Deep venous thrombosis and pulmonary embolism

Epidemiological status and risk factors of deep vein thrombosis in patients with femoral neck fracture

Objectives

The purpose of this study was to investigate the incidence of deep vein thrombosis (DVT) and clarify the risk factors of DVT in patients with femoral neck fracture.

Methods

A self-designed questionnaire was used to collect the clinical data of 1209 patients with femoral neck fracture in our hospital from January 2019 to December 2019. The content of the questionnaire mainly includes general information, past medical history, history of present illness, operation related information, occurrence of DVT. The collected data were entered into Excel to analyze the incidence and risk factors of DVT in patients with femoral neck fracture. Chi square test and binary logistic regression model was used to screen the risk factors of DVT.

Results

1209 cases of femoral neck fracture were included in this study. The incidence of DVT was 28.0% (339 patients). Among them, 71.7% (243 patients) were preoperative DVT and 28.3% (96 patients) were postoperative DVT. For the risk-factor analysis, gender, age, time from injury to hospitalization, operative method, anesthesia method and intraoperative blood loss were independent risk factors for DVT.

Conclusion

The incidence of DVT in patients with femoral neck fracture is relatively high, and there are many related risk factors.

Risk Factors for Venous Thromboembolism Following Prolonged Air Travel: A “Prospective” Study

The aim of this study was to analyze patients with air-travel-related venous leg thromboembolism (VTE) concerning the occurrence of patient-related and cabin-related risk factors. Twenty-five patients, still in hospital, with deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with onset of symptoms during or after air travel were questioned according to a study protocol. There were 14 women and 11 men with an age range of 36-79 years. Flight times were 5-18 hours. All patients had DVT, and nine (36%) had PE as well. The proximal extensions of the thrombus were in tibial vein, five patients; popliteal vein, two patients; superficial femoral vein, three patients; common femoral vein, four patients; greater saphenous vein, four patients; and iliac vein, seven patients. All but two patients (92%) had one or more patient-related risk factors; the mean was three. Overweight was present in 76% of the patients; chronic heart disease in 44%; hormone medication in 40%; chronic disease, except chronic heart disease and malignancy in 32%; history of previous VTE in 28%; malignancy in 28%; smoking in 20%; recent lower limb injury in 16%; and recent surgery in 12%. Only two patients had no known patient-related risk factor. The flight travel itself does not seem to be an important risk factor in healthy individuals. However, when patient-related risk factors are superimposed, there is increasing evidence that cabin-related risk factors, such as immobilization, cramped “coach” position, insufficient fluid intake, low humidity, and hypoxia contribute to development of VTE. Improved information is required so that passengers can prepare their travel in good time. Active precautions are recommended.

Prophylactic Placement of an Inferior Vena Cava Filter During Aspiration Thrombectomy for Acute Deep Venous Thrombosis of the Lower Extremity

Purpose:

To evaluate the effect of an inferior vena cava (IVC) filter during aspiration thrombectomy for acute deep vein thrombosis (DVT) in the lower extremity.

Materials and Methods:

From July 2004 to December 2013, a retrospective analysis of 106 patients with acute DVT was performed. All patients received an IVC filter and were treated initially with aspiration thrombectomy. Among the 106 patients, DVT extension into the IVC was noted in 27 but was not evident in 79. We evaluated the presence of trapped thrombi in the filters after the procedure. The sizes of the trapped thrombi were classified into 2 grades based on the ratio of the maximum transverse length of the trapped thrombus to the diameter of the IVC (Grades I [≤ 50%] and II [> 50%]).

Results:

A trapped thrombus in the filter was detected in 46 (43%) of 106 patients on final venograms. The sizes of the trapped thrombi were grade I in 12 (26.1%) patients and grade II in 34 (73.9%). Among the 27 patients with DVT extension into the IVC, 20 (74.1%) showed a trapped thrombus in the filter, 75% (15 of 20) of which were grade II. Among the 79 patients without DVT extension into the IVC, 26 (32.9%) showed a trapped thrombus in the IVC filter, 73% (19 of 26) of which were grade II.

Conclusions:

Thrombus migration occurred frequently during aspiration thrombectomy of patients with acute DVT in the lower extremity. However, further studies are needed to establish a standard protocol for the prophylactic placement of an IVC filter during aspiration thrombectomy.

Effect of various pneumoperitoneum pressures on femoral vein hemodynamics during laparoscopic cholecystectomy

High intra-abdominal pressure and reverse Trendelenburg position during laparoscopic cholecystectomy (LC) are risk factors for venous stasis in lower extremity. Lower limb venous stasis is one of the major pathophysiological elements involved in the development of peri-operative deep vein thrombosis. Low pressure pneumoperitoneum (7-10 mmHg) has been recommended in patients with limited cardiac, pulmonary or renal reserve. The purpose of this study was to observe the effect of various pneumoperitoneum pressures on femoral vein (FV) hemodynamics during LC. A total of 50 patients undergoing elective LC were enrolled and they were prospectively randomized into two groups containing 25 patients each. In group A high pressure pneumoperitoneum (14 mmHg) and in group B low pressure pneumoperitoneum (8 mmHg) was maintained. Comparison of pre-operative and post-operative coagulation profile was done. Preoperative and intraoperative change in femoral vein diameter (FVD) (AP and LAT), cross-sectional area (CSA) and peak systolic flow (PSF) during varying pneumoperitoneum pressure was recorded in FV by ultrasound Doppler. First measurement (pre-operative) was carried out just after the induction of anesthesia before creation of pneumoperitoneum and second measurement (intra-operative) was taken just before completion of surgery with pneumoperitoneum maintained. Changes in coagulation parameters were less significant at low pressure pneumoperitoneum. There was statistical significant difference in the pre-operative and intra-operative values of FVD, CSA and PSF in both groups when analyzed independently (P = 0.00). There was no significant difference in pre-operative values of FVD, CSA and PSF (P > 0.05) among two groups but when the comparison was made between the intra-operative values, there was significant increase in FVD (AP) (P = 0.016), CSA (P = 0.00) and decrease in PSF (P = 0.00) at high pressure pneumoperitoneum. This study provides evidence of using low pressure pneumoperitoneum during LC as changes in FV hemodynamics and coagulation parameters were less pronounced at low pressure pneumoperitoneum.

A phantom model study to identify the most effective manual aspiration thrombectomy for acute deep-vein thrombosis of the lower extremity

AIM

To identify the most effective manual aspiration thrombectomy (MAT) method for the initial endovascular management of acute deep-vein thrombosis (DVT) in the lower extremity using a phantom model.

MATERIALS AND METHODS

An acute DVT phantom model was created by infusing a bovine acute thrombus in a 20-mm diameter, 120-cm long plastic tube with banding of the distal portion. A total of 32 types of aspiration methods using combinations of two aspiration catheters (8 and 10 Fr), four syringes (10, 20, 40, and 50 ml), and four different aspiration methods (I, II, III, and IV) were performed. Each method was performed 10 times. The total weight of the aspirated thrombus was measured and compared among the 32 aspiration methods. The aspiration methods were classified based on the length of the dynamic catheter withdrawal (0 cm [method I], 15 cm [II], 30 cm [III], or >45 cm [IV]) while maintaining continuous negative pressure using a syringe. Analysis of variance and Student's t-test were used for statistical analysis.

RESULTS

There were no statistically significant differences in the total amount of aspirated thrombus among the various types of aspiration catheters and syringes; however, different aspiration methods showed significantly different results. Acute thrombus was most effectively aspirated by method IV irrespective of the catheter and syringe used. The longer the length of dynamic catheter withdrawal, the greater the amount of total thrombi that could be aspirated, irrespective of the type of aspiration catheter and syringe used (IV > III > II > I; p<0.05).

CONCLUSION

MAT can be performed most effectively using method IV. Effective MAT relies on the length of the dynamic catheter withdrawal while maintaining continuous negative pressure using a syringe in the initial endovascular management of acute DVT in the lower extremity.

Sedentary behaviour and cardiovascular disease: a review of prospective studies

BACKGROUND

Current estimates from objective accelerometer data suggest that American adults are sedentary for ∼7.7 h/day. Historically, sedentary behaviour was conceptualized as one end of the physical activity spectrum but is increasingly being viewed as a behaviour distinct from physical activity.

METHODS

Prospective studies examining the associations between screen time (watching television, watching videos and using a computer) and sitting time and fatal and non-fatal cardiovascular disease (CVD) were identified. These prospective studies relied on self-reported sedentary behaviour.

RESULTS

The majority of prospective studies of screen time and sitting time has shown that greater sedentary time is associated with an increased risk of fatal and non-fatal CVD. Compared with the lowest levels of sedentary time, risk estimates ranged up to 1.68 for the highest level of sitting time and 2.25 for the highest level of screen time after adjustment for a series of covariates, including measures of physical activity. For six studies of screen time and CVD, the summary hazard ratio per 2-h increase was 1.17 (95% CI: 1.13-1.20). For two studies of sitting time, the summary hazard ratio per 2-h increase was 1.05 (95% CI: 1.01-1.09).

CONCLUSIONS

Future prospective studies using more objective measures of sedentary behaviour might prove helpful in quantifying better the risk between sedentary behaviour and CVD morbidity and mortality. This budding science may better shape future guideline development as well as clinical and public health interventions to reduce the amount of sedentary behaviour in modern societies.

Restoration of patency in iliofemoral deep vein thrombosis with catheter-directed thrombolysis does not always prevent post-thrombotic damage

OBJECTIVES

To evaluate the long-term results of catheter-directed thrombolysis (CDT) and the feasibility of stent placement for lower extremity deep vein thrombosis (DVT).

DESIGN & METHODS

Retrospective study of 34 patients (10 men and 24 women, mean age 55, S.D. 13 years) with lower extremity DVT underwent CDT at Seoul National University Hospital from January 1999 to October 2003. Patient characteristics, risk factors of DVT, extent of thrombosis, and short-term and long-term results of CDT and/or stent placement were analysed.

RESULTS

Mean follow-up times were 47 S.D. 16 months. The primary technical success rate was 97% (complete lysis 68%, partial 29%). During the follow-up periods 11 (32%) patients showed re-thrombosis. Sixteen (47%) of 34 patients showed chronic change of vessels during the follow-up periods. By Cox Proportional Hazard analysis, extent of thrombolysis was a statistically significant factor affecting the freedom of re-thrombosis and chronic change (P=0.008 and P=0.001). Nine (44%) of 21 deployed stents were obstructed, and the overall stent patency at 3 years was 56.7%. The only factor affecting the stent patency was stent length more than 6 cm (P=0.002, HR 13, 95% CI 2.7-59).

CONCLUSION

Long-term results of CDT are not satisfactory because of the high recurrence rate of DVT and it cannot prevent chronic post-thrombotic damage to the affected vessels despite long-term anticoagulation therapy. Careful long-term surveillance of the venous function is highly recommended after CDT.

Long-term outcomes of catheter directed thrombolysis for lower extremity deep venous thrombosis without prophylactic inferior vena cava filter placement

BACKGROUND

While the predominant treatment of lower extremity deep venous thrombosis (DVT) remains systemic anticoagulation, there is a growing consensus that more aggressive percutaneous catheter directed thrombolysis (CDT) carries both short-term and long-term benefits. There remains controversy as to whether an inferior vena cava (IVC) filter is always required during CDT.

OBJECTIVE

To define the short- and long-term outcomes of CDT with and without prophylactic IVC filter placement for lower extremity DVT.

METHODS

A database of patients treated by CDT from 1996 to 2006 was compiled. Results were standardized to current Society for Vascular Surgery criteria. Average follow-up was 2.1 years, range of 1-8 years. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a Cox proportional hazard model for time dependent variables. Data are presented as mean +/- SD where appropriate.

RESULTS

Sixty-nine patients (39% male, average age 48 +/- 17 years) underwent CDT: (27 received pharmacological thrombolysis, 12 received mechanical thrombolysis, and 30 received mechanical and pharmacological thrombolysis). Fourteen patients (20%) had IVC filter placement prior to or during CDT. Twenty-one had a hypercoagulable state. Technical success with grade III lysis of clot burden was achieved in 63%. Fifty-one patients required an adjuvant stent. Overall, 90-day all-cause mortality was 4% and peri-procedural morbidity was 4%. No patients developed a pulmonary embolus (PE) during therapy. By Kaplan-Meier analysis 83%, 83%, and 75% of patients were free of recurrent DVT at 1, 2, and 3 years, respectively. Hypercoagulability was associated with DVT recurrence by Cox proportional hazards analysis. No analyzed factor was predictive of PE.

CONCLUSION

Catheter directed thrombolysis without universal prophylactic IVC filter placement is safe and effective in treating acute DVT. Pulmonary embolization did not occur during CDT. Selective rather than routine IVC filter placement is a safe and appropriate approach.

Obesity: basic science and medical aspects relevant to anaesthetists

Obesity is becoming a major public health problem throughout the world. It is now the second leading cause of death in the United States and is associated with significant, potentially life-threatening co-morbidities. Significant advances in the understanding of the physiology of body weight regulation and the pathogenesis of obesity have been achieved. A better understanding of the physiology of appetite control has enabled advances in the medical and surgical treatment of obesity. Visceral or abdominal obesity is associated with an increased risk of cardiovascular disease and type 2 diabetes. Various drugs are used in the treatment of mild obesity but they are associated with adverse effects. Surgery has become an essential part of the treatment of morbid obesity, notwithstanding the potential adverse events that accompany it. An appreciation of these problems is essential to the anaesthetist and intensivist involved in the management of this group of patients.

Airline Chair-Rest Deconditioning

Air passenger miles will likely double by year 2020. The altered and restrictive environment in an airliner cabin can influence haematological homeostasis in passengers and crew. Flight-related deep venous thromboemboli (DVT) have been associated with at least 577 deaths on 42 of 120 airlines from 1977 to 1984 (25 deaths/million departures), whereas many such cases go unreported. However, there are four major factors that could influence formation of possible flight-induced DVT: sleeping accommodations (via sitting immobilisation); travellers' medical history (via tissue injury); cabin environmental factors (via lower partial pressure of oxygen and lower relative humidity); and the more encompassing chair-rest deconditioning (C-RD) syndrome. There is ample evidence that recent injury and surgery (especially in deconditioned hospitalised patients) facilitate thrombophlebitis and formation of DVT that may be exacerbated by the immobilisation of prolonged air travel. In the healthy flying population, immobilisation factors associated with prolonged (>5 hours) C-RD such as total body dehydration, hypovolaemia and increased blood viscosity, and reduced venous blood flow (pooling) in the legs may facilitate formation of DVT. However, data from at least four case-controlled epidemiological studies did not confirm a direct causative relationship between air travel and DVT, but factors such as a history of vascular thromboemboli, venous insufficiency, chronic heart failure, obesity, immobile standing position, more than three pregnancies, infectious disease, long-distance travel, muscular trauma and violent physical effort were significantly more frequent in DVT patients than in controls. Thus, there is no clear, direct evidence yet that prolonged sitting in airliner seats, or prolonged experimental chair-rest or bed-rest deconditioning treatments cause DVT in healthy people.

Sirolimus does not increase the risk for postoperative thromboembolic events among renal transplant recipients

BACKGROUND

Deep venous thrombosis (DVT) tends to occur in greater frequency among cyclosporine (CsA)-treated renal-transplant recipients. Because administration of sirolimus may increase the whole-blood concentrations of CsA, we sought to assess the impact of the combination regimen on the incidence, predisposing factors, and consequences of postoperative DVT, transplant renal-vein or artery thrombosis, and pulmonary embolus.

METHODS

We retrospectively evaluated two cohorts of renal transplant recipients: CsA/prednisone (Pred)+/-azathioprine (n=136, group A) or sirolimus+CsA+Pred (n=354, group B) using Fisher's exact t and chi-square tests, as well as Kaplan-Meier analyses, odds ratios, and multiple logistic regression methods.

RESULTS

The 7 of 136 (5.1%) incidence of thrombotic events in group A was similar to the 20 of 354 (5.6%) incidence in group B (P=0.513; NS) and occurred no more frequently ipsilateral to the transplant. Although the occurrence of an acute-rejection episode was not associated with the DVT diagnosis, all affected patients displayed elevated serum creatinine (Scr) values, which remained slightly higher than baseline following recovery (group A 1.63+/-1.22-1.95+/-0.93 mg/dL; group B 1.70+/-1.11-2.01+/-0.88 mg/dL). Renal biopsies failed to show evidence of intrarenal coagulopathy. No patient lost a graft as a complication of DVT, nor did these events produce other lasting adverse effects. Patients in the sirolimus group showed a strong correlation between the occurrence of DVT and the previous existence of an ipsilateral or contralateral lymphocele.

CONCLUSION

Addition of sirolimus to a CsA+Pred regimen does not increase the incidence of postoperative thrombotic events among renal transplant recipients.

Surgery for colorectal cancer

Colorectal cancer remains the second commonest cause of cancer death in North America and Western Europe. Surgery remains the mainstay of treatment. The aim of surgery should be to achieve cure and to avoid locoregional recurrence. The fixity of the primary tumour determines resectability, and the extent of spread determines ultimate survival. Patients with rectal cancer present a particular problem. There is good evidence that lower local recurrence rates may be achieved both by improvements in surgical technique and the use of adjuvant radiotherapy. The importance of adequate treatment of the circumferential tumour margin cannot be over-emphasised; meticulous attention is required to ensure an adequate circumferential excision. The lowest incidences of locoregional recurrence are reported by surgeons who perform total mesorectal excision. Anorectal function, sexual and urinary dysfunction may occur after rectal excision. Both postoperative and pre-operative radiotherapy can reduce the incidence of local recurrence. However, in view of the low recurrence rates obtained with TME alone, the role of adjuvant radiotherapy requires further evaluation. Several aspects of the surgical management of colorectal cancer, for example, the role of transanal local excision of selected rectal cancers and laparoscopic surgery, the management of obstructed cases and the role of follow-up remain to be defined clearly.

Percutaneous AngioJet thrombectomy in the management of extensive deep venous thrombosis

PURPOSE

This study was undertaken to evaluate the efficacy of a percutaneous mechanical thrombectomy (PMT) device for rapid thrombus removal following deep venous thrombosis (DVT).

MATERIALS AND METHODS

Over a 37-month period, 17 patients (14 women; mean age, 41 y +/- 20) with extensive DVT were treated with initial attempts at PMT with use of the AngioJet rheolytic thrombectomy device. Sites of venous thrombosis included lower extremities in 14 patients and upper extremity and brachiocephalic veins in three. The etiology for venous thrombosis was malignancy in seven, idiopathic etiology in three, May-Thurner syndrome and immobilization in three each, and oral contraceptive use and hypercoagulable disorder in one each. The primary endpoint was venographic evidence of thrombus extraction. Perioperative complications, mortality, and recurrence-free survival were also evaluated.

RESULTS

After PMT, four of 17 patients (24%) had venographic evidence of >90% thrombus removal, six of 17 (35%) had 50%-90% thrombus removal, and seven of 17 (41%) had <50% thrombus extraction. Adjunctive thrombolytic therapy was used in nine of 13 patients with <90% thrombus extraction by PMT; six patients (35%) had contraindications to pharmacologic thrombolytic therapy. An underlying lesion responsible for the occlusion was uncovered in 10 patients (59%). Significant improvement in clinical symptoms was seen in 14 of 17 patients (82%). No complications were noted directly relating to the use of the AngioJet thrombectomy catheter. None of the patients were lost to follow-up during a mean of 8.9 months +/- 5.3 (range, 2-21 months). At 4 and 11 months, recurrence-free survival rates were 81.6% and 51.8%, respectively.

CONCLUSION

PMT with adjunctive thrombolytic therapy is a minimally invasive, low-risk therapeutic option in patients with extensive DVT, associated with clinical benefits including thrombus removal, patency, and relief of symptoms.

Risk factors for venous thromboembolism following prolonged air travel. Coach class thrombosis

Venous thromboembolism (VTE) in legs and lungs is a potentially life-threatening condition. The incidence of VTE associated with air travel is still unknown, but it may have increased. Most travelers who develop symptoms do so within 24 hours after their flight takes off. Predisposing risk factors may be divided into patient-related and cabin-related factors, both of which are described. It is emphasized that better information and better inflight precautions can minimize these risk factors.

Deep venous thrombosis and pulmonary embolism in bilateral lower-extremity amputee patients

OBJECTIVE

To determine the incidence of deep venous thrombosis and pulmonary emboli and the value of an inferior vena cava filter in patients with bilateral lower-extremity amputations, and to determine the incidence of pulmonary emboli after filter placement.

DESIGN

Retrospective study with a follow-up of 3 to 64 months.

SETTING

Inner-city university hospital.

PATIENTS

Twenty-seven consecutive patients with bilateral lower-limb amputation.

RESULTS

Age, sex, and race were assessed, and had no impact on the incidence of pulmonary embolus in these patients with lower-extremity amputation.

CONCLUSION

No clinical objective evidence of pulmonary emboli occurred after placement of an inferior vena caval filter.

North Baden venous lysis trial (NBVL): multicentre prospective randomized phlebographically controlled trial on the effect of ultra-high versus conventional doses of streptokinase in fresh leg-pelvis venous thromboses

Since no previous randomized comparison has been carried out between ultra-high and conventional dosage streptokinase therapy of fresh venous thromboses, the NBVL trial was carried out as a prospective, randomized, multicentre, phlebographically monitored comparison of the results and adverse effects of these two fibrinolytic treatment options. Using the normal exclusion criteria, 156 patients with a leg-pelvis venous thrombosis presumed to be a maximum of 14 days old were treated with 1.5 million U streptokinase/h for 6h daily (n = 77, group A) or conventional dosage with 100,000 U streptokinase per hour (n = 79, group B). There were 15 patients (eight in group A, seven in group B) who had to stop therapy prematurely, and eight patients (five in group A, three in group B) could not be evaluated because of incorrect monitoring times. The phlebograms were evaluated using IFP-C scores. These showed a reduction in the IFP score from 4.55 to 2.2 in the 64 patients in group A after a mean of 2.7 +/- 0.6 therapy cycles with administration of 24.4 +/- 5.7 million U streptokinase, i.e. 47% of the baseline value. The 69 patients in group B had a reduction in score from 4.2 to 2.93 after a mean of 3.7 +/- 1.2 days of treatment with administration of 8.6 +/- 3.3 million units, i.e. a fall of 30% in the baseline values (p = 0.007). There were 132 out of 281 completely occluded venous segments in group A (47%) and 81 out of 279 segments in group B (29%) that showed complete patency. Eight out of 27 three-segment occlusions in group A and only one of 26 in group B showed complete patency. The IFP score improved by 55% in the 45 men in group A, compared with only 30% in the 47 men in group B (p = 0.002). When both dosages are combined, men showed a greater improvement in IFP score than women (42 versus 29%; p = 0.02). The IFP score improved more in the 20 patients aged more than 60 years in group A than in the 19 patients aged over 60 years of age in group B (61 versus 20%; p = 0.003). No other significant differences in effect were seen on analysis of sub-groups and individual factors (sex, age, presumed age of thrombus and side of thrombosis). In the 77 patients in group A, haemorrhagic complications were less frequent than in the 79 patients in group B (22.1 versus 36.7%; p = 0.054), especially concerning urogenital haemorrhage (6.5 versus 22.8%; p = 0.004). Women were affected more frequently by haemorrhagic complications than men (35.2 versus 26.5%), and the 19 patients aged more than 65 years old were affected more than the 137 younger patients (21.1 versus 13.9%). There were no deaths, and clinically insignificant pulmonary emboli occurred three times. Ultra-high dosage streptokinase shows better and more rapid thrombolytic treatment for popliteal-femoral-iliac venous thromboses and causes fewer haemorrhagic complications than conventional dosage streptokinase. The better effect of ultra-high dosage can be observed particularly for three-segment occlusion as well as in male patients. In older patients, accurate diagnosis is required because of the higher rate of haemorrhagic complications.

Upper extremity deep venous thrombosis and its impact on morbidity and mortality rates in a hospital-based population

PURPOSE

Although much attention has been focused on lower extremity deep venous thrombosis (LEDVT), there is a relative paucity of data regarding the impact of upper extremity deep venous thrombosis (UEDVT) on morbidity and mortality rates. To increase our knowledge with the latter disease, we have reviewed our experience at our institution with 170 patients who had brachial, axillary, and subclavian vein thromboses.

METHODS

Over the past 5 years, UEDVT was diagnosed in 170 patients by duplex scanning. The indications for duplex examination were either upper extremity swelling (95%) or as part of the workup for pulmonary embolism (5%). There were 103 women (61%) and 67 men (39%), with ages ranging from 9 to 101 years (mean, 68 +/- 17 years). The diagnosis was made in 152 patients (89%) while they were admitted to the hospital and in 18 patients (11%) in the outpatient clinic. Risk factors included presence of a central venous catheter or pacemaker in 110 patients (65%), malignancy in 63 patients (37%), concomitant LEDVT in 19 patients (11%), and history of LEDVT in 18 patients (11%). Fifty-six patients (33%) had multiple risk factors, whereas 36 patients (21%) had no obvious risk factor.

RESULTS

The 1-month and 3-month mortality rates for the entire study group were 16% and 34%, respectively. Patients who had concomitant LEDVT, were 75 years of age or older, and were not treated with anticoagulation medication had a significantly higher 1-month mortality rate. Patients whose diagnoses were made in the outpatient setting were statistically younger and had a lower 3-month mortality rate when compared with the patients whose diagnoses were made as inpatients. Pulmonary embolism was documented by ventilation/perfusion scan in 12 patients (7%). Although no patient in the group in which UEDVT was diagnosed on an outpatient basis was documented to have a pulmonary embolism and 12 patients (8%) in the inpatient group had pulmonary emboli, this difference was not statistically significant. Anticoagulation medication did not totally prevent pulmonary embolism in this review. All patients were followed-up for between 0 to 49 months (mean, 13 +/- 1 months). No swelling of the affected arm was observed in 145 patients (94%); four patients complained of mild intermittent swelling (2%), and seven patients reported significant swelling (4%).

CONCLUSIONS

Contrary to previous reports, these data suggest that UEDVT is associated with a low incidence of postthrombotic upper extremity swelling, but a significant incidence of pulmonary embolism and rate of mortality. This review suggests that UEDVT is at least as serious a disease entity as LEDVT and should be managed as aggressively as LEDVT.

The effect of orlistat on the pharmacokinetics and pharmacodynamics of warfarin in healthy volunteers

To assess the effect of orlistat on the pharmacokinetics and pharmacodynamics of warfarin, a third-party blind, placebo-controlled, randomized, two-way crossover study was performed in 12 healthy volunteers. Each participant received single 30-mg oral doses of racemic warfarin sodium (Coumadin; DuPont Pharma, Wilmington, DE) administered on the eleventh day of treatment with 120 mg orlistat (treatment A) and placebo (treatment B) three times a day for 16 days; the two treatments were separated by a 3-week washout period. Serial blood samples were collected before and at appropriate intervals after each dose of warfarin to determine plasma concentrations of R-warfarin and S-warfarin and blood prothrombin time (PT) and plasma Factor VII concentration. In addition, serum concentrations of vitamin K1 and its epoxide and of osteocalcin and its undercarboxylated form were measured before breakfast on days -7, 1, 4, 6, and 10. Equivalent results between treatments with orlistat and placebo were found with regard to all pharmacokinetic parameters of R- and S-warfarin (except for time to maximum concentration of R-warfarin). Pharmacodynamic parameters of warfarin (PT and Factor VII) and vitamin K nutritional status parameters (ratios of vitamin K1 to vitamin K1 epoxide and undercarboxylated osteocalcin to osteocalcin) also were unaltered by orlistat. Orlistat administered at doses of 120 mg three times daily did not significantly alter the pharmacokinetics and pharmacodynamics of a single 30-mg oral dose of warfarin in healthy volunteers.

Pulmonary embolism following laparoscopic cholecystectomy: report of two cases and review of the literature

Laparoscopic abdominal surgery is considered a low-risk procedure for postoperative thromboembolic disease. We report two cases of pulmonary embolism following laparoscopic cholecystectomy, review the incidence of deep venous thrombosis and pulmonary embolism in laparoscopic cholecystectomy, and suggest a specific prophylactic scheme for patients undergoing laparoscopic cholecystectomy. In spite of the low incidence of postoperative thromboembolic disease following minimally invasive procedures, the risk of pulmonary embolism must not be underestimated and its symptoms must not be underdiagnosed.

Venous thromboprophylaxis in oesophageal cancer surgery

In a retrospective study of 127 patients who underwent resection for oesophageal cancer without anticoagulant thromboprophylaxis, the incidence of clinically established postoperative deep vein thrombosis (DVT) was 1.6 per cent. In a prospective study the Sue-Ling DVT risk factor index was calculated for 53 consecutive patients with oesophageal cancer; the mean (s.d.) value was -4.4(3.5). For 29 patients who underwent resection the following policy of thromboprophylaxis was applied. Patients undergoing transthoracic oesophagectomy with risk score > -4 (four patients) and those undergoing transhiatal resection with risk score > -1 (four) received both anticoagulant and mechanical thromboprophylaxis; the remaining 21 patients received only mechanical thromboprophylaxis. No patient developed DVT after operation. There were no haemorrhagic complications in the group undergoing anticoagulant thromboprophylaxis. The selective approach, based on the Sue-Ling risk factor index and type of operation, spared 72 per cent of the patients operated on from undergoing anticoagulant thromboprophylaxis and produced favourable results in this small series.

Medical complications of head injury

There are many common and significant medical complications of head injury. These include (1) cardiovascular problems such as hyperdynamic state, myocardial injury, and dysrhythmias; (2) respiratory changes such as neurogenic pulmonary edema, hypoxia, abnormal ventilatory patterns, pulmonary infections, and pulmonary emboli secondary to deep vein thrombosis; (3) consumption coagulopathy; (4) water and electrolyte derangements--hypo- and hypernatremia; (5) hypothalamic/pituitary dysfunction--syndrome of inappropriate secretion of antidiuretic hormone and diabetes insipidus; (6) increased general metabolism with loss of immunocompetence, respiratory compromise, and complications of decreased activity; (7) gastrointestinal difficulties, particularly stress gastritis; and (8) infectious problems including those related to contamination from open wounds and foreign bodies such as monitors.