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Biomedical subjects

R A Thisted

Publications and source records attributed to R A Thisted.

52 records · Page 3Linked to original sources

In vitro effects of aprotinin on activated clotting time measured with different activators.

The effects in vitro of aprotinin on the activated clotting time measured with both celite- and kaolin-activated tubes were investigated in 21 consecutive patients requiring cardiopulmonary bypass. Four whole-blood samples (2 ml per sample) from each patient were tested simultaneously with Hemochron automated timing systems (International Technidyne Corp., Edison, N.J.) before, during, and after cardiopulmonary bypass. One tenth milliliter of either aprotinin (at a final concentration of 80, 120, or 180 KIU/ml) or saline solution was mixed in vitro with blood samples before determination of the activated clotting time. Aprotinin had no inhibitory effect on the activated clotting times of unheparinized blood. After heparin administration, aprotinin in the above concentrations prolonged the activated clotting times measured with celite-activated tubes by 47% to 71%, as compared with the measurements of the activated clotting time without the addition of aprotinin. The activated clotting times in kaolin-activated tubes were not increased, however, by the in vitro addition of aprotinin. Our in vitro results indicate that aprotinin in concentrations from 80 to 180 KIU/ml does not significantly enhance the inhibitory effects of heparin on the intrinsic coagulation system as evaluated by measurement of the activated clotting times in kaolin-activated tubes. The anticoagulation effect of heparin in patients receiving aprotinin infusion should be monitored with kaolin-activated instead of celite-activated tubes because the celite makes the measured activated clotting time unreliable in patients receiving aprotinin therapy. These in vitro results require confirmation in vivo in patients receiving aprotinin therapy.

Aged↗

Reassessment of preoperative laboratory testing has changed the test-ordering patterns of physicians.

To test the hypothesis that physicians have substantially reduced the ordering of unwarranted preoperative tests, the authors reviewed 2,093 medical records of patients having four surgical procedures performed at three institutions in three cities in 1979, 1981, 1983, 1985 or 1987. Excluding hemoglobin measurements, the incidence of ordering preoperative laboratory tests unwarranted by findings on history or physical examination decreased from 32.2 to 25.9 percent during this decade, representing a 19.6 percent reduction. This decrease was irregular and varied from operation to operation, test to test and institution to institution. Overall, the percentage of preoperative tests ordered that were unwarranted decreased from 66.9 percent in 1979 to 60.1 percent in 1987. Extrapolating these results, the authors estimate that more than $320 million was saved annually by elimination of unwarranted tests and that the potential savings could exceed $1.35 billion a year. Unexpectedly, the preoperative ordering of medically indicated tests also decreased (from 92.9 to 80.9 percent, representing a 12.9 percent reduction). Because the benefit of performing justified tests is probably greater than the benefit of avoiding unwarranted tests, the net change has probably not been beneficial. A better system for obtaining justified tests and for eliminating the unwarranted tests may be necessary before a net benefit occurs. Punitive measures to reduce testing without prior establishment of such a system may save money, but impair health.

Chicago↗

Alcohol after sedation with i.v. midazolam-fentanyl: effects on psychomotor functioning.

Patients who arrive home several hours after outpatient surgery may drink alcohol. The extent to which residual drugs used in outpatient surgery interact with alcohol is not known. The purpose of this study was to determine if two i.v. drugs commonly used together in outpatient surgery, midazolam and fentanyl, have residual effects which would interact with alcohol drunk 4 h after injection. Twelve healthy male volunteers participated in a double-blind, randomized, placebo-controlled and cross-over study. Subjects were studied four times successively with a period of 1 week between trials. On each day of testing, the subjects received randomly, by slow i.v. injection (30 s), either saline followed immediately by saline, or midazolam 0.1 mg kg-1 followed immediately by fentanyl 2 micrograms kg-1. Four hours after the injection, the subjects consumed a beverage which either did or did not contain alcohol 0.7 g kg-1. Before and 1, 3, 5 and 7 h after injection (and before and 1 and 3 h after consumption of beverage), psychomotor performance and mood were assessed. While both the combination midazolam-fentanyl and alcohol had independent effects on the dependent measures in this study, there was no interaction between midazolam-fentanyl and alcohol (no potentiating of effects of alcohol by i.v. sedation). We conclude that the effects of benzodiazepines and opioids that are short-acting and used in outpatient surgery have probably dissipated by the time a patient arrives home, and that effects from alcohol ingested at home will probably not be affected by recent administration of these drugs.

Adult↗

Alcohol after midazolam sedation: does it really matter?

Patients who arrive home several hours after ambulatory surgery may drink alcohol. The extent to which the residual effects of drugs used in ambulatory surgery interact with alcohol, perhaps potentiating alcohol effects, is not known. Accordingly, the purpose of this study was to determine whether intravenous midazolam had residual effects that would interact with alcohol consumed 4 h after the midazolam injection. Healthy male volunteers (n = 16) participated in a double-blind, randomized, placebo-controlled crossover trial. Subjects were studied four times successively with 1 wk between trials. On each test day the subjects randomly received by slow intravenous injection (30 s) either saline or 0.1 mg/kg of midazolam. Four hours after injection, the subjects consumed a beverage that either did or did not contain 0.7 g/kg of alcohol. Before and 1, 3, 5, and 7 h after injection (and before and 1 and 3 h after beverage consumption), psychomotor performance and mood were assessed. Whereas both midazolam and alcohol alone had effects on the dependent measures in this study, there were no significant interactions between the two drugs (i.e., potentiation of alcohol effects by midazolam or potentiation of midazolam by alcohol). We conclude that the effects of a short-acting benzodiazepine used in ambulatory surgery have probably dissipated by the time a patient arrives home, and that effects from alcohol ingested at home will probably not be influenced by the recent administration of a short-acting benzodiazepine such as midazolam.

Adult↗

The automated interview versus the personal interview. Do patient responses to preoperative health questions differ?

Laboratory testing of presurgical patients has been shown to be excessive, thereby increasing costs, reducing resources for other health care uses, and increasing risks to both patients and physicians. As one step toward reducing the number of unnecessary preoperative tests ordered, we used an automated method to aid preoperative assessment of 239 patients in Chicago and in Winnipeg. The "HealthQuiz," a small hand-held device containing a computer chip and video screen, uses a decision tree to ask a minimum of 60 health-related questions (the patient's response to certain questions determines the number of questions presented). The device then generates a summary printout of patient answers, the health areas needing further attention, and the laboratory tests most likely to uncover clinically important abnormalities in that patient. HealthQuiz responses are intended to aid the physician and not to replace the personal interview. As an aid, the automated interview highlights possible problem areas for in-depth pursuit by the physician. The need for nonselective batteries of tests is eliminated because recommendations for tests are based on specific elements of a patient's history. To be effective, responses to the HealthQuiz should be the same as responses to similar questions asked by a physician. We tested that premise in this study. Patient's answers to the HealthQuiz were compared with their responses to a randomly selected set of the same questions in a personal interview. Ninety-seven percent of the response pairs were identical, and most of the 3% that differed involved changes from "not sure" replies to the HealthQuiz. Laboratory tests suggested by responses to the two methods of questioning did not differ.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Patient-applied podofilox for treatment of genital warts.

In a double-blind trial, 0.5% podofilox (podophyllotoxin) or placebo was applied by patients to their own genital warts in up to four treatment cycles. At some time during the study, 25 of the 56 podofilox treated patients and none of the 53 placebo group were completely wart-free. At the end of the treatment, 73.6% of the original warts in podofilox treated patients were gone compared with only 8.3% of those in the placebo group (mean percentage of total original wart area was reduced by 82.3% compared with 4.2%). 82% of the treated warts in the podofilox group and 13% in the placebo group had resolved at 6 weeks. Recurrence was observed in 34% of the previously resolved warts. Consistent with this rate of recurrence, new warts developed in a third of the subjects in each group at sites remote from the treatment site. There were no systemic adverse reactions, although transient inflammation, erosion, pain, and burning were common.

Administration, Topical↗

Increased risk for gestational diabetes mellitus associated with insulin receptor and insulin-like growth factor II restriction fragment length polymorphisms.

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first recognition during pregnancy. We have examined restriction fragment length polymorphisms (RFLPs) near "candidate diabetogenic genes" as one approach to identify molecular markers for GDM genes. Genotypes for insulin hypervariable region (HVR), insulin-like growth factor II (IGF2), insulin receptor (INSR), and glucose transporter (GLUT1) RFLPs were studied in 96 GDM and 164 control subjects, matched to GDM for race, age, and gravidity. Logistic regression analysis was used to explore the relationship between genotypes at these candidate gene loci and GDM, while adjusting for the effects of potential confounding variables. Among black subjects, the INSR allele 1 (P = 0.001) and interactions between INSR allele 1 with body mass index (BMI) (P = 0.002) and history of DM in subject's mother (P = 0.004) contributed significantly to GDM risk. Among Caucasian subjects, a similar relationship between the INSR allele 1 (P = 0.007) and INSR allele 1-BMI interactions (P = 0.011) on GDM risk were observed. In Caucasians, an additional significant risk factor was determined by an INSR allele 1-IGF2 allele 2 interaction (P = 0.018). No risk factors were identified in Hispanic subjects. These data continue to support the hypothesis that GDM is a heterogeneous disorder with respect to phenotypic and genotypic features. Furthermore, our data suggest that risk for GDM in black and Caucasian subjects is not due to obesity perse but to interactions between obesity and INSR alleles. In Caucasian women, INSR and IGF2 alleles interact to confer additional risk for GDM. Thus genes underlying susceptibility to GDM in some women may be similar to genes conferring risk to NIDDM, while in others novel genes may contribute to GDM risk.

Chromosome Mapping↗

Chymodiactin in patients with herniated lumbar intervertebral disc(s). An open-label, multicenter study.

To extent the safety information for Chymodiactin (chymopapain for injection), 37 neurologic and orthopedic surgeons conducted an open-label, multicenter, phase 3 clinical study. A total of 1,498 patients with one or two herniated lumbar intervertebral discs were enrolled. Therapeutic results were generally favorable, with the percentages of patients achieving either excellent or good (or successful) results ranging from 79.6% to 88.9%, depending on criteria employed in the tabulation. There were 13 cases of anaphylaxis, and 2 of these patients died of complications of anaphylaxis. Two additional patients experienced serious neurologic problems. The first of these two patients developed transverse myelitis and paraplegia approximately 3 weeks following chemonucleolysis. Transdural discograms at three levels had been done approximately 2 days prior to chemonucleolysis, in violation of the protocol. The second patient developed acute cauda equina syndrome, and, despite emergency laminectomy, had permanent neurologic sequelae. Back spasm and stiffness/soreness were the most frequently encountered adverse experiences.

Adolescent↗

Lactic acidemia in Reye's syndrome.

Plasma lactate level was measured in 21 patients with Reye's syndrome and was compared with neurologic state as rated on a simple coma scale. Significant elevations in plasma lactate, ranging from 2 to 15 mEq/liter, were noted in all patients. There was a close correspondence between stage of coma at the time the sample was drawn and lactate levels. The correlation of plasma lactate level with clinical stage could not be accounted for by differences in glucose. PO2, PCO2, pH, blood pressure, or serum osmolality. In contrast, blood ammonia level correlated with the severity of the encephalopathy early in the course only and often returned to normal in patients with persistent coma. Only measurements of hepatic dysfunction such as SGOT and SGPT levels of failed to correlate with clinical state. All patients had a metabolic acidosis; in five patients it was uncompensated. Lactate accounted for nearly all (mean 81%) of the observed base deficit. The findings suggest that lactic acidemia is an important metabolic component of Reye's syndrome.

Acidosis↗

Prediction of homicide with the Rorschach.

The use of a step-wise multiple discriminant analysis indicated that the Rorschach variables of S, A, P and m could discriminate with a good degree of accuracy the Rorschach protocols of murderers from those of nonmurderers. These empirically derived linear discriminant functions may serve as a useful adjunct to the clinical interpretation of Rorschach protocols in a criminal population.

Adult↗

Cervical injury in head trauma.

Criteria for excluding cervical spine injury in patients who have sustained blunt head or neck trauma were prospectively studied at four hospitals in the Chicago area. The authors attempted to define a subset of these adult patients who, based on clinical criteria, could reliably be excluded from cervical spine radiography, thus avoiding unnecessary radiation and saving considerable time and money in their evaluation. Patients fell into four groups: (1) patients who were awake, alert, and had no complaint of neck pain or tenderness on physical examination; (2) patients who were awake, alert, but had complaint of neck pain or tenderness on physical examination laterally over the trapezius muscle only; (3) patients who were awake, alert, but had complaint of central neck pain or tenderness on physical examination over the cervical spine or center of the neck; and (4) patients who were not fully awake or alert, were clinically intoxicated, had other painful or distracting injuries, or had focal neurologic findings. Patients in group 4 had significantly more fractures (21/387) when compared with all other patients (7/478). Patients with central neck pain or tenderness (group 3) had significantly more fractures (7/237) than patients without pain or tenderness or with these findings limited to the trapezius area (0/236). It is clear that patients who have altered mental status, abnormal examination findings, distracting injury, or pain or tenderness over the cervical spine must have cervical spine radiographs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A comparison of intraarticular morphine and bupivacaine for pain control after outpatient knee arthroscopy. A prospective, randomized, double-blinded study.

To determine the duration of pain relief and efficacy of intraarticular morphine compared with bupivacaine after outpatient knee arthroscopy under local anesthesia, we gave patients one of three postoperative intraarticular injections: 4 mg morphine, 0.25% bupivacaine, or 0.9% saline. Visual analog scale scores and supplemental pain medication use were recorded at 0 to 30 minutes, 2, 4, 6, 8 to 12, and 24 hours after surgery. The score on the visual analog scale at 24 hours was significantly lower in the morphine group than in the bupivacaine or control groups. The cumulative amount of pain medication used was significantly lower in the morphine and bupivacaine groups at 2 to 6 hours after surgery than in the saline control group. The morphine group used the least supplemental pain medication during the 12 to 24 hour interval (P = 0.06). We found that the use of intraarticular morphine or bupivacaine after outpatient knee arthroscopy will decrease the amount of narcotic medication needed for pain relief during the early postoperative period. In addition, morphine provided prolonged pain relief up to 24 hours when compared with bupivacaine or placebo, and the patients in the morphine group tended to take less supplemental pain medication during the first postoperative day.

Adolescent↗

The impact of contralateral breast cancer on the outcome of breast cancer patients treated by mastectomy.

PURPOSE: To evaluate the clinical and pathological features of breast cancer patients who develop contralateral breast cancer (CBC) and assess the impact of the second breast cancer on their prognosis. PATIENTS AND METHODS: This retrospective study includes 2136 women with stage I-III breast cancer treated between 1927 and 1987 at the University of Chicago Hospitals. A total of 132 (6.2%) developed CBC during a median follow-up period of 14.2 years; all of them were treated with mastectomy for both breast cancers. We compare the prognostic characteristics, treatments, and outcomes of patients who developed bilateral breast cancer with those who had only unilateral breast cancer (UBC). We also compare the features of the first and the second tumors among patients with bilateral breast cancer (BBC). RESULTS: The annual incidence rate for CBC remained constant at an average rate of 0.23%, resulting in a cumulative incidence rate of 6.2%. Patients with BBC were significantly younger than those with UBC (median age, 51 years vs 54 years). No other significant differences were observed between BBC and UBC patients. Among BBC patients, the second cancer was smaller (2.0 cm vs 3.0 cm) and was associated with a lower incidence of axillary node involvement (29% vs 52%). The development of CBC was associated with worse survival (hazard ratio = 1.46 in comparison with patients who did not develop CBC, 95% CI of 1.09-1.95). On multivariate analysis, factors that decreased the disease-specific survival (DSS) in patients with BBC were a higher number of positive lymph nodes of the first and second cancers, a larger size of the second cancer, and a shorter interval between the two primaries. DISCUSSION: At the time of diagnosis of first breast cancer, BBC patients were significantly younger than UBC patients. The second cancer among the BBC patients was at an earlier stage than the first one; however, no difference was noticed in the pathological feature between the cancer in the UBC patients and the first cancer of BBC patients. There is an indication that the longer the interval between the two cancers, the better the survival of the BBC patients.

Adult↗

Intravenous lidocaine does not cause shivering-like tremor or alter thermoregulation.

We tested the hypotheses that systemic absorption of epidural lidocaine: (1) contributes to the shivering-like tremor seen during epidural anesthesia by causing central nervous system disinhibition of spinal reflexes, or (2) activates or alters thermoregulatory mechanisms. In a double-blind, placebo, cross-over study, nine healthy volunteers were given intravenous lidocaine (or saline) to approximate the plasma levels of lidocaine achieved during epidural anesthesia for major abdominal surgery. Five volunteers were studied in a warm room (to test for nonthermoregulatory tremor), and four volunteers were studied in a cold room (to test the effects of lidocaine on normal thermoregulation). Central temperatures, peripheral vasoconstriction, tremor and clonus were unaffected by intravenous lidocaine. We conclude that the systemic absorption of epidural lidocaine does not contribute to tremor or shivering by these mechanisms.

Adult↗