Thromboprophylaxis in major abdominal surgery for cancer

AIMS

To review the epidemiology and pathogenesis of venous thromboembolism (VTE) in surgical cancer patients, in addition to the use of thromboprophylaxis in major abdominal surgery, such as low-molecular-weight heparin (LMWH) and fondaparinux.

METHODS

Systematic review of the literature, focussing on risk factors for VTE, parenteral methods of thromboprophylaxis, approaches to prolonged prophylaxis, and effects on patient survival.

FINDINGS

Patients with cancer undergoing abdominal surgery are at substantially higher risk for VTE than patients without cancer. Furthermore, prolonged thromboprophylaxis for up to 4 weeks is more effective than short-term administration in these high-risk patients. The concurrent use of graduated compression stockings has a synergistic effect on the reduction in VTE risk.

CONCLUSIONS

Thromboprophylaxis with LMWH has been shown to minimise the incidence of thromboembolic events, and is a well-established therapy worldwide. The American College of Chest Physicians recommends the routine use of thromboprophylaxis, with LMWH or unfractionated heparin, in patients with cancer who are undergoing surgical procedures, and the appropriate use of these thromboprophylactic agents has significant implications for the clinical care and quality of life of surgical patients with cancer.

Pediatric acute renal failure: outcome by modality and disease

Two hundred and twenty-six children who underwent renal replacement therapy (RRT) from 1992 to 1998 were retrospectively reviewed. The mean age, at the onset of RRT, was 74+/-11.7 months and weight was 25.3+/-9.7 kg. RRT therapies included hemofiltration (HF; n=106 children for an average of 8.7+/-2.3 days), hemodialysis (HD; n=61 children for an average of 9.5+/-1.7 days), and peritoneal dialysis (PD; n=59 children for an average of 9.6+/-2.1 days). Factors influencing patient survival included: (1) low blood pressure (BP) at onset of RRT (33% survival with low BP, vs. 61% with normal BP, vs 100% with high BP; P<0.05), (2) use of pressors anytime during RRT (35% survival in those on pressors vs. 89% survival in those not requiring pressors; P<0.01), (3) diagnosis (primary renal failure with a high likelihood of survival vs secondary renal failure; P<0.05), (4) RRT modality (40% survival with HF, vs. 49% survival with PD, vs. 81% survival with HD; P<0.01 HD vs PD or HF), and (5) pressor use was significantly higher in children on HF (74%) vs HD (33%) or PD (81%; P<0.05 HD vs HF or PD). In conclusion, pressor use has the greatest prediction of survival, rather than RRT modality. Patient survival in children with the need for RRT for ARF is similar to in adults and, as in adults, is best predicted by the underlying diagnosis and hemodynamic stability.

AN-69 membrane reactions are pH-dependent and preventable

We report two pediatric patients who required blood priming for continuous venovenous hemodiafiltration. Both of these patients developed a significant hypotensive episode with initiation of continuous venovenous hemodiafiltration with immediate resolution on discontinuation. The most notable common characteristics of these patients were the use of the Multi-flo 60 (AN-69) dialyzer membrane and blood priming. No similar episodes were encountered when patients were primed with saline or albumin. The AN-69 membrane is exquisitely pH sensitive. The lower the pH concentration of the blood passing by the membrane, the greater the activation of bradykinin, a known hypotensive-inducing agent, by the dialyzer. On review of blood available from our blood bank, the following parameters became apparent. The pH of standard blood available from our blood bank ranged from 6.1 to 6.4. The blood obtained from our blood bank had significant hyperkalemia, hyponatremia, and hypocalcemia. No reactions were noted when patients were primed with normal saline, which has a pH of around 5.9. We speculate that the presence of endogenous blood substances, such as bradykinin, may have induced the hypotensive episodes. We describe two techniques we developed that should allow for the increased safe and effective use of the AN-69 membranes in continuous venovenous hemodiafiltration circuits. These observations indicate the requirement for careful and close attention to detail when delivering renal replacement therapy to anyone, but especially patients weighing less than 10 kg.

Management of acute renal failure in the pediatric patient: hemofiltration versus hemodialysis

Although outcome data for acute renal failure (ARF) in the adult population (analyzed by etiology of ARF, severity of illness, and modality of treatment) are readily available, few similar data exist for the pediatric population. Pediatric survival rate data vary widely, based upon era of analysis, age and size of child, and cause of ARF. Few comparative data are available that address impact by modality chosen to treat ARF. Comparison of 122 children who were treated by hemodialysis (HD; n = 58) versus hemofiltration (HF; n = 64) reveals a combined survival rate of 65%. Survival by modality was higher for HD (83%) than for HF (48%). The major diagnosis treated with HF was sepsis (29/64; 45%), with a survival rate of 31%, whereas the major diagnosis treated with HD (27/58; 46%) was primary renal failure, with a survival rate of 96%. Seventy-one percent of children undergoing HF required pressor support for hypotension, whereas only 24% of those receiving HD needed pressor support (P < 0.01). We conclude that the choice of renal replacement therapy (RRT) modality needs to be determined by the best treatment available. To adequately evaluate therapy measures, further analyses of outcome need to consider those factors that determine choice of RRT and those that affect survival independent of ARF.

The infant with primary hyperoxaluria and oxalosis: from diagnosis to multiorgan transplantation

The care of an infant with primary hyperoxaluria and oxalosis is discussed. After an unheralded presentation, followed by 9 months of intensive treatment that included combined hemodialysis and peritoneal dialysis, the infant successfully underwent combined liver and kidney transplantation to definitely address both kidney failure and the underlying metabolic defect. Discussion of this approach, including ongoing input from the parents, addresses both the implications of undertaking the "best therapy" for this disease as well as the ethical dilemma passed by the decision whether to proceed or not to proceed with therapy.

Automated high-performance liquid chromatographic method for the determination of nedocromil sodium in human urine using bimodal column switching

An automated HPLC method is described for the determination of nedocromil sodium in human urine. An HPLC autosampler is used to inject urine samples onto a short reversed-phase column. This column acts as a concentration column and performs a preliminary extraction. The concentration column is automatically back-flushed onto an ion-exchange column where final separation of nedocromil sodium from urine constituents occurs. Recovery, accuracy, precision, sensitivity and specificity were investigated. The method has been applied to urine samples from clinical studies, and the results were compared to those obtained using a radioimmunoassay developed previously.

Determination of dopexamine hydrochloride in human blood by high-performance liquid chromatography with electrochemical detection

A method is described for the determination of dopexamine hydrochloride at concentrations of 5 to 100 ng/ml in human blood using electrochemical detection. The method uses a Hypersil ODS column and a mobile phase containing heptane sulphonate, orthophosphoric acid, diisopropylamine and disodium EDTA. Blood samples are stabilised immediately after collection by the use of dipotassium EDTA and a high concentration of sodium metabisulphite. The sample preparation procedure consists of a simple de-proteinisation with perchloric acid. The method is accurate, with inter-assay accuracies ranging from 100 to 104%, and is free of interference by blood from different individuals. Known and potential metabolites of dopexamine hydrochloride and a wide range of drugs do not interfere with the method. The method is precise with inter-assay coefficients of variation of 10.6% at 5 ng/ml and of less than 4.2% at higher concentrations. Stabilised blood samples may be stored for over six months at -25 degrees C prior to analysis.

Comparison of the vaginal flora in sexually abused and nonabused girls

The presence of sexually transmitted pathogens in the vagina of the sexually abused girl may provide direct evidence of sexual abuse; the presence of other abnormal vaginal organisms may provide indirect evidence of abuse. To identify abnormal vaginal organisms, we prospectively studied the flora of 209 sexually abused girls (cases) and compared it with that in a concurrent control group of 108 girls. Case and control subjects were from the same community, were predominantly white, and 71% of each group were 3 to 10 years of age. The sexually transmitted pathogens (Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis, herpes simplex virus) were isolated exclusively from the case group at a low frequency (less than 1%). The isolation of Mycoplasma species exclusively in the case group (4%), and of Gardnerella vaginalis in 7% of the case group versus 1% of the control group, suggests that both these organisms may be sexually transmitted. Other bacteria also were collectively more frequent in the case group (16% vs 6%). There may be an association between sexual activity and colonization of the lower genital tract in young girls.

Descriptive study of genital variation in healthy, nonabused premenarchal girls

This descriptive colposcopic study of the genitals of symptom-free young girls not thought to have been sexually abused was undertaken to contribute toward our understanding of normal female genital anatomy in this age group. Girls were examined and photographed, with labial traction in a supine frog-leg position while they were under anesthesia before minor elective surgery. The final study sample consisted of 79 premenarchal girls, aged between 3 months and 11 years 7 months (mean, 5 years 4 months). The study demonstrated wide anatomic variation and a high frequency of minor irregularities that have previously been noted in studies of sexually abused girls. Specific findings included increased vascularity (44%), midline avascular areas (27%), "ragged" posterior fourchette epithelium (18%), notch configuration of the posterior fourchette (10%), delicate tethers between the hymen and perihymen (14%), hymenal bumps between the 3 and 9 o'clock positions (11%), and asymmetry of the hymenal tissue (9%). Girls who at initial examination had apparently abnormal vestibules had either large hymenal orifices (11%) or multiple irregularities (11%). The study emphasizes the danger of overinterpreting small anatomic findings when one is evaluating the possibility of sexual abuse in girls; such findings may lie within the range of normal variation.

Sexually abused adolescents: a distinct group among sexually abused children presenting to a children's hospital

Case records were retrospectively reviewed for 40 adolescents presenting to a paediatric sexual abuse service with a history of acute (23 cases) or chronic (17 cases) abuse. The chronic cases disclosed the abuse to a family member, the abuse was intrafamilial, and they had similarities to the chronically abused younger child. The acute cases disclosed the abuse outside the family, and were abused by strangers or acquaintances. Some acutely abused adolescents had similarities to child victims of stranger assault; however a larger sub-group was identified (14 of 23; 35% of total) whose indescriminate behaviour may have placed them at increased risk of abuse. They were characterized by previous contact with police and welfare agencies, alcohol/drug abuse, voluntary sexual activity, contraceptive use, genital infections and apparent indifference to the abuse. Half the total group felf emotionally unsupported, and four subsequently attempted suicide. This study identifies unique problems of sexually abused adolescents, and recognizes potential multiple problems in those acutely abused.

The effects of caseous lymphadenitis on wool production and bodyweight in young sheep

Two hundred Merino wether hoggets were used to examine the effect of Corynebacterium pseudotuberculosis infection (caseous lymphadenitis) on wool production and bodyweight. Sheep which were challenged with C. pseudotuberculosis (artificially infected) and not vaccinated against this disease produced 0.20 kg less clean wool than unchallenged controls during the following 12 months. The incidence of sheep with lesions in the group that was vaccinated prior to challenge was 55% lower than in unvaccinated challenged sheep but their wool production was not significantly different from either the controls or the unvaccinated challenged sheep. Vaccinated sheep were also heavier than unvaccinated sheep 12 months after challenge. These results indicate that caseous lymphadenitis infection may reduce wool production.

A radioimmunoassay method for the determination of nedocromil sodium in plasma and urine

A radioimmunoassay method for the determination of nedocromil sodium (FPL 59002 disodium salt) in human plasma and urine is described. The method employs a primary antiserum raised in a sheep, and a mono-tyramide derivative of nedocromil sodium labelled with iodine-125 as a heterogeneous radioligand. Free and bound radioligand are separated using a secondary anti-sheep IgG antiserum. All three reagents are added simultaneously to samples containing nedocromil sodium prior to an overnight incubation. The method has a limit of detection of 0.25 ng ml(-1), when plasma sample volumes of 100 microl are analysed, and is accurate and precise. Inter-assay relative standard deviations (N = 18) of 15.1, 5.0 and 5.6% were found at concentrations in plasma of 0.5, 2.0 and 6.0 ng ml(-1) respectively. The method is specific as indicated by negligible cross-reaction of the anti-nedocromil sodium antiserum with a range of drugs. The method is applicable to the analysis of samples from subjects who have inhaled nedocromil sodium from a pressurised aerosol.

Clinical experience with technetium-99m DTPA aerosol with perfusion scintigraphy in suspected pulmonary embolism

To evaluate the clinical value of radioaerosol imaging, 156 patients with suspected pulmonary embolism (PE) were studied. In 25 patients, a preperfusion xenon-133 (Xe-133) study was compared with a postperfusion study using Tc-99m DTPA aerosol. It was found that they were of equal value most of the time (56%), but that the aerosol study was more often helpful. Because of this, and the technical ease of using six standard views with radioaerosol, the series was completed using perfusion scintigraphy followed by radioaerosol images. In 19 patients the perfusion scintigraphy with Tc-99 macroaggregated albumin (Tc-99m MAA) was normal or nearly normal and no aerosol study was required. Tc-99m DTPA aerosol images were satisfactory when the count rate was at least twice and preferably three times that of the previous perfusion study. There were 17 studies (11%) classified as intermediate. There were 26 patients classified as high probability for PE, and angiographic or autopsy correlation was available in 14. All of the 14 proved to have PE. In the 113 patients classified as low probability, there were ten with angiographic or autopsy correlation. In the ten, there was one patient with a small pulmonary embolus found at autopsy. Clinical follow-up for over two months confirmed the absence of PE in the remainder of this group. Aerosol studies have proven technically easier to perform and a satisfactory substitute for xenon imaging in suspected PE.

The effect of zeranol and testosterone on Merino wethers exposed to highly oestrogenic subterranean clover pasture

Groups of Merino wethers treated with 2 doses of zeranol (6 mg and 12 mg), or testosterone cyclopentyl propionate (150 mg) and untreated controls were grazed at 2 sites, one an oestrogenic subterranean clover (Trifolium subterraneum) pasture and the other a low oestrogen medic (Medicago truncatula) pasture. The influence of oestrogenic subterranean clover on these treatments was assessed by measuring changes in teat length, bulbourethral gland weight and pathology, bodyweight, carcase weight, dressing percentage and greasy and clean fleece weights. Teat lengths were increased by all treatments except 6 mg of zeranol where increases were not significant, and although increased by exposure to oestrogenic pasture this effect were not additive. Bulbourethral gland weights were increased by both of the zeranol treatments and by oestrogenic pasture, and these effects appeared to be additive. Differences observed histologically indicated that testosterone protected whereas zeranol exacerbated the influence of oestrogen. The bodyweights of all treated groups were heavier than the controls, but carcase weights were not significantly different. However an effect was seen in the group given the 6 mg dose of zeranol on the low oestrogen site, where the dressing percentage was significantly lower than in the control and testosterone treated groups. Differences in greasy and clean fleece weights were not significant except that the washing yield of the testosterone-treated group was significantly lower at the low oestrogen site.

Induction of autoimmune diseases with adjuvants: separation of delayed hypersensitivity and antibody formation from diseases in experimental thyroiditis and aspermatogenesis with Legionella adjuvant

The induction of autoimmune diseases in animals was studied with Legionella and mycobacteria as adjuvants, emulsified in oil with antigen extracts of thyroid, testis, spinal cord, and peripheral nerve. Both adjuvants were equally effective in inducing delayed hypersensitivity and humoral antibody to the tissue antigens. The Legionella adjuvant, however, induced little or no thyroiditis and aspermatogenesis, whereas the mycobacterial adjuvant induced thyroiditis and aspermatogenesis. Both adjuvants caused allergic encephalomyelitis and peripheral neuritis. The results indicated that delayed hypersensitivity by itself may not be sufficient to cause thyroiditis and aspermatogenesis. Legionella adjuvant apparently lacked the ability to induce certain immune factor(s) which caused the disease in experimental thyroiditis and aspermatogenesis. The differential properties of Legionella adjuvant and mycobacterial adjuvant in inducing immunity to autoantigens could provide a useful means to study the pathogenic and immunoregulatory mechanisms of some experimental autoimmune diseases.

A survey of ovine dermatophilosis in Western Australia

A random sample of 200 Merino sheep owners was interviewed by telephone during April 1983 and asked questions relating to the prevalence of ovine dermatophilosis in their flocks, methods used for prevention and treatment of dermatophilosis, management strategies employed and the location and annual rainfall of each farm. The response rate was 99.5%. During the previous 12 months 62.3% of farmers had observed dermatophilosis in their flocks. The prevalence within flocks was highest in hoggets (mean 2.2%, range 0 to 75%) followed by lambs (mean 0.8%, range 0 to 25%), ewes (mean 0.6%, range 0 to 20%) and wethers (0.2%, range 0 to 20%). The mean weight of wool identified as affected by dermatophilosis was 58 kg (range 0 to 882 kg). Preventive measures were used on 57% of farms and the most common methods were changes in dipping practice (23.6%) and culling of affected sheep (21%). An average of 13.7 sheep per farm were culled for dermatophilosis and of these, 82% were sold and the remainder (18%) were killed on the farm. Antibiotics, of which most were combinations of penicillin and streptomycin were used to treat dermatophilosis on 8.5% of farms and treatments other than antibiotics were used on 10% of farms. The prevalence of dermatophilosis and its relationship to various environmental and management factors varied with the age and sex of sheep. Discriminant analysis indicated that of the factors studied, average annual rainfall, month of lambing, average fibre diameter and the month ewes were shorn were related to the prevalence of dermatophilosis in lambs.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental allergic neuritis-like disease in rabbits after injection with influenza vaccines mixed with gangliosides and adjuvants

An experimental allergic neuritis-like disease was induced in rabbits 3 to 8 weeks after injection with large doses of influenza vaccines mixed with gangliosides, cholesterol, and Freund complete adjuvant. The inclusion of gangliosides was essential to induce the experimental allergic neuritis-like disease. In trials with six different lots of vaccine, both swine influenza and non-swine influenza vaccines produced by four different manufacturers induced experimental allergic neuritis-like disease in 26 of 43 inoculated rabbits.

Radioimmunoassay of sodium cromoglycate in human plasma

A sensitive radioimmunoassay method for sodium cromoglycate in human plasma is described. The lowest quantifiable concentration of sodium cromoglycate is 0.93 nmol/l when 0.1 ml plasma samples are analysed. Direct analysis of sodium cromoglycate concentrations in plasma samples collected up to several hours after the administration of single therapeutic doses of the compound is possible. An antiserum raised in a sheep, radioligand heterogeneously labelled with iodine-125, and a second antibody technique for the separation of bound and free radioligand are employed. The inter-assay coefficient of variation is less than 14% (n = 23). The range of the method is limited; both 0.01 and 0.1 ml volumes of plasma must be analysed to encompass the concentration range 0.93-139 nmol/l which may be encountered in plasma samples from patients and human volunteers. The method is specific for sodium cromoglycate as indicated by a low cross-reactivity of the anti-cromoglycate antiserum with a number of drugs.

Visceral target organs in systemic St. Louis encephalitis virus infection of hamsters

Ultrastructural aspects of St. Louis encephalitis virus infection of the major extraneutral organs and tissues of suckling hamsters were examined. In the pancreas, both the exocrine and endocrine portions were equally affected by the virus. A feature apparently unique to flaviviruses was the accumulation of virus particles in all types of secretory granules in this organ. Virus particles were seen within myocardial fibers and within the smooth muscle cells and endothelial cells of small blood vessels of the heart. In the intestines, the lamina propria was the most severely infected, with virus particles accumulated in all cell types.

Experimental infection of rhesus monkeys with Lassa virus and a closely related arenavirus, Mozambique virus

As a model for the pathogenesis of Lassa fever in humans, nine rhesus monkeys were inoculated with Lassa virus. Three monkeys had had a previous asymptomatic experimental infection with Mozambique virus, a closely related arenavirus; these monkeys were protected from illness and viremia and manifested only mild pathologic lesions. The other animals developed severe disease and viremia. At necropsy, hepatocellular necrosis, interstitial pneumonia, a unique pulmonary arteritis, adrenal gland necrosis, encephalitis, and uveitis were prominent pathologic lesions which correlated with the organ titers of virus. One animal infected with Lassa virus developed prolonged viremia, a typical immune response, and sudden onset of lower limb paralysis after recovery; at necropsy chronic proliferative arteritis of the spinal cord, brain, and heart was evident. Similarities and differences in the pathologic lesions in this model and Lassa fever in humans indicate that care must be taken in interpreting the results of experiments concerning immune prophylaxis, pathogenesis, and treatment in rhesus monkeys.

Pathologic and virologic study of fatal Lassa fever in man

Postmortem examination of 21 virologically documented cases of Lassa fever, including 6 complete autopsies, was performed as part of a field study of community-acquired Lassa fever in Sierra Leone. The most consistently observed lesions were hepatocellular, adrenal, and splenic necrosis and adrenal cytoplasmic inclusions. Neither these lesions, nor other milder and less constantly observed lesions such as myocarditis, renal tubular injury, and interstitial pneumonia, appeared severe enough to explain the cause of death in Lassa fever. The central nervous system (CNS) contained no specific lesions. Viral titrations demonstrated high viral content in liver, lung, spleen, kidney, heart, placenta, and mammary gland. Clinical laboratory data included elevation of hepatic enzymes, creatine phosphokinase (CPK), and blood urea nitrogen (BUN). Because of the paucity of pathologic lesions in spite of widely disseminated viral infection, further investigation of humoral inflammatory mechanisms is indicated.

St Louis encephalitis. Quantitative histologic and immunofluorescent studies

Using techniques of stereology, we measured the severity of lesions in ten cases of acute St Louis encephalitis (SLE) from the 1975 epidemic in northern Illinois. Percentage of fractional volume and numerical profile density on area (N/A) of cellular nodules and N/A of blood vessels with perivascular inflammatory cellular infiltration were significantly correlated in 17 anatomic regions of the CNS. Ranking of the severity of lesions in these regions agreed with subjective estimates of other cases of SLE. Immunofluorescent tests established the presence of SLE viral antigen in cell bodies of neurons. Our findings contribute to better understanding of the pathology of SLE in man.

Experimental chronic rabies in the cat

Two cats, inoculated with a street rabies virus strain, survived with only some progressive debility and atrophy of musculature in the injected limb for 136 weeks. They had continuously increasing titers of neutralizing antibody in serum and in cerebrospinal fluid, and terminally they had high antibody titers in the brain. Virus was isolated from two brain specimens of one cat obtained at necropsy; isolation was successful only by explant culture and inoculation of explanted tissue into mice. Virus antigen was detected in eight sites in the brain and spinal cord of the same cat by frozen-section immunofluorescence. Lesions in the central nervous system consisted of neuronal degeneration and neuronophagia, associated with the prescence of inclusion bodies and widespread inflammatory cell inflitration into brain and spinal cord parenchyma, perineuronal sites, and perivascular spaces. The inflitrates contained lymphocytes, monocytes-macrophages, and a high proportion of plasma cells. These experimental cases of chronic progressive rabies resembled more closely subacute sclerosing panecephalitis of man than the usual subacute fatal rabies encephalitis of man and other mammalian species.

Variation in virulence for mice and rhesus monkeys among St. Louis encephalitis virus strains of different origin

The virulence characteristics of 67 strains of St. Louis encephalitis (SLE) virus isolated from various sources in North, Middle, and South America were compared in mice and rhesus monkeys. Each virus strain was titrated in mice exactly 21 days old and virulence was expressed as the ratio of intracerebral (ic)/intraperitoneal (ip) LD50. Virus strains fell into three groups: 1) high virulence (ic/ip LD50 ratio approximately 1.0); 2) intermediate virulence (variable mortality over a wide dose range); and 3) low virulence (ic/ip LD50 less than or equal to 0.00002). Virus strains isolated during Culex pipiens and Cx. nigripalpus--borne epidemics in the eastern United States were highly virulent for mice, whereas a high proportion of the endemic virus strains isolated from Cx. tarsalis in the western United States were attenuated. Virus strains isolated from birds (the usual host for SLE virus) were highly virulent, in contrast to strains from rodents and carnivores, which were attenuated. Isolates from humans exhibited variable virulence characteristics. In experimentally-infected mice, virulence correlated with high viremia, replication in extraneural tissues, and earlier neuroinvasion. Mouse virulence correlated with clinical and histopathologic markers of pathogenicity for ic inoculated rhesus monkeys. Monkeys immunized with nonpathogenic strains by subcutaneous inoculation were partially protected against ic challenge with a virulent virus strain. The virulence classification of SLE virus strains is discussed in terms of epidemiologic correlations. This classification provides a framework for future studies on the antigenic, genetic, and biochemical bases for SLE virus strain variation.