilinogen and pentacarboxylporphyrinogen I, respectively, as substrates. CV5 for these assays in this laboratory are 8.3% and 14.2%, respectively. rocytes,it is possible that detection of these diseases could be compromised when coexisting conditions or interventions stimulate erythropoiesis. It will be of interest, for example, to determine if erythrocyte uroporphyrinogen decarboxylase increases during therapeutic phlebotomy in patients with porphyria cutanea tarda. The intent of this therapy, which is effective in both inherited and acquired forms of porphyria cutanea tarda, is to stimulate erythropoiesis and thereby utilize and reduce iron stores. If phlebotomy does increase erythrocyte uroporphyrinogen decarboxylase, it might be recommended that the enzyme activity be measured before institution of phlebotomy.

Reimbursement over the Atlantic

Abstract: Two unrelated issues came to mind as I reflected on a recent harrowing experience. One was the heated debate over the imbalance in financial reward between medical-surgical procedures and so-called cognitive activity or (forgive me) non-procedures. The second was the solid foundation of traditional Western medical education on which I was fortunate enough to capitalize. It seems that in medicine we have developed a curriculum that is effective, even for those of us who only practice part-time and cannot be on the cutting edge of technology with its latest generation of cephalosporins. It is a credit to traditional medical education that when occasionally challenged by friends, family, and the few patients for whom I take responsibility, I can draw on the strong foundation of fundamentals available in every U.S. medical school. This method does not require enormous amounts of detail close at hand, but simply a logical sequence of steps to organize symptoms and signs, focus on a few potential organ systems, and then make a diagnosis. This leaves the obscure and the incurable for textbooks and keener minds. Now, having said this, I must quickly admit that I do not have the same confidence when it comes to medical emergencies. I have willingly stepped aside for the eager emergency medical technicians in public places where my interim help as a physician was sought. Frankly, I was glad to yield as I barked a few officious platitudes so that all present might have no doubt as to who was in charge. A once-proud knight in white cotton pants who could cannulate any orifice in an emergency, I now secretly hope none of my middle-aged golf partners suffer a medical catastrophe over a 2-foot putt. This introduction will explain why I was less than eager to respond when an announcement requesting a physician came over the intercom 1 hour into my transatlantic flight to Berlin and Warsaw. I should declare here and now that there were other reasons for my reluctance, not the least of which was the Scotch and champagne before takeoff. Despite my concerns, I could never deny my profession. Yet, I am more than happy to defer to some young buck eager to make an impression. My preferred role is always sage advisor and arch second-guesser. I have a healthy respect for the obstacle that teamwork presents to a couple of unacquainted physicians. You guessed it. Nobody responded. There was another sandbagger on the flight. We met as we passed through the galley. After the usual preliminary questions about specialty he quickly begged off. He was retired, he said, and would prefer not to get involved. His guilt was palpable. This provoked a fleeting thought on my part about malpractice coverage in international skies. But I was committed now and not to be deterred. After all, this was what it was all about. My mother had announced to me early on, just following her decision that I become a physician, Make sure you choose a specialty so that you can stand up at the country club when they call for a doctor. I never have been sure to which specialty she was referring, but I blame her that I am not a dermatologist today. The supervising stewardess informed me that one of her flight attendants was unresponsive. This sounded like a medical emergency to me. I was surprised at how calmly she proclaimed this. I attributed it to the kind of grace under pressure that one expects from the folks in the wild blue yonder. Trying to emulate her demeanor, I followed her to a perfectly normal-appearing uniformed attendant whom I recognized as the first person to serve me when I boarded the flight. She now appeared about the same, except that she seemed unwilling to speak. She had, I was told, gradually reached this condition over the period of an hour. She had become forgetful and slow and would do nothing but lean against the center divider with her arms folded across her chest. She appeared alert, had no gross evidence of a neurologic deficit, and was certainly in no distress. Still, there she was. I had to do something. The Captain suggested that she might have suffered a stroke. The thought had not occurred to me. I quickly assured everyone that I had already eliminated that diagnosis. She was too young. too attractive. I prayed they would see logic where I could not. Nor did I know anything about this woman. It seems flight crews are not necessarily permanent teams but are often thrown together at the last moment; her colleagues could not help with any history. So here I stood, all eyes on me, and all ears hanging on every brilliant utterance (I was reminded of the old E.F. Hutton ad). I felt enormous pressure to say something profound. I asked her name. Helga, I was told. After a few insipid questions to which I received nothing but Helga's icy stare, I decided I needed some time away from my audience to pull my thoughts together. I pronounced to the Captain that this was as close to veterinary medicine as I had been since forced to care for screaming children during a stint in the military. Helga had a look about her that reminded me of panic. Hers or my own, I cannot say. I informed the Captain that this appeared to be a stable situation and a more thorough examination risked the exposure of this potential panic I feared. Then, I warned the Captain, we'll have to tie her to the seat for 7 hours. The Captain quickly agreed; Helga was led quietly to her seat and strapped in. I mumbled something about the possibility of drugs or a psychological disorder and uneasily returned to my cold dinner. Although I was assured by my retired colleague that my judgment was sound, I struggled with the problem and could think of nothing else for the next hour or so. I spotted one of the most helpful of the female attendants coming my way. It occurred to me to ask her if we could go through Helga's luggage. She was ahead of me. She came, she said, to show me Helga's purse. Imagine my little heart when we discovered the bottles and bottles of injectable insulin. I paused to allow my professional life to pass quickly before my eyes and commanded the attendant to direct me to my patient. There was my Helga, the same bright stare, the cute smirk, but now in all its glory, the early stages of decerebrate rigidity. Just so that you have a clear vision of the situation, I should point out that I had a choice as I ministered to my patient. I could have sat next to her like a companion or I could be her physician and place myself in front of her. I bravely chose the latter. In order to accomplish that, I found myself kneeling on the floor in front of her. It was from this position that I made a pitiful effort to feed her orange juice, managing only to soak her blouse with the life-saving liquid. It was during the next few minutes as I was trying to work out the mechanics for an emergency orange juice enema that my stewardess/nurse/angel asked whether I was interested in reviewing the standard emergency medical kit. I was just about to ask for such a kit, I said archly, and asked that she fetch it immediately. I felt my stewardess/nurse's confidence in me grow as I proceeded two steps behind her. The emergency kit had an inventory printed on the case. The available light in our cubby did not allow my presbyopic eyes to read the print, but again my able assistant served me well. I could comment on the comprehensiveness of the kit, but our time would be better spent describing my mixture of feelings when the angel of the air uttered the precious words 50% dextrose and water. On the one hand, I was pleased that the cure for my patient was available. On the other hand, I must admit that my pleasure quickly turned to semi-panic as my thoughts raced to the certain confrontation I would soon have to face with that old devil, the venipuncture. I must say I was once considered quite adept with the manual procedures one learns as a trainee, and later in my career was the procedurist of choice for those few procedures necessary to a nephrologist. Venipuncture is one thing, venipuncture on one's hands and knees, in a moving aircraft, done by a slightly rusty physician is quite another. My final delight came when I reviewed the package and found a 50-cc syringe with the needle connection dead in the center of the barrel. Now, in addition to my other concerns, I would have to forego the luxury of steadying the barrel on the limb, and would have to attack at about 35 degrees and at a moving target. I wanted to be someplace else. The sweet, sterile liquid was drawn up, the tourniquet in place on the rigid left arm, a small vein palpable and visible just lateral to the antecubital fossa. At exactly this critical moment the pilot made the familiar announcement: Ladies and gentlemen, we will experience a bit of turbulence for a few minutes. All of this in the usual reassuring drawl with which frequent fliers are so familiar. I hope the picture is clear. Who is it that said, I'd rather be lucky than good? The needle found its way in very nicely. I aspirated a puff of the most gorgeous red blood I have ever seen and experienced euphoria. Now I carefully injected the glucose solution. No swelling appeared around the puncture site! At about the 35-cc mark I looked at Helga. How was she feeling, I asked. I'm fine, she responded. The response of the hypoglycemic patient to intravenous glucose remains one of the most dramatic events in medicine. She was, in a matter of moments, virtually recovered. It is a peripheral issue certainly, but of interest, that she denied taking any insulin, denied being a diabetic, and, in fact, was quite indignant when asked why she had insulin in her handbag. She insisted on returning to her station and even rejected German medical attention when they boarded the plane in Berlin. At my suggestion, the Captain arranged for her to be removed from the flight and to be observed by a physician in Berlin until she was out of danger. I must say I enjoyed hero status for the ba

Autologous blood collection in pregnancy. Prospective study

Abstract: Autologous blood predonation during pregnancy, with the aim of autotransfusion after delivery, has gained increasing consensus over the last few years. However, there are still some controversial aspects. In particular, the cost/benefit ratio of institutionalizing the above mentioned practice would appear altogether unfavourable (too many women would be really in need of transfusion after delivery). The aim of the present study is to assess the results of our experience using autotransfusion in obstetrics. This longitudinal and prospective study was carried out on a sample of 29 pregnant women who donated 1 unit of blood during the last month of their pregnancy. Phlebotomy was preceded by a verification of the permitting conditions (Hb > or = 11 g/dl; Ht > or = 33%). Before, during and after phlebotomy, the patients underwent cardiotocographic monitoring and periodic observation of vital parameters. The hematologic parameters registered during the various test (before predeposit, before delivery, in puerpery) were statistically analysed. The hemochromo values appeared satisfactory in all cases at the time of admittance for labour. As a consequence of a hematic loss higher than usual at the moment of delivery, in many cases the hemoglobin values during puerpery did not enable us to exclude a priori the advisability of a transfusion. From the study we see how the cost/benefit ratio of the predeposit practice in obstetrics is less unfavourable than commonly thought.

Use of a phlebotomy service in a paediatric unit

Abstract: This article evaluates the literature and research concerning venepuncture and the use of a phlebotomy service in an acute paediatric setting. It also highlights concerns expressed by nursing and medical staff about the introduction of such a service.