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Biomedical subjects

P G Hattersley

Publications and source records attributed to P G Hattersley.

At least 19 recordsLinked to original sources
PubMed1983

Heparin therapy for thromboembolic disorders. A prospective evaluation of 134 cases monitored by the activated coagulation time.

One hundred thirty-four patients with venous thrombosis or pulmonary embolism, confirmed by radiological techniques, received continuous-pump heparin therapy while their responses were monitored by the activated coagulation time (ACT). The suggested protocol was as follows: (1) give an intravenous bolus of about 50 units/kg; (2) follow with 15 to 25 units/kg/hr; (3) modify infusion rate to maintain ACT of 150 to 190 s; (4) after two or three days with ACT in target range, start oral warfarin sodium therapy; (5) after three to five days of warfarin therapy, if prothrombin time is two to 2 1/2 times the control value, discontinue heparin administration. One hundred thirty-two patients responded, with no heparin failures. Dangerous bleeding occurred in two who received excessive amounts of heparin. Some patients, mostly with short ACTs, responded slowly; some, many with long ACTs, had minor bleeding. The protocol proved successful and safe when followed closely.

Adolescent↗
PubMed1983

Adjusting heparin infusion rates from the initial response to activated coagulation time.

A mathematical description of the dose-response curve of heparin to the activated coagulation time is applied retrospectively to 20 patients treated with continuous heparin infusion. The adjusted heparin dose was compared with a calculated prediction using the theoretical mathematical model. The main actual dose was 28 U/kg/h, and the mean predicted dose was 25.8 U/kg/h. The correlation coefficient was 0.862 (p3 0.05). These data are used to develop a dosing adjustment chart. Special considerations prior to using the calculation or dosing adjustment chart are discussed. The use of this model may allow the clinician to determine more rapidly a therapeutic heparin dosage than previous empiric approaches.

Adult↗
PubMed1980

Sources of error in heparin therapy of thromboembolic disease.

We observed a series of patients with thromboembolic disease treated intravenously with heparin sodium and monitored by the activated coagulation time (ACT) of whole blood. When patients responded slowly, had dangerous hemorrhage, or had ACTs well outside our target range, we analyzed infusion records to determine actual infusion rates. We found the following sources of error: (1) lack of pump precision, (2) interruption of infusion, (3) errors in making up solutions, and (4) failure of infusion or charting techniques.

Adult↗
PubMed1977

Unrecognized causes of platelet transfusion failure in the presence of anti-HL-A antibodies.

When in a patient who is receiving random donor platelet infusions there is an inadequate rise in platelet count and anti-human HL-A antibodies are noted in the serum, it is natural to assume that platelet destruction results from an immunologic cause. Nonimmunologic causes of such failure do occur, however. Two of the most common are disseminated intravascular coagulation and splenomegaly.

Adult↗
PubMed1976

The effect of increased contact activation time on the activated partial thromboplastin time.

With the kaolin-cephalin activated partial thromboplastin time technic, the plasmas of persons who have Fletcher factor deficiency have shown considerable shortening of clotting times when contact activation has been lengthened from 3 (PTT-3) to 10 minutes (PTT-10). The authors demonstrate that in plasma of most normal individuals, and in coagulopathies of other sorts, only slight shortening usually occurs. Abnormal shortening occurs in plasmas of a few otherwise normal people, the "slow activators," and patients receiving coumarin drugs, who have greatly prolonged prothrombin times. Longer activation may produce greatly prolonged PTT's in plasmas containing heparin in relatively high concentrations. The authors discuss the significance of these findings.

Blood Coagulation Disorders↗
PubMed1976

Progress report: the activated coagulation time of whole blood (ACT).

The activated coagulation time of whole blood (ACT) has, in the nearly ten years since its first description in the literature, proven itself one of the best laboratory tests for the control of heparin therapy, both for patients undergoing treatment for thromboembolic disease and for those on extracorporeal circulation. It is simple, largely free from subjective variation, precise, and quick. Prolongation of the ACT in the heparinized individual is directly proportional to the concentration of heparin in the blood, and the test accurately reflects the semilogarithmic disappearance of the anticoagulant effect in most patients. In addition, the test serves well as a bedside screening test for deficiencies of the intrinsic coagulation mechanism. The author summarizes the sutdies that have been carried out on this technic since its original description, and briefly presents three protocols for heparinization of patients who have thromboembolic disease.

Blood Coagulation Disorders↗
PubMed1975

A walking donor program for an intensive care nursery.

Repeated transfusions of small increments of blood are frequently required for the sick newborn infant to correct endogenous hypovolemia and/or to replace blood obtained repeatedly for monitoring purposes. Current practices of blood banks are rarely geared to supply the small amounts of blood used for these individual transfusions. To provide a more efficient system, a walking donor program was established in which an appropriate hospital-based individual is cross matched as a donor for an infant for the duration of the infant's hospital stay. The program eliminates wastage of blood and donors and reduces the number of infectious agents to which the infant may be exposed.

ABO Blood-Group System↗
PubMed1974

Neutrophilic hypersegmentation without macrocytic anemia.

In five months of examining some 25,000 blood smears of hospital and clinic patients, 200 patients were found whose blood had hypersegmented neutrophiles without macrocytosis of the erythrocytes. Sixty-five of these patients subsequently received adequate laboratory work-up. Seven proved to have a bacterial inhibitor in their serum which interfered with the microbiological assay of folic acid. Of these patients, six had normal B-12 levels. Of the remaining 58, 45 had a deficiency of folate, of vitamin B-12 or of both. In 13, no such deficiency could be established. Of these, seven proved to be uremic. It is concluded that the additional effort required to search carefully for hypersegmentation, even in the absence of erythroid macrocytosis, is thoroughly justified, and that a large percentage of those patients in whose blood hypersegmented neutrophiles are found will prove to have important deficiencies of folate or B-12, or will prove to be uremic.

Adolescent↗
PubMed1971

The activated coagulation time of whole blood as a routine pre-operative sceening test.

Patients with disorders of hemostasis who undergo surgical procedures are in danger of hemorrhage. While the careful medical history remains the most sensitive test of a bleeding tendency, some such patients can give no suggestive history. In three patients with coagulopathy-one with mild classical hemophilia, one with Christmas disease, and one with warfarin toxicity-the abnormality was missed by routine preoperative history but promptly detected by the routine preoperative use of the activated coagulation time (act). Either this test or the activated partial thromboplastin time should be included in the routine preoperative work-up, along with appropriate additional tests of the hemostatic mechanism.

Adult↗