RESUMEN
In this brief review of the literature it is pointed out that during platelet activation and degranulation platelet alpha granules leave the platelet interior through blebs in platelet plasma membrane and through the tips of the pseudopods, and then accumulate in the external milieu. There they undergo disintegration and secondary adhesion to the platelet plasma membranes. During their disintegration they expose their tightly packed GPIIb-IIIa complexes, annexin V stainable aminophospholipids, factor V, and the membrane markers CD62 and CD63. There is also demasking of lysosomal acid phosphatase activity and microvesicle formation. Lysosomal nature of platelet alpha granules is mentioned. It is suggested that platelet alpha granules are the sole source of platelet procoagulant activity and platelet microparticles (MP) or microvesicles (MV). The implications of this concept for antiplatelet therapy are discussed. A relationship of this process to tissue factor exposure and apoptosis is suggested.
Asunto(s)
Coagulación Sanguínea/fisiología , Plaquetas/fisiología , Gránulos Citoplasmáticos/fisiología , Activación Plaquetaria/fisiología , Animales , Plaquetas/ultraestructura , HumanosRESUMEN
In two patients eclampsia started 9 days postpartum. Headache and visual disturbances preceded seizures but none of the classic pre-eclamptic signs oedema, proteinuria, and hypertension were present until shortly before seizure onset. Brain herniation (patient 1) and status epilepticus (patient 2) necessitated neurointensive care management. Brain MRI initially showed only frontal sulcal effacement in one patient but later showed white matter hyperintensities on T2 weighted images and a previously undescribed pattern of cortical-subcortical postgadolinium enhancement on T1 weighted images in both. Neurological deficits and MRI findings were reversed with therapy in both patients. It is concluded that late postpartum eclampsia can manifest without classic prodromi and that characteristic MRI findings may lag behind clinical manifestation.
Asunto(s)
Encéfalo/patología , Eclampsia/patología , Síndromes de Preexcitación/patología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Periodo Posparto , EmbarazoRESUMEN
We report a 56-year-old male patient developing hypoxemia after surgical replacement of infected valves of a left ventricular assist device (LVAD, Novacor) which had supported him during the previous 15 months. Contrast transesophageal echocardiography (TEE) revealed an atrial septal defect with intermittent right-to-left shunt across a patent foramen ovale. We postulate that the shunt detected in this patient occurred as a consequence of reduced pulmonary vascular compliance due to positive end-expiratory pressure (PEEP) and an increase of mean intrathoracic pressure. Furthermore, we hypothesize that synchronized LVAD operation exacerbates any potential right-to-left shunt due to the profound left ventricular unloading which occurs during LVAD support. In this first report of a right-to-left shunt from a previously unrecognized patent foramen ovale in a Novacor patient, the subsequent transient hypoxemia could be managed by avoiding PEEP of more than 3 mmHg, and mean airway pressure of more than 11 mmHg and by careful volume replacement in order to prevent the pump from completely emptying the left ventricle (LV) and the left atrium (LA). Thus, prior to every LVAD implantation a transesophageal contrast echocardiography with Valsalva maneuver should be performed to identify intracardiac right-to-left shunt.
Asunto(s)
Defectos del Tabique Interatrial/complicaciones , Corazón Auxiliar , Hipoxia/etiología , Complicaciones Posoperatorias/etiología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To evaluate the accuracy of a new continuous cardiac output monitor in critically ill patients. DESIGN: Criterion standard study. SETTING: Cardiac surgery intensive care unit in a university hospital. PATIENTS: Twenty cardiac surgical patients requiring intensive care treatment with pulmonary artery catheters after surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cardiac output was monitored continuously with a modified pulmonary artery catheter that has a heating filament on the outside of the catheter. Four modes of data processing with different response times ("Normal," "Fast," "FastFilter," and "Urgent" modes) used by the monitoring system. A total of 240 determinations of cardiac output were performed using conventional bolus thermodilution technique; these results were compared with those obtained using three of the four continuous measuring modes available ("Normal," "FastFilter," and "Urgent"). Cardiac output ranged from 3.47 to 15.77 L/min (bolus thermodilution). The mean (bias) +/- SD of differences (precision) for all measurements was 0.40+/-1.26 L/min in the Normal mode (cardiac output <10 L/min: 0.34+/-0.66 L/min), 0.53+/-1.27 L/min in the FastFilter-mode (cardiac output <10 L/min: 0.60+/-0.75 L/min), and 0.63+/-1.34 L/min in the Urgent mode (cardiac output <10 L/min: 0.57+/-0.82 L/min). CONCLUSIONS: Continuous cardiac output measurement using the thermodilution technique is reasonably accurate, reliable, and applicable in routine clinical practice. The values obtained using the Normal mode of the monitor agreed significantly better with the conventional thermodilution method than the results of the two other modes studied (FastFilter and Urgent). In addition, measurements in two patients with cardiac output values of >10 L/min did not agree with the results of the bolus thermodilution method.
Asunto(s)
Gasto Cardíaco , Procedimientos Quirúrgicos Cardíacos , Cuidados Críticos , Termodilución/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Evaluación como Asunto , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/estadística & datos numéricos , Estudios Prospectivos , Estadísticas no Paramétricas , Termodilución/métodos , Termodilución/estadística & datos numéricosRESUMEN
In the last 10 years an increasing number of cases of group A streptococcal toxic shock syndrome have appeared in various clinical settings. The manifestation of this syndrome includes rapidly progressive multiorgan failure and soft-tissue necrosis. This report presents a case of streptococcal toxic shock syndrome caused by Streptococcus pyogenes with severe necrotizing fasciitis of the abdominal wall following hysterectomy. Aggressive surgical intervention with debridement of all necrotic tissue necessitated resection of the complete abdominal wall (skin, subcutaneous tissue, muscle and peritoneum). The abdominal wall defect was covered with free myocutaneous flaps and split-skin grafts. Optimal treatment, including adequate antibiotic therapy and radical surgical intervention, is an indispensable prerequisite of successful outcome.
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Fascitis Necrotizante/etiología , Fascitis Necrotizante/terapia , Histerectomía/efectos adversos , Complicaciones Posoperatorias/microbiología , Choque Séptico/etiología , Fascitis Necrotizante/microbiología , Fascitis Necrotizante/cirugía , Femenino , Humanos , Persona de Mediana Edad , Complicaciones Posoperatorias/terapia , Choque Séptico/microbiología , Choque Séptico/terapiaRESUMEN
UNLABELLED: Treatment of severe acute respiratory distress syndrome (ARDS) with extracorporeal membrane oxygenation (ECMO) can be lifesaving but requires maximal use of intensive care resources over prolonged periods of time, resulting in high costs. Little is known about the health-related quality of life (HRQL) in long-term survivors. This case-controlled retrospective study was designed to assess the health-related quality of life in long-term survivors of ARDS and ECMO-therapy. METHODS: 14 long-term survivors of ARDS (APACHE II score = 24, Lung Injury Score = 3.25, median values) treated using ECMO between 1992 and 1995 (median time interval between data collection and discharge from the ICU 16 months) and 14 ARDS-patients conventionally treated during the same period (group I) were identified and completed the SF-36 Health Status Questionnaire (Medical Outcome Trust, Boston, USA). 14 healthy subjects (group II) were drawn at random from a large data base generated to provide normal values for the SF-36 in a German population. All three groups were comparable with respect to sex and age. RESULTS: Long-term survivors of ECMO-therapy reported significant reductions in physical functioning when compared with patients treated by mechanical ventilation alone (group I, -12.5%, p < 0.05) and with healthy controls (group II, -50%, p < 0.05) and showed a higher incidence of chronic physical pain (+5% and +24%, respectively, p < 0.05). There were no differences with regard to the mental health dimensions of the SF-36 (e.g. vitality, mental health index or social functioning) between ECMO-patients and all controls. Nine patients (64.3%) from the ECMO group versus all patients treated conventionally (group I) had full-time employment (p = 0.46, Chi2 test). CONCLUSIONS: The majority of long-term survivors of ECMO-treatment show good physical and social functioning, including a high rate of employment. The more aggressive approach of ECMO-therapy and a possibly more severe underlying disease process may explain impairments in health-related quality of life outcomes after ECMO-treatment. Despite these limitations, long-term survivors of ECMO-therapy are able to reach a highly satisfactory health-related quality of life.
Asunto(s)
Oxigenación por Membrana Extracorpórea , Calidad de Vida , Síndrome de Dificultad Respiratoria/psicología , Síndrome de Dificultad Respiratoria/terapia , APACHE , Actividades Cotidianas , Adolescente , Adulto , Estudios de Casos y Controles , Empleo , Oxigenación por Membrana Extracorpórea/efectos adversos , Femenino , Humanos , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad , Síndrome de Dificultad Respiratoria/mortalidad , Estudios Retrospectivos , Conducta Social , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
OBJECTIVES: Despite considerable progress in intensive care management of the acute respiratory distress syndrome (ARDS), little is known about health-related quality of life in long-term survivors. In addition, intensive care treatment can be extremely stressful, and many survivors of ARDS report adverse experiences such as respiratory distress, anxiety, or pain during intensive care unit (ICU) treatment. This study was performed to assess health-related quality of life in survivors of ARDS and to test the hypothesis that adverse experiences during ICU treatment result in posttraumatic stress disorder (PTSD) and negative effects on health-related quality of life. DESIGN: Retrospective, cohort, case-controlled analyses. SETTING: A 12-bed multidisciplinary ICU of a tertiary care university hospital, capable of providing extracorporeal life support for adults with severe ARDS. PATIENTS: We studied 80 patients who were admitted to our hospital from 1985 to 1995 and who survived an episode of ARDS. ARDS was defined according to the criteria of the American-European Consensus Conference on ARDS. INTERVENTIONS: Health-related quality of life was measured using the Health Status Questionnaire of the self-administered Medical Outcomes Study Short Form Survey that consists of 36 questions (SF-36) and the German version of the Post Traumatic Stress Syndrome 10-Questions Inventory (PTSS-10), a self-report scale for the diagnosis of posttraumatic stress disorder based on the Diagnostic and Statistical Manual (Third Edition) criteria (American Psychiatric Association). The number of adverse experiences (anxiety, respiratory distress, pain, and nightmares) during intensive care was evaluated by means of a structured questionnaire. For each patient with ARDS, three age- and gender-comparable controls were randomly selected from databases providing normal values for the SF-36 and PTSS-10 scores in populations at risk for posttraumatic stress disorder. MEASUREMENTS AND MAIN RESULTS: Survivors of ARDS showed statistically significant impairments in all eight health dimensions of the SF-36 when compared with normal controls (median reduction 21.3%, p < .006) with maximal impairments in physical function (median reduction 28.9%, p = .000) and a 38% higher frequency of chronic pain (p = .0001). Three of 34 patients reporting none, or one, adverse experience had evidence of posttraumatic stress disorder vs. 19 of 46 patients remembering multiple traumatic episodes (p = .007). Patients reporting multiple adverse experiences described the lowest health-related quality of life, with maximal impairments in psychosocial functioning (p < .005) and only small limitations in physical function. CONCLUSIONS: Long-term survivors of ARDS describe a good overall health-related quality of life. Major impairments in mental health domains of health-related quality of life are associated with the development of posttraumatic stress disorder and are a possible result of traumatic experiences during ICU therapy.
Asunto(s)
Calidad de Vida , Síndrome de Dificultad Respiratoria/complicaciones , Síndrome de Dificultad Respiratoria/psicología , Trastornos por Estrés Postraumático/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cuidados Críticos/psicología , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Síndrome de Dificultad Respiratoria/terapia , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
Both acetylsalicylic acid and vitamin E have been shown to be beneficial in the prevention of stroke and heart attacks. It is implied that their combination in the treatment of thrombotic complications of atherosclerosis may have added benefits. It is suggested that vitamin E may work as a platelet lysosome stabilizing agent.
Asunto(s)
Arteriosclerosis/prevención & control , Aspirina/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Trombosis/prevención & control , Vitamina E/uso terapéutico , Trastornos Cerebrovasculares/prevención & control , Interacciones Farmacológicas , Humanos , Infarto del Miocardio/prevención & control , Activación PlaquetariaRESUMEN
Mortality of severe acute respiratory distress syndrome (ARDS) in Germany is about 60%. Respiratory therapy can make the lung injury worse by high positive airway pressures, high tidal volumes and high inspiratory oxygen concentrations. Extracorporeal membrane oxygenation (ECMO) was employed to reduce aggressive mechanical ventilation, but it has not been proved to be superior to conventional ventilation. However, encouraged by recently developed improvements in the technique and concept of ECMO, we introduced this therapy into our program for the treatment of ARDS. PATIENTS AND METHODS. All patients with severe ARDS (lung injury score > 2.5) admitted to our multidisciplinary intensive care unit from March 1992 to March 1995 were evaluated prospectively. After admission, the patients first underwent a conventional therapeutic approach, including pressure-controlled inverse-ratio ventilation, permissive hypercapnia, changes in body position (in particular, the prone position), negative fluid balance, anti-biotics, and low-dose hydrocortisone infusion. ECMO via a covalently heparin-coated, venovenous bypass-system with a vortex pump and two membrane lungs was performed if ARDS did not improve after 24-96 h of conventional therapy and if two of three of the slow-entry criteria for ECMO were fulfilled: (1) PaO2/FiO2 < 150 mmHg at PEEP > 5 mbar; (2) semistatic compliance < 30 ml/mbar; (3) right-left shunt > 30%. Only in cases of life-threatening hypoxemia (PaO2 < 50 mmHg at FiO2 1.0 and PEEP > 5 mbar for > 2 h (fast-entry criteria) was ECMO instituted immediately. RESULTS. Sixty patients fulfilled the entry criteria for our study. Thirty-nine patients were treated with a conventional protocol, 37 after improvement of ARDS and 2 who had not improved but in whom there were contraindications to the use of ECMO. ECMO was performed in 10 patients who had not improved, but who fulfilled the slow-entry criteria and in 11 primarily hypoxemic patients who fulfilled the fast-entry criteria. The survival rate was 30/39 (77%) for the conventional therapy group, 6/10 (60%) for the slow-entry group, and 11/11 (100%) for the fast-entry group. The onset of ECMO allowed a significant decrease in peak and mean airway pressures, tidal volume, ventilatory rate, minute volume and inspiratory oxygen concentration. Sufficient gas exchange was provided, and pulmonary artery pressures significantly decreased on bypass. The most frequent complications on bypass were pneumothorax (15/21 patients) and bleeding (7/21 patients). CONCLUSION. In comparison with the historical results at our own institution, the present study demonstrates an improvement in the survival rate from 56% to 78% since ECMO has become available. We conclude that venovenous ECMO with a heparin-bonded bypass circuit is an effective additional option for the treatment of patients with severe ARDS.
Asunto(s)
Oxigenación por Membrana Extracorpórea , Heparina , Síndrome de Dificultad Respiratoria/terapia , Adolescente , Adulto , Anciano , Cuidados Críticos , Oxigenación por Membrana Extracorpórea/instrumentación , Humanos , Recién Nacido , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Intercambio Gaseoso Pulmonar/fisiología , Respiración Artificial , Síndrome de Dificultad Respiratoria/fisiopatología , Pruebas de Función RespiratoriaRESUMEN
AIM: Monitoring of jugular-venous O2-saturation (SjO2) enables the assessment of cerebral oxygen supply and the rapid detection of cerebral desaturation in patients with severe head injury. Furthermore, it may help to optimize circulation, ventilation, and intracranial hypertension therapy in these patients. This study was performed to evaluate the reliability of SjO2-monitoring as well as to measure cerebral O2-extraction and the frequency of episodes of cerebral desaturation after traumatic brain injury. METHODS: In 16 patients with severe head injury (GCS 3-8), SjO2 (fibreoptic system), arterial blood pressure, and intracranial pressure were continuously recorded after admission of the patients to the intensive care unit. Fluctuations of SjO2 (> 10% within 30 min), which were not included by therapeutic measures, were classified by off-line analysis as irregular-isolated or irregular-combined, if accompanied by similar fluctuations of ICP and arterial blood pressure. Recordings which were unreliable due to technical reasons, mainly because of wall adherence of the tip of the fibreoptic catheter, were evaluated separately. Episodes of cerebral desaturations (SjO2 < 50%) were assessed with regard to their frequency, duration (5-10/> 10 min) and underlying mechanisms. Cerebral O2-extraction was calculated as the difference between arterial and cerebrovenous O2-saturation and averaged for each day after trauma. RESULTS: Mean time of measurement for each patient was 194 hrs, a total of 3106 hrs were recorded. The correlation coefficient between in-vivo and in-vitro measured SjO2 was r = 0.62 (n = 367, p < 0.001). Reliable and artifact-free measurements of SjO2 were obtained only during 58.3% of all hours. Irregular-isolated fluctuations of the SjO2 occurred in 22.2% of the hours, and technical problems in 14.5%. Erroneous readings due to irregular-combined fluctuations of the jugular-venous O2-saturation were detected in 5.0% of the time periods. A total number of 66 episodes of cerebral desaturation (SjO2 < 50%) were found in all 16 patients, 41 of them had a duration of more than 10 minutes. Cerebral hypoxia was attributed to low cerebral perfusion pressure in 35% and hypocapnia in 17%. Global cerebral O2-extraction was significantly elevated at the day of injury compared to days 1-5 after trauma (37.4% vs. 28.9%-31.9%, p < 0.05). CONCLUSIONS: Monitoring of SjO2 in severe head injury provides an estimate of cerebral oxygen supply and may improve the assessment of therapeutic measures in these patients. The high incidence of erroneous readings of the SjO2 is a major drawback of this method. Initially after trauma, a high extraction of oxygen was found, followed by a marked decrease in the subsequent days, presumably reflecting an early, decreased cerebral blood flow and a hyperaemic flow pattern thereafter. Continuous measurements of SjO2 may contribute to advanced, organ-specific cerebral monitoring in severe craniocerebral trauma. The reliability of data, however, should be considerably improved for common clinical use.
Asunto(s)
Lesiones Encefálicas/sangre , Encéfalo/irrigación sanguínea , Tecnología de Fibra Óptica/instrumentación , Hipoxia Encefálica/sangre , Monitoreo Fisiológico/instrumentación , Oximetría/instrumentación , Adulto , Anciano , Femenino , Humanos , Hipoxia Encefálica/diagnóstico , Presión Intracraneal/fisiología , Venas Yugulares , Masculino , Persona de Mediana EdadRESUMEN
Severe head injury is frequently associated with focal or global disturbances of cerebral blood flow and metabolism. Routine monitoring of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in these patients does not provide information about critically reduced local or global cerebral blood flow. Measurements of cerebral lactate difference, Lactate-Oxygen-Index (LOI) and cerebral oxygen extraction were evaluated for advanced monitoring by comparing these parameters with ICP, cranial computed tomography (CCT) findings, and outcome in a group of severely head-injured patients. In 21 patients with severe brain trauma (GCS < or = 8), arterial as well as jugular venous lactate levels and oxygen saturation were measured in vitro every 6 h after admission of patients to the intensive care unit (ICU) throughout the acute course of treatment. Arterial blood pressure, blood gases, and ICP were assessed by standard monitoring measurements. CCT was performed initially after admission of the patients to the hospital, during the acute period in the ICU, if indicated, and 10 to 14 days after trauma. Outcome was classified according to the Glasgow outcome scale (GOS) at six months after injury. Data were averaged in each patient for every day after trauma and over the entire monitoring period. Resulting values were tested for correlation by regression analysis. Additionally, the data of the group of patients with normal to minimally elevated mean ICP (ICP < 20 mmHg, n = 12) were compared to those of the patients with increased mean ICP (ICP > 20 mmHg, n = 9). The cerebral lactate difference in all patients on the day of trauma was significantly increased as compared to the later period (0.20 vs. 0.11-0.07 mmol/l, p < 0.05), but was not different with high or normal to minimally elevated ICP. In patients with intracranial hypertension, the cerebral lactate difference remained significantly increased from the first to the fifth day after injury, whereas it normalized in this period in the group with normal to minimally elevated ICP. Averaged over the acute course, patients with increased ICP had significantly higher mean lactate differences (0.18 +/- 0.16 vs. 0.067 +/- 0.025 mmol/l, p = 0.001) and higher mean LOIs (0.072 +/- 0.071 vs. 0.028 +/- 0.013, p = 0.011). There was a significant correlation of increased mean cerebral lactate difference to poor outcome (r = 0.46, p = 0.035). Cerebral oxygen extraction in all patients tended to increase on the day of trauma (36.7% vs. 29.2% to 31.5% during the subsequent course), but this difference was not significant. The initial degree of brain swelling, classified by CCT according to Marshall et al. (1991), showed no correlation with cerebral lactate differences, ICP, O2-extraction, or outcome. Neither was there a correlation of cerebral oxygen extraction to ICP nor to outcome. In conclusion, the severity of brain trauma and outcome of patients was reflected by increased cerebral lactate production. Unchanged values of global cerebral oxygen extraction suggest that the regulatory mechanisms of brain oxygen supply were not impaired by trauma. Measurements of cerebral lactate differences and brain oxygen extraction may contribute to advanced monitoring in severe head injury.
Asunto(s)
Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/fisiopatología , Presión Intracraneal , Lactatos/metabolismo , Adolescente , Adulto , Anciano , Lesiones Encefálicas/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
Cardiac output measurement is part of routine monitoring in critically ill patients. In patients on extracorporeal lung assist, thermodilution cardiac output measurement may lead to erroneous results caused by indicator loss into the extracorporeal circuit. Seven patients on venovenous extracorporeal lung assist were studied using different extracorporeal blood flows. We compared conventional thermodilution cardiac output determinations with dye dilution cardiac output measurement, with dye injection into the pulmonary artery. The latter method is not affected by the extracorporeal circuit. The conventional thermodilution method overestimated cardiac output up to a maximum of 300%, providing results up to 10 L/min higher than true cardiac output. The mean difference between thermodilution and true cardiac output as determined by dye dilution with pulmonary artery indicator injection was 3.0 +/- 2.41 L/min. There was no correlation between thermodilution cardiac output values and true cardiac output (r = 0.06). We conclude that conventional thermodilution is not a suitable method for cardiac output measurement in patients on extracorporeal lung assist, especially if high extracorporeal blood flows are applied.
Asunto(s)
Gasto Cardíaco , Circulación Extracorporea , Respiración Artificial , Síndrome de Dificultad Respiratoria/fisiopatología , Síndrome de Dificultad Respiratoria/terapia , Adulto , Técnica de Dilución de Colorante , Femenino , Humanos , Masculino , Persona de Mediana Edad , TermodiluciónRESUMEN
OBJECTIVE: The purpose of this study was to evaluate the reliability and accuracy of a new continuous intra-arterial blood gas monitoring system (IABG; PB3300, Puritan Bennett) over a prolonged period of time (> 7 days). DESIGN: Prospective criterion standard study. SETTING: Anesthesiological intensive care unit in a university hospital. PATIENTS: 11 sensors were tested in 10 mechanically ventilated patients with severe respiratory failure. INTERVENTIONS: PO2, PCO2, and pH measured using IABG were compared to values obtained from 2 conventional blood gas analyzers. The quality of blood pressure tracings was assessed using a scoring system consisting of 5 grades. RESULTS: The median study period was 205h/sensor (range: 169-506h). 320 blood samples were obtained. The ranges of measured parameters were: PO2 = 46-433 mmHg, PCO2 = 25-79 mmHg, pH = 7.25-7.55. The mean (SD) differences for the whole study period were: -4.3 (11.9) mmHg for PO2, for the clinically important range (PO2 < 150 mmHg) -1.9 (5.4) mmHg, -2.8 (4.5) mmHg for PCO2, and -0.03 (0.04) for the pH value. The MD (SD) in relation to the sensor lifetime were for days 1-3: -1.1 (5.1) mmHg for PO2, -0.4 (3.9) mmHg for PCO2, and -0.01 (0.03) for the pH value; for days 4-6: -1.5 (6.0) mmHg for PO2, -3.3 (4.0) mmHg for PCO2, and -0.03 (0.03) for the pH value; for days 7-9: -2.5 (4.7) mmHg for PO2, -5.1 (4.6) mmHg for PCO2, and -0.04 (0.04) for the pH value; for days > 9: -4.9 (4.4) mmHg for PO2, -5.3 (4.1) mmHg for PCO2, and -0.05 (0.03) for the pH value. CONCLUSIONS: The IABG reliably measured blood gases and pH values with acceptable clinical performance based on the overall results. There was, however, a decline in the agreement of the sensors and conventional values with increasing sensor lifetime. The mean differences (bias) and the standard deviation of differences (precision) of PO2, PCO2 and the pH values were acceptable for clinical purposes up to day 6. The arterial blood pressure tracings and blood withdrawal were not adversely affected. No side effects due to the sensors occurred. In summary, a prolonged sensor use for a period of up to 6 days appears to be reasonable. This system offers on-line information on oxygenation, ventilation, and acid-base status and allows immediate detection of acute and potentially life-threatening events.
Asunto(s)
Análisis de los Gases de la Sangre/instrumentación , Cuidados Críticos , Monitoreo Fisiológico/instrumentación , Respiración Artificial , Insuficiencia Respiratoria/sangre , Adulto , Anciano , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Valores de Referencia , Insuficiencia Respiratoria/etiología , Insuficiencia Respiratoria/terapiaRESUMEN
Continuous monitoring of blood gases and pH could add substantially to patient safety. During the last decade, efforts have been made to develop continuous optochemical blood gas sensors. The initial evaluation of such fibreoptic-based systems showed major patient-interface problems [11]. We evaluated a new intra-arterial blood gas monitoring system (PB3300, Puritan-Bennett, Carlsbad CA) under routine clinical conditions. METHODS. After institutional review board approval and with written informed consent, 38 sensors were tested in 25 patients with acute respiratory failure (e.g., the acute respiratory distress syndrome, complications after lung transplantation). Two conventional bench-top blood gas analysers (ABL 520 and ABL 300, Radiometer, Copenhagen) served as criterion standards. The mean differences (bias) and standard deviations (SD) of the differences (precision) were calculated according to the method of Bland and Altman [2]. In addition, linear regression analysis and correlation coefficients were calculated. The quality of blood pressure tracings was assessed using a grading system. RESULTS. The median sensor lifetime was 81.3 h; 869 blood samples (median 14 per sensor) were analysed for the comparison of continuous and conventional blood gas analysis. The ranges for measured parameters were: pH: 6.92 to 7.55; PCO2: 20 to 83 torr; PO2: 31 to 518 torr. The mean differences (SD) were: pH: -0.03 (0.03) or -0.4 (0.4)%; PCO2: -2.6 (4.1) torr or -6.9 (10.9)%; PO2: -3.4 (10.5) torr or -2.9 (7.0)%. The results of linear regression analysis and the correlation coefficients are depicted in Table 2. The mean grade of blood pressure tracings was satisfactory for the clinical setting. CONCLUSIONS. The continuous blood gas monitor is sufficiently accurate and precise for clinical use. Bias and precision are better than those known from former studies evaluating fibreoptic blood gas monitors under experimental conditions [7]. Cost-effectiveness was not an issue of this study.
Asunto(s)
Análisis de los Gases de la Sangre/instrumentación , Dióxido de Carbono/sangre , Estudios de Evaluación como Asunto , Femenino , Tecnología de Fibra Óptica , Humanos , Concentración de Iones de Hidrógeno , Masculino , Fibras Ópticas , Oxígeno/sangre , Análisis de RegresiónRESUMEN
Pulmonary embolism is the most common cause of maternal death during pregnancy. CASE REPORT. We report a 28-year-old obstetric patient (35th gestational week) who was admitted to the hospital because of intermittent vaginal bleeding caused by placenta totalis et accreta. Eleven days after admission she suffered a cardiac arrest. After cardiopulmonary resuscitation, an emergency caesarian section was performed and a healthy child was delivered. Abdominal sonography (B-mode) showed a floating thrombus in the inferior vena cava. Perfusion scintigraphy and cavography were normal; a computed tomography i.v. contrast medium study confirmed the presence of the thrombus. An open thrombectomy was performed to protect the patient from further pulmonary emboli. After 8 days she left the intensive care unit without residual complications. CONCLUSION. This case emphasises the importance of bedside sonography as a diagnostic method of identifying the source of a thrombus in patients with suspected pulmonary embolism.
Asunto(s)
Complicaciones del Embarazo , Embolia Pulmonar/etiología , Trombosis/complicaciones , Vena Cava Inferior , Adulto , Femenino , Humanos , Embarazo , Trombosis/diagnóstico por imagen , UltrasonografíaRESUMEN
Innovative methods of providing workplace education for health care professionals may be a key to the survival of rural hospitals in America. Such methods must overcome time, distance, cost and organizational constraints, and take into account the structure of the learning experience. The Texas Hospital Education and Research Foundation has recently been involved in two programs that tested new approaches to worker education using distance-learning strategies. The projects--resource sharing among rural directors of nursing and training for cancer tumor registrars--used computer-conferencing technology. A new model using existing satellite, audio-conferencing, and computer-based instruction augmented by computer conferencing is proposed. The Computer-Related Assisted Distance Learning Enhancement (CRADLE) model integrates existing technologies to provide education to health care workers at their desktop. The Cancer Learning Center (CLC) tested peer collaboration, the primary component of the model. The ultimate goal is to have the system available to all tumor registrars in Texas, and to secure funding to implement rural nursing and rural high-school health occupations education projects. Current projects from set-up through results are presented.