Vascular malformations as underlying cause of chronic thromboembolism and pulmonary hypertension

We report four patients with chronic thromboembolic pulmonary hypertension (CTEPH) presumably due to recurrent pulmonary embolism from low-flow vascular malformations, and give a review of the literature. Venous malformations, such as those observed in Klippel- Trenaunay syndrome (KTS) can be associated with hypercoagulability, thrombosis and recurrent pulmonary embolism and ultimately CTEPH. Since many physicians appear unfamiliar with these potential complications, patients may experience a delayed diagnosis of this progressive and potentially life-threatening CTEPH.

Short-course antibiotic treatment in acute exacerbations of chronic bronchitis and COPD: a meta-analysis of double-blind studies

BACKGROUND

A study was undertaken to determine whether a short course of antibiotic treatment (< or = 5 days) is as effective as the conventional longer treatment in acute exacerbations of chronic bronchitis and chronic obstructive pulmonary disease (COPD).

METHODS

MEDLINE, EMBASE and the Cochrane central register of controlled trials were searched to July 2006. Studies considered eligible were double-blind randomised clinical trials including adult patients > or = 18 years of age with a clinical diagnosis of exacerbation of COPD or chronic bronchitis, no antimicrobial therapy at the time of diagnosis and random assignment to antibiotic treatment for < or = 5 days versus > 5 days. The primary outcome measure was clinical cure at early follow-up on an intention-to-treat basis.

RESULTS

21 studies with a total of 10 698 patients were included. The average quality of the studies was high: the mean (SD) Jadad score was 3.9 (0.9). At early follow-up (< 25 days), the summary odds ratio (OR) for clinical cure with short treatment versus conventional treatment was 0.99 (95% CI 0.90 to 1.08). At late follow-up the summary OR was 1.0 (95% CI 0.91 to 1.10) and the summary OR for bacteriological cure was 1.05 (95% CI 0.87 to 1.26). Similar summary ORs were observed for early cure in trials with the same antibiotic in both arms and in studies grouped by the antibiotic class used in the short-course arm.

CONCLUSIONS

A short course of antibiotic treatment is as effective as the traditional longer treatment in patients with mild to moderate exacerbations of chronic bronchitis and COPD.

Systemic and local high mobility group box 1 concentrations during severe infection

OBJECTIVE

High mobility group box 1 (HMGB1) has been implicated as a late mediator in sepsis. We here sought to determine the extent of HMGB1 release in patients with sepsis stratified to the three most common infectious sources and to determine HMGB1 concentrations at the site of infection during peritonitis or pneumonia.

DESIGN

Observational studies in patients and healthy humans challenged with lipopolysaccharide.

SETTING

Three intensive care units and one clinical research unit.

PATIENTS AND SUBJECTS

Three patient populations were studied: 1) 51 patients with sepsis due to pneumonia (n = 29), peritonitis (n = 12), or urinary tract infection (n = 10); 2) 17 patients with peritonitis; and 3) four patients with community-acquired pneumonia. In addition, eight healthy subjects were studied after intravenous injection of lipopolysaccharide (4 ng/kg).

INTERVENTIONS

One population of healthy volunteers received lipopolysaccharide intravenously.

MEASUREMENTS AND MAIN RESULTS

Patients with severe sepsis due to pneumonia displayed elevated circulating HMGB1 concentrations at both days 0 and 3 after inclusion. Patients with sepsis due to peritonitis had elevated HMGB1 levels at day 0 but not at day 3, whereas urinary tract infection was associated with a delayed HMGB1 response, with elevated levels only at day 3. HMGB1 concentrations did not differ between survivors and nonsurvivors and were not correlated to either disease severity or concurrently measured cytokine levels. In line with these observations, although intravenous lipopolysaccharide injection clearly elevated plasma cytokine levels, HMGB1 remained undetectable. In patients with peritonitis, HMGB1 concentrations in abdominal fluid were more than ten-fold higher than in concurrently obtained plasma. In pneumonia patients, HMGB1 levels were higher in bronchoalveolar lavage fluid obtained from the site of infection than in lavage fluid from healthy controls.

CONCLUSIONS

In severe sepsis, the kinetics of HMGB1 release may differ depending on the primary source of infection. In patients with severe infection, HMGB1 release may predominantly occur at the site of infection.

Lung epithelial injury markers are not influenced by use of lower tidal volumes during elective surgery in patients without preexisting lung injury

Clara cell protein levels are elevated in plasma of individuals with mild or subclinical lung injury. We studied the influence of two mechanical ventilation strategies on local and systemic levels of Clara cell protein (CC16) and compared them with levels of soluble receptor for advanced glycation end products (sRAGE) and surfactant proteins (SP)-A and -D in patients undergoing elective surgery. Saved samples from a previously reported investigation were used for the study. Forty patients planned for elective surgery were randomized to mechanical ventilation with either a conventional tidal volume (V(T)) of 12 ml/kg without positive end-expiratory pressure (PEEP) or low V(T) of 6 ml/kg and 10 cmH(2)O PEEP. Plasma and bronchoalveolar lavage fluid (BALF) was collected directly after intubation and after 5 h of mechanical ventilation. While systemic levels of SP-A and SP-D remained unchanged, systemic levels of CC16 and sRAGE increased significantly in both groups after 5 h (P < 0.001 for both). BALF levels of SP-A, SP-D, CC16, and sRAGE remained unaffected. No differences were found between the two mechanical ventilation strategies regarding any of the measured biological markers. In conclusion, systemic levels of CC16 and sRAGE rise after 5 h in patients receiving mechanical ventilation for elective surgery. Mechanical ventilation with lower tidal volumes and PEEP did not have a different effect on levels of biomarkers of lung epithelial injury compared with conventional mechanical ventilation.

Pulmonary arterial stent implantation in an adult with Williams syndrome

We report a 38-year-old patient who presented with pulmonary hypertension and right ventricular dysfunction due to pulmonary artery stenoses as a manifestation of Williams syndrome, mimicking chronic thromboembolic pulmonary hypertension. The patient was treated with balloon angioplasty and stent implantation. Short-term follow-up showed a good clinical result with excellent patency of the stents but early restenosis of the segments in which only balloon angioplasty was performed. These stenoses were subsequently also treated successfully by stent implantation. Stent patency was observed 3 years after the first procedure.

Interstitial lung disease as the first manifestation of systemic sclerosis

We describe three patients with progressive fibrosing interstitial lung disease (ILD) as the first and only manifestation of systemic sclerosis. In one patient the presence of anti-Scl-70 autoantibodies suggested systemic sclerosis to be the underlying cause of the disease. In the two other subjects, however, anti-Scl-70 antibodies were negative. In these patients the lung disease preceded other manifestations of systemic sclerosis by several years. Diagnosis, prognosis and treatment of systemic sclerosisassociated ILD is discussed.

Brain natriuretic peptide as noninvasive marker of the severity of right ventricular dysfunction in chronic thromboembolic pulmonary hypertension

BACKGROUND

Right ventricular (RV) dysfunction is associated with increased morbidity and mortality in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who undergo pulmonary endarterectomy (PEA). We studied whether plasma brain natriuretic peptide (BNP) levels can be used to identify RV dysfunction in CTEPH patients. Therefore, plasma BNP levels were studied in relation to cardiac remodeling and function as determined by cardiac magnetic resonance imaging (MRI).

METHODS

Thirty-eight patients with CTEPH (55 +/- 15 years), and ten healthy controls (46 +/- 15 years) were studied. The BNP was determined by an immunoradiometric assay.

RESULTS

The CTEPH patients had a mean pulmonary artery pressure of 49 +/- 13 mm Hg, cardiac index 2.1 +/- 0.7 l x min(-1) x m(-2), and pulmonary vascular resistance of 867 +/- 432 dynes x s x cm(-5). In CTEPH patients, compared with controls, right ventricular (RV) remodeling was demonstrated. In the patients, BNP was increased and correlated (all p < 0.0001; Spearman rank test) with MRI parameters of RV remodeling and function: end diastolic (r = 0.71) and end systolic (r = 0.74) volumes, RV mass (r = 0.68), leftward ventricular septal bowing (r = -0.80) and ejection fraction (EF; r = -0.81). By receiver operating curve analysis, BNP levels of 11.5 picomole (pmol)/L and 48.5 pmol/L, respectively, detected RV dysfunction as defined by RVEF less than 0.45 and less than 0.30, respectively, with high sensitivity and specificity. Hemodynamically, BNP levels greater than 48.5 pmol/L identified the most severely affected patients.

CONCLUSIONS

In CTEPH patients, BNP levels correlate with RV remodeling and can be used to identify RV dysfunction. Future studies are warranted on the role of BNP to identify "high risk" CTEPH patients and its relation to postoperative hemodynamic outcome, RV failure, and mortality.

Pulmonary arterial hypertension in congenital heart disease: An epidemiologic perspective from a Dutch registry

BACKGROUND

Pulmonary arterial hypertension (PAH) associated with congenital heart disease is usually the result of a large systemic-to-pulmonary shunt, and often leads to right ventricular failure and early death. The purpose of this study was to determine the prevalence of PAH among adult patients included in a national registry of congenital heart disease and to assess the relation between patient characteristics and PAH.

METHODS

Patients with PAH associated with a septal defect were identified from the registry. Gender, age, underlying diagnosis, previous closure, age at repair and NYHA classification were recorded. PAH was defined as a systolic pulmonary arterial pressure (sPAP) greater than 40 mm Hg, estimated by means of echocardiographical evaluation.

RESULTS

The prevalence of PAH among all 5970 registered adult patients with congenital heart disease was 4.2%. Of 1824 patients with a septal defect in the registry, 112 patients (6.1%) had PAH. Median age of these patients was 38 years (range 18-81 years) and 40% were male. Of these patients, 58% had the Eisenmenger syndrome. Among the patients with a previously closed septal defect, 30 had PAH (3%). Ventricular septal defect (VSD) was the most frequent underlying defect (42%) among patients with PAH and a septal defect. Female sex (Odds ratio=1.5, p=0.001) and sPAP (Odds ratio=0.04, p<0.001) were independently associated with a decreased functional class.

CONCLUSION

PAH is common in adult patients with congenital heart disease. In our registry the prevalence of PAH in septal defects is around 6%. More than half of these patients have the Eisenmenger syndrome, which accounts for 1% of the total population in the CONCOR registry. Whether the prevalence of PAH will decrease in the future as a result of early detection and intervention remains to be awaited.

Recombinant human activated protein C inhibits local and systemic activation of coagulation without influencing inflammation during Pseudomonas aeruginosa pneumonia in rats

OBJECTIVE

Alveolar fibrin deposition is a hallmark of pneumonia. It has been proposed that recombinant human activated protein C exerts lung-protective effects via anticoagulant and anti-inflammatory pathways. We investigated the role of the protein C system in pneumonia caused by Pseudomonas aeruginosa, the organism that is predominantly involved in ventilator-associated pneumonia.

DESIGN

An observational clinical study and a controlled, in vivo laboratory study.

SETTING

Multidisciplinary intensive care unit and a research laboratory of a university hospital.

PATIENTS AND SUBJECTS

Patients with unilateral ventilator-associated pneumonia and male Sprague-Dawley rats.

INTERVENTIONS

Bilateral bronchoalveolar lavage was performed in five patients with unilateral ventilator-associated pneumonia. A total of 62 rats were challenged with intratracheal P. aeruginosa (10 colony-forming units), inducing pneumonia. Rats were randomized to treatment with normal saline, recombinant human activated protein C, heparin, or recombinant tissue plasminogen activator.

MEASUREMENTS AND MAIN RESULTS

Patients with pneumonia demonstrated suppressed levels of protein C and activated protein C in bronchoalveolar lavage fluid obtained from the infected site compared with the contralateral uninfected site. Intravenous administration of recombinant human activated protein C in rats with P. aeruginosa pneumonia limited bronchoalveolar generation of thrombin-antithrombin complexes, largely preserving local antithrombin activity. However, recombinant human activated protein C did not have effects on neutrophil influx and activity, expression of pulmonary cytokines, or bacterial clearance.

CONCLUSIONS

In patients with ventilator-associated pneumonia, the pulmonary protein C pathway is impaired at the site of infection, and local anticoagulant activity may be insufficient. Recombinant human activated protein C prevents procoagulant changes in the lung; however, it does not seem to alter the pulmonary host defense against P. aeruginosa pneumonia.

Three vs. 10 days of amoxycillin-clavulanic acid for type 1 acute exacerbations of chronic obstructive pulmonary disease: a randomised, double-blind study

The optimal duration of antibiotic treatment for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is unknown. This study compared the outcome of treatment for 3 vs. 10 days with amoxycillin-clavulanic acid of hospitalised patients with AECOPD who had improved substantially after initial therapy for 3 days. Between November 2000 and December 2003, 56 patients with AECOPD were enrolled in the study. Unfortunately, because of the low inclusion rate, the trial was discontinued prematurely. Patients were treated with oral or intravenous amoxycillin-clavulanic acid. Patients who showed improvement after 72 h were randomised to receive oral amoxycillin-clavulanic acid 625 mg or placebo, four times daily for 7 days. The primary outcome measure of the study was clinical cure after 3 weeks and 3 months. Of 46 patients included in the final analysis, 21 were in the 3-day treatment group and 25 were in the 10-day treatment group. After 3 weeks, 16 (76%) of 21 patients in the 3-day treatment group were cured, compared with 20 (80%) of 25 in the 10-day treatment group (difference -3.8%; 95% CI -28 to 20). After 3 months, 13 (62%) of 21 patients were cured, compared with 14 (56%) of 25 (difference 5.9%; 95% CI -23 to 34). Microbiological success, symptom recovery, the use of corticosteroids, the duration of oxygen therapy and the length of hospital stay were comparable for both treatment groups. It was concluded that 3-day treatment with amoxycillin-clavulanic acid can be a safe and effective alternative to the standard 10-day treatment for hospitalised patients with AECOPD who have improved after initial therapy for 3 days.

A novel echocardiographic predictor of in-hospital mortality and mid-term haemodynamic improvement after pulmonary endarterectomy for chronic thrombo-embolic pulmonary hypertension

AIMS

To study whether pre-operative assessment, using echocardiography, of the timing of a particular feature in the pulmonary flow (pulmonary flow systolic notch) may predict in-hospital mortality and mid-term haemodynamic improvement after pulmonary endarterectomy (PEA) for chronic thrombo-embolic pulmonary hypertension (CTEPH).

METHODS AND RESULTS

Fifty-eight of 61 consecutive CTEPH patients (aged 53 +/- 14 years; 36 women) who underwent PEA between June 2002 and June 2005 were studied. Clinical, haemodynamic, and echocardiographic variables were assessed pre-operatively and at 3 months post-PEA. Timing of the notch was expressed as notch ratio (NR). Pre-operatively, seven patients had no notch, 33 had NR < 1.0, and 18 had NR > 1.0. NR was associated with in-hospital mortality (P < 0.01). Moreover, multivariable analysis revealed that among pre-operative variables, NR was an independent predictor of residual-increased pulmonary artery systolic pressure (>40 mmHg) at 3 months post-PEA (P = 0.01). Receiver operator characteristic analysis established NR = 1.0 as optimal cutoff to distinguish patients at risk of such unfavourable outcomes, with NR > 1.0 conferring higher risk.

CONCLUSION

NR is related with in-hospital mortality and residual pulmonary hypertension after PEA. NR > 1.0 is associated with a higher risk of such unfavourable outcomes. NR may be considered a determinant of eligibility for PEA.

Embolization for hemoptysis in chronic thromboembolic pulmonary hypertension: report of two cases and a review of the literature

Hemoptysis is a known complication in patients with bronchial artery hypertrophy due to a variety of chronic pulmonary disorders. Bronchial artery hypertrophy is observed in most patients with chronic thromboembolic pulmonary hypertension (CTEPH), but surprisingly little is known about the incidence of hemoptysis in these patients. In this paper, we report on 2 patients with CTEPH and recurrent severe hemoptysis, who were treated by bronchial artery embolization. One patient recovered and 1 patient died as a consequence of the bleeding. A systematic review revealed 21 studies on the underlying pathology in 1,844 patients with moderate to severe hemoptysis. CTEPH was reported to be the cause of bleeding in 0.1% (n = 2), pulmonary arterial hypertension without chronic thromboembolic disease in 0.2% (n = 4), and acute pulmonary embolism in 0.7% (n = 12) of the patients. In contrast to this, 5 patients (6%) in our own series of 79 CTEPH patients suffered from moderate to severe hemoptysis requiring medical intervention. Severe hemoptysis appears to be an uncommon, but possibly underreported, life-threatening complication in CTEPH patients. As most CTEPH patients require life-long anticoagulants a therapeutic dilemma may ensue. Therefore, we propose that even mild hemoptysis in CTEPH patients warrants prompt evaluation, and treatment by embolization should be offered as first choice in CTEPH patients.

Six-minute walk distance as parameter of functional outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

OBJECTIVES

In chronic thromboembolic pulmonary hypertension, objective data to assess the functional outcome after pulmonary endarterectomy are lacking. We studied the 6-minute walk distance in relation to the clinical and hemodynamic severity of disease, and assessed the effect of pulmonary endarterectomy on the 6-minute walk distance.

METHODS

A total of 50 consecutive patients with chronic thromboembolic pulmonary hypertension were studied. Subsequently, pulmonary endarterectomy was performed in 42 patients, 35 of whom underwent a 6-minute walk distance 1 year after surgery.

RESULTS

The mean +/- standard error of the mean 6-minute walk distance was 391 +/- 19 m. The 6-minute walk distance decreased in proportion to New York Heart Association functional class and correlated (all P < .0001) with mean pulmonary artery pressure (r = -0.62), cardiac output (r = 0.76), total pulmonary resistance (r = -0.75), mixed venous oxygen saturation (r = 0.77), and brain natriuretic peptide (r = -0.65). One year after pulmonary endarterectomy, the 6-minute walk distance increased from 417 +/- 19 m to 517 +/- 16 m (P < .0001). The change from baseline in 6-minute walk distance correlated with the changes after 1 year in New York Heart Association functional class (P < .01) and brain natriuretic peptide (r = 0.57, P < .002), and with the observed hemodynamic changes directly after pulmonary endarterectomy (change in mean pulmonary artery pressure: r = 0.52; change in cardiac output: r = 0.70; change in total pulmonary resistance r = 0.70; all P < .001). In patients with residual pulmonary hypertension after pulmonary endarterectomy, the 6-minute walk distance was significantly lower than in hemodynamically normalized patients. However, the absolute increase in the 6-minute walk distance was higher in patients with residual pulmonary hypertension (137 +/- 26 m and 82 +/- 20 m, respectively; P = .03).

CONCLUSIONS

The 6-minute walk distance was demonstrated to reflect the clinical and hemodynamic severity of disease in patients with chronic thromboembolic pulmonary hypertension. One year after pulmonary endarterectomy, the 6-minute walk distance had increased significantly, and the change in the 6-minute walk distance correlated with the observed clinical and hemodynamic improvement.

Salmeterol enhances pulmonary fibrinolysis in healthy volunteers

OBJECTIVE

Various lung diseases are associated with local activation of coagulation and concurrent inhibition of fibrinolysis. Although salmeterol, a beta2-adrenoceptor agonist with profound bronchodilatory properties, has been studied extensively, the effects of this compound on the pulmonary hemostatic balance are not elucidated.

DESIGN

A single-blinded, placebo-controlled study.

SETTING

University hospital and laboratory.

SUBJECTS

A total of 32 human volunteers.

INTERVENTIONS

Subjects inhaled 100 microg of salmeterol or placebo (t = -30 mins) followed by 100 microg of lipopolysaccharide (LPS) or normal saline (t = 0 mins; n = 8 per group).

MEASUREMENTS AND MAIN RESULTS

Measurements were performed in bronchoalveolar lavage fluid obtained 6 hrs postchallenge. Inhalation of LPS enhanced pulmonary coagulation as determined by an increase in the concentrations of thrombin-antithrombin complexes, factor VIIa, and soluble tissue factor in bronchoalveolar lavage fluid (all p < .05 vs. saline). LPS concurrently inhibited pulmonary fibrinolysis, as reflected by a decrease in bronchoalveolar lavage fluid plasminogen activator activity together with an increase in plasminogen activator inhibitor type 1 (both p < .05 vs. saline). Moreover, LPS inhalation was associated with a suppression of the anticoagulant protein C pathway, as indicated by an increase in soluble thrombomodulin and decreases in protein C and activated protein C levels in bronchoalveolar lavage fluid (all p < .05 vs. saline). Salmeterol, either with or without LPS inhalation, enhanced fibrinolysis (plasminogen activator activity and tissue-type and urokinase-type plasminogen activator levels) but did not influence LPS-induced changes in coagulation or the protein C pathway.

CONCLUSIONS

Salmeterol has profibrinolytic properties in the normal lung and when applied in a model of sterile pulmonary inflammation.

Toll-like receptor mRNA levels in alveolar macrophages after inhalation of endotoxin

Toll-like receptors (TLRs) are pattern-recognition receptors that have been implicated in the initiation of innate immune responses upon the first encounter with invading pathogens. The airways are frequently exposed to various types of lipopolysaccharide (LPS) from the environment or from pathogens. The current study was designed to determine the effect of LPS on TLR gene expression in human alveolar macrophages in vivo. In total, 16 healthy subjects were enrolled in a single-blinded, placebo-controlled study. Subjects inhaled 100 microg LPS or normal saline (n = 8 per group). Measurements were performed in alveolar macrophages purified from bronchoalveolar lavage fluid obtained 6 h post-challenge. Inhalation of LPS by healthy human volunteers resulted in enhanced alveolar macrophage expression of mRNAs encoding TLRs 1, 2, 7, 8 and CD14, and reduced expression of mRNAs encoding TLR4 and lymphocyte antigen 96. In conclusion, lipopolysaccharide differentially influences the toll-like receptor mRNA expression profile in human alveolar macrophages in vivo.

Reverse right ventricular remodeling after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: Utility of magnetic resonance imaging to demonstrate restoration of the right ventricle

OBJECTIVES

Pulmonary arterial hypertension causes right ventricular remodeling; that is, right ventricular dilatation, hypertrophy, and leftward ventricular septal bowing. We studied the effect of pulmonary endarterectomy on the restoration of right ventricular remodeling in patients with chronic thromboembolic pulmonary hypertension by magnetic resonance imaging.

METHODS

In 17 patients with chronic thromboembolic pulmonary hypertension, before and at least 4 months after pulmonary endarterectomy, and in 12 healthy controls, right ventricular and left ventricular end-diastolic and end-systolic volumes (milliliters) and mass (grams per meter squared) and leftward ventricular septal bowing (1 divided by the radius of curvature in centimeters) were determined by magnetic resonance imaging.

RESULTS

Before pulmonary endarterectomy, right ventricular volumes, left ventricular end-diastolic volume, right ventricular mass, and leftward ventricular septal bowing differed significantly between patients with chronic thromboembolic pulmonary hypertension and healthy control subjects. After pulmonary endarterectomy, pulmonary hemodynamics improved, and right and left ventricular volumes and leftward ventricular septal bowing normalized; right ventricular mass decreased significantly (46 +/- 14 to 31 +/- 9 g x m(-2), P< .0005), but did not completely normalize. The change in total pulmonary resistance correlated with the change in right ventricular ejection fraction (r = 0.50, P < .05), right ventricular mass (r = 0.63, P < .01), and leftward ventricular septal bowing (r = 0.50, P < .05).

CONCLUSIONS

Right ventricular remodeling was observed in patients with chronic thromboembolic pulmonary hypertension and restored almost completely after a hemodynamically successful pulmonary endarterectomy. Magnetic resonance imaging is a valuable tool to evaluate cardiac remodeling and function in patients with chronic thromboembolic pulmonary hypertension, both before and after pulmonary endarterectomy.

Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents alveolar coagulation in patients without lung injury

BACKGROUND

Alveolar fibrin deposition is a hallmark of acute lung injury, resulting from activation of coagulation and inhibition of fibrinolysis. Previous studies have shown that mechanical ventilation with high tidal volumes may aggravate lung injury in patients with sepsis and acute lung injury. The authors sought to determine the effects of mechanical ventilation on the alveolar hemostatic balance in patients without preexistent lung injury.

METHODS

Patients scheduled for an elective surgical procedure (lasting > or = 5 h) were randomly assigned to mechanical ventilation with either higher tidal volumes of 12 ml/kg ideal body weight and no positive end-expiratory pressure (PEEP) or lower tidal volumes of 6 ml/kg and 10 cm H2O PEEP. After induction of anesthesia and 5 h later bronchoalveolar lavage fluid and blood samples were obtained, and markers of coagulation and fibrinolysis were measured.

RESULTS

In contrast to mechanical ventilation with lower tidal volumes and PEEP (n = 21), the use of higher tidal volumes without PEEP (n = 19) caused activation of bronchoalveolar coagulation, as reflected by a marked increase in thrombin-antithrombin complexes, soluble tissue factor, and factor VIIa after 5 h of mechanical ventilation. Mechanical ventilation with higher tidal volumes without PEEP caused an increase in soluble thrombomodulin in lavage fluids and lower levels of bronchoalveolar activated protein C in comparison with lower tidal volumes and PEEP. Bronchoalveolar fibrinolytic activity did not change by either ventilation strategy.

CONCLUSIONS

Mechanical ventilation with higher tidal volumes and no PEEP promotes procoagulant changes, which are largely prevented by the use of lower tidal volumes and PEEP.

Idiopathic pulmonary arterial hypertension in Dutch Caucasian patients is not associated with human herpes virus-8 infection

Samples of lung tissue, taken at time of lung transplant, from 13 Dutch Caucasian patients with idiopathic pulmonary arterial hypertension (iPAH) and 14 patients with non-idiopathic PAH were studied for the presence of human herpes virus-8 (HHV-8). By immunohistochemical staining, in none of patients expression of HHV-8 latency-associated nuclear antigen 1 (LANA-1) was demonstrated. Using two nested polymerase chain reactions (PCR) to amplify part of the open reading frame (ORF) 65 and ORF 73, we failed to detect HHV-8 DNA in all samples studied. These results argue strongly against a role for HHV-8 in the pathogenesis of iPAH.

Early procoagulant shift in the bronchoalveolar compartment of patients with secondary peritonitis

BACKGROUND

In acute respiratory distress syndrome or pneumonia, a procoagulant shift is observed in bronchoalveolar lavage fluid (BALF). The effect of a primarily extrapulmonary infection on coagulation and fibrinolysis in the pulmonary compartment is unclear.

METHODS

In 35 patients, 87 bronchoalveolar lavages were performed on the day of operation for secondary peritonitis (day 0) and on days 2 and 3 after surgery. Two noninfectious control groups were included: subjects undergoing bronchoalveolar lavage after elective surgery (n=8) and those undergoing long-term mechanical ventilation (n=10).

RESULTS

In BALF from patients with peritonitis, a tissue factor (TF)/factor VIIa-mediated activation of coagulation was shown (high levels of thrombin-antithrombin complexes). Levels of fibrinolysis activators decreased rapidly after day 0, whereas levels of inhibitors increased. The net effect was reduced fibrinolysis (plasminogen activator activity). The sequential comparison of plasma levels of TF pathway inhibitor showed higher levels in patients who died (28-day mortality; P<.001). Sequential levels of TF in BALF were higher in patients with low PaO2 : FiO2 ratios (<200; P=.039). Differences between patients and control subjects were more pronounced in BALF than in plasma.

CONCLUSIONS

Secondary peritonitis induces an early activation of the coagulation and inhibition of fibrinolysis in the systemic and bronchoalveolar compartments, possibly via a compartmentalized response. This imbalance may be associated with reduced oxygen delivery and an adverse outcome in secondary peritonitis.

Medical Therapies for Chronic Thromboembolic Pulmonary Hypertension: An Evolving Treatment Paradigm

Pulmonary endarterectomy (PEA) is recommended as the treatment of choice for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, only a proportion of patients fulfill the criteria for surgical intervention. In addition, operated patients with CTEPH may experience a gradual hemodynamic and symptomatic decline related to a secondary hypertensive arteriopathy in the small precapillary pulmonary vessels. It has also been questioned what can be done to reduce risks from PEA surgery to improve outcome in "high risk" patients with CTEPH with substantial impairment of pulmonary hemodynamics before surgery. Such patients may benefit from preoperative reduction of pulmonary vascular resistance by means of medical therapy. Conventional medical treatments, such as anticoagulation, diuretics, digitalis, and chronic oxygen therapy, show low efficacy in the treatment of CTEPH as they do not affect underlying disease processes. Over the last decade, several novel therapies have been developed for pulmonary arterial hypertension (PAH), including prostacyclin analogs (epoprostenol, beraprost, iloprost), endothelin receptor antagonists (bosentan, sitaxsentan, ambrisentan), and phosphodiesterase-5 inhibitors (sildenafil). Evidence of efficacy in PAH, coupled with studies showing histopathologic similarities between CTEPH and PAH, provides a rationale to extend the use of some of these medications to the treatment of CTEPH. However, direct evidence from clinical trials in CTEPH is limited to date. This article reviews evidence supporting, and issues surrounding, the possible use of novel PAH medications in CTEPH.

Antibiotics and steroids for exacerbations of COPD in primary care: compliance with Dutch guidelines

BACKGROUND

The Dutch College of General Practitioners' guidelines specify that antibiotics should only be used for severe cases of chronic obstructive pulmonary disease (COPD). However, GPs tend to administer antibiotics rather than a short course of steroid treatment regardless of severity.

AIM

The aim of this study was to determine how GPs use current guidelines in treating exacerbations of COPD, in particular whether short courses of oral steroids and antibiotics are prescribed in accordance with the Dutch guidelines for COPD.

DESIGN OF STUDY

Retrospective analysis of medical records.

SETTING

Primary healthcare centres.

METHOD

Medical records of patients registered at four primary healthcare centres in the Netherlands were retrospectively analysed for the period March 2001-March 2003.

RESULTS

Of 35,589 patients, 1.3% were registered as having a diagnosis of COPD. In 2 years, 47% of the patients had no exacerbation, 35% had one or two exacerbations, and 18% had three or more exacerbations. Of 536 exacerbations, GPs prescribed a short course of oral steroids in 30% of cases, antibiotics in 29%, steroids combined with an antibiotic in 23%, and no oral steroid course or antibiotic was prescribed in 18%. Prescriptions for patients with three or more exacerbations differed significantly from those for patients with one or two exacerbations.

CONCLUSIONS

Treatment is often not in accordance with current guidelines; in particular, antibiotics are prescribed more often than recommended.

Local activation of the tissue factor-factor VIIa pathway in patients with pneumonia and the effect of inhibition of this pathway in murine pneumococcal pneumonia

OBJECTIVE

The tissue factor (TF)-factor VIIa (FVIIa) complex not only is essential for activation of blood coagulation but also affect the inflammatory response during sepsis. The objective of this study was to determine the role of TF-FVIIa in pneumonia caused by Streptococcus pneumoniae, the most important causative organism in community-acquired pneumonia and a major cause of sepsis.

DESIGN

A controlled, in vivo laboratory study.

SETTING

Research laboratory of a health sciences university.

PATIENTS AND SUBJECTS

Patients with unilateral community-acquired pneumonia and female BALB/c mice.

INTERVENTIONS

Bilateral bronchoalveolar lavage was performed in patients with community-acquired pneumonia. In mice, pneumonia was induced by intranasal inoculation with S. pneumoniae with or without concurrent inhibition of TF-FVIIa by subcutaneous injections of recombinant nematode anticoagulant protein (rNAPc2).

MEASUREMENTS AND MAIN RESULTS

Patients with unilateral community-acquired pneumonia demonstrated elevated concentrations of FVIIa, soluble TF, and thrombin-antithrombin complexes in bronchoalveolar lavage fluid obtained from the infected site compared with the uninfected site. Mice with S. pneumoniae pneumonia displayed increased TF expression and fibrin deposits in lungs together with elevated thrombin-antithrombin complex levels in bronchoalveolar lavage fluid; inhibition of TF-FVIIa by rNAPc2 attenuated the procoagulant response in the lung but did not affect host defense, as reflected by an unaltered outgrowth of pneumococci and an unchanged survival.

CONCLUSIONS

These data suggest that TF-FVIIa activity contributes to activation of coagulation in the lung during pneumococcal pneumonia but does not play an important role in the antibacterial host defense in this murine model.

Effectiveness of discontinuing antibiotic treatment after three days versus eight days in mild to moderate-severe community acquired pneumonia: randomised, double blind study

OBJECTIVE

To compare the effectiveness of discontinuing treatment with amoxicillin after three days or eight days in adults admitted to hospital with mild to moderate-severe community acquired pneumonia who substantially improved after an initial three days' treatment.

DESIGN

Randomised, double blind, placebo controlled non-inferiority trial.

SETTING

Nine secondary and tertiary care hospitals in the Netherlands.

PARTICIPANTS

Adults with mild to moderate-severe community acquired pneumonia (pneumonia severity index score < or = 110).

INTERVENTIONS

Patients who had substantially improved after three days' treatment with intravenous amoxicillin were randomly assigned to oral amoxicillin (n = 63) or placebo (n = 56) three times daily for five days.

MAIN OUTCOME MEASURES

The primary outcome measure was the clinical success rate at day 10. Secondary outcome measures were the clinical success rate at day 28, symptom resolution, radiological success rates at days 10 and 28, and adverse events.

RESULTS

Baseline characteristics were comparable, with the exception of symptom severity, which was worse in the three day treatment group. In the three day and eight day treatment groups the clinical success rate at day 10 was 93% for both (difference 0.1%, 95% confidence interval--9% to 10%) and at day 28 was 90% compared with 88% (difference 2.0%,--9% to 15%). Both groups had similar resolution of symptoms. Radiological success rates were 86% compared with 83% at day 10 (difference 3%,--10% to 16%) and 86% compared with 79% at day 28 (difference 6%,--7% to 20%). Six patients (11%) in the placebo group and 13 patients (21%) in the active treatment group reported adverse events (P = 0.1).

CONCLUSIONS

Discontinuing amoxicillin treatment after three days is not inferior to discontinuing it after eight days in adults admitted to hospital with mild to moderate-severe community acquired pneumonia who substantially improved after an initial three days' treatment.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rapidly progressive and deadly disease, resulting from incomplete resolution of acute pulmonary embolism. Historically, the incidence of CTEPH was significantly underestimated but it may be as high as 3.8% following acute pulmonary embolism. Although the medical management of CTEPH may be supportive, the only curative treatment is pulmonary endarterectomy (PEA). However, a careful screening programme is mandatory to select CTEPH patients who are likely to benefit from PEA. In this review we discuss the pathophysiology, clinical and diagnostic pitfalls, surgical treatment, outcome after surgery, and the potential benefit of medical treatment in inoperable CTEPH patients.