DVT Surveillance Program in the ICU: Analysis of Cost-Effectiveness

Background Venous Thrombo-embolism (VTE – Deep venous thrombosis (DVT) and/or pulmonary embolism (PE) – in traumatized patients causes significant morbidity and mortality. The current study evaluates the effectiveness of DVT surveillance in reducing PE, and performs a cost-effectiveness analysis. Methods All traumatized patients admitted to the adult ICU underwent twice weekly DVT surveillance by bilateral lower extremity venous Duplex examination (48-month surveillance period – SP). The rates of DVT and PE were recorded and compared to the rates observed in the 36-month pre-surveillance period (PSP). All patients in both periods received mechanical and pharmacologic prophylaxis unless contraindicated. Total costs – diagnostic, therapeutic and surveillance – for both periods were recorded and the incremental cost for each Quality Adjusted Life Year (QALY) gained was calculated. Results 4234 patients were eligible (PSP – 1422 and SP – 2812). Rate of DVT in SP (2.8%) was significantly higher than in PSP (1.3%) – p Conclusions Surveillance of traumatized ICU patients increases DVT detection and reduces PE incidence. Costs in terms of QALY gained compares favorably with other interventions accepted by society

Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet

Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall ~400 m to the present level at 6.5–3.5 ka, and could have contributed 1.4–2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet

Actigraphy in the Critically Ill: Correlation With Activity, Agitation, and Sedation

Objectives To determine the feasibility of continuous measurement of limb movement via wrist and ankle actigraphy (an activity measure) in critically ill patients and to compare actigraphy measurements with observed activity, subjective scores on sedation-agitation scales, and heart rate and blood pressure of patients. • Methods In a prospective, descriptive, correlational study, all activity of 20 adult patients in medical and coronary care units in a university medical center were observed for 2 hours and documented. Wrist and ankle actigraphy, heart rate, and systolic and diastolic blood pressure data were collected every minute. The Comfort Scale and the Richmond Agitation-Sedation Scale were completed at the beginning of the observation period and 1 and 2 hours later. •Results Wrist actigraphy data correlated with scores on the Richmond Agitation-Sedation Scale (r = 0.58) and the Comfort Scale (r = 0.62) and with observed stimulation and activity events of patients (r = 0.45). Correlations with systolic, diastolic, and mean arterial pressures were weaker. Wrist and ankle actigraphy data were significantly correlated (r = 0.69; P < .001); however, their mean values (wrist, 418; ankle, 147) were significantly different (t = 5.77; P < .001). • Conclusions Actigraphy provides a continuous recording of patients’ limb movement. Actigraphy measurements correlate well with patients’ observed activity and with subjective scores on agitation and sedation scales. Actigraphy may become particularly important as a continuous measurement of activity for use in behavioral research and may enhance early recognition and management of the excessive activity that characterizes agitation

Results of logistic regression showing the independent predictors of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE).

<p>OR: odds ratio, CI: confidence interval, ISS: injury severity score, AIS: abbreviated injury scale.</p><p>Results of logistic regression showing the independent predictors of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE).</p

Figure showing a sensitivity analysis on the incremental cost to obtain one additional QALY.

<p>The bars represent upper and lower bounds on the incremental cost relative to the base case of $29,102 (dashed line) with respect to the bounds on each parameter value. In this figure, the discount rate ranges from 0% to 5%, the difference in the PE incidence rate between PSP and SP ranges from 0.2% to 1.4%, the PE fatality rate ranges from 5% to 10%, and the health state utility ranges from 0.8 to 1.0.</p

Patient populations in the two periods of study.

<p>*p<0.05: PSP vs SP. PSP: pre-surveillance period, SP: surveillance period, ISS: injury severity score, RTS: revised trauma score, AIS: Abbreviated Injury Scale.</p><p>Patient populations in the two periods of study.</p

Figure showing the rates of deep vein thrombosis (DVT) and pulmonary embolism (PE) during the pre-surveillance period (PSP: 2001–03) and the surveillance period (SP: 2004–07).

<p>#p<0.05 – DVT (PSP vs SP); *p<0.05 – PE (PSP vs SP).</p

Incremental dollar cost per quality adjusted life year (QALY) saved for selected interventions as compared to the cost of deep venous thrombosis surveillance (DVT Sur.).

<p>The bars represent range of cost from the best case scenario (most cost effective) to the worst case scenario (least cost effective) for each intervention. CPR: cardio-pulmonary resuscitation, APC: activated protein C for sepsis, tPA for AMI: tissue plasminogen activator for acute myocardial infarction, CABG: coronary artery bypass grafting, NICU: neonatal intensive care unit. The bracketed number represents the reference the data is derived from.</p