Ajuste a la ventilación mecánica guiado por curvas presión-volumen de flujo lento en pacientes con síndrome de distress respiratorio agudo e injuria pulmonar aguda / Mechanical ventilatory parameters guided by the low flow pressure-volume curve in patients with acute lung injury/acute respiratory distress syndrome

Background: Mechanical ventilation may contribute to lung injury and then enhance systemic inflammation. Optimal ventilatory parameters such as tidal volume (V T) and positive end expiratory pressure (PEEP) can be determined using different methods. Low flow pressure volume (P/V-LF) curve is a useful tool to assess the respiratory system mechanics and set ventilatory parameters. Aim: To set V T and PEEP according P/V-LF curve analysis and evaluate its effects on gas exchange and hemodynamic parameters. Materials and methods: Twenty seven patients underwent P/V-LF within the first 72 hours of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). P/V-LF curves were obtained from the ventilator and both lower and upper inflexion points determined. Gas exchange and hemodynamic parameters were measured before and after modifying ventilator settings guided by P/V-LF curves. Results: Ventilatory parameters set according P/V-LF curve, led to a rise of PEEP and reduction of V T: 11.6±2.8 to 14.1±2.1 cm H2O, and 9.7±2.4 to 8.8±2.2 mL/kg (p <0.01). Arterial to inspired oxygen fraction ratio increased from 158.0±66 to 188.5±68.5 (p <0.01), and oxygenation index was reduced, 13.7±8.2 to 12.3±7.2 (p <0.05). Cardiac output and oxygen delivery index (IDO2) were not modified. Demographic data, gas exchange improvement and respiratory system mechanics showed no significant difference between patients with extra-pulmonary and pulmonary ALI/ARDS. There was no evidence of significant adverse events related with this technique. Conclusion: P/V-LF curves information allowed us to adjust ventilatory parameters and optimize gas exchange without detrimental effects on oxygen delivery in mechanically ventilated ALI/ARDS patients.

Adición de un cortocircuito arterio-venoso durante el soporte vital extracorpóreo veno-arterial de un paciente con síndrome cardiopulmonar por Hantavirus: Caso clínico / Addition of an arterio-venous shunt during veno-arterial extracorporeal life support in a patient with Hantavirus pulmonary syndrome

A subgroup of patients infected with the Hantavirus develops a pulmonary syndrome (HPS) characterized by severe acute respiratory failure and myocardial depression, that has a high mortality rate. Extracorporeal life support (ECLS) could be a valuable therapeutic tool in such patients. We report a 24 years old male with HPS that was successfully managed when an arterio-venous shunt was added to a conventional veno-arterial ECLS technique. Precise criteria have been developed to predict which patients should be considered for this treatment.

Volumen sanguíneo intratorácico versus presión arterial de oclusión pulmonar como estimadores de precarga cardíaca en pacientes críticos / Intrathoracic blood volume versus pulmonary artery occlusion pressure as estimators of cardiac preload in critically ill patients

Background:Monitoring of cardiac preload by determination of pulmonary artery occlusion pressure (PAOP) has been traditionally used to guide fluid therapy to optimize cardiac output (CO). Since factors such as intrathoracic pressure and ventricular compliance may modify PAOP, volumetric estimators of preload have been developed. The PiCCO system is able to measure CO and intrathoracic blood volume (ITBV) by transpulmonary thermodilution. Aim: To compare a volumetric (ITBV) versus a pressure (PAOP) determination to accurately estimate cardiac preload in severely ill patients. Patients and Methods: From June 2001 to October 2003, 22 mechanically ventilated patients with hemodynamic instability underwent hemodynamic monitoring with pulmonary artery catheter (PAC) and PiCCO system. ITBV index (ITBVI), PAOP and CI were measured simultaneously by both methods. One hundred thirty eight deltas (D) were obtained from the difference of ITBVI, PAOP, CI-PAC and CI-PiCCO between 6-12 am and 6-12 pm. Linear regression analysis of DITBVI versus Ð CI-PiCCO and Ð PAOP versus DCI-PAC were made. Results: Mean age of patients was 60.8 ± 19.4 years. APACHE II was 23.9 ± 7. Fifteen patients met criteria for acute respiratory distress syndrome (ARDS). Delta ITBVI significantly correlated with DCI-PiCCO (r=0.54; 95% confidence interval = 0.41-0.65; p <0.01). There was no correlation between DPAOP and Ð CI-PAC. Conclusion: ITBVI correlated better with CI than PAOP, and therefore it seems to be a more accurate estimator of preload in unstable, mechanically ventilated patients.

Nocardiosis diseminada en tres pacientes inmunocompetentes / Disseminated nocardiosis in 3 immunocompetent patients

Nocardia asteroide infections, an aerobic actinomycete, have several forms and lungs, skin and brain are the organs most frequently involved. When the infection suspected, special staining methods must be ordered to identify the agent. We report three immunocompetent patients with disseminated nocardiosis, 2 presenting with nodular lesions of skin and lungs and one presenting with pulmonary involvement and brain abscesses. The importance of clinical suspicion and early diagnosis of nocardiosis is emphasized

Presentaciones inhabituales de infecciones del tracto urinario en 6 casos / Unusual presentation of urinary tract infections in 6 cases

Urinary tract infections may have different clinical presentations that may range from asymptomatic bacteriuria to purulent collections and severe sepsis. We report 6 diabetic patients, 3 presenting with a renal carbuncle and 3 with an emphysematous pyelonephritis. All required medical and surgical treatment and had a good evolution. Two carbuncles were caused by beta-hemolitic type B streptococcus. This is the second notification of this agent as causative of renal abscesses, probably reaching the kidney through hematogenous dissemination from cutaneous foci

Septicemia por streptococcus pneumoniae: análisis de 40 casos / Septicemia by streptococcus pneumoniae: analysis of 40 cases

Sepsis due to streptococcus pneumoniae has a high mortality. We report a retrospective review of 40 episodes of S pneumonia sepsis in adult patients during a two yaer period in a general hospital, that represented 11,3 percent of all sepsis observed in such hospital. Ninety two percent of infections were community acquired and in 95 percent, the portal of entry was the respiratory tract. 85 percent of patients had at least one risk factor such as alcohol abuse, unconsciousness of chronic pulmonary disease. Nine patients had suppurative complications (empyema in 4 cases, spontaneous bacterial peritonitis in 2, septic arthritis in 2 and meningitis in 1 case) and 12 (30 percent) died. The potential benefit of antipneumococcal vaccine as prevention should be considered in high risk subjects