Evaluation of unfractionated heparin versus low-molecular-weight heparin and fondaparinux for pharmacologic venous thromboembolic prophylaxis in critically ill patients with cancer.

Essentials Critically ill cancer patients require pharmacologic prophylaxis for venous thromboembolism (VTE). Patients from 566 hospitals in the United States between 2010 and 2014 were included. Low-molecular-weight heparin (LMWH) prophylaxis was not associated in a reduction of VTE rates. LMWH prophylaxis was associated with a reduction in bleeding and heparin induced thrombocytopenia. SUMMARY: Background Critically ill patients with cancer are at increased risk of venous thromboembolism (VTE) from physical and cellular factors, requiring pharmacologic prophylaxis to reduce the risk of VTE. Objectives To assess whether low-molecular-weight heparin (LMWH) prophylaxis reduces in-hospital rates of VTE or improves clinical outcomes compared with unfractionated heparin (UFH) prophylaxis in critically ill patients with cancer. Methods We used a propensity-matched comparative-effectiveness cohort from the Premier Database. Patients aged 18 years or older with a primary diagnosis of cancer, intensive care unit admission and VTE prophylaxis within 2 days of admission between 1 January 2010 and 31 December 2014 were included. Patients were divided into LMWH or UFH prophylaxis groups. Results A total of 103 798 patients were included; 75 321 (72.6%) patients received LMWH and 28 477 (27.4%) patients received UFH. Propensity analysis matched (2 : 1) 42 343 LMWH patients and 21 218 UFH patients. Overall, LMWH was not associated with a decreased incidence of VTE (5.32% vs. 5.50%). LMWH prophylaxis was associated with a reduction in pulmonary embolism (0.70% vs. 0.99%), significant bleeding (13.3% vs. 14.8%) and heparin-induced thrombocytopenia (HIT) (0.06% vs. 0.19%). In non-metastatic solid disease, LMWH was associated with decreased VTE (4.27% vs. 4.84%) and PE (0.47% vs. 0.95%). Conclusions The use of an LMWH for VTE prophylaxis was not associated with a reduction in the incidence of in-hospital VTE as compared with UFH, but was associated with significant reductions in PE, clinically important bleeding events, and incidence of HIT in critically ill patients with cancer.

Proactive integrated care improves quality of life in patients with COPD.

Self-management strategies improve a variety of health-related outcomes for patients with chronic obstructive pulmonary disease (COPD). These strategies, however, are primarily designed to improve chronic disease management and have not focused on early detection and early treatment of exacerbations. In COPD, the majority of exacerbations go unreported and treatment is frequently delayed, resulting in worsened outcomes. Therefore, a randomised clinical trial was designed to determine whether integration of self-management education with proactive remote disease monitoring would improve health-related outcomes. A total of 40 Global Initiative for Chronic Obstructive Lung Disease stage 3 or 4 COPD patients were randomised to receive proactive integrated care (PIC) or usual care (UC) over a 3-month period. The primary and secondary outcomes were change in quality of life, measured by the St George's Respiratory Questionnaire (SGRQ), and change in healthcare costs. PIC dramatically improved SGRQ by 10.3 units, compared to 0.6 units in the UC group. Healthcare costs declined in the PIC group by US$1,401, compared with an increase of US$1,709 in the UC group, but this was not statistically significant. PIC uncovered nine exacerbations, seven of which were unreported. Therefore, proactive integrated care has the potential to improve outcomes in chronic obstructive pulmonary disease patients through effects of self-management, as well as early detection and treatment of exacerbations.

Use of exogenous erythropoietin in critically ill patients.

OBJECTIVE: Review the literature regarding the use of recombinant human erythropoietin (rHuEPO) to prevent red blood cell (RBC) transfusion in critically ill patients. DATA SOURCES: A computerized search of MEDLINE and EMBASE from 1966 through June 2003 was conducted using the terms erythropoietin, anemia, hemoglobin, critical care, intensive care, surgery, trauma, burn, and transfusion. References of selected articles were reviewed. A manual search of critical care, surgery, trauma, burn, hematology, and pharmacy journals was conducted to identify relevant abstracts. RESULTS: Six randomized studies have evaluated exogenous administration of erythropoietin to prevent RBC transfusions in critically ill patients. Studies vary with respect to rHuEPO dosage regimens, dose of concurrently administered iron, patient characteristics, and transfusion thresholds. Administration of rHuEPO rapidly produces erythropoiesis to reduce the need for RBC transfusions. The largest study conducted to date used weekly rHuEPO administration and found a modest decrease in transfusion requirements although the time to first transfusion was delayed. Reduced intensive care unit (ICU) length of stay (LOS) was shown in only one study of surgical/trauma patients. Reduced LOS after ICU discharge was found in another study of severely ill patients (APACHE II score >22). Other clinical outcomes were not altered by rHuEPO use. No adverse events were associated with rHuEPO use although studies were not designed to evaluate safety. CONCLUSIONS: rHuEPO reduces the need for transfusions. A cost-effectiveness analysis of rHuEPO for this indication is needed. Defining an optimal dosage regimen, identifying patients most likely to respond to rHuEPO, and determining risk factors for ICU associated anaemia would provide information for appropriate rHuEPO utilization.

Effect of endotoxin on ventilation and breath variability: role of cyclooxygenase pathway.

To evaluate the effects of endotoxemia on respiratory controller function, 12 subjects were randomized to receive endotoxin or saline; six also received ibuprofen, a cyclooxygenase inhibitor, and six received placebo. Administration of endotoxin produced fever, increased respiratory frequency, decreased inspiratory time, and widened alveolar-arterial oxygen tension gradient (all p < or = 0.001); these responses were blocked by ibuprofen. Independent of ibuprofen, endotoxin produced dyspnea, and it increased fractional inspiratory time, minute ventilation, and mean inspiratory flow (all p < or = 0.025). Endotoxin altered the autocorrelative behavior of respiratory frequency by increasing its autocorrelation coefficient at a lag of one breath, the number of breath lags with significant serial correlations, and its correlated fraction (all p < 0.05); these responses were blocked by ibuprofen. Changes in correlated behavior of respiratory frequency were related to changes in arterial carbon dioxide tension (r = 0.86; p < 0.03). Endotoxin decreased the oscillatory fraction of inspiratory time in both the placebo (p < 0.05) and ibuprofen groups (p = 0.06). In conclusion, endotoxin produced increases in respiratory motor output and dyspnea independent of fever and symptoms, and it curtailed the freedom to vary respiratory timing-a response that appears to be mediated by the cyclooxygenase pathway.

Down-regulation of nitric oxide production by ibuprofen in human volunteers.

Ibuprofen has been shown in vitro to modulate production of nitric oxide (NO), a mediator of sepsis-induced hypotension. We sought to determine whether ibuprofen alters NO production and, thereby, vascular tone, in normal and endotoxin-challenged volunteers. Techniques for detecting NO were validated in 17 subjects infused with sodium nitroprusside, a NO donor. Then, endotoxin (4 ng/kg) or saline (vehicle alone) was administered in a single-blinded, crossover design to 12 other subjects randomized to receive either ibuprofen (2400 mg p.o.) or a placebo. Endotoxin decreased mean arterial pressure (MAP; P =.002) and increased alveolar NO flow rates (P =.04) and urinary excretion of nitrite and nitrate (P =.07). In both endotoxemic and normal subjects, ibuprofen blunted the small fall in MAP associated with bed rest (P =.005) and decreased alveolar NO flow rates (P =.03) and urinary excretion of nitrite and nitrate (P =.02). However, ibuprofen had no effect on the decrease in MAP caused by endotoxin, although it blocked NO production to the point of disrupting the normal relationship between increases in exhaled NO flow rate and decreases in MAP (P =.002). These are the first in vivo data to demonstrate that ibuprofen down-regulates NO in humans. Ibuprofen impaired the NO response to bed rest, producing a small rise in blood pressure. Although ibuprofen also interfered with the ability of endotoxin to induce NO production, it had no effect on the fall in blood pressure, suggesting that the hemodynamic response to endotoxin is not completely dependent on NO under these conditions.

Detection of macrophage inflammatory protein (MIP)-1alpha and MIP-1beta during experimental endotoxemia and human sepsis.

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta regulate leukocyte activation and trafficking. To assess the role of MIP-1alpha and MIP-1beta in human inflammation, healthy subjects were studied during experimental endotoxemia with prior administration of ibuprofen, a cyclooxygenase inhibitor, or dimeric p75 tumor necrosis factor (TNF)-alpha receptor, a TNF antagonist; septic patients were also studied. Following endotoxin, blood levels of both MIP-1 molecules rose acutely and fell to baseline by 6 h (P=. 001). While MIP-1 mediates fever in animals independent of cyclooxygenase blockade, in subjects given endotoxin and ibuprofen, MIP-1 levels increased and fever was suppressed. MIP-1 levels were not diminished by inhibiting circulating TNF-alpha in humans. In septic patients, elevated levels of MIP-1alpha and MIP-1beta were detected within 24 h of sepsis and fell in parallel with TNF-alpha and interleukin-6 (P<.01). MIP-1alpha and MIP-1beta increase during acute inflammation but are not associated with fever in endotoxemic humans during cyclooxygenase blockade.

Effects of recombinant soluble type I interleukin-1 receptor on human inflammatory responses to endotoxin.

Effects of soluble recombinant human type I interleukin-1 receptor (sIL-1RI) were evaluated in 18 volunteers given intravenous endotoxin and randomized to placebo (n = 6), low-dose (n = 6), or high-dose (n = 6) sIL-1RI. Soluble IL-1RI decreased IL-1 beta (P = .001), but decreased IL-1ra (P = .0001), and resulted in 10-fold and 43-fold dose-related increases in sIL-1RI-IL-1ra complexes compared with placebo (P < or = .001). High-dose sIL-1RI was associated with increased levels of immunoactive tumor necrosis factor-alpha (P = .02), IL-8 (P = .0001), and cell-associated IL-1 beta (P = .047). C-reactive protein levels were higher after sIL-1RI than placebo (P = .035). Soluble IL-1RI decreased the severity of chills (P = .03), but did not alter other symptoms, changes in temperature, systemic hemodynamic responses, or changes in leukocyte and platelet number. Thus, sIL-1RI had no discernable antiinflammatory effect following endotoxin administration due in part to low levels of circulating IL-1 beta and neutralization of IL-1ra inhibitory function. This latter interaction represents an indirect mechanism of agonist activity elicited by sIL-1RI and may contribute to increases in inflammatory mediators, limiting therapy with sIL-1RI during endotoxemia.

Experimental human endotoxemia increases cardiac regularity: results from a prospective, randomized, crossover trial.

OBJECTIVE: To determine whether human endotoxemia is associated with a loss of the physiologic beat-to-beat variability of heart rate. DESIGN: Prospective, randomized, crossover, single-blind study. SETTING: Clinical research center in a federal, nonuniversity hospital. SUBJECTS: Healthy volunteers. INTERVENTIONS: Intravenous administration of reference (Escherichia coli) endotoxin or saline placebo, with or without previous administration of oral ibuprofen. MEASUREMENTS AND MAIN RESULTS: Electrocardiograms were continuously recorded and digitized using series of 1000 beat epochs of R-R intervals over 8 hrs. Analyses included measures in the time domain (standard deviation), frequency domain (power spectra), and a measure of regularity (approximate entropy). Endotoxin administration was associated with loss of variability by all measures. This loss of variability remained significant even with administration of ibuprofen, which blocked the development of fever and endotoxin-related symptoms. CONCLUSIONS: Infusion of endotoxin into human volunteers causes loss of heart rate variability, as measured by standard deviation and power spectra, as well as an increase in heart rate regularity, as measured by approximate entropy. Changes in approximate entropy occurred earlier than changes in other heart rate variability measures and may be a useful means of detecting early sepsis. This reduction in regularity is consistent with a model in which the pathogenesis of multiple organ system dysfunction syndrome involves the physiologic uncoupling of vital organ systems.

Human polymorphonuclear leukocytes lack detectable nitric oxide synthase activity.

Nitric oxide regulates polymorphonuclear leukocyte (PMN) function, but whether or not human PMNs express nitric oxide synthase (NOS) activity is controversial. We studied NOS activity in human PMNs by using human aortic endothelial cells (HAECs) for comparison. The conversion of L-arginine to L-citrulline, a relatively specific measure of NOS activity, was easily measured and inducible in fractionated HAECs, and > 90% of all L-arginine conversion was blocked by the NOS inhibitor, N omega-amino-L-arginine (L-NAA). In fractionated PMNs, L-arginine conversion was low and was unaffected by L-NAA. In addition, NOS activity was not induced in PMNs by LPS, IL-1 beta, or IFN-gamma. In a whole-cell assay, total L-arginine conversion was much lower in human PMNs compared with HAECs (3.38 +/- 0.21 vs 157.5 +/- 10.28 pmol/h/10(6) cells, respectively; p < 0.01). This conversion in whole PMNs was not increased in vitro by LPS, IFN-gamma, IL-1 beta, or TNF-alpha nor decreased by W13, a calmodulin inhibitor. Furthermore, PMNs isolated from four volunteers before and after challenge with i.v. LPS (4 ng/kg) showed no increase in L-arginine to L-citrulline conversion. Nitrite and nitrate release from human PMNs was 35-fold lower than for HAECs and was not inhibited by L-NAA. These data suggest that human PMNs do not express NOS activity.