ABSTRACT
Near-infrared spectroscopy (NIRS) could be a useful continuous, non-invasive technique for monitoring the effect of partial pressure of carbon dioxide (PaCO2) fluctuations in the cerebral circulation during ventilation. The aim of this study was to examine the efficacy of NIRS to detect acute changes in cerebral blood flow following PaCO2 fluctuations after confirming the autoregulation physiology in piglets. Fourteen piglets (<72 h of life) were studied. Mean arterial blood pressure, oxygen saturation, pH, glycemia, hemoglobin, electrolytes, and temperature were monitored. Eight animals were used to evaluate brain autoregulation, assessing superior cava vein Doppler as a proxy of cerebral blood flow changing mean arterial blood pressure. Another 6 animals were used to assess hypercapnia generated by decreasing ventilatory settings and complementary CO2 through the ventilator circuit and hypocapnia due to increasing ventilatory settings. Cerebral blood flow was determined by jugular vein blood flow by Doppler and continuously monitored with NIRS. A decrease in PaCO2 was observed after hyperventilation (47.6±2.4 to 29.0±4.9 mmHg). An increase in PaCO2 was observed after hypoventilation (48.5±5.5 to 90.4±25.1 mmHg). A decrease in cerebral blood flow after hyperventilation (21.8±10.4 to 15.1±11.0 mL/min) and an increase after hypoventilation (23.4±8.4 to 38.3±10.5 mL/min) were detected by Doppler ultrasound. A significant correlation was found between cerebral oxygenation and Doppler-derived parameters of blood flow and PaCO2. Although cerebral NIRS monitoring is mainly used to detect changes in regional brain oxygenation, modifications in cerebral blood flow following experimental PaCO2 changes were detected in newborn piglets when no other important variables were modified.
Subject(s)
Hypocapnia , Respiration, Artificial , Animals , Animals, Newborn , Carbon Dioxide , Cerebrovascular Circulation/physiology , Hypercapnia , Oxygen , SwineABSTRACT
Near-infrared spectroscopy (NIRS) could be a useful continuous, non-invasive technique for monitoring the effect of partial pressure of carbon dioxide (PaCO2) fluctuations in the cerebral circulation during ventilation. The aim of this study was to examine the efficacy of NIRS to detect acute changes in cerebral blood flow following PaCO2 fluctuations after confirming the autoregulation physiology in piglets. Fourteen piglets (<72 h of life) were studied. Mean arterial blood pressure, oxygen saturation, pH, glycemia, hemoglobin, electrolytes, and temperature were monitored. Eight animals were used to evaluate brain autoregulation, assessing superior cava vein Doppler as a proxy of cerebral blood flow changing mean arterial blood pressure. Another 6 animals were used to assess hypercapnia generated by decreasing ventilatory settings and complementary CO2 through the ventilator circuit and hypocapnia due to increasing ventilatory settings. Cerebral blood flow was determined by jugular vein blood flow by Doppler and continuously monitored with NIRS. A decrease in PaCO2 was observed after hyperventilation (47.6±2.4 to 29.0±4.9 mmHg). An increase in PaCO2 was observed after hypoventilation (48.5±5.5 to 90.4±25.1 mmHg). A decrease in cerebral blood flow after hyperventilation (21.8±10.4 to 15.1±11.0 mL/min) and an increase after hypoventilation (23.4±8.4 to 38.3±10.5 mL/min) were detected by Doppler ultrasound. A significant correlation was found between cerebral oxygenation and Doppler-derived parameters of blood flow and PaCO2. Although cerebral NIRS monitoring is mainly used to detect changes in regional brain oxygenation, modifications in cerebral blood flow following experimental PaCO2 changes were detected in newborn piglets when no other important variables were modified.
ABSTRACT
Background: Transmitted drug resistance (TDR) occurs in patients with HIV infection who are not exposed to antiretroviral drugs but who are infected with a virus with mutations associated with resistance. Aim: To determine the prevalence of TDR and characterize HIV reverse transcriptase and protease mutation patterns. Material and Methods: HIV infected antiretroviral treatment-naive patients treated in three centers between 2014 and 2018 were studied. A genotyping study was carried out. The HIVdb Program (Stanford University) and the World Health Organization (WHO) TDR surveillance mutation list were used to register resistance-associated mutations. Results: We enrolled 220 patients aged a median of 29 (interquartile range (IQR) 24-34) years, 99% men. Median CD4 count was 365 cells/μL (IQR 250-499 cells/μL) and median viral load was 39.150 copies/mL (IQR 9,270 −120,000). The overall prevalence of RTD was 10.45% (95% CI 6.7-15.2, N = 23/220). The higher frequency of TDR was against non-nucleoside reverse transcriptase inhibitors, reaching 9.0% (95% CI 5.6-13.6), followed by nucleoside reverse transcriptase inhibitors reaching 1.8% (95% CI 0.49-4.5) and protease inhibitors reaching 0.45% (95% CI 0.01-2.5). The mutations in reverse transcriptase were M41L, L210W, D67N, K70E, M184V, K103N (6.36%, 95% CI 3.5-10.4), G190A, E138A, K101E, and I84V in protease. Conclusions: These results should prompt a change in recommendations for starting antiretoviral therapy, especially in first-line regimens that include non-nucleoside reverse transcriptase inhibitors.
Subject(s)
Aged , Female , Humans , Male , HIV Infections , HIV-1 , Anti-HIV Agents , HIV Infections/drug therapy , HIV Infections/epidemiology , Chile/epidemiology , Prevalence , HIV-1/genetics , Anti-HIV Agents/therapeutic use , Anti-HIV Agents/pharmacology , Drug Resistance, Viral/genetics , Genotype , MutationABSTRACT
BACKGROUND: Transmitted drug resistance (TDR) occurs in patients with HIV infection who are not exposed to antiretroviral drugs but who are infected with a virus with mutations associated with resistance. AIM: To determine the prevalence of TDR and characterize HIV reverse transcriptase and protease mutation patterns. MATERIAL AND METHODS: HIV infected antiretroviral treatment-naive patients treated in three centers between 2014 and 2018 were studied. A genotyping study was carried out. The HIVdb Program (Stanford University) and the World Health Organization (WHO) TDR surveillance mutation list were used to register resistance-associated mutations. RESULTS: We enrolled 220 patients aged a median of 29 (interquartile range (IQR) 24-34) years, 99% men. Median CD4 count was 365 cells/µL (IQR 250-499 cells/µL) and median viral load was 39.150 copies/mL (IQR 9,270 -120,000). The overall prevalence of RTD was 10.45% (95% CI 6.7-15.2, N = 23/220). The higher frequency of TDR was against non-nucleoside reverse transcriptase inhibitors, reaching 9.0% (95% CI 5.6-13.6), followed by nucleoside reverse transcriptase inhibitors reaching 1.8% (95% CI 0.49-4.5) and protease inhibitors reaching 0.45% (95% CI 0.01-2.5). The mutations in reverse transcriptase were M41L, L210W, D67N, K70E, M184V, K103N (6.36%, 95% CI 3.5-10.4), G190A, E138A, K101E, and I84V in protease. CONCLUSIONS: These results should prompt a change in recommendations for starting antiretoviral therapy, especially in first-line regimens that include non-nucleoside reverse transcriptase inhibitors.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Aged , Anti-HIV Agents/pharmacology , Anti-HIV Agents/therapeutic use , Chile/epidemiology , Drug Resistance, Viral/genetics , Female , Genotype , HIV Infections/drug therapy , HIV Infections/epidemiology , HIV-1/genetics , Humans , Male , Mutation , PrevalenceABSTRACT
Background: The main cause of virological failure during AIDS treatment is the resistance to antiretroviral medications (ARV). Aim: To search for mutations associated with ARV resistance in recently HIV-1 infected patients naïve to treatment, in Chile. Material and Methods: Patients over 18 years old with HIV-1 infection, naïve to antiretroviral drugs before the study were included. Patients with CD4 cell counts less than 200 cells/mm³, viral load below 2.000 copies/mL or any condition indicative of advanced AIDS were excluded. Criteria for diagnosis of recent infection (< 18 months) were a previous negative test for HIV antibodies or a history of an acute retroviral syndrome in the past 18 months. Resistance to drugs was analyzed using the TRUGENEtm HIV-1 assay from Bayer and the OpenGene DNA sequencing system. Results: Ninety nine percent of patients had at least one mutation, 27 percent had 4 or more mutations, but high level resistance to ARV was found only in 2.7 percent of cases. Point mutations for non nucleoside reverse transcriptase inhibitors (NNRTI) were detected in 4.1 percent of cases (K103N in 1 patient, V179D in 2 patients), for nucleoside reverse transcriptase inhibitors (NRTI) in 8.1 percent of cases (T215S in 1 patient, V118I in 4 patients, M41L in 1 patient) and for protease inhibitors (PI) in 1.3 percent of cases. All mutations detected in the protease gene were secondary. Of these, the most common were L63P/T (38 patients), L10I/V (27 patients) and V77I (26 patients). Resistance to two or more antiretroviral classes was not detected. Conclusions: This study supports that, by now, primary resistance has a low prevalence in Chile. Therefore, a genotyping test before starting antiretroviral therapy is not necessary.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , HIV-1 , Anti-HIV Agents/adverse effects , Drug Resistance, Viral/genetics , HIV Infections/drug therapy , Mutation/genetics , HIV-1 , Anti-HIV Agents/therapeutic use , Chile , HIV Infections/virology , Mutation/drug effectsABSTRACT
We report a 42 years old HIV negative male admitted for fever of unknown origin. Initial laboratory evaluation showed elevated hepatic transaminases and alkaline phosphatase and an hipodense hepatic imagen was visualized in the CT scan. Hepatic biopsy demonstrated tuberculous granulomas and alcohol fast acid rods with Ziehl Neelsen stain. Anti-tuberculous treatment resulted in resolution of fever, improvement of general condition and normalization of laboratory parameters.
Subject(s)
Antitubercular Agents/therapeutic use , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Hepatic/diagnosis , Tuberculosis, Splenic/diagnosis , Adult , Biopsy , Fever of Unknown Origin/microbiology , HIV Seronegativity , Humans , Male , Tomography, X-Ray Computed , Tuberculosis, Hepatic/drug therapy , Tuberculosis, Splenic/drug therapyABSTRACT
Reportamos el caso de un hombre de 42 años, seronegativo para VIH, con fiebre de origen desconocido (FOD), asociada a elevación de transaminasas y fosfatasas alcalinas con patrón colestásico e imágenes hepáticas hipodensas en la tomografía axial computada. La biopsia hepática demostró la presencia de granulomas tuberculosos con visualización de un bacilo con alcohol-ácido resistencia. El cuadro respondió al tratamiento con fármacos antituberculosos presentando caída de curva febril, mejoría del estado general y normalización de parámetros de laboratorio.
We report a 42 years old HIV negative male admitted for fever of unknown origin. Initial laboratory evaluation showed elevated hepatic transaminases and alkaline phosphatase and an hipodense hepatic imagen was visualized in the CT scan. Hepatic biopsy demonstrated tuberculous granulomas and alcohol fast acid rods with Ziehl Neelsen stain. Anti-tuberculous treatment resulted in resolution of fever, improvement of general condition and normalization of laboratory parameters.
Subject(s)
Humans , Male , Adult , Antitubercular Agents/therapeutic use , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Hepatic/diagnosis , Tuberculosis, Splenic/diagnosis , Biopsy , Fever of Unknown Origin/microbiology , Tomography, X-Ray Computed , Tuberculosis, Hepatic/drug therapy , Tuberculosis, Splenic/drug therapyABSTRACT
Las infecciones nosocomiales en pacientes críticos exigen de una terapia antinfecciosa de excepción por la gravedad de las mismas y por su refractariedad a los antimicrobianos habituales. En las unidades de pacientes críticos deben implementarse políticas para evitar la selección de cepas multiresistentes que comprometa la eficacia de estos antimicrobianos; útiles para limitar esta selección son: reducción en el uso de profilaxis quirúrgica, rotación de antimicrobianos, abreviar los plazos de tratamiento e implementar el de-escalamiento de agentes antibacterianos apoyado en un diagnóstico microbiológico rápido y sensible. Se revisan las múltiples estrategias propuestas para optimizar el efecto antimicrobiano de los antibióticos: aplicación de conceptos farmacocinéticos y farmacodinámicos, uso de nuevas presentaciones lipídicas de anfotericina B, el empleo inhalatorio de aminoglucósidos y la terapia ½de candado¼ para las infecciones de catéteres vasculares centrales. Se discuten también la descontaminación selectiva en el paciente en ventilación mecánica y el tratamiento con mupirocina tópica de la portación nasal de Staphylococcus aureus resistente a meticilina como herramientas para prevenir algunas infecciones severas
Subject(s)
Humans , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacokinetics , Drug Resistance, Bacterial , Intensive Care Units , Cross InfectionSubject(s)
Humans , Bacterial Infections , Diabetic Foot/complications , Amputation, Surgical , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Bacterial Infections , Osteomyelitis , Diabetic Foot/classification , Diabetic Foot/diagnosis , Diabetic Foot/microbiology , Wound HealingABSTRACT
Four hundred and eighty six infected adults (90,7 percent men) were prospectively followed from 1988 to 1993 at a multi-professional center in Santiago, Chile. 87,8 percent of male patients (pts), 84 percent of them homo/bisexual, and 64,4 percent of women acquired the infection sexually. At the beginning of the follow up (F/U) 51 percent of men and 71 percent of women were asymptomatic and 30 percent of the total group had AIDS. (AIDS definition: CDC 1993, excluded CD4 lymphocyte count <200 x mm3). 240/486 (49,4 percent) had developed AIDS at the end of the study (12/31/93). AIDS defining events (ADE) were: interstitial pneumonia (confirmed or suggestive as caused by P. carinii [PCP]), 25 percent; tuberculosis (all forms), 22.1 percent; wasting, 13.8 percent; Kaposi Sarcoma, 9.2 percent; esophageal candidiasis, 6.7 percent; isosporiasis, 5,4 percent. Of all PCP cases, 72 percent were ADE, the rest, post AIDS'. As expected, AIDS pts continued having major complications (mainly bacterial pneumonias, PCPs, esophagitis, tuberculosis and diarrhea due to I. belli and Cryptosporidium. Less frequently, but also observed, were toxoplasmic encephalitis and cryptococcal meningitis). Known mortality (excluded abandonment of F/U) was 27 percent for the whole group and varied from 5.8 percent, 51,6 percent to 69.2 percent for the first, 4th and 6th yaer of F/U respectively. For II-III CDC pts the mortality was 5 percent and 57 percent and for IV CDC pts it was 38 percent and 100 percent during the first and 6th year of F/U respectively. 36 percent, 53 percent, 74 percent and 85 percent of the pts followed for 1, 3, 5 and 6 years respectively had developed AIDS by the end of 1993. Multifactorial causes with either diarrhea, wasting or both were responsible for the death in half the pts in whom this was known, 15 percent died of respiratory complications and 5,7 percent of cryptococcal meningitis. 80 percent of AIDS pts survived their ADE. This study has provided information about the clinical profile of the HIV infection and natural history of the disease in Chile
Subject(s)
Humans , Male , Female , Adult , Middle Aged , HIV Infections/diagnosis , Acquired Immunodeficiency Syndrome/diagnosis , Homosexuality/statistics & numerical data , HIV Infections/transmission , HIV Infections/epidemiology , Natural History of Diseases , Disease-Free Survival , Sex Distribution , Acquired Immunodeficiency Syndrome/epidemiology , Acquired Immunodeficiency Syndrome/transmissionABSTRACT
Se efectuó un estudio prospectivo de determinación de concentración inhibitoria mínima (CIM) de ceftazidima (CZD) en cepas de E. coli, K. pneumoniae y P. aeruginosa obtenidas en un hospital docente en Chile, en los años 1985, 1988 y 1991. Se observó un aumento estadísticamente significativo de la resistencia de CZD en los tres tipos de bacilos gram negativos (BGN) estudiados. La CIM 90 de E. coli aumentó de 0,25 µg/ml en 1988 a 1 µg/ml en 1991, con un 100 por ciento de cepas sensibles en 1988 contra un 94,1 por ciento en 1991 (p=0,019). En 1991 se aislaron 4 cepas resistentes a concentraciones de CZD de 128 µg/ml. La CIM 90 de K. pneumoniae aumentó de 4 µg/ml en 1985 a más de 128 µg/ml en 1991, con un 95,3 por ciento de cepas sensibles en 1985 contra un 55,6 por ciento en 1991 (p<0,001). Se encontraron 23 cepas resistentes a concentraciones de CZD de 128 g/ml. La CIM 90 de P. aeruginosa aumentó de 4 g/ml en 1985 a 128 g/ml en 1991, con un 93 por ciento de cepas sensibles en 1985 contra un 46,2 por ciento en 1991 (p<0,001). La distribución de la resistencia es diferente en los tres tipos de BGN estudiados, siendo K. pneumoniae quien demuestra la adquisión más rápida y de niveles más altos de resistencia a CZD. La tasa de resistencia a CZD encontrada en nuestro estudio es concordante con tasas reportadas en otros hospitales sudamericanos y más alta que la habitualmente reportada en hospitales de EEUU