Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.1197120

Diagnosis Of Pulmonary Embolism

Pulmonary embolism (PE)is a relevant clinical occurrence. Despite advances in diagnostic modalities,PE remains a commonly under diagnosed and lethal disease. In North America it has been reported that the occurrence of 600 000 PE cases are accountable for 50 000 to 200 000 deaths annually [1-4 ]. Unexpected deaths due to pulmonary embolism are frequently diagnosed post mortem. When diagnosis is established in the emergency department, appropriate anticoagulation is usually effective in reducing the possibility of recurrence and death. Undiagnosed PE has a hospital mortality rate as high as 30% that falls to near 8% if diagnosed and treated properly [3-6 ]. The mortality rate in ambulatory patients is less than 2%[7]. Clinicians are aware of unexpected deaths due to pulmonary embolism and that appropriate anticoagulation is usually effective in reducing the possibility of recurrence and death. For this reason,image methods are requested whenever there is clinical suspicion of PE. The diagnostic 'gold standard' is pulmonary angiography, against which other imaging modalities have been historically evaluated. Pulmonary angiography is an invasive and expensive procedure,with limited availability and potentially serious complications. There is limited radiological experience with this method as it is not always recognised that,with sub-segmental clot,interobserver disagreement occurs in up to one third of cases [8]. Despite being the 'gold standard',pulmonary angiograms are not infallible. A patient with a normal pulmonary angiogram can still expect a 2.2% (95%CI, 0.3 to 8.0%) venous thromboembolic event rate at the one-year follow-up [9]. © 2005 Springer-Verlag Italia.167182Anderson, F.A., Wheeler, H.B., Goldberg, R.J., A population-based perspective of the hospital incidence and case fatality rates of deep venous thrombosis and pulmonary embolism: The Worchester DVT study (1991) Arch Intern Med, 151, pp. 151-938Lilienfeld, D.E., Chan, E., Ehland, J., Mortality from pulmonary embolism in the United States: 1962 to 1984 (1990) Chest, 98, pp. 98-1072Dalen, J.E., Alpert, J.S., Natural history of pulmonary embolism (1975) Prog Cardiovasc Dis, 17, pp. 17-270Clagett, G.P., Anderson Jr., F.A., Heit, J., Prevention of venous thromboembolism (1995) Chest, 108, pp. S312-S334Dismuke, S.E., Wagner, E.H., Pulmonary embolism as a cause of death. The changing mortality in hospitalized patients (1986) JAMA, 255 (15), pp. 2039-2042Carson, J.L., Kelley, M.A., Duff, A., The clinical course of pulmonary embolism (1992) N Engl J Med, 326, pp. 326-1245Alpert, J.S., Smith, R., Carlson, J., Mortality in patients treated for pulmonary embolism (1976) JAMA, 236, pp. 236-1480Diffin, D.C., Leyendecker, J.R., Johnson, S.P., Effect of anatomic distribution of pulmonary emboli on interobserver agreement in the interpretation of pulmonary angiography (1998) Am J Roentgenol, 171, p. 1085Hull, R.B., Hirsh, J., Carter, C., Pulmonary angiography, ventilation lung scanning, and venography for clinically suspected pulmonary embolism with abnormal perfusion lung scan (1993) Ann Intern Med, 98, pp. 98-899Dixon, A.K., Coulden, R.A., Peters, A.M., The non-invasive diagnosis of pulmonary embolus (2001) BMJ, 323, pp. 323-413Value of ventilation/perfusion scan in acute pulmonary embolism. The PIOPED investigators (1990) JAMA, 263, pp. 263-2765. , AnonymousBritish thoracic society guidelines for the management of suspected acute pulmonary embolism. british thoracic society standards of care committee pulmonary embolism guideline development group (2003) Thorax, 58, pp. 58-483. , AnonymousRajendran, J.G., Jacobson, A.F., Review of 6-month mortality following low-probability lung scans (1999) Arch Intern Med, 159, pp. 159-352Hartmann, I., Hagen, P., Melissant, C., Diagnosing acute pulmonary embolism: Effect of chronic obstructive pulmonary disease on the performance of Ddimer testing, ventilation/perfusion scintigraphy, spiral computed tomographic angiography, and conventional angiography (2000) Am J Respir Crit Care Med, 162, pp. 162-2237Righini, M., Goehring, C., Bounameaux, H., Effects of age on the performance of common diagnostic tests for pulmonary embolism (2000) Am J Med, 109, pp. 109-361Worsley, D.F., Alavi, A., Radionuclide imaging of acute pulmonary embolism (2001) Radiol Clin N Am, 39, pp. 39-1052Forbes, K.P., Reid, J.H., Murchison, J.T., Do preliminary chest X-ray findings define the optimum role of pulmonary scintigraphy in suspected pulmonary embolism? (2001) Clin Radiol, 56, pp. 56-400Broekhuizen-De Gast, H.S., Tiel-Van Buul, M.M., Ubbink, M., The value of the 'non-diagnostic' lung scan - Further classification as to the risk of pulmonary embolism is not reliable (2000) Ned Tijdschr Geneeskd, 144, pp. 144-1542Remy-Jardin, M., Remy, J., Wattinne, L., Central pulmonary thromboembolism: Diagnosis with spiral volumetric CT with the single-breath-hold technique: Comparison with pulmonary angiography (1992) Radiology, 185, pp. 185-387Goodman, L.R., Lipchik, R.J., Kuzo, R.S., Acute pulmonary embolism: The role of computed tomographic imaging (1997) J Thorac Imaging, 12, pp. 12-86Hartmann, I., Hagen, P., Melissant, C., Diagnosing acute pulmonary embolism: Effect of chronic obstructive pulmonary disease on the performance of Ddimer testing, ventilation/perfusion scintigraphy, spiral computed tomographic angiography, and conventional angiography (2000) Am J Respir Crit Care Med, 162, pp. 162-2237Mayo, J.R., Remy-Jardin, M., Muller, N.L., Pulmonary embolism: Prospective comparison of spiral CT with ventilation-perfusion scintigraphy (1997) Radiology, 205, pp. 205-452Garg, K., Welsh, C.H., Feyerabend, A.J., Pulmonary embolism: Diagnosis with spiral CT and ventilation-perfusion scanning - Correlation with pulmonary angiographic results or clinical outcome (1998) Radiology, 208, pp. 208-208Van Rossum, A.B., Pattynama, P.M., Mallens, W.M., Can helical CT replace scintigraphy in the diagnostic process in suspected pulmonary embolism? A retrolective- prolective cohort study focusing on total diagnostic yield (1998) Eur Radiol, 8, pp. 8-96Blachere, H., Latrabe, V., Montaudon, M., Pulmonary embolism revealed onhelical CT angiography: Comparison with ventilation-perfusion radionuclide lung scanning (2000) Am J Roentgenol, 174, pp. 174-1047Cueto, S.M., Cavanaugh, S.H., Benenson, R.S., Computed tomography scan versus ventilation-perfusion lung scan in the detection of pulmonary embolism (2001) J Emerg Med, 21, pp. 21-164Ferretti, G.R., Bosson, J.L., Buffaz, P.D., Acute pulmonary embolism: Role of helical CT in 164 patients with intermediate probability at ventilation-perfusion scintigraphy and normal results at duplex US of the legs (1997) Radiology, 205, pp. 205-458Lorut, C., Ghossains, M., Horellou, M., A non-invasive diagnostic strategy including spiral computed tomography in patients with suspected pulmonary embolism (2000) Am J Respir Crit Care Med, 162, pp. 162-1418Stein, P.D., Henry, J.W., Gottschalk, A., Reassessment of pulmonary angiography for the diagnosis of pulmonary embolism: Relation of interpreter agreement to the order of the involved pulmonary arterial branch (1999) Radiology, 210, pp. 210-691Cooper, T.J., Protero, D.L., Gillett, M.G., Laboratory investigations in the diagnosis of pulmonary thromboembolism (1992) Quart J Med, 301, pp. 301-376Coche, E.E., Muller, N.L., Kim, K.I., Acute pulmonary embolism: Ancillary findings at spiral CT (1998) Radiology, 207, pp. 207-760Cross, J.J.L., Kemp, P.M., Walsh, C.G., A randomized trial of spiral CT and ventilation perfusion scintigraphy for the diagnosis of pulmonary embolism (1998) Clin Radiol, 53, pp. 53-182Musset, D., Parent, F., Meyer, G., Diagnostic strategy for patients with suspected pulmonary embolism: A prospective multicentre outcome study (2002) Lancet, 360, pp. 360-1920Remy-Jardin, M., Tillie-Leblond, I., Szapiro, D., CT angiography of pulmonary embolism in patients with underlying respiratory disease: Impact of multislice CT (MSCT) on image quality and negative predictive value (2002) Eur Radiol, 12, pp. 12-1978Cham, M.D., Yankelevitz, D.F., Shaham, D., Deep venous thrombosis: Detection by using indirect CT venography (2000) Radiology, 216, pp. 216-751. , The pulmonary angiography-indirect ct venography cooperative groupDuwe, K., Shiau, M., Budorick, N., Evaluation of the lower extremity veins in patients with suspected pulmonary embolism: A retrospective comparison of helical CT venography and sonography (2000) Am J Roentgenol, 175, pp. 175-1531Garg, K., Kemp, J.L., Wojcik, D., Thromboembolic disease: Comparison of combined CT pulmonary angiography and venography with bilateral leg sonography in 70 patients (2000) Am J Roentgenol, 175, pp. 175-1001Ghaye, B., Szapiro, D., Willems, V., Combined CT venography of the lower limbs and spiral CT angiography of pulmonary arteries in acute pulmonary embolism: Preliminary results of a prospective study (2000) J Belg Radiol, 83, pp. 83-278Au, V.W., Walsh, G., Fon, G., Computed tomography pulmonary angiography with pelvic venography in the evaluation of thrombo-embolic disease (2001) Australas Radiol, 45, pp. 45-145Loud, P.A., Katz, D.S., Bruce, D.A., Deep venous thrombosis with suspected pulmonary embolism: Detection with combined CT venography and pulmonary angiography (2001) Radiology, 219, pp. 219-502Nicolas, M., Debelle, L., Laurent, V., Incremental lower extremity CT venography, a simplified approach for the diagnosis of deep venous thrombosis in patients with pulmonary embolism (2001) J Radiol, 82, pp. 82-256Peterson, D.A., Kazerooni, E.A., Wakefield, T.W., Computed tomographic venography is specific but not sensitive for diagnosis of acute lower-extremity deep venous thrombosis in patients with suspected pulmonary embolus (2001) J Vasc Surg, 34, pp. 34-804Cham, M.D., Yankelevitz, D.F., Shaham, D., Deep venous thrombosis: Detection by using indirect CT venography (2000) Radiology, 216, pp. 216-751. , The pulmonary angiography-indirect ct venography cooperative groupRademaker, J., Griesshaber, V., Hidajat, N., Combined CT pulmonary angiography and venography for diagnosis of pulmonary embolism and deep vein thrombosis: Radiation dose (2001) J Thorac Imaging, 16, pp. 16-299Risk of and prophylaxis for venous thromboembolism in hospital patients. Thromboembolic risk factors (THRIFT) consensus group (1992) BMJ, 305, pp. 305-574. , AnonymousRosen, M., Sands, D., Morris, J., Does a physician's ability to accurately assess the likelihood of pulmonary embolism increase with training? (2000) Acad Med, 75, pp. 75-1205Wells, P.S., Anderson, D.R., Rodger, M., Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: Increasing the models utility with the simplired D-dimer (2000) Thromb Haemost, 83, pp. 83-420Wells, P.S., Ginsberg, J.S., Anderson, D.R., Use of a clinical model for safe management of patients with suspected pulmonary embolism (1998) Ann Intern Med, 129, pp. 129-1005Wells, P.S., Anderson, D.R., Rodger, M., Excluding pulmonary embolism at the bedside without diagnostic imaging: Management of patients with suspected pulmonary embolism presenting to the emergency department by using a simple clinical model and D-dimer (2001) Ann Intern Med, 135, pp. 135-107Wicki, J., Perneger, T.V., Junod, A.F., Assessing clinical probability of pulmonary embolism in the emergency ward (2001) Arch Intern Med, 161, pp. 92-97Kline, J.A., Nelson, R.D., Jackson, R.E., Criteria for the safe use of D-dimer testing in emergency department patients with suspected pulmonary embolism: A multicenter US study (2002) Ann Emerg Med, 39, pp. 144-152Kline, J.A., Mitchell, A.M., Kabrhel, C., Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism (2004) J Thromb Haemost. Aug, 2 (8), pp. 1247-1255Hager, K., Platt, D., Fibrin degeneration product concentration (D-dimers) in the course of ageing (1995) Gerontology, 41, pp. 41-165Kruskal, J.B., Commerford, P.J., Franks, J.J., Fibrin and fibrinogen related antigens in patients with stable and unstable coronary disease (1987) N Eng J Med, 317, pp. 317-1365Gustafsson, C., Blomback, M., Britton, M., Coagulation factors and the increased risk of stroke in non valvular atrial fibrillation (1990) Stroke, 21, pp. 21-51Becker, D.M., Philbrick, J.T., Bachhuber, T.L., D-dimer tesing and acute venous thromboembolism (1996) Arch Intern Med, 156, pp. 156-946Giroud, M., Dutrillaux, F., Lemesle, M., Coagulation abnormalities in lacunar and cortical ischaemic stroke are quite different (1998) Neurol Res, 20, pp. 20-18Foti, M., Gurewich, V., Fibrin degradation products and impedance plethysmography (1980) Arch Intern Med, 140, pp. 140-906Whitaker, A., Rowe, E., Masci, P., Identification of D dimer-E complex in disseminated intravascular coagulation (1980) Thromb Res, 18, pp. 18-459Kelly, J., Rudd, A., Lewis, R.R., Plasma D-Dimers in the diagnosis of venous thromboembolism (2002) Arch Intern Med, 162, pp. 162-256Bounameaux, H., Schneider, P.A., Reber, G., Measurement of plasma Ddimer for diagnosisof deep vein thrombosis (1989) Am J Cl Pathol, 91, pp. 91-85Bounameaux, H., De Moerloose, P., Perrier, A., Plasma measurement of Ddimer as diagnosis aid in suspected venous thromboembolism: An overview (1994) Thromb Haemost, 71, pp. 71-76Lorut, C., Laaban, J.P., Achkar, A., Diagnostic value of plasma D-dimer in suspected venous thromboembolism (1996) Sem Hop Paris, 72, pp. 72-685Robins, E.D., Julian, D.G., Travis, D.M., A physiologic approach to the diagnosis of acute pulmonary embolism (1959) New Engl J Med, 260, pp. 586-591Thys, F., Elamly, A., Marion, E., Roesler, J., PaCO2/ETCO2 gradient: Early indicator of thrombolysis efficacy in a massive pulmonary embolism (2001) Resuscitation, 49, pp. 49-108Anderson, J.T., Owings, J.T., Goodnight, J.E., Bedside non invasive detection acute pulmonary embolism in critically ill surgical patients (1999) Archives of Surgery, 134, pp. 134-875Burki, N., The dead space to tidal volume ratio in the diagnosis of pulmonary embolism (1986) Am Rev Respir Dis, 133, pp. 133-685Eriksson, L., Wollmer, P., Olsson, C.G., Diagnosis of pulmonary embolism based upon alveolar deadspace analysis (1989) Chest, 96, pp. 96-362Kline, J.A., Israel, E.G., Michelson, E.A., Diagnostic accuracy of bedside Ddimer assay and alveolar dead-space measurement for rapid exclusion of pulmonary embolism (2001) JAMA, 285, pp. 285-768Rodger, M.A., Jones, G., Rasuli, P., Steady-state end-tidal alveolar dead space fraction and D-dimer (2001) Chest, 120, pp. 120-119Hatle, L., Rokseth, R., The arterial to end-expiratory carbon dioxide tension gradient in acute pulmonary embolism and other cardiopulmonary diseases (1974) Chest, 66, pp. 66-357Olsson, K., Jonson, B., Olsson, C.G., Diagnosis of pulmonary embolism by measurement of alveolar dead space (1998) J Int Med, 244, pp. 244-207Johanning, J.M., Veverka, T.J., Bays, R.A., Evaluation of suspected pulmonary embolism utilizing end-tidal CO2 and D-Dimer (1999) Am J Surg, 178, pp. 178-102Moreira, M.M., Rgg, T., Triagem nao invasiva para a exclusao diagnostica de pacientes com suspeita de tromboembolismo pulmonar (TEP) (2005) Revista Brasileira de Terapia Intensiva, 16, pp. 16-137Kline, J.A., Wells, P.S., Methodology for a rapid protocol to rule out pulmonary embolism in the emergency department (2003) Ann Emerg Med, 42, pp. 42-27

Neurogenic Pulmonary Edema: Report Of Two Cases [edema Pulmonar Neurogênico: Relato De Dois Casos]

Neurogenic pulmonary edema is a rare and serious complication in patients with head injury. It also may develop after a variety of cerebral insults such as subarachnoid hemorrhage, brain tumors and after epileptic seizures Thirty six patients with severe head injury and four patients with cerebrovascular insults treated in Intensive Care Unit of HC-UNICAMP from January to September 1995 were evaluated. In this period there were two patients with neurogenic pulmonary edema, one with head injury and other with intracerebral hemorrhage Diagnosis was made by rapid onset of pulmonary edema, severe hypoxemia, decrease of pulmonary complacence and diffuse pulmonary infiltrations, without previous history of tracheal aspiration or any other risk factor for developement of adult respiratory distress syndrom In the first case, with severe head trauma, neurogenic pulmonary edema was diagnosed at admission one hour after trauma, associated with severe systemic inflammatory reaction. and good outcome in three days. The second case, with hemorragic vascular insult, developed neurogenic pulmonary edema the fourth day after drenage of intracerebral hematom and died.552305309Bembridge, M., Madej, T.H., Neurogenic pulmonary oedema (1985) Anaesthesia, 40, pp. 202-204Braude, N., Ludgrove, T., Neurogenic pulmonary oedema precipitated by induction of anaesthesia (1989) Br J Anaesth, 62, pp. 101-103Brito, J.C.F., Diniz, M.C.A., Rosas, R.R., Silva, J.A.G., Edema pulmonar agudo neurogênico relato de caso (1995) Arq Neuropsiquiatr, 53, pp. 288-293Brown, R.H., Beyerl, B.D., Iseke, R., Lavy, M.H., Medulla oblongata oedema associated with neurogenic pulmonary oedema: Case report (1986) J Neurosurg, 64, pp. 494-500Casey, W.F., Neurogenic pulmonary oedema (1983) Anaesthesia, 38, pp. 985-988Dettbarn, C.L., Davidson, L.J., Pulmonary complications in the patient with acute head injury: Neurogenic pulmonary oedema (1989) Heart Lung, 18, pp. 583-589Ell, S.R., Neurogenic pulmonary oedema, a review of the literature and a perspective (1991) Inv Radiol, 26, pp. 499-506Falcão, A.L.E., Dantas, V.F., Sardinha, L.C., Quagliato, E.A.B., Diagosavac, D., Araújo, S., Terzi, R.G.G., Highlighting intracranial pressure monitoring in patients with severe acute brain trauma (1995) Arq Neuropsiquiatr, 53, pp. 390-394Falcão, A.L.E., Dantas, V.F., Saraiva, J.F.K., Sardinha, L.C., Araújo, S., Terzi, R.G.G., Bedside ICP monitoring in head trauma patients by using a simple. safe and low cost metodology (1992) Clin Int Care, 3 (SUPPL.), p. 112Graf, C.J., Rossi, N.P., Pulmonary oedema and central nervous system.A clinico-pathological study (1975) Surg Neurol, 4, pp. 319-325Kauffman, H.H., Timberlake, G., Voelker, J., Glenn, P.T., Medical complications of head injury (1993) Med Clin North Am Jan, 70, pp. 43-60Knudsen, F., Jensen, H.P., Peterson, P.L., Neurogenic pulmonary edema treatment with dobutamine (1991) Neurosurgery, 29, pp. 269-270Li, C., Gefter, W.B., Acute pulmonary edema induced by overdosage of phenothiazines (1992) Chest, 101, pp. 102-104Malik, A.B., Mechanisms of neurogenic pulmonary edema (1985) Circ Res, 57, pp. 1-18Melone, E., Bonnet, F., Lepreslo, E., Fevrier, M.J., Djindjian, M., Francois, Y., Gray, F., Debras, C., Altered capillary permeability in neurogenic pulmonary edema (1985) Int Care Med, 11, pp. 323-325Murphy, P.G., Jackson, R., Kirollos, R., Gibson, J.S., Chennells, P., Adult respiratory distress syndrome after attenuated strangulation (1993) Br J Anasth, 70, pp. 583-586Pender, E.S., Pollack, C.V., Neurogenic pulmonary edema: Case reports and review (1992) J Em Med, 10, pp. 45-51Pollack, V., Pollack, E.S., Neurogenic pulmonary edema (1993) J Emerg Med, 11, pp. 207-210Simmons, R.L., Martin, A.M., Heisterkamp, C.A., Ducher, T.B., Respiratory insufficiency in combat casualties. II Pulmonary edema following head injury (1969) Ann Surg, 170, pp. 39-41Simon, R.P., Neurogenic pulmonary edema (1993) Neurol Clin, 11, pp. 309-323Simon, R.P., Medullary lesion inducing pulmonary edema a magnetic resonance imaging study (1991) Ann Neurol, 30, pp. 727-730Toucho, H., Kavasawa, J., Sishido, H., Yamada, K., Yamazaki, Y., Neurogenic pulmonary edema in the acute stage of hemorrhagic cerebrovascular disease (1989) Neurosurgery, 25, pp. 762-768Wauchob, T.D., Brooks, R.J., Harrison, K.M., Neurogenic pulmonary oedema (1984) Anaesthesia, 39, pp. 529-534Wright, R.S., Feuerman, T., Brown, J., Neurogenic pulmonary edema after trigeminal nerve blockade (1989) Chest, 96, pp. 436-43

Volumetric Capnography As A Noninvasive Diagnostic Procedure In Acute Pulmonary Thromboembolism [capnografia Volumétrica Como Auxílio Diagnóstico Não-invasivo No Tromboembolismo Pulmonar Agudo]

Pulmonary thromboembolism is a common condition. Its diagnosis usually requires pulmonary scintigraphy, computed angiotomography, pulmonary arteriography and, in order to rule out other diagnoses, the measurement of D-dimer levels. Due to the fact that these diagnostic methods are not available in most Brazilian hospitals, the validation of other diagnostic techniques is of fundamental importance. We describe a case of a woman with chronic pulmonary hypertension who experienced a pulmonary thromboembolism event. Pulmonary scintigraphy, computed angiotomography and pulmonary arteriography were used in the diagnosis. The D-dimer test result was positive. Volumetric capnography was performed at admission and after treatment. The values obtained were compared with the imaging test results.345328332Owings, J.T., Kraut, E., Battistella, F., Cornelius, J.T., O'Malley, R., Timing of the occurrence of pulmonary embolism in trauma patients (1997) Arch Surg, 132 (8), pp. 862-866. , discussion 866-7Chemla, D., Castelain, V., Hervé, P., Lecarpentier, Y., Brimioulle, S., Haemodynamic evaluation of pulmonary hypertension (2002) Eur Respir J, 20 (5), pp. 1314-1331Moreira, M.M., Terzi, R.G.G., Vieira, R.W., Petrucci Jr, O., Fração tardia do espaço morto (fDlate) antes e após embolectomia pulmonar. (2005) Rev Bras Cir Cardiovasc, 20 (1), pp. 81-84Rodger, M.A., Jones, G., Rasuli, P., Raymond, F., Djunaedi, H., Bredeson, C.N., Steady-state end-tidal alveolar dead space fraction and D-dimer: Bedside tests to exclude pulmonary embolism (2001) Chest, 120 (1), pp. 115-119Eriksson, L., Wollmer, P., Olsson, C.G., Albrechtsson, U., Larusdottir, H., Nilsson, R., Diagnosis of pulmonary embolism based upon alveolar dead space analysis (1989) Chest, 96 (2), pp. 357-362Grimby, G., Söderholm, B., Spirometric studies in normal subjects. III. Static lung volumes and maximum voluntary ventilation in adults with a note on physical fitness (1963) Acta Med Scand, 173 (2), pp. 199-206Thys, F., Elamly, A., Marion, E., Roeseler, J., Janssens, P., El Gariani, A., PaCO(2)/ETCO(2) gradient: Early indicator of thrombolysis efficacy in a massive pulmonary embolism (2001) Resuscitation, 49 (1), pp. 105-108Verschuren, F., Heinonen, E., Clause, D., Roeseler, J., Thys, F., Meert, P., Volumetric capnography as a bedside monitoring of thrombolysis in major pulmonary embolism (2004) Intensive Care Med, 30 (11), pp. 2129-213

Death Concepts And Brain Death Diagnostic Criteria [dos Conceitos De Morte Aos Critérios Para O Diagnóstico De Morte Encefálica]

The authors present considerations about death and brain death concepts, as well the legal aspects for its diagnosis in Brazil. They also present the UNICAMP Protocol for the Diagnosis of Brain Death, revised and according with the current law, with standard techniques for the diagnostic exam. They emphasize the importance of a mature ethical position for this frequent and challenging situation.544705710Benzel, E.C., Gross, C.D., Hadden, T.A., Kesterson, L., Landreneau, M.D., The apnea test for the determination of brain death (1989) J Neurosurg, 71, pp. 191-194Cowley, L.T., Young, E., Raffin, T.A., Care of dying: An ethical and historical perspective (1992) Crit Care Med, 20, pp. 1473-1482Dantas, V.P.F., Torres, M.P., Araújo, S., Vieira, R.J., Falcão, A.L.E., Sardinha, L.A.C., Terzi, R.G.G., Morte encefálica: Considerações gerais e protocolo para o seu diagnóstico (1992) Rev Bras Terap Intens, 4, pp. 50-54Determining brain death in adults. Report of the Quality Standards Subcommittee of the AAN (1995) World NeurologyHeytens, L., Verlooy, J., Gheuens, J., Bossaert, L., Lazarus sign and extensor posturing in a brain-dead patient: Case report (1989) J Neurosurg, 71, pp. 449-451França, G.V., (1991) Medicina Legal Ed3, pp. 238-286. , Rio de Janeiro: Guanabara KooganFuhrer, M.C.A., (1990) Resumo de Direito Civil. Ed7, pp. 12-30. , São Paulo: Editora Revista dos TribunaisGomes, J.C.M., Ética médica e UTI: Reflexões à luz do Código de Ética (1992) J Bras Med, 62, pp. 48-57Manreza, L.A., Stávale, M.A., Considerações básicas sobre morte encefálica (1996) Bases Da Terapia Intensiva Neurológica, pp. 647-652. , Stávale MA (ed). São Paulo: Livraria SantosPallis, C., Brainstem death (1990) Handbook of Clinical Neurology, Vol 13(57): Head Injury, 13 (57), pp. 441-496. , Vinken PJ, Bruyn GW, Klawans HL (eds) and Braakman R (co-ed). Amsterdam: ElservierRopper, A.H., Unusual spontaneous movements in brain-dead patients (1984) Neurology, 34, pp. 1089-1092Ropper, A.H., Kennedy, S.K., Russel, L., Apnea testing in the diagnosis of brain death (1981) J Neurosurg, 55, pp. 942-946Schafer, J.A., Caronna, J.J., Duration of apnea needed to confirm brain death (1978) Neurology, 28, pp. 661-666Turmel, A., Roux, A., Bojanowski, M.W., Spinal man after declaration of brain death (1991) Neurosurgery, 28, pp. 298-30

Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction

Bedside Icp Monitoring In Head Trauma Patients By Using A Simple, Safe And Low Cost Methodology

[No abstract available]32 SUPPL.112NKT Photonics A/S,PolarOnyx, Inc.,The Society of Photo-Optical Instrumentation Engineers (SPIE

Diagnostic investigation of ventilator-associated pneumonia using bronchoalveolar lavage: comparative study with a postmortem lung biopsy

The purpose of the present study was to validate the quantitative culture and cellularity of bronchoalveolar lavage (BAL) for the diagnosis of ventilator-associated pneumonia (VAP). A prospective validation test trial was carried out between 1992 and 1997 in a general adult intensive care unit of a teaching hospital. Thirty-seven patients on mechanical ventilation with suspected VAP who died at most three days after a BAL diagnostic procedure were submitted to a postmortem lung biopsy. BAL effluent was submitted to Gram staining, quantitative culture and cellularity count. Postmortem lung tissue quantitative culture and histopathological findings were considered to be the gold standard exams for VAP diagnosis. According to these criteria, 20 patients (54%) were diagnosed as having VAP and 17 (46%) as not having the condition. Quantitative culture of BAL effluent showed 90% sensitivity (18/20), 94.1% specificity (16/17), 94.7% positive predictive value and 88.8% negative predictive value. Fever and leukocytosis were useless for VAP diagnosis. Gram staining of BAL effluent was negative in 94.1% of the patients without VAP (16/17). Regarding the total cellularity of BAL, a cut-off point of 400,000 cells/ml showed a specificity of 94.1% (16/17), and a cut-off point of 50% of BAL neutrophils showed a sensitivity of 90% (19/20). In conclusion, BAL quantitative culture, Gram staining and cellularity might be useful in the diagnostic investigation of VAP

Diagnostic investigation of ventilator-associated pneumonia using bronchoalveolar lavage: comparative study with a postmortem lung biopsy

The purpose of the present study was to validate the quantitative culture and cellularity of bronchoalveolar lavage (BAL) for the diagnosis of ventilator-associated pneumonia (VAP). A prospective validation test trial was carried out between 1992 and 1997 in a general adult intensive care unit of a teaching hospital. Thirty-seven patients on mechanical ventilation with suspected VAP who died at most three days after a BAL diagnostic procedure were submitted to a postmortem lung biopsy. BAL effluent was submitted to Gram staining, quantitative culture and cellularity count. Postmortem lung tissue quantitative culture and histopathological findings were considered to be the gold standard exams for VAP diagnosis. According to these criteria, 20 patients (54%) were diagnosed as having VAP and 17 (46%) as not having the condition. Quantitative culture of BAL effluent showed 90% sensitivity (18/20), 94.1% specificity (16/17), 94.7% positive predictive value and 88.8% negative predictive value. Fever and leukocytosis were useless for VAP diagnosis. Gram staining of BAL effluent was negative in 94.1% of the patients without VAP (16/17). Regarding the total cellularity of BAL, a cut-off point of 400,000 cells/ml showed a specificity of 94.1% (16/17), and a cut-off point of 50% of BAL neutrophils showed a sensitivity of 90% (19/20). In conclusion, BAL quantitative culture, Gram staining and cellularity might be useful in the diagnostic investigation of VAP.993100