Does Early Ambulation Increase the Risk of
PULMONARY EMBOLISM in Deep Vein Thrombosis? A REVIEW OF THE LITERATURE Therapeutic measures targeting deep vein thrombosis (DVT) are often aggressive to prevent pulmonary embolism (PE). Once receiving anticoagulation therapy, however, there are different viewpoints on whether patients should remain sedentary or be allowed to ambulate, particularly in the home setting. The current literature was reviewed in a systematic fashion to ascertain the risks and benefits of activity level in patients with DVT with regard to PE formation. All studies uniformly demonstrated at least no significant differences in PE formation with either activity level in these DVT patients. There is no evidence to suggest that ambulation by anticoagulated DVT patients in the home setting increases the risk of PE development. Anupama R. Pillai, MSN, and Jay S. Raval, MD 336
Home Healthcare Nurse
www.homehealthcarenurseonline.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Introduction
rest combined with immobilization in patients with DVT may result in hypertensive stasis that Venous thromboembolism (VTE), which includes decreases the endogenous endothelial fibrinodeep vein thrombosis (DVT) and pulmonary emlytic activity. Traditionally, patients with DVT bolism (PE), is a common problem causing sigwere treated with strict bed rest and elevation nificant morbidity and mortality. There are an of the affected extremity for 5 to 8 days with anestimated 300,000 to 600,000 cases of VTE annuticoagulation and compression therapy. Bed rest ally in the United States with 60,000 to 100,000 was recommended for fear that the thrombotic deaths (Beckman et al., 2010). The incidence of mass might break free from the deep veins due PE in the United States is estimated to be 112 per to leg movement and subsequently lead to PE, 100,000 adults per year (Wiener et al., 2011). In although this recommendation was not evidence almost 50% of patients, PE has already occurred based (Schellong et al., 1999). In fact, bed rest by the time a DVT diagnosis is established and can promote venous stasis, possibly enhancing one third of these patients are asymptomatic thrombus propagation and increasing the risk of (Augustinos & Ouriel, 2004). Although DVT and fatal pulmonary emboli, especially in older paPE are pathophysiologically related entities, tients (Partsch, 2005). Prolonged there are notable differences. contributes to many DVT occurs three times more There are an estimated immobility other undesirable outcomes, inoften than PE, and the major adcluding loss of lean muscle, deverse outcome of DVT without PE 300,000 to 600,000 is postphlebitic syndrome, which cases of venous throm- creased functional capacity, skin breakdown, and constipation. is a late adverse complication boembolism annually The current treatment for DVT caused by permanent damage to consists of several different regithe venous valves of the leg in the United States mens, including bed rest with or (Goldhber, 2008). with 60,000 to without elevation of the affected A major theory delineating the 100,000 deaths. extremity, an ambulation/exercise pathogenesis of VTE, known as program, the application of warm Virchow triad, proposes that VTE and/or cool compresses, and use of compresoccurs as a result of (a) alterations in blood sion therapy with anticoagulation. If DVT can be flow (i.e., stasis), (b) vascular endothelial injury, treated in a safe manner that foregoes bed rest and (c) alterations in the constituents of the and hospitalization, it will enable patients to blood (i.e., inherited or acquired hypercoagumaintain independence, enhance patient satisfaclable state). A risk factor for thrombosis has been tion, and decrease healthcare costs. However, identified in over 80% of patients with venous both patients with DVT and the home healthcare thrombosis (Bauer, 2012). Furthermore, genetic clinicians providing care for these individuals and acquired factors together can contribute to may be apprehensive about initiating treatments the development of VTE. The two most common and increasing activity levels outside of the hosgenetic mutations are the factor V Leiden and the pital setting due to the fear of developing PE. The prothrombin gene mutations (Goldhber, 2008). purpose of this article is to review the evidence However, most patients who develop VTE do in the recent literature to ascertain whether amnot have predisposing genetic factors. Acquired bulation increases the risk of PE in anticoagulated factors that contribute to the development of patients with DVT as compared to bed rest. VTE include long-distance air travel, obesity, cigarette smoking, oral contraceptives, pregnancy, postmenopausal hormone replacement, Methods surgery, trauma, and medical conditions such The PubMed database (January 1, 1946 to June as antiphospholipid antibody syndrome, cancer, 30, 2011) was searched for publications using systemic arterial hypertension, and chronic obkeywords which included “DVT, PE, bed rest, and structive pulmonary disease (Goldhber, 2008). ambulation,” “DVT, heparin,” “walking versus bed A growing body of evidence suggests that the rest,” “DVT, bed rest, and ambulation,” “bed rest, biological condition of the endothelium plays a DVT, PE incidence,” “deep vein thrombosis, momajor role in the pathophysiology of DVT recanabilization, and PE,” and “deep vein thrombosis lization (Manganaro et al., 2008). Prolonged bed and walking.” Investigations with any study
vol. 32 • no. 6 • June 2014
Home Healthcare Nurse
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
337
designs were included if the treatment groups and outcomes were clearly described, similar anticoagulant regimens were used in both groups, and PE was analyzed as an outcome variable. Articles were excluded if publication dates were earlier than 2000. Of 89 references retrieved from PubMed, 6 met the inclusion criteria for this study. Although these studies differed in their methodologies, the data collected were of high quality. Data extracted included general study information, quality assessments including randomization, descriptions of participants, interventions, and outcome measures. The quality of studies was graded using the McMaster criteria as follows: (a) systematic review/metaanalysis of multiple randomized controlled trials (RCTs) or a large RCT without important limitations (double blind, intention-totreat approach, report dropout rate, and adherence rate) and with adequate power to answer the clinical question; (b) well-designed quasiexperimental study with indisputable results; (c) RCT or systematic review/metaanalysis of multiple RCT that do not meet Level I criteria above; (d) quasiexperimental study other than those meeting Level II criteria above; (e) observational study (case-control, cohort), descriptive study (correlational, comparative), or systematic review/metaanalysis of multiple observational and descriptive studies.
Results Of the six studies reviewed in this article, five were RCTs. The sixth was a single-center retrospective analysis of consecutive DVT patients. The purpose, methodology, variables, effect size, and quality grading are summarized in Table 1. Each of the studies is subsequently described briefly. The purpose of the randomized study conducted by Partsch and Blättler (2000) was to evaluate the benefits of compression and walking exercises in comparison with bed rest and the frequency of new PE in the acute stage of proximal DVT. A convenience sample of 45 patients with acute symptomatic proximal DVT, confirmed with ultrasound scan or phlebography, were randomized to one of three groups: Group A consisted of inelastic Unna boot bandages (Varicex F Zinc Plaster, Lohmann & Rauscher, Inc., Topeka, KS) with walking exercises (n = 15); Group B consisted of elastic compression stockings
338
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with walking exercises (n = 15), and Group C underwent bed rest with bathroom privileges and no compression (n = 15). All patients received overlapping oral anticoagulants and subcutaneous dalteparin sodium. Whereas Groups A and B were encouraged to walk as much as possible on the ward and on the hospital grounds, Group C was advised to stay in bed (except to use toilet). The study found that the rate of resolution of pain and swelling was significantly faster when the patient ambulated with compression. The occurrence of new PE detected by the second lung scan on Day 9 was not significantly different in the three groups. Ambulatory patients treated with low-molecular-weight heparin (LMWH) and compression therapy did not have an increased risk of PE as compared to patients on bed rest regardless of the size or location of the thrombi. The findings indicated that ambulatory patients with Unna boots or compression stockings do not have a significantly greater risk of PE compared to those on bed rest. Aschwanden et al. (2001) conducted a prospective, randomized, parallel group study in Switzerland with a convenience sample of 129 patients to compare the frequency of new PE in bed rest versus ambulatory patients with confirmed DVT. The patients were randomly assigned to one of the two groups; bed rest (n = 60) or ambulation (n = 69); randomization was stratified according to gender and extension of thrombosis. All patients received dalteparin sodium and baseline ventilation/perfusion (V/Q) scan within 24 hours of inclusion in the study. Patients in the bed rest group were allowed to leave the bed only after a second pulmonary scan was performed on Day 4. Patients in the ambulation group were encouraged to ambulate for more than 4 hours/day under a study nurse’s supervision. Adherence to the protocols was strict. At the end of the fourth day, 16 new cases of clinically asymptomatic PE were detected: 6 in the bed rest group and 10 in the ambulatory group. However, the intergroup difference in the frequency of new PE was not statistically significant, and regression analysis did not confirm any significant relationship between new PEs and patient-activity level. Ambulation did not cause a significant difference in the occurrences of new PEs. Trujillo-Santos et al. (2005) conducted a prospective, multicenter, nonblinded, nonrandomized observational study of patients
www.homehealthcarenurseonline.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
enrolled in the “The Computerized Registry of Patients with Venous Thromboembolism” (RIETE registry) to evaluate the differences in clinical outcomes during the first 15 days of VTE therapy among patients treated with strict bed rest versus those who were permitted to ambulate. A convenience sample, which included consecutive patients with symptomatic, objectively confirmed DVT or PE were included in the study after giving verbal consent. No pulmonary scan was conducted at the baseline. However, if the patient exhibited symptoms of a PE at hospital admission or with follow-up shorter than 30 days, they were excluded from the study. All patients received LMWH. Of the 2,038 patients with DVT, 1,050 (52%) were prescribed bed rest and 988 (48%) were permitted to ambulate. Seven of the 1050 (0.7%) patients in the bed rest group and 4 of the 988 (0.4%) patients in the ambulation group developed new PE, and the rates of PE between the two groups were not significantly different. Patients who ambulated had a 39% lower risk of developing new PE compared with those on bed rest, although this difference did not achieve statistical significance. Jünger et al. (2006) conducted a prospective, randomized trial in Germany that enrolled 102 consecutive patients diagnosed with DVT based on duplex sonography or phlebography and anticoagulated with LMWH (dalteparin). All patients received a baseline V/Q scan or a pulmonary spiral computed tomography (CT) scan. The patients were randomized into two parallel groups. The control group was prescribed strict bed rest for at least 5 days and was permitted to perform breathing exercises. The patients in the treatment group were instructed to move around the ward during the minimum 5-day hospital stay. All patients were given a lower leg and thigh compression dressing made of shortstretch bandages up to the groin. At day 10 to 12 of the study, a second pulmonary V/Q scan or spiral CT scan was performed in order to detect or rule out new PEs. The mobile group had a 1.9% rate of clinically relevant PE versus 10% in the immobile group; these rates were not significantly different. Manganaro et al. (2008) conducted a retrospective, single-center, nonblinded, nonrandomized study to evaluate the progression/ regression of DVT by comparing bed rest and
vol. 32 • no. 6 • June 2014
Patients who ambulated had a 39% lower risk of developing new pulmonary embolism compared with those on bed rest, although this difference did not achieve statistical significance.
mobilization in a sample of 252 consecutive patients with DVT confirmed by d-dimer and duplex ultrasonography. No pulmonary scan was conducted at baseline. All patients were anticoagulated with subcutaneous nadroparin. Researchers recommended oral anticoagulation therapy at a dose titrated to obtain an international normalized ratio of 2.0 to 3.0 as secondary prophylaxis for 152 patients (there is no mention of which oral anticoagulation agent was used or to which group the patients belonged). Although all patients were recommended to use compression stockings, only 34% (85 patients) followed this recommendation. The authors monitored the occurrence of PE at 30 days in all patients by echocardiography to detect evidence of right ventricular overload. V/Q scanning was conducted when clinically indicated. At the time of the 30-day follow-up visit, 172 (68%) patients had freely walked and were defined as mobile patients, whereas 80 (32%) patients had not walked and were defined as immobile patients. Of these immobile patients, 48 (19%) were permanently immobilized in bed because of a medical condition, and 32 (13%) had received the recommendation of bed rest by the attending physician to prevent PE and had been immobilized for an average of 7 days. Eleven out of 252 patients developed PE; 10 of them were immobile. Of note, 4 out of these 10 individuals were immobilized for 7 days or more. This predilection for the immobilized patients to develop PE compared to the mobile group was statistically significant. Romera-Villegas et al. (2008) conducted a prospective randomized trial between January 2005 and December 2007; 219 patients with acute lower limb DVT were enrolled in the study and the mean age was 64 years. Inclusion
Home Healthcare Nurse
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
339
Table 1. Summary of Studies Including Purpose, Methods, Variables, Quality Grading, and Effect Size Study
Purpose
Methodology
Variables
Effect Size
Partsch & Blättler (2000) (Level III–RCT)
To evaluate the benefits of compression and walking exercises in comparison with bed rest in the acute stage of proximal DVT
Prospective, randomized, nonblinded, controlled trial in which three groups of adjuvant treatment modalities are compared in patients with acute DVT, confirmed by ultrasound and anticoagulated with dalteparin sodium Number of subjects: Total n = 45 Group A (n = 15): Inelastic Unna boot bandages + walking exercises Group B (n = 15): Elastic compression stockings + walking exercises Group C (n = 15): Bed rest and no compression 64% male, 52.2 to 61.7 years of age Setting: Wilhelminen Hospital, Vienna, Austria
Unna boot with walking or compression stocking with walking versus bed rest with no compression in the acute stage of DVT Mobile patients were encouraged to ambulate as much as possible on the ward and on the hospital grounds Immobilized patients stayed in bed except to use the toilet Outcome: Incidence of new PE confirmed by V/Q scan
RR 1.5, 95% CI [0.17–13.225] Patients who walk have a 1.5 time greater risk of developing new PE than those on bed rest
Aschwanden et al. (2001) (Level III–RCT)
To compare frequency of objectively assessed new PE in hospitalized patients with proven proximal DVT being either strictly immobilized for 4 days or encouraged to ambulate under the supervision of a study nurse
Prospective, randomized, single center, openlabel, parallel group study in which patients with DVT confirmed by duplex sonography and anticoagulated with dalteparin sodium were hospitalized for > 4 days and randomized to an immobilized or an ambulating group Number of subjects: Total n = 129 Mobile, n = 69 Immobile, n = 60 56% male, 65 ± 17 years of age Setting: University of Basel University Hospitals– Basel, Switzerland
Mobilization versus bed rest Mobile patients (with compression therapy) were encouraged to ambulate for more than 4 hr/day and bed rest patients were kept strictly in bed for 4 days Outcome: Incidence of new PE confirmed by V/Q scan on Day 4
RR 1.449, 95% CI [0.56–3.752] Patients who walk have a 1.4 time greater risk of developing new PE than those on bed rest
Trujillo-Santos et al. (2005) (Level V–observational cohort study)
To evaluate the differences in clinical outcomes during the first 15 days of VTE therapy among patients treated with strict bed rest versus those who were allowed to ambulate
Prospective, nonrandomized multicenter, nonblinded, observational study of patients enrolled in the RIETE registry. Patients with symptomatic, objectively confirmed DVT or PE were included in the study after giving oral consent (convenience sample) Number of subjects: Total n = 2038 Ambulation, n = 988 Bed rest, n = 1050 52%–58% male, 59% > 65 years, 56%–60% > 70 kg; all received LMWH Setting: Inpatient setting of 88 Spanish hospitals enrolled in the RIETE registry No power analysis mentioned
Ambulation versus bed rest Bed rest defined as total bed rest or being sedentary for up to 3 days, with or without bathroom privileges; ambulation was not clearly defined; adherence not reported Outcome: PE during the first 15 days of therapy PE was objectively confirmed with lung scan, helical CT, or pulmonary angiography
RR 0.607, 95% CI [0.178–2.068] Patients who ambulate have 39% lower risk of developing new PE than those on bed rest
(continues)
criteria were 1 year, no life-threatening clinical conditions, and signed informed consent. The patients were randomized into two groups. In Group A, 105 patients (47.9%) were hospitalized and received 5 days of bed rest; in Group B, 114 patients (52.1%) received care at home with early walking and compression stockings. The primary end point was the presence of symptomatic PE during the first 10 days of treatment. The relationships between the duration of symptoms,
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location of the thrombus, and symptomatic PE were also analyzed. Five cases of symptomatic PE were detected (2.3%), two in Group A (hospitalized and bed rest) and three in Group B (home and early ambulation). There was no significant difference in the occurrence of new PE between the two groups. In aggregate, the findings of these six articles suggest that in patients with DVT, there is no greater risk for development of PE in those who ambulate compared to those on bed rest.
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Table 1. Summary of Studies Including Purpose, Methods, Variables, Quality Grading, and Effect Size, Continued Study
Purpose
Methodology
Variables
Effect Size
Manganaro et al. (2008) (Level V–observational retrospective study)
Retrospective analysis of DVT cases comparing bed rest and mobilization and using all variables potentially relevant to a risk and benefit evaluation
Retrospective, single-center, nonrandomized study, nonblinded Number of subjects: Total n = 252 Mobilization, n = 172 Bed rest, n = 80 (48 patients immobilized because of medical condition; 32 patients per physician prescription) Convenience sample, confirmed DVT by D-dimer levels and duplex ultrasonography was the only inclusion criteria; any patient with PE at admission or at any period
PULMONARY EMBOLISM in Deep Vein Thrombosis? A REVIEW OF THE LITERATURE Therapeutic measures targeting deep vein thrombosis (DVT) are often aggressive to prevent pulmonary embolism (PE). Once receiving anticoagulation therapy, however, there are different viewpoints on whether patients should remain sedentary or be allowed to ambulate, particularly in the home setting. The current literature was reviewed in a systematic fashion to ascertain the risks and benefits of activity level in patients with DVT with regard to PE formation. All studies uniformly demonstrated at least no significant differences in PE formation with either activity level in these DVT patients. There is no evidence to suggest that ambulation by anticoagulated DVT patients in the home setting increases the risk of PE development. Anupama R. Pillai, MSN, and Jay S. Raval, MD 336
Home Healthcare Nurse
www.homehealthcarenurseonline.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Introduction
rest combined with immobilization in patients with DVT may result in hypertensive stasis that Venous thromboembolism (VTE), which includes decreases the endogenous endothelial fibrinodeep vein thrombosis (DVT) and pulmonary emlytic activity. Traditionally, patients with DVT bolism (PE), is a common problem causing sigwere treated with strict bed rest and elevation nificant morbidity and mortality. There are an of the affected extremity for 5 to 8 days with anestimated 300,000 to 600,000 cases of VTE annuticoagulation and compression therapy. Bed rest ally in the United States with 60,000 to 100,000 was recommended for fear that the thrombotic deaths (Beckman et al., 2010). The incidence of mass might break free from the deep veins due PE in the United States is estimated to be 112 per to leg movement and subsequently lead to PE, 100,000 adults per year (Wiener et al., 2011). In although this recommendation was not evidence almost 50% of patients, PE has already occurred based (Schellong et al., 1999). In fact, bed rest by the time a DVT diagnosis is established and can promote venous stasis, possibly enhancing one third of these patients are asymptomatic thrombus propagation and increasing the risk of (Augustinos & Ouriel, 2004). Although DVT and fatal pulmonary emboli, especially in older paPE are pathophysiologically related entities, tients (Partsch, 2005). Prolonged there are notable differences. contributes to many DVT occurs three times more There are an estimated immobility other undesirable outcomes, inoften than PE, and the major adcluding loss of lean muscle, deverse outcome of DVT without PE 300,000 to 600,000 is postphlebitic syndrome, which cases of venous throm- creased functional capacity, skin breakdown, and constipation. is a late adverse complication boembolism annually The current treatment for DVT caused by permanent damage to consists of several different regithe venous valves of the leg in the United States mens, including bed rest with or (Goldhber, 2008). with 60,000 to without elevation of the affected A major theory delineating the 100,000 deaths. extremity, an ambulation/exercise pathogenesis of VTE, known as program, the application of warm Virchow triad, proposes that VTE and/or cool compresses, and use of compresoccurs as a result of (a) alterations in blood sion therapy with anticoagulation. If DVT can be flow (i.e., stasis), (b) vascular endothelial injury, treated in a safe manner that foregoes bed rest and (c) alterations in the constituents of the and hospitalization, it will enable patients to blood (i.e., inherited or acquired hypercoagumaintain independence, enhance patient satisfaclable state). A risk factor for thrombosis has been tion, and decrease healthcare costs. However, identified in over 80% of patients with venous both patients with DVT and the home healthcare thrombosis (Bauer, 2012). Furthermore, genetic clinicians providing care for these individuals and acquired factors together can contribute to may be apprehensive about initiating treatments the development of VTE. The two most common and increasing activity levels outside of the hosgenetic mutations are the factor V Leiden and the pital setting due to the fear of developing PE. The prothrombin gene mutations (Goldhber, 2008). purpose of this article is to review the evidence However, most patients who develop VTE do in the recent literature to ascertain whether amnot have predisposing genetic factors. Acquired bulation increases the risk of PE in anticoagulated factors that contribute to the development of patients with DVT as compared to bed rest. VTE include long-distance air travel, obesity, cigarette smoking, oral contraceptives, pregnancy, postmenopausal hormone replacement, Methods surgery, trauma, and medical conditions such The PubMed database (January 1, 1946 to June as antiphospholipid antibody syndrome, cancer, 30, 2011) was searched for publications using systemic arterial hypertension, and chronic obkeywords which included “DVT, PE, bed rest, and structive pulmonary disease (Goldhber, 2008). ambulation,” “DVT, heparin,” “walking versus bed A growing body of evidence suggests that the rest,” “DVT, bed rest, and ambulation,” “bed rest, biological condition of the endothelium plays a DVT, PE incidence,” “deep vein thrombosis, momajor role in the pathophysiology of DVT recanabilization, and PE,” and “deep vein thrombosis lization (Manganaro et al., 2008). Prolonged bed and walking.” Investigations with any study
vol. 32 • no. 6 • June 2014
Home Healthcare Nurse
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
337
designs were included if the treatment groups and outcomes were clearly described, similar anticoagulant regimens were used in both groups, and PE was analyzed as an outcome variable. Articles were excluded if publication dates were earlier than 2000. Of 89 references retrieved from PubMed, 6 met the inclusion criteria for this study. Although these studies differed in their methodologies, the data collected were of high quality. Data extracted included general study information, quality assessments including randomization, descriptions of participants, interventions, and outcome measures. The quality of studies was graded using the McMaster criteria as follows: (a) systematic review/metaanalysis of multiple randomized controlled trials (RCTs) or a large RCT without important limitations (double blind, intention-totreat approach, report dropout rate, and adherence rate) and with adequate power to answer the clinical question; (b) well-designed quasiexperimental study with indisputable results; (c) RCT or systematic review/metaanalysis of multiple RCT that do not meet Level I criteria above; (d) quasiexperimental study other than those meeting Level II criteria above; (e) observational study (case-control, cohort), descriptive study (correlational, comparative), or systematic review/metaanalysis of multiple observational and descriptive studies.
Results Of the six studies reviewed in this article, five were RCTs. The sixth was a single-center retrospective analysis of consecutive DVT patients. The purpose, methodology, variables, effect size, and quality grading are summarized in Table 1. Each of the studies is subsequently described briefly. The purpose of the randomized study conducted by Partsch and Blättler (2000) was to evaluate the benefits of compression and walking exercises in comparison with bed rest and the frequency of new PE in the acute stage of proximal DVT. A convenience sample of 45 patients with acute symptomatic proximal DVT, confirmed with ultrasound scan or phlebography, were randomized to one of three groups: Group A consisted of inelastic Unna boot bandages (Varicex F Zinc Plaster, Lohmann & Rauscher, Inc., Topeka, KS) with walking exercises (n = 15); Group B consisted of elastic compression stockings
338
Home Healthcare Nurse
with walking exercises (n = 15), and Group C underwent bed rest with bathroom privileges and no compression (n = 15). All patients received overlapping oral anticoagulants and subcutaneous dalteparin sodium. Whereas Groups A and B were encouraged to walk as much as possible on the ward and on the hospital grounds, Group C was advised to stay in bed (except to use toilet). The study found that the rate of resolution of pain and swelling was significantly faster when the patient ambulated with compression. The occurrence of new PE detected by the second lung scan on Day 9 was not significantly different in the three groups. Ambulatory patients treated with low-molecular-weight heparin (LMWH) and compression therapy did not have an increased risk of PE as compared to patients on bed rest regardless of the size or location of the thrombi. The findings indicated that ambulatory patients with Unna boots or compression stockings do not have a significantly greater risk of PE compared to those on bed rest. Aschwanden et al. (2001) conducted a prospective, randomized, parallel group study in Switzerland with a convenience sample of 129 patients to compare the frequency of new PE in bed rest versus ambulatory patients with confirmed DVT. The patients were randomly assigned to one of the two groups; bed rest (n = 60) or ambulation (n = 69); randomization was stratified according to gender and extension of thrombosis. All patients received dalteparin sodium and baseline ventilation/perfusion (V/Q) scan within 24 hours of inclusion in the study. Patients in the bed rest group were allowed to leave the bed only after a second pulmonary scan was performed on Day 4. Patients in the ambulation group were encouraged to ambulate for more than 4 hours/day under a study nurse’s supervision. Adherence to the protocols was strict. At the end of the fourth day, 16 new cases of clinically asymptomatic PE were detected: 6 in the bed rest group and 10 in the ambulatory group. However, the intergroup difference in the frequency of new PE was not statistically significant, and regression analysis did not confirm any significant relationship between new PEs and patient-activity level. Ambulation did not cause a significant difference in the occurrences of new PEs. Trujillo-Santos et al. (2005) conducted a prospective, multicenter, nonblinded, nonrandomized observational study of patients
www.homehealthcarenurseonline.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
enrolled in the “The Computerized Registry of Patients with Venous Thromboembolism” (RIETE registry) to evaluate the differences in clinical outcomes during the first 15 days of VTE therapy among patients treated with strict bed rest versus those who were permitted to ambulate. A convenience sample, which included consecutive patients with symptomatic, objectively confirmed DVT or PE were included in the study after giving verbal consent. No pulmonary scan was conducted at the baseline. However, if the patient exhibited symptoms of a PE at hospital admission or with follow-up shorter than 30 days, they were excluded from the study. All patients received LMWH. Of the 2,038 patients with DVT, 1,050 (52%) were prescribed bed rest and 988 (48%) were permitted to ambulate. Seven of the 1050 (0.7%) patients in the bed rest group and 4 of the 988 (0.4%) patients in the ambulation group developed new PE, and the rates of PE between the two groups were not significantly different. Patients who ambulated had a 39% lower risk of developing new PE compared with those on bed rest, although this difference did not achieve statistical significance. Jünger et al. (2006) conducted a prospective, randomized trial in Germany that enrolled 102 consecutive patients diagnosed with DVT based on duplex sonography or phlebography and anticoagulated with LMWH (dalteparin). All patients received a baseline V/Q scan or a pulmonary spiral computed tomography (CT) scan. The patients were randomized into two parallel groups. The control group was prescribed strict bed rest for at least 5 days and was permitted to perform breathing exercises. The patients in the treatment group were instructed to move around the ward during the minimum 5-day hospital stay. All patients were given a lower leg and thigh compression dressing made of shortstretch bandages up to the groin. At day 10 to 12 of the study, a second pulmonary V/Q scan or spiral CT scan was performed in order to detect or rule out new PEs. The mobile group had a 1.9% rate of clinically relevant PE versus 10% in the immobile group; these rates were not significantly different. Manganaro et al. (2008) conducted a retrospective, single-center, nonblinded, nonrandomized study to evaluate the progression/ regression of DVT by comparing bed rest and
vol. 32 • no. 6 • June 2014
Patients who ambulated had a 39% lower risk of developing new pulmonary embolism compared with those on bed rest, although this difference did not achieve statistical significance.
mobilization in a sample of 252 consecutive patients with DVT confirmed by d-dimer and duplex ultrasonography. No pulmonary scan was conducted at baseline. All patients were anticoagulated with subcutaneous nadroparin. Researchers recommended oral anticoagulation therapy at a dose titrated to obtain an international normalized ratio of 2.0 to 3.0 as secondary prophylaxis for 152 patients (there is no mention of which oral anticoagulation agent was used or to which group the patients belonged). Although all patients were recommended to use compression stockings, only 34% (85 patients) followed this recommendation. The authors monitored the occurrence of PE at 30 days in all patients by echocardiography to detect evidence of right ventricular overload. V/Q scanning was conducted when clinically indicated. At the time of the 30-day follow-up visit, 172 (68%) patients had freely walked and were defined as mobile patients, whereas 80 (32%) patients had not walked and were defined as immobile patients. Of these immobile patients, 48 (19%) were permanently immobilized in bed because of a medical condition, and 32 (13%) had received the recommendation of bed rest by the attending physician to prevent PE and had been immobilized for an average of 7 days. Eleven out of 252 patients developed PE; 10 of them were immobile. Of note, 4 out of these 10 individuals were immobilized for 7 days or more. This predilection for the immobilized patients to develop PE compared to the mobile group was statistically significant. Romera-Villegas et al. (2008) conducted a prospective randomized trial between January 2005 and December 2007; 219 patients with acute lower limb DVT were enrolled in the study and the mean age was 64 years. Inclusion
Home Healthcare Nurse
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
339
Table 1. Summary of Studies Including Purpose, Methods, Variables, Quality Grading, and Effect Size Study
Purpose
Methodology
Variables
Effect Size
Partsch & Blättler (2000) (Level III–RCT)
To evaluate the benefits of compression and walking exercises in comparison with bed rest in the acute stage of proximal DVT
Prospective, randomized, nonblinded, controlled trial in which three groups of adjuvant treatment modalities are compared in patients with acute DVT, confirmed by ultrasound and anticoagulated with dalteparin sodium Number of subjects: Total n = 45 Group A (n = 15): Inelastic Unna boot bandages + walking exercises Group B (n = 15): Elastic compression stockings + walking exercises Group C (n = 15): Bed rest and no compression 64% male, 52.2 to 61.7 years of age Setting: Wilhelminen Hospital, Vienna, Austria
Unna boot with walking or compression stocking with walking versus bed rest with no compression in the acute stage of DVT Mobile patients were encouraged to ambulate as much as possible on the ward and on the hospital grounds Immobilized patients stayed in bed except to use the toilet Outcome: Incidence of new PE confirmed by V/Q scan
RR 1.5, 95% CI [0.17–13.225] Patients who walk have a 1.5 time greater risk of developing new PE than those on bed rest
Aschwanden et al. (2001) (Level III–RCT)
To compare frequency of objectively assessed new PE in hospitalized patients with proven proximal DVT being either strictly immobilized for 4 days or encouraged to ambulate under the supervision of a study nurse
Prospective, randomized, single center, openlabel, parallel group study in which patients with DVT confirmed by duplex sonography and anticoagulated with dalteparin sodium were hospitalized for > 4 days and randomized to an immobilized or an ambulating group Number of subjects: Total n = 129 Mobile, n = 69 Immobile, n = 60 56% male, 65 ± 17 years of age Setting: University of Basel University Hospitals– Basel, Switzerland
Mobilization versus bed rest Mobile patients (with compression therapy) were encouraged to ambulate for more than 4 hr/day and bed rest patients were kept strictly in bed for 4 days Outcome: Incidence of new PE confirmed by V/Q scan on Day 4
RR 1.449, 95% CI [0.56–3.752] Patients who walk have a 1.4 time greater risk of developing new PE than those on bed rest
Trujillo-Santos et al. (2005) (Level V–observational cohort study)
To evaluate the differences in clinical outcomes during the first 15 days of VTE therapy among patients treated with strict bed rest versus those who were allowed to ambulate
Prospective, nonrandomized multicenter, nonblinded, observational study of patients enrolled in the RIETE registry. Patients with symptomatic, objectively confirmed DVT or PE were included in the study after giving oral consent (convenience sample) Number of subjects: Total n = 2038 Ambulation, n = 988 Bed rest, n = 1050 52%–58% male, 59% > 65 years, 56%–60% > 70 kg; all received LMWH Setting: Inpatient setting of 88 Spanish hospitals enrolled in the RIETE registry No power analysis mentioned
Ambulation versus bed rest Bed rest defined as total bed rest or being sedentary for up to 3 days, with or without bathroom privileges; ambulation was not clearly defined; adherence not reported Outcome: PE during the first 15 days of therapy PE was objectively confirmed with lung scan, helical CT, or pulmonary angiography
RR 0.607, 95% CI [0.178–2.068] Patients who ambulate have 39% lower risk of developing new PE than those on bed rest
(continues)
criteria were 1 year, no life-threatening clinical conditions, and signed informed consent. The patients were randomized into two groups. In Group A, 105 patients (47.9%) were hospitalized and received 5 days of bed rest; in Group B, 114 patients (52.1%) received care at home with early walking and compression stockings. The primary end point was the presence of symptomatic PE during the first 10 days of treatment. The relationships between the duration of symptoms,
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location of the thrombus, and symptomatic PE were also analyzed. Five cases of symptomatic PE were detected (2.3%), two in Group A (hospitalized and bed rest) and three in Group B (home and early ambulation). There was no significant difference in the occurrence of new PE between the two groups. In aggregate, the findings of these six articles suggest that in patients with DVT, there is no greater risk for development of PE in those who ambulate compared to those on bed rest.
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Table 1. Summary of Studies Including Purpose, Methods, Variables, Quality Grading, and Effect Size, Continued Study
Purpose
Methodology
Variables
Effect Size
Manganaro et al. (2008) (Level V–observational retrospective study)
Retrospective analysis of DVT cases comparing bed rest and mobilization and using all variables potentially relevant to a risk and benefit evaluation
Retrospective, single-center, nonrandomized study, nonblinded Number of subjects: Total n = 252 Mobilization, n = 172 Bed rest, n = 80 (48 patients immobilized because of medical condition; 32 patients per physician prescription) Convenience sample, confirmed DVT by D-dimer levels and duplex ultrasonography was the only inclusion criteria; any patient with PE at admission or at any period
