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Biomedical subjects

G R Buchanan

Publications and source records attributed to G R Buchanan.

At least 127 records · Page 7Linked to original sources
PubMed1990

Bone pain as an initial symptom of childhood acute lymphoblastic leukemia: association with nearly normal hematologic indexes.

We reviewed the records of all patients with a diagnosis of ALL made at our center during a 13-year period to determine the relationship between bone pain and the hematologic findings at diagnosis of acute lymphoblastic leukemia. Of 296 eligible patients, 179 (60%) had no bone pain (group 1), 65 (22%) had some bone pain (group 2), and 52 (18%) had prominent bone pain that overshadowed other manifestations of the leukemia (group 3). Statistically significant differences were found between the groups for hemoglobin concentration (p less than 0.001), leukocyte count (p = 0.014), absolute neutrophil count (p = 0.002), percentage of circulating blast cells (p = 0.009), and platelet count (p less than 0.001). Children in group 3 had values closer to normal for all these values than those of patients in the other groups. Group 3 patients had symptoms an average of more than 2 weeks longer before diagnosis, and had significantly lower serum uric acid and higher calcium levels than patients in the other groups had. No differences were detected among the groups in age at diagnosis, gender, or survival rate. We conclude that children with acute lymphoblastic leukemia who have prominent bone pain preceding the diagnosis frequently have nearly normal hematologic values and that this feature may contribute to a delay in diagnosis.

Bone and Bones↗
PubMed1990

The bleeding time may be longer in children than in adults.

The bleeding time, the most frequently performed test reflecting in vivo platelet function, is the duration of blood flow from a standardized incision on the volar surface of the forearm. Normal values have been determined in adult subjects, but with the exception of neonates, data on the range of bleeding time values in pediatric patients are unavailable. Standard hematology textbooks imply that bleeding time values in children are similar to those of adults. We have reviewed our 9 years of experience with 137 children (mean age 6.5 years) who were referred for diagnostic evaluation of a bleeding disorder but whose history and physical examination were felt by us to be inconsistent with an abnormality of hemostasis. Bleeding time values in these individuals (mean 6.0 min, 95th percentile 9.0 min) were compared with those of 85 normal adult volunteers (mean 4.4 min, 95th percentile 6.5 min). The Simplate-I disposable device and vertical (perpendicular to elbow crease) incision direction were used in both groups. This difference between the pediatric and adult bleeding time values is statistically significant (p less than 0.0001). Neither age nor sex had a significant effect on the pediatric bleeding time measurements. We conclude that the bleeding time, when performed as described, is longer in children than in adults and that pediatric standards for bleeding time should be used in order to avoid a spurious diagnosis of a primary hemostatic disorder in some normal children.

Adolescent↗
PubMed1990

Early hospital discharge of children with cancer treated for fever and neutropenia: identification and management of the low-risk patient.

Children with leukemia and solid tumors are often hospitalized for empiric broad-spectrum antibiotic therapy because of fever during periods of chemotherapy-induced neutropenia. Conventional practice dictates that parenteral antibiotics be continued until the patient is afebrile and has recovered from neutropenia, ie, until the absolute neutrophil count (ANC) exceeds 500 cells per cubic millimeter. However, the practice in our center has been to discontinue parenteral antibiotic therapy and discharge many such patients before resolution of neutropenia. Since the feasibility and safety of this approach has not been studied, we reviewed the records of 114 consecutive hospitalizations for fever and neutropenia in 61 patients during a 13-month period. Seventy-seven children (68%) were discharged to their homes while still neutropenic after they had been afebrile for 1 to 2 days on parenteral antibiotics, had negative blood cultures, appeared well, and usually had some evidence of bone marrow recovery. Five patients (4.4%) developed recurrent fever and required rehospitalization within 7 days of discharge. Only three of the 77 patients (3.9%) who were sent home with neutropenia had recurrent fever. Each had a brief and uneventful second hospitalization. Two of the 37 children discharged with an ANC over 500 cells per cubic millimeter required rehospitalization. A declining ANC and advanced malignancy were risk factors in predicting recurrence of fever following discharge. A rising monocyte count was a predictor of imminent recovery from neutropenia. These results suggest that "early" discharge of an afebrile yet still neutropenic patient is safe when the patient is in remission, has no evidence of serious infection, appears clinically stable, and has indications of bone marrow recovery. The conventional approach of routinely continuing the hospitalization until resolution of neutropenia may be unnecessary in such low-risk patients.

Bacterial Infections↗
PubMed1990

Diagnosis and management of relapse in acute lymphoblastic leukemia.

Although the results are steadily improving, the treatment of the child with lymphoblastic leukemia in relapse remains unsatisfactory. Owing to the very nature of relapse, it is highly unlikely that future chemotherapy protocols will provide curative treatment for the majority of patients with recurrent disease. Therefore, the greatest possible emphasis must be given to further improvements and refinements in front-line (initial) therapy so as to prevent relapse from ever occurring. Our goal should be to put the relapse leukemia specialist "out of business."

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Septic arthritis in children with hemophilia.

Four of the 139 children with hemophilia followed up at our center have developed septic arthritis during the past 6 years (2.9% incidence). Two infections were caused by Streptococcus pneumoniae and one each by Staphylococcus aureus and Haemophilus influenzae type B. Common features at time of presentation included fever and a 2- to 7-day history of joint pain and swelling unresponsive to factor replacement infusions. Since three of the patients were human immunodeficiency virus seropositive, we propose that human immunodeficiency virus infection may be responsible for the disproportionately high number of cases of septic arthritis observed in our patient population.

Adolescent↗
PubMed1989

Overview of ITP treatment modalities in children.

Patients with idiopathic thrombocytopenia purpura (ITP) are frequently encountered by the pediatrician and pediatric hematologist. The clinical and laboratory features of ITP are quite uniform and facilitate prompt and accurate diagnosis. Bone marrow examination is not required in most cases since patients with alternative diagnoses (such as ALL) have greatly different presenting features. Acute ITP cannot be differentiated from the chronic form of the disease at presentation, nor can chronic disease be prevented by specific therapy administered for apparent acute ITP. Much controversy has revolved around whether an active interventionist (pharmacologic) or non-interventionist approach is preferred for management of ITP. The platelet count in both acute and chronic ITP often rises following treatment with prednisone and/or intravenous gamma globulin (IV GG), but such responses are transient and do not clearly provide protection against the rare complication of life-threatening hemorrhage. There are numerous disadvantages to an interventionist approach to therapy. Children with chronic ITP may require splenectomy if the disease is symptomatic enough to interfere with life-style, but the majority of these patients, too, require no specific therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Splenic phagocytic function in children with sickle cell anemia receiving long-term hypertransfusion therapy.

To determine the effects of blood transfusions on splenic function in older patients with sickle cell anemia, we investigated splenic function in 12 patients who had had cerebrovascular accidents and who were being treated at two collaborating centers using different transfusion protocols. Splenic function was assessed by radionuclide scan and pocked erythrocyte count. Patients were 6 to 18 years of age and had been receiving transfusions for 7 months to 10 years (median 4.2 years). Of the 12 children, five had normal or increased splenic size and function (normal scan and normal or minimally elevated pocked erythrocyte count). All were receiving intensive transfusion therapy, with the aim of maintaining the hemoglobin S level at less than 20%. The other seven patients had abnormal splenic function (absent radionuclide uptake and elevated pocked erythrocyte count); each was receiving less intensive transfusion therapy, with the pretransfusion hemoglobin S level usually at 30% to 40%. No patient developed bacterial septicemia while receiving hypertransfusion therapy. We conclude that splenic function during a long-term transfusion program is variable, depending in part on the "intensity" of transfusion therapy. Apparent splenic involution and fibrosis may be a reversible event in some patients.

Adolescent↗
PubMed1989

A comparative study of variables affecting the bleeding time using two disposable devices.

A number of variables affect the result of the bleeding time, the most frequently used test assessing primary hemostasis. Although the test is now usually performed with one of several commercially available disposable devices, most previous studies of the bleeding time have evaluated only the original template device described nearly 20 years ago. Therefore, we compared two commonly used bleeding time devices (Surgicutt and Simplate) with regard to multiple variables affecting the test in 40 hematologically normal young adults. Bleeding time was performed by the modified Ivy method according to the manufacturers' instructions in both horizontal (transverse) and vertical directions, before and two hours after a test dose of 650 mg of aspirin was administered. With both horizontal and vertical incisions, Simplate bleeding time values were greater than with the Surgicutt device (P = 0.0025). Bleeding time in the horizontal direction was greater than vertical with both devices (P = 0.0001). Values in males and females were not significantly different. Aspirin sensitivity, the difference between preaspirin and postaspirin values, was greatest with the use of the Surgicutt device in the horizontal position (mean postaspirin value 8.0 minutes). Both devices produced a reproducible uniform incision, caused minimal discomfort, and resulted in little or no scarring. The authors conclude that the results with Surgicutt and Simplate devices were comparable in many respects but that a horizontal Surgicutt bleeding time might be most sensitive in detecting disorders of primary hemostasis. Comparative studies of different bleeding time devices in normal subjects are necessary in order to accurately assess their clinical utility.

Adult↗
PubMed1989

Spontaneous resolution of primary erythrocytosis in two girls.

We report two girls with primary erythrocytosis in whom extensive diagnostic studies revealed no underlying cause. Normal growth of colonies derived from erythroid burst forming units (BFU-E) was observed, and serum erythropoietin concentrations were within or below the normal range. The absence of a rise in serum erythropoietin levels after isovolemic phlebotomy implicated the erythroid marrow as the site of the pathophysiologic abnormality in both patients. Spontaneous resolution of erythrocytosis occurred during the second decade of life. Our experience suggests that primary erythrocytosis may be self-limited in some children. In these cases, the proliferative abnormality may be sufficiently subtle as to not be detected by standard in vitro culture systems, which support the growth of colonies derived from erythroid progenitors.

Aging↗
PubMed1988

Elevated serum transaminase values during therapy for acute lymphoblastic leukemia correlate with prior blood transfusions.

Fifty-nine children treated with acute lymphoblastic leukemia (ALL) were evaluated for abnormalities of liver function in order to monitor chemotherapy-induced hepatotoxicity. Twenty-one patients (36%) had elevations of alanine aminotransferase (ALT) in a pattern consistent with either drug-induced hepatocellular injury or non-A, non-B (NANB) hepatitis. These 21 patients (Group 1) were compared with the other 38 children (Group 2) with regard to a number of clinical and laboratory characteristics. Patients in Group 1 were older (P = 0.002) and had lower platelet counts (P less than 0.001) and hemoglobin values (P = 0.075) at diagnosis than Group 2 patients. The median number of units of blood products transfused was significantly greater in Group 1 patients (9.0 versus 1.0 units, P less than 0.001). The two groups were similar with regard to chemotherapy regimens. Children with ALL who present at an older age and who have more marked anemia and thrombocytopenia require more blood transfusions and are more likely to develop elevated ALT values in a pattern consistent with acute or chronic NANB hepatitis. These findings suggest a predominant role of NANB posttransfusion hepatitis--rather than or in addition to chemotherapy-induced hepatic injury--as a cause for elevated ALT values in children with ALL. In view of the potentially serious consequences of NANB hepatitis, a change in transfusion support practices may be warranted.

Adolescent↗
PubMed1988

Deoxycoformycin treatment for childhood T-cell acute lymphoblastic leukemia early in second remission: a Pediatric Oncology Group Study.

2-Deoxycoformycin (DCF) was added to an intensive Pediatric Oncology Group protocol (#8303) for children with T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma in first relapse. Twenty-seven patients received one or more courses of DCF at 15 mg/m2/day as a 3-day continuous infusion immediately after achieving a second remission with a four-drug reinduction regimen. Renal and neuromuscular toxicities were frequent and occasionally severe despite the provision of a source of adenosine deaminase by means of a packed red cell transfusion 1 day following the infusion of DCF. Hepatic toxicity, manifested by transaminase elevations, accompanied 62% of the courses. The median duration of the second complete remission was 4 months (range 2-16+ months), with only two of the 27 patients still in remission at 13+ and 16+ months. Plasma concentrations of deoxyadenosine (dAdo) and the ratio of red cell deoxyadenosine triphosphate to adenosine triphosphate (dATP:ATP) were measured prior to the DCF infusion and on day 4. A dATP:ATP ratio of 1.0 or greater was seen in two patients with acute renal failure. There was no apparent correlation between toxicity or response and the plasma dAdo concentrations. DCF administered according to this dose and schedule was excessively toxic and did not appreciably prolong the duration of the second complete remission in children with T-cell lymphoblastic malignancies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Prophylactic cryoprecipitate in congenital afibrinogenemia.

Two siblings with congenital afibrinogenemia received prophylactic infusions of cryoprecipitate in order to prevent serious hemorrhage during early childhood. Three bags (units) of this fibrinogen-containing blood product were administered every 7-10 days for 15 months in one case and 24 months in the other. Hemorrhage was nearly completely prevented during the period of prophylaxis. Side effects from cryoprecipitate were not observed. Prophylactic infusion of cryoprecipitate, made practical by the relatively long half-life of fibrinogen, should be considered in other patients with this disorder.

Afibrinogenemia↗