07 Nov 07
Posted in Echocardiography, Heart failure/Cardiogenic shock at 13:01 by Laci
By C Satpathy, TK Mishra, R Satpathy, HK Satpathy and E Barone
Am Fem Physician 2007;73:841-846
Diastolic heart failure occurs when signs and symptoms of heart failure are present but left ventricular systolic function is preserved (i.e., ejection fraction greater than 45 percent). The incidence of diastolic heart failure increases with age; therefore, 50 percent of older patients with heart failure may have isolated diastolic dysfunction. With early diagnosis and proper management the prognosis of diastolic dysfunction is more favorable than that of systolic dysfunction. Distinguishing diastolic from systolic heart failure is essential because the optimal therapy for one may aggravate the other. Although diastolic heart failure is clinically and radiographically indistinguishable from systolic heart failure, normal ejection fraction and abnormal diastolic function in the presence of symptoms and signs of heart failure confirm diastolic heart failure. The pharmacologic therapies of choice for diastolic heart failure are angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, and beta blockers.
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06 Nov 07
Posted in Admission to ICU, Critical Care, Mechanical ventilation at 19:05 by Laci
By M J Wildman, C Sanderson, J Groves, B C Reeves, J Ayres, D Harrison, D Young, K Rowan
BMJ 2007;335:xxx-xxx
To determine whether clinicians’ prognoses in patients with severe acute exacerbations of obstructive lung disease admitted to intensive care match observed outcomes in terms of survival.
Design
Prospective cohort study.
Setting
92 intensive care units and three respiratory high dependency units in the United Kingdom.
Participants
832 patients aged 45 years and older with breathlessness, respiratory failure, or change in mental status because of an exacerbation of COPD, asthma, or a combination of the two.
Main outcome measures
Outcome predicted by clinicians. Observed survival at 180 days.
Results
517 patients (62%) survived to 180 days. Clinicians’ prognoses were pessimistic, with a mean predicted survival of 49% at 180 days. For the fifth of patients with the poorest prognosis according to the clinician, the predicted survival rate was 10% and the actual rate was 40%. Information from a database covering 74% of intensive care units in the UK suggested no material difference between units that participated and those that did not. Patients recruited were similar to those not recruited in the same units.
Conclusions
Because decisions on whether to admit patients with COPD or asthma to intensive care for intubation depend on clinicians’ prognoses, some patients who might otherwise survive are probably being denied admission because of unwarranted prognostic pessimism.
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01 Nov 07
Posted in Critical Care, Echocardiography, General at 19:54 by Laci
By B Hoit
Cardiovascular morbidity and mortality resulting from congestive heart failure are major concerns for the critical care physician. Although heart failure is commonly associated with impaired systolic function, in up to one half of cases, heart failure occurs exclusively on the basis of an impairment of diastolic function. Diastole is the summation of processes by which the heart loses its ability to generate force and shorten and returns to its precontractile state. The two principal processes responsible for diastole are relaxation and passive pressure-volume properties of the ventricle. Echocardiography provides a comprehensive, noninvasive evaluation of diastolic filling of the ventricle, myocardial relaxation, and ventricular stiffness; the information obtained by echocardiography has prognostic value and is a guide to proper therapy. This article reviews the physiology of diastole, the pathogenesis of diastolic heart failure, and the diagnosis of diastolic dysfunction, with a focus on the diagnostic utility of echocardiography and an emphasis on those areas of greatest interest to the critical care physician.
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Posted in Critical Care, Echocardiography at 19:52 by Laci
By P Vignon, V Allot, J Lesage, J-F Martaillé, J-C Aldigier, B François and H Gastinne
Critical Care 2007, 11:R43
Conventional pulsed wave Doppler parameters are known to be preload dependent, whereas newly proposed Doppler indices may be less influenced by variations in loading conditions. The aim of the present study was to evaluate the effects of haemodialysis-induced preload reduction on both conventional and new Doppler parameters for the assessment of left ventricular (LV) diastolic function.
Methods
This prospective observational study was conducted in a medical-surgical intensive care unit (ICU) and nephrology department of a teaching hospital. In total, 37 haemodialysis patients with end-stage renal disease (age [mean ± standard deviation]: 52 ± 13 years) and eight ventilated ICU patients with acute renal failure receiving vasopressor therapy (age 57 ± 16 years; Simplified Acute Physiology Score II 51 ± 17) were studied. Echocardiography was performed before and after haemodialysis. Conventional pulsed wave Doppler indices of LV diastolic function as well as new Doppler indices, including Doppler tissue imaging early diastolic velocities (E’ wave) of the septal and lateral portions of the mitral annulus, and propagation velocity of LV inflow at early diastole (Vp) were measured and compared before and after ultrafiltration.
Results
The volume of ultrafiltration was greater in haemodialysis patients than in ICU patients (3.0 ± 1.1 l versus 1.9 ± 0.9 l; P = 0.005). All conventional pulsed wave Doppler parameters were altered by haemodialysis. In haemodialysis patients, E’ velocity decreased after ultrafiltration when measured at the septal mitral annulus (7.1 ± 2.5 cm/s versus 5.9 ± 1.7 cm/s; P = 0.0003), but not at its lateral portion (8.9 ± 3.1 cm/s versus 8.3 ± 2.6 cm/s; P = 0.37), whereas no significant variation was observed in ICU patients. Vp decreased uniformly after ultrafiltration, the difference being significant only in haemodialysis patients (45 ± 11 cm/s versus 41 ± 13 cm/s; P = 0.04). Although of less magnitude, ultrafiltration-induced variations in Doppler parameters were also observed in haemodialysis patients with altered LV systolic function.
Conclusion
In contrast to other Doppler parameters, Doppler tissue imaging E’ maximal velocity measured at the lateral mitral annulus represents an index of LV diastolic function that is relatively insensitive to abrupt and marked preload reduction.
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