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Objetivo: Describir el valor del índice SaO2/FiO2 en nativos residentes sanos, pacientes con diferentes patologías así como gestantes durante el control prenatal a gran altitud. Material y métodos: Serie de casos llevada a cabo en el Hospital del Norte de la ciudad de Alto, La Paz (Bolivia) localizado a 4 090 metros sobre el nivel del mar, durante el periodo 01 Octubre 2018-31 Enero de 2019. Se incluyeron 119 participantes en quienes se calculó el índice SaO2/FiO2 con respiración a aire ambiente de manera casual, al momento de ingreso o control prenatal de los participantes. Resultados: El promedio del índice SaO2/FiO2 en nativos residentes sanos es de 426, en pacientes no neumópatas 376, neumópatas 312 y gestantes normoevolutivas 423. Existe una correlación negativa alta por r de Pearson entre el desarrollo de la gestación y el índice SaO2/FiO2. Conclusión: El presente estudio ofrece información novedosa acerca de los valores de referencia de SaO2/FiO2 para gran altitud, tanto de nativos residentes "sanos" así como pacientes neumópatas, no neumópatas y gestantes.
Objective. To describe SaO2/FiO2 (oxygen saturation/fraction of inspired oxygen) index in healthy native dwellers, patients with or without chronic lung diseases and pregnant women at high altitude. Material and methods. Case series at Hospital del Norte from El Alto city, La Paz-Bolivia, located at 4090 meters above sea level, during 1 October 2018 to 31 January 2019. 119 participants were included, and SaO2/FiO2 index was measured by using a pulse oximeter. Results. SaO2/FiO2 index average was 426 in healthy dwellers, 376 in patients with non-respiratory pathologies, 312 in patients with pulmonary diseases, and 423 in pregnant women. A high negative correlation (r of Pearson) was observed between pregnancy evolution and SAO2/FIO2 index. Conclusion. This study provides novel data about SaO2/FiO2 index at high altitude either of healthy native dwellers, patients with or without pulmonary diseases and pregnant women.
Subject(s)
Oxygen Radical Absorbance CapacityABSTRACT
BACKGROUND: A low fraction of inspired oxygen (FiO2) increases venous deoxygenated hemoglobin concentrations, making the color of the blood darker. The present study was aimed to determine the effects of FiO2 on the ability to discriminate venous from arterial blood. METHODS: One-hundred and sixty surgical patients undergoing percutaneous central venous access of the internal jugular vein were randomly assigned to receive an FiO2 of 0.2, 0.4, 0.6, or 1.0 (n = 40 each) for at least 20 min prior to central line placement under general anesthesia. Vascular access was achieved with a 22-gauge needle; 2 ml of blood was withdrawn and shown to three physicians including the operator. Each of them was asked to identify the blood as 'arterial', 'venous' or 'not sure'. Simultaneous blood gas analysis of the samples was performed on blood taken from the puncture site and the artery after visual comparison to confirm blood's origin and hemodynamic measurements. RESULTS: Lowering FiO2 progressively increased venous deoxygenated hemoglobin concentrations (2.24 +/- 1.12, 3.30 +/- 1.08, 3.66 +/- 1.15, and 3.71 +/- 1.33 g/dl) in groups having an FiO2 of 1.0, 0.6, 0.4 and 0.2, respectively (P < 0.001), thereby facilitating the 'venous' blood identification (P < 0.001). Neither heart rate nor mean arterial pressure differed among the groups. None developed hypoxemia (percutaneous hemoglobin oxygen saturation < 90%) in any group during the study period. CONCLUSIONS: A low FiO2 increases venous deoxygenated hemoglobin levels, thereby facilitating the recognition by clinicians of its venous origin in percutaneous central venous catheterization under general anesthesia.
Subject(s)
Humans , Anesthesia, General , Hypoxia , Arterial Pressure , Arteries , Blood Gas Analysis , Catheterization, Central Venous , Central Venous Catheters , Heart Rate , Hemodynamics , Hemoglobins , Jugular Veins , Oxygen , PuncturesABSTRACT
The effects of inspired oxygen fractions (FiO2) of 1 and 0.6 on bispectral index (BIS) in dogs with high intracranial pressure, submitted to a continuous rate infusion of propofol were evaluated. Eight dogs were anesthetized on two occasions, receiving, during controlled ventilation, an FiO2 = 1 (G100) or an FiO2 = 0.6 (G60). Propofol was used for induction (10mg.kg-1, IV), followed by a continuous rate infusion (0.6mg.kg-1.minute-1). After 20 minutes, a fiber-optic catheter was implanted on the surface of the right cerebral cortex to monitor the intracranial pressure, the baseline measurements of BIS values, signal quality index, suppression ratio number, electromyogram indicator, end-tidal carbon dioxide partial pressure, mean arterial pressure, intracranial pressure and cerebral perfusion pressure were taken. Then, the blood flow from the right jugular vein was interrupted in order to increase intracranial pressure and after 20 minutes additional recordings were performed at 15-minute intervals (T0, T15, T30, T45 and T60). The arterial oxygen partial pressure varied according to the changes in oxygen. For the other parameters, no significant differences were recorded. The BIS monitoring was not influenced by different FiO2.
Avaliaram-se os efeitos das frações inspiradas de oxigênio (FiO2) de 1 e 0,6 sobre o índice biespectral (BIS) em cães com pressão intracraniana elevada e submetidos a infusão contínua de propofol. Oito animais foram anestesiados em duas ocasiões, recebendo durante a ventilação controlada FiO2 = 1(G100) ou FiO2 = 0,6 (G60). Propofol foi usado para indução (10mg.kg-1) e seguido por infusão contínua (0,6mg.kg-1minuto-1). Após vinte minutos da implantação do cateter de fibra óptica do monitor de pressão intracraniana, na superfície do córtex cerebral direito, realizaram-se as mensurações basais de BIS, índice de qualidade de sinal, taxa de supressão, eletromiografia, pressão parcial de dióxido de carbono ao final da expiração, pressão arterial média, pressão intracraniana e pressão de perfusão cerebral. Em seguida, interrompeu-se o fluxo sanguíneo da veia jugular direita, para o aumento da pressão intracraniana e depois de 20 minutos, novas mensurações foram realizadas em intervalos de 15 minutos (T0, T15, T30, T45 e T60). A pressão parcial de oxigênio no sangue arterial variou conforme a FiO2. Para os outros parâmetros não foram registradas diferenças significativas. Conclui-se que o monitoramento pelo BIS não foi afetado pelo emprego de diferentes FiO2.
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Objective To investigate the influence of inspired oxygen fraction (FiO2) on the ratio of PaO2/FiO2(P/F) during the implementation of lung protective ventilation strategy in patients with acute respiratory distress syndrome(ARDS) in order to unravel its clinical significance. Method This was a prospective study of 16 selected patients with ARDS treated with mechanical ventilation ( MV ) to get ratio of P/F in range of 100 to 200 by PEEP≥5 cmH2O and high inspired oxygen. After lung recruitment maneuvers by BiPAP with high pressure (PH) of 40 cmH2O for40 s, the MV was maintained the basic requirement for stabilizing the patients for 30 minutes. A series of FiO2 were set at fractions of 0.5,0.6,0.7,0.8,0.9 and 1in random sequence, and the changes of respiratory mechanics, blood gas and hemodynamics under the different concentrations of FiO2 were analyzed by using SPSS version 13.0 software. Results ( 1 ) The ratio of P/F increased as FiO2 increased, and it's significant as FiO2 increased to 0.7 or above. As the fractions of FiO2 were set at 0.5 and 1. O, the ratios of P/F changed in 24.70% ± 23.36% respectively. ( 2 ) Of them,6 patients ( 37.5% ) treated with FiO2 set at 0.5 had the ratio of P/F ＜ 200, and the fraction of FiO2 was increased to 1.0, the P/F ＞ 200. (3) FiO2 and Qs/Qt were negatively correlated ( r = - 0.390, P = O. 027 ),the higher inspired oxygen fraction, the lower shunt. When the fractions of FiO2 were set at 0.5 and 1.0 ,there was a positive correlation between △Qs/Qt and △P/F( r = 0.82, P = 0.005 ). Conclusions The inspired oxygen fraction affects the ratio of P/F, which may be resulted from shunt and it may influence the diagnosis of ARDS.
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A pressão intrapleural normalmente é menor que a pressão intrapulmonar. Consequentemente , os pulmões tendem ao colapso e se retraem, afastando-se da parede torácica. No início do século XX, Pasteur descreveu a atelectasia pulmonar, que ocorre com frequência durante a indução anestésica, persiste no período pós-operatório e pode contribuir de maneira significativa para a morbidade e o aumento nos gastos com medicamentos. Em medicina veterinária, no entanto, a atelectasia não é frequentemente diagnosticada, apesar de que isso não implica afirmar que tal afecção não ocorra, visto que existem relatos do desenvolvimento desse quadro em cães e em outras espécies. No contexto da anestesia geral, essa complicação pulmonar pode ser encontrada em animais que respiram 80 a 100 por cento de oxigênio. A partir dessas informações, torna-se necessário que o profissional da anestesiologia veterinária obtenha conhecimentos complementares sobre o tema. Com este trabalho, objetivou-se descrever alguns dos mecanismos da atelectasia e seus pontos relevantes, de modo a familiarizar os profissionais quanto aos pormenores dessa importante, e nem sempre bem compreendida, alteração fisiológica respiratória.
Pleural pressure is usually lower than pulmonary pressure. Therefore, the lungs tend to collapse and increase its distance from thoracic walls. At the beginning of 20th century, Pasteur described the pulmonary atelectasis, which develops during induction of anesthesia and persists to the postoperative period. It can contribute significantly to morbidity and to increase the medical expenses. In veterinary medicine, pulmonary atelectasis is not frequently diagnosed, which doesn't rule out the occurrence of this disease, since there are reports of atelectsasis in dogs. This pulmonary complication can be found in animals that breathe 80 percent to 100 percent oxygen in anesthetic procedures. Based on this information, the veterinary anesthesiologist is required to search for complementary knowledge regarding to pulmonary atelectasis. This study, therefore, aimed to describe some of the mechanisms involved in the development of atelectasis. It aimed also to familiarize the anesthesiologist to this not always well- understood physiological breathing change.
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BACKGROUND: Most recently, the antiemetic effects of high inspired oxygen have been discussed and various results have been reported according to the types of surgeries and the groups of patients. In ophthalmic surgical patients, surgical procedures involving intraoperative manipulation of the eye and giving rise to residual eye discomfort were associated with the increased incidences of postoperative nausea and vomiting (PONV). The antiemetic effect of 80% inspired oxygen for the patients undergoing vitreoretinal surgery is unknown. Therefore, we examined the efficacy of 80% inspired oxygen in the decrease of the PONV incidences after vitreoretinal surgery under general anesthesia. METHODS: 170 adults under 70 years of age have received standardized sevoflurane anesthesia. After tracheal intubation, they were randomly assigned to two groups: 30% inspired oxygen in air (Group 30), and 80% inspired oxygen in air (Group 80). Postoperative nausea and vomiting were evaluated at the 2, 6, and 24 h postoperatively by an investigator unaware of patients' allocation. RESULTS: There was a significantly lower incidence of PONV during the first 2 h postoperatively in the Group 80 (22%) compared with the Group 30 (40%) (P = 0.024). The Group 80 (33.8%) showed the decreased incidence of PONV during the first 24 h postoperatively compared with the Group 30 (48.8%), but these differences were not statistically significant (P = 0.081). CONCLUSIONS: The use of 80% inspired oxygen during vitreoretinal surgery reduced the incidence of PONV during the first 2 h postoperatively.
Subject(s)
Adult , Humans , Anesthesia , Anesthesia, General , Antiemetics , Incidence , Intubation , Oxygen , Postoperative Nausea and Vomiting , Research Personnel , Vitreoretinal SurgeryABSTRACT
Objective To discuss the apparatus of inspired oxygen in hyperbaric oxygen(HBO)chamber for patients after tracheotomy.Methods Many kinds of apparatus of inspired oxygen were analyzed,including composition,usage and characteristics.Results The apparatus of inspired oxygen play an active role in treating patients.But in the above apparatus,there are great differences in serving range,efficiency of inspired oxygen,curative effect,reliability and so on.Conclusions When serious patients after tracheotomy are treated in HBO chamber earlier,it is very important to select reasonable apparatus.
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BACKGROUND: Preoxygenation is routine prior to rapid sequence induction of general anesthesia for a cesarean section. The aim of this study was to evaluate the preoxygenation techniques of tidal volume breathing (TVB) and deep breathing (DB) for a cesarean section. METHODS: One hundred twenty ASA I and II patients scheduled for a cesarean section under general anesthesia participated in the study. Preoxygenation was performed with 5, 7, and 10 L/min 100% oxygen. The following techniques were tested: 1) normal TVB for a 5-min period (TVB/5 min) and 2) DB for a 2-min period (4 DB/0.5 min, 8 DB/min, 12 DB/1.5 min and 16 DB/2 min). Inspired (FIO2) and end-tidal oxygen fraction (FETO2), end-tidal carbon dioxide pressure (ETCO2) and oxygen saturation (SpO2) were measured at 0.5-min intervals. RESULTS: During TVB, FETO2 increased rapidly between 0.5 and 3.5 min and plateaued by 3.5 min at 78.5%, 83.3% and 90.8% with 5, 7 and 10 L/min 100% oxygen, respectively. Four DB/0.5 min increased FETO2 to 64.7%, 67.2% and 72.3% at 5, 7, and 10 L/min 100% oxygen, respectively. As compared with four DB/0.5 min, the values of FETO2 with TVB/1.5 min and TVB/2 min were high at 7, 10 and 5 L/min 100% oxygen. CONCLUSIONS: We concluded that TVB/2 min was more effective than four DB/0.5 min in achieving preoxygenation but eight DB/min could be used in case of an emergent operation.
Subject(s)
Female , Humans , Pregnancy , Anesthesia, General , Carbon Dioxide , Cesarean Section , Oxygen , Respiration , Tidal VolumeABSTRACT
We define acute respiratory failure(ARF) as present whenever the ratio of arterial oxygen tension (PaO2) and inspired oxygen concentrarion(FiO2) is below the normal predicted range for the patient's age and/or the arterial carbon dioxide tension(PaCO2) is above 45 in the absence of respiratory compention for metabolic alkalosis. Adult respiratory distress syndrome(ARDS) which is associated with shock, trauma, infection, inhalation of toxic gas, aspiration of gastric content and drugs etc, first received wide-spread attention in 1967. ARDS is a descriptive term that is characterized by a combination of refractory hypoxemia and severly decreased lung compliance. Numerous specific incidents or illnesses may be complicated by, or associated with ARDS. Early diagnosis and improvement in physiological therapy including PEEP therapy have been successful in treating the early and mild episodes of ARDS. This report describes three cases of ARF following anesthesia and reviews the literature.