Prophylactic agents for venous thrombosis in elective hip surgery. Meta-analysis of studies using venographic assessment.

BACKGROUND: We determined the relative efficacy of various agents or combinations of agents in the prophylaxis of deep venous thrombosis after elective hip arthroplasty. METHODS: Peer-reviewed, English-language, human studies articles from 1975 through 1991 were obtained through a MEDLINE database search. Additional references were obtained from bibliographies. Articles that compared the effect of two or more prophylactic agents or placebo in preventing deep venous thrombosis as assessed by venography were selected for further review. Only studies of elective hip surgery in which all patients had venographic screening for thrombosis were included. Twenty-three of 101 studies met these criteria. Data were abstracted by one of us. Methodologic criteria and outcome data from each study were recorded and analyzed. RESULTS: There was significant heterogeneity in the deep venous thrombosis rate among studies. Although the rates were lowest for low-molecular-weight heparin with or without the use of stockings, adjusted-dose heparin, and warfarin, many agents had similar low rates. There was less heterogeneity when the relative risk was used as a summary statistic for studies in which two agents were compared. With pairwise comparisons, low-molecular-weight heparin performed better than every agent with which it was compared. Other agents performed well but were not consistently better. CONCLUSIONS: Multiple agents or combinations are effective prophylaxis for deep venous thrombosis, but none decreases the rate to zero. There was overlap in the 95% confidence intervals for the probability of deep venous thrombosis for various agents and especially for the probabilities for proximal thrombi. Many agents have not been compared directly with each other, but low-molecular-weight heparin consistently performed well.

Trends in the incidence of deep vein thrombosis and pulmonary embolism: a 25-year population-based study.

BACKGROUND: The incidence of venous thromboembolism has not been well described, and there are no studies of long-term trends in the incidence of venous thromboembolism. OBJECTIVES: To estimate the incidence of deep vein thrombosis and pulmonary embolism and to describe trends in incidence. METHODS: We performed a retrospective review of the complete medical records from a population-based inception cohort of 2218 patients who resided within Olmsted County, Minnesota, and had an incident deep vein thrombosis or pulmonary embolism during the 25-year period from 1966 through 1990. RESULTS: The overall average age- and sex-adjusted annual incidence of venous thromboembolism was 117 per 100000 (deep vein thrombosis, 48 per 100000; pulmonary embolism, 69 per 100000), with higher age-adjusted rates among males than females (130 vs 110 per 100000, respectively). The incidence of venous thromboembolism rose markedly with increasing age for both sexes, with pulmonary embolism accounting for most of the increase. The incidence of pulmonary embolism was approximately 45% lower during the last 15 years of the study for both sexes and all age strata, while the incidence of deep vein thrombosis remained constant for males across all age strata, decreased for females younger than 55 years, and increased for women older than 60 years. CONCLUSIONS: Venous thromboembolism is a major national health problem, especially among the elderly. While the incidence of pulmonary embolism has decreased over time, the incidence of deep vein thrombosis remains unchanged for men and is increasing for older women. These findings emphasize the need for more accurate identification of patients at risk for venous thromboembolism, as well as a safe and effective prophylaxis.

Predictors of recurrence after deep vein thrombosis and pulmonary embolism: a population-based cohort study.

BACKGROUND: The appropriate duration of oral anticoagulation after a first episode of venous thromboembolism (VTE) is uncertain and depends upon VTE recurrence rates. OBJECTIVE: To estimate VTE recurrence rates and determine predictors of recurrence. METHODS: Patients in Olmsted County, Minnesota, with a first lifetime deep vein thrombosis or pulmonary embolism diagnosed during the 25-year period from 1966 through 1990 (N = 1,719) were followed forward in time through their complete medical records in the community for first VTE recurrence. RESULTS: Four hundred four patients developed recurrent VTE during 10,198 person-years of follow-up. The overall (probable/definite) cumulative percentages of VTE recurrence at 7, 30, and 180 days and 1 and 10 years were 1.6% (0.2%), 5.2% (1.4%), 10.1% (4.1%), 12.9% (5.6%), and 30.4% (17.6%), respectively. The risk of recurrence was greatest in the first 6 to 12 months after the initial event but never fell to zero. Independent predictors of first overall VTE recurrence included increasing age and body mass index, neurologic disease with paresis, malignant neoplasm, and neurosurgery during the period from 1966 through 1980. Independent predictors of first probable/definite recurrence included diagnostic certainty of the incident event and neurologic disease in patients with hospital-acquired VTE. Recurrence risk was increased by malignant neoplasm but varied with concomitant chemotherapy, patient age and sex, and study year. CONCLUSIONS: Venous thromboembolism recurs frequently, especially within the first 6 to 12 months, and continues to recur for at least 10 years after the initial VTE. Patients with VTE with neurologic disease and paresis or with malignant neoplasm are at increased risk for recurrence, while VTE patients with transient or reversible risk factors are at less risk.

Risk factors for deep vein thrombosis and pulmonary embolism: a population-based case-control study.

BACKGROUND: Reported risk factors for venous thromboembolism (VTE) vary widely, and the magnitude and independence of each are uncertain. OBJECTIVES: To identify independent risk factors for deep vein thrombosis and pulmonary embolism and to estimate the magnitude of risk for each. PATIENTS AND METHODS: We performed a population-based, nested, case-control study of 625 Olmsted County, Minnesota, patients with a first lifetime VTE diagnosed during the 15-year period from January 1, 1976, through December 31, 1990, and 625 Olmsted County patients without VTE. The 2 groups were matched on age, sex, calendar year, and medical record number. RESULTS: Independent risk factors for VTE included surgery (odds ratio [OR], 21.7; 95% confidence interval [CI], 9.4-49.9), trauma (OR, 12.7; 95% CI, 4.1-39.7), hospital or nursing home confinement (OR, 8.0; 95% CI, 4.5-14.2), malignant neoplasm with (OR, 6.5; 95% CI, 2.1-20.2) or without (OR, 4.1; 95% CI, 1.9-8.5) chemotherapy, central venous catheter or pacemaker (OR, 5.6; 95% CI, 1.6-19.6), superficial vein thrombosis (OR, 4.3; 95% CI, 1.8-10.6), and neurological disease with extremity paresis (OR, 3.0; 95% CI, 1.3-7.4). The risk associated with varicose veins diminished with age (for age 45 years: OR, 4.2; 95% CI, 1.6-11.3; for age 60 years: OR, 1.9; 95% CI, 1.0-3.6; for age 75 years: OR, 0.9; 95% CI, 0.6-1.4), while patients with liver disease had a reduced risk (OR, 0.1; 95% CI, 0.0-0.7). CONCLUSION: Hospital or nursing home confinement, surgery, trauma, malignant neoplasm, chemotherapy, neurologic disease with paresis, central venous catheter or pacemaker, varicose veins, and superficial vein thrombosis are independent and important risk factors for VTE.

Predictors of survival after deep vein thrombosis and pulmonary embolism: a population-based, cohort study.

BACKGROUND: Because reported survival after venous thromboembolism (VTE) varies widely, we performed a population-based retrospective cohort study to estimate survival, compare observed with expected survival, and determine predictors of short-term (< or =7 days) and long-term survival (>7 days) after VTE. METHODS: We followed the 25-year (1966-1990) inception cohort (n = 2218) of Olmsted County, Minnesota, patients with deep vein thrombosis alone (DVT) or pulmonary embolism with or without deep vein thrombosis (PE+/-DVT) forward in time until death or the last clinical contact. RESULTS: During 14 629 person-years of follow-up, 1333 patients died. Seven-day, 30-day, and 1-year VTE survival rates were 74.8% (DVT, 96.2%; PE+/-DVT, 59.1%), 72.0% (DVT, 94.5%; PE+/-DVT, 55.6%), and 63.6% (DVT, 85.4%; PE+/-DVT, 47.7%), respectively. Observed survival after DVT, PE+/-DVT, and overall was significantly worse than expected for Minnesota whites of similar age and sex (P<.001). More than one third of deaths occurred on the date of onset or after VTE that was unrecognized during life. Short-term survival improved during the 25-year study period, while long-term survival was unchanged. After adjusting for comorbid conditions, PE+/-DVT was an independent predictor of reduced survival for up to 3 months after onset compared with DVT alone. Other independent predictors of both short- and long-term survival included age, body mass index, patient location at onset, malignancy, congestive heart failure, neurologic disease, chronic lung disease, recent surgery, and hormone therapy. Additional independent predictors of long-term survival included tobacco smoking, other cardiac disease, and chronic renal disease. CONCLUSIONS: Survival after VTE, and especially after PE+/-DVT, is much worse than reported, and significantly less than expected survival. Compared with DVT alone, symptomatic PE+/-DVT is an independent predictor of reduced survival for up to 3 months after onset, implying that treatment for the 2 disorders should be different.

Infections due to group C streptococci in man.

Although a common cause of infection in animals, group C streptococci are rarely noted to be pathogenic in man. A total of 150,000 blood cultures obtained at the Mayo Clinic from 1968 to 1977 revealed group C streptococci in only eight patients. Acute bacterial endocarditis, meningitis, pheumonia, cellulitis and bacteremia due to group C streptococci are described in a host who had undergone immunosuppression (immunosuppressed host), and the relatively few cases previously reported are reviewed. Although severe, these infections may respond favorably to penicillin therapy. Endocarditis caused by group D streptococci is acute and destructive, and associated with early cardiac decompensation. The manifestations of cellulitis and pneumonia are similar to those when group A streptococci are causative organisms. Meningitis due to group C streptococci is acute and severe, and responds slowly to antimicrobial therapy. Colonization also occurs.

The epidemiology of venous thromboembolism in the community.

The incidence of venous thromboembolism exceeds 1 per 1000; over 200,000 new cases occur in the United States annually. Of these, 30% die within 30 days; one-fifth suffer sudden death due to pulmonary embolism. Despite improved prophylaxis, the incidence of venous thromboembolism has been constant since 1980. Independent risk factors for venous thromboembolism include increasing age, male gender, surgery, trauma, hospital or nursing home confinement, malignancy, neurologic disease with extremity paresis, central venous catheter/transvenous pacemaker, prior superficial vein thrombosis, and varicose veins; among women, risk factors include pregnancy, oral contraceptives, and hormone replacement therapy. About 30% of surviving cases develop recurrent venous thromboembolism within ten years. Independent predictors for recurrence include increasing age, obesity, malignant neoplasm, and extremity paresis. About 28% of cases develop venous stasis syndrome within 20 years. To reduce venous thromboembolism incidence, improve survival, and prevent recurrence and complications, patients with these characteristics should receive appropriate prophylaxis.

Methemoglobinemia from topically applied anesthetic spray.

Topically applied anesthetic spray is commonly used as part of premedication for general anesthesia and for endoscopic procedures; it is rarely associated with side effects. In this report, we describe two cases of toxic methemoglobinemia that resulted from topically applied anesthetic spray used before endoscopy. In both cases, standard doses were used; however, methemoglobin levels of 45% and 38% developed within 1 hour of the procedure. Both patients had normal levels of erythrocyte methemoglobin reductase, an indication that this rare but potentially fatal side effect can occur in persons who have no predisposing factors. Because toxic methemoglobinemia is easily treated, our report emphasizes the need to recognize this problem when topically applied anesthetic sprays are used.

A patient with pulseless extremities: an unusual manifestation of cardiac tamponade.

We describe a 51-year-old man who came to our institution with cold cyanotic extremities. He was receiving radiation therapy for adenocarcinoma of the lung and superior vena cava syndrome. Findings on initial physical examination were notable for absent peripheral pulses and increased jugular venous pulsations. Shortly after admission, the patient experienced severe dyspnea and tachypnea. Arterial blood gas studies revealed mild metabolic acidosis. A chest roentgenogram showed an enlarged cardiac silhouette and the known mass in the right upper lobe of the lung. An electrocardiogram demonstrated no evidence of ischemia but low-voltage QRS complexes. An emergency echocardiogram disclosed a large pericardial effusion and evidence of hemodynamic compromise. With use of echocardiographic-guided pericardiocentesis, 600 ml of bloody fluid was removed; the pulses were immediately palpable in the patient's extremities. Although symptoms associated with the extremities are unusual as the initial complaint of patients with cardiac tamponade, we illustrate several key physical findings and abnormal results of laboratory test characteristic of this disorder. In addition, we underscore the importance of considering this diagnosis, especially in patients with a malignant tumor, and we describe the prompt response to therapy.

Poststreptococcal reactive arthritis in adults: a case series.

OBJECTIVE: To guide primary care physicians regarding the diagnosis and treatment of poststreptococcal reactive arthritis (PSReA) in adults. PATIENTS AND METHODS: We retrospectively reviewed an indexed database of all patients evaluated or hospitalized between 1976 and 1998 at Mayo Clinic Rochester and identified 35 patients with the diagnosis of reactive streptococcal arthritis, arthralgia, or arthritides. Twenty-nine patients with the diagnosis of acute rheumatic fever (ARF), septic streptococcal arthritis, or nonspecific reactive arthritis were excluded. RESULTS: PSReA was confirmed in 6 adults (3 women, 3 men; age range, 25-66 years). All patients were symptomatic with polyarthritis and oligoarthritis disproportionate to the objective findings on physical examination. Although all patients had negative throat cultures at the onset of arthritis, increased titers of anti-DNase B and antistreptolysin O confirmed recent streptococcal infection. Antecedent events included pharyngitis in 3 patients (who had received a minimum of a 10-day course of penicillin) and toxic shock syndrome in 1 patient. The latency of onset of arthritis ranged from 4 days to 6 weeks. The arthritic symptoms had a protracted course beyond the typical maximum of 3 weeks described for ARF. Treatment with aspirin did not provide symptomatic relief in any of the patients, whereas the response to therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) was at least partial in all cases. Symptomatic relief occurred in 1 patient who received indomethacin and in 1 patient treated with prednisone. Penicillin prophylaxis was recommended in 1 patient. CONCLUSION: PSReA should be included in the differential diagnosis of all adult patients presenting with arthritis. Treatment strategies include aspirin, other NSAIDs, and corticosteroids. In adult patients with PSReA, there is no evidence to support the use of penicillin prophylaxis at this time.

Recent advances in the management of venous thromboembolism.

Deep venous thrombosis and pulmonary embolism are frequently diagnosed in patients encountered in a primary-care practice. In the past 10 years, many important advances have been made regarding the management of these disorders. Risk factors have been better defined than in the past. Several new prophylactic measures--such as external pneumatic compression of the lower extremities, dihydroergotamine in combination with heparin, adjusted-dose heparin, and two-step warfarin therapy--can be used to help prevent deep venous thrombosis in surgical patients. The use of serial impedance plethysmography has expanded options for noninvasive diagnosis of deep venous thrombosis. Correlations between pulmonary embolism and ventilation-perfusion lung scan patterns have been clarified. Although much has been learned about heparin and warfarin that affect common management decisions, the indications for thrombolytic therapy for venous thromboembolism remain controversial. Finally, studies have shown that calf vein thrombi that are not detectable by impedance plethysmography and that show no evidence of proximal propagation by serial impedance plethysmography do not require treatment.

Renal insufficiency in community patients with mild asymptomatic microhematuria.

Primary-care physicians often must decide when patients with asymptomatic microhematuria warrant further testing for renal parenchymal disease. Because previous data had shown a greater frequency of elevated serum creatinine concentration in a population with asymptomatic microhematuria than in control subjects without hematuria, we reviewed the records of 125 patients with isolated asymptomatic microhematuria and elevated serum creatinine (AM/EC) and 83 comparison patients with no hematuria and elevated serum creatinine (NH/EC) from a previous population-based study to determine the relationship between renal parenchymal disease and isolated asymptomatic microhematuria. Serum creatinine was often elevated transiently because of volume depletion or shock, or elevations occurred in relationship to a terminal illness. Thus, only 63 AM/EC patients and 45 NH/EC control subjects had primary renal parenchymal disease or systemic disorders that caused an elevated serum creatinine. The patients selected from the asymptomatic microhematuria population because of elevated serum creatinine most often had low-grade hematuria and were typically 75 years of age or older. No disease was consistently found more frequently in the AM/EC patients than in the NH/EC group. Intervention at the time of the detection of hematuria might have altered the prognosis in 8% and probably would not have altered the prognosis in 78%. Therefore, exhaustive diagnostic testing to detect renal parenchymal diseases cannot be advised in asymptomatic elderly patients with low-grade (grade 1) microhematuria unless more specific indications are present.

Venous thromboembolism associated with hip and knee arthroplasty: current prophylactic practices and outcomes.

Joint registry and hospital data bases for 5,024 total hip and total knee arthroplasties done between 1986 and 1988 at the Mayo Clinic were used to study prophylactic measures and frequency of symptomatic deep venous thrombosis and pulmonary embolism. In virtually all patients, graduated compression stockings were used, with or without another type of prophylaxis. Only 44 of 3,115 patients who underwent hip arthroplasty (1.4%) and 32 of 1,909 patients who underwent knee arthroplasty (1.7%) had definite or probable deep venous thrombosis or pulmonary embolism. Death definitely or possibly attributable to pulmonary embolism occurred in 11 patients who underwent hip arthroplasty (0.35%) and 1 patient who underwent knee arthroplasty (0.05%). Although patients with a history of deep venous thrombosis or pulmonary embolism were more likely to receive warfarin than were patients without such a history, the relative risk of symptomatic deep venous thrombosis or pulmonary embolism in patients who underwent hip arthroplasty and received warfarin postoperatively was approximately half that in patients who received other types of prophylaxis. The risk of death from pulmonary embolism was similarly diminished in the group that received warfarin. The lower rates of these complications in the patients who received warfarin support the prophylactic use of this agent after total hip arthroplasty.

Pancreatic pseudocyst that compressed the inferior vena cava and resulted in edema of the lower extremities.

To our knowledge, edema of the lower extremities has not previously been reported as a sign of a pancreatic pseudocyst. In this case report, we describe a 66-year-old man in whom such a lesion compressed the inferior vena cava and caused pronounced leg swelling. After drainage of the pseudocyst, the edema did not recur. Although the most well-known complications of pancreatic pseudocyst are pain, hemorrhage, rupture, infection, and obstruction of adjacent viscera, bilateral edema of the lower extremities can be the initial manifestation of this lesion.

Meningitis due to group C streptococci in an adult.

Group C streptococci are generally considered to be a rare cause of infection in man. Infections due to these microorganisms, however, are common in several animal species. To our knowledge, the literature contains only two previous cases of meningitis in man which were due to group C streptococci. In one of these cases meningitis developed as a complication of endocarditis due to group C streptococci. Our recent clinical experience with a patient with severe acute meningitis caused by group C streptococci is reported and the pertinent literature is reviewed. The illness manifested itself as a severe form of acute meningitis, with slow but statisfactory response to therapy with penicillin.

Acute toxicity after excessive ingestion of colchicine.

A 15-year-old girl was admitted to a hospital in Rochester, Minnesota, 40 hours after the ingestion of 24 mg of colchicine. She suffered severe cardiovascular, pulmonary, hematologic, gastrointestinal, renal, metabolic, and neuromuscular complications but ultimately survived. Colchicine is an uncommon but potentially serious source of acute toxicity. An overdose warrants prompt attention in a setting where intensive medical support is available.

Benign positional vertigo: incidence and prognosis in a population-based study in Olmsted County, Minnesota.

A retrospective review of our population-based medical records linkage system for residents of Olmsted County, Minnesota, revealed 53 patients (34 women and 19 men; mean age, 51 years) with newly diagnosed benign positional vertigo in 1984. The age- and sex-adjusted incidence was 64 per 100,000 population per year (95% confidence interval, 46 to 81 per 100,000). The incidence of benign positional vertigo increased by 38% with each decade of life (95% confidence interval, 23 to 54%). One patient had an initial stroke during follow-up; thus, the relative risk for new stroke associated with benign positional vertigo was 1.62 (95% confidence interval, 0.04 to 8.98) in comparison with the expected occurrence based on incidence rates for an age- and sex-adjusted control population. The observed survival among the 53 Olmsted County residents with benign positional vertigo diagnosed in 1984 was not significantly different from that of an age- and sex-matched general population. Patients with benign positional vertigo seem to have a good prognosis.

The venous stasis syndrome after deep venous thrombosis or pulmonary embolism: a population-based study.

OBJECTIVES: To estimate the incidence and determine predictors of venous stasis syndrome and venous ulcers after deep venous thrombosis and pulmonary embolism. PATIENTS AND METHODS: This population-based retrospective cohort study reviewed medical records of 1527 patients with incident deep venous thrombosis or pulmonary embolism between 1966 and 1990. We recorded baseline characteristics, event type (deep venous thrombosis with or without pulmonary embolism or pulmonary embolism alone), leg side and site of deep venous thrombosis (proximal with or without distal deep venous thrombosis vs distal deep venous thrombosis alone), and venous stasis syndrome and venous ulcer. RESULTS: Two hundred forty-five patients developed venous stasis syndrome. One-year, 5-year, 10-year, and 20-year cumulative incidence rates were 7.3%, 14.3%, 19.7%, and 26.8%, respectively. By 20 years the cumulative incidence of venous ulcers was 3.7%. Patients with deep venous thrombosis with or without pulmonary embolism were 2.4-fold (95% confidence interval, 1.7-fold-3.2-fold) more likely to develop venous stasis syndrome than patients with pulmonary embolism and no diagnosed deep venous thrombosis. In patients aged 40 years or younger with proximal compared with distal-only deep venous thrombosis, venous stasis syndrome was 3.0-fold more likely (95% confidence interval, 1.6-fold-4.7-fold). In patients with unilateral leg deep venous thrombosis, venous stasis syndrome usually developed in the concordant leg (P < .001). There was a 30% (95% confidence interval, 2%-62%) increased risk for venous ulcer per decade of age at the incident venous thromboembolism. CONCLUSIONS: The cumulative incidence of venous stasis syndrome continues to increase for 20 years after venous thromboembolism. Pulmonary embolism alone is less likely to cause venous stasis syndrome.

The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial.

OBJECTIVE: To compare the canalith repositioning procedure (CRP) with a sham maneuver for the treatment of benign paroxysmal positional vertigo. PATIENTS AND METHODS: We recruited 50 patients with a history of positional vertigo and unilateral positional nystagmus on physical examination (Dix-Hallpike maneuver). Patients were randomized to either the CRP (n = 24) or a sham maneuver (n = 26). Measured outcomes included resolution of vertigo and positional nystagmus at follow-up examination. RESULTS: The mean duration of follow-up was 10 days for both groups. Resolution of symptoms was reported by 12 (50%) of the 24 patients in the CRP group and by 5 (19%) of the 26 patients in the sham group (P = .02). The results of the Dix-Hallpike maneuver were negative for positional nystagmus in 16 (67%) of 24 patients in the CRP group and in 10 (38%) of 26 patients in the sham group (P = .046). CONCLUSION: The CRP is effective treatment of benign paroxysmal positional vertigo, and this procedure can be performed by general internists on outpatients with this disorder.

Incidence of venous thromboembolism in hospitalized patients vs community residents.

OBJECTIVE: To estimate the incidence rates of deep venous thrombosis (DVT) and pulmonary embolism (PE) in hospitalized patients and to compare these with incidence rates in community residents. PATIENTS AND METHODS: We performed a retrospective review of the complete medical records from a population-based inception cohort of patients who resided in Olmsted County, Minnesota, and had an incident DVT or PE from 1980 through 1990. RESULTS: From 1980 through 1990, 911 Olmsted County residents experienced their first lifetime event of definite, probable, or possible venous thromboembolism. Of these residents, 253 had been hospitalized for some reason other than a diagnosis of DVT or PE (in-hospital cases), and 658 were not hospitalized at onset of venous thromboembolism (community residents). The average annual age- and sex-adjusted incidence of in-hospital venous thromboembolism was 960.5 (95% confidence interval, 795.1-1125.9) per 10,000 person-years and was more than 100 times greater than the incidence among community residents at 7.1 (95% confidence interval, 6.5-7.6) per 10,000 person-years. The incidence of venous thromboembolism rose markedly with increasing age for both groups, with PE accounting for most of the age-related increase among in-hospital cases. Incidence rates in the 2 groups changed little over time despite a reduction in the average length of hospital stay between 1980 and 1990. CONCLUSIONS: Venous thromboembolism is a major national health problem, especially among elderly hospitalized patients. This finding emphasizes the need for accurate identification of hospitalized patients at risk for venous thromboembolism and a better understanding of the mechanisms involved so that safe and effective prophylaxis can be implemented.