Efeito da reabilitação cardiopulmonar e metabólica em pacientes que apresentaram dessaturação da oxihemoglobina induzida pelo exercício após alta hospitalar pela COVID-19: série de casos / Effect of cardiopulmonary and metabolic rehabilitation in patients with exercise-induced oxyhemoglobin desaturation after hospital discharge from COVID-19: case series

INTRODUÇÃO: A dessaturação da oxihemoglobina induzida pelo exercício em pacientes pós-COVID-19 parece estar associada à redução da difusão e dos volumes pulmonares, à maior dispneia e baixa capacidade funcional, sendo relacionada à maior mortalidade e pior prognóstico. A reabilitação cardiopulmonar e metabólica (RCPM) é relevante, pois visa restaurar a funcionalidade, tolerância ao esforço e a qualidade de vida (QV). OBJETIVO: Verificar os efeitos da RCPM em pacientes que apresentaram dessaturação da oxihemoglobina induzida pelo exercício após alta hospitalar pela COVID-19 e ainda observar a diferença entre os treinamentos contínuo de moderada intensidade (TCMI) e o intervalado de alta intensidade (TIAI) na tolerância ao esforço, nos sintomas e na QV. MÉTODOS: Trata-se do relato de uma série de 4 casos que foram hospitalizados por COVID-19 e que após alta hospitalar apresentaram dessaturação da oxihemoglobina induzida pelo esforço durante o teste do degrau de 6 minutos (TD6). Os pacientes foram avaliados por meio de espirometria de repouso, mensuração da força da musculatura inspiratória, TD6, teste da caminhada de 6 minutos (TC6), teste de repetições máximas do quadríceps e bíceps braquial e responderam ao questionário SF-36 de QV. Submetidos a um protocolo de treinamento contendo treino da musculatura inspiratória e treino resistido para grandes grupos musculares, adicionalmente, 2 pacientes fizeram TCMI (com 60-80% da frequência cárdica de reserva (FCR)) e 2 TIAI (com 40% da FCR na fase off, durante 4 minutos e 80 a 100%, na fase on, durante 2 minutos) em esteira por 30 minutos e, por fim, após 3 meses foram reavaliados. RESULTADOS: Observouse aumento da tolerância ao esforço, da força muscular inspiratória e periférica, além da melhora da QV e redução dos sintomas em todos os pacientes após a RCPM, porém houve incrementos maiores nos pacientes submetidos ao TIAI comparados ao TCMI na distância percorrida em metros (caso 1- 156 (23% de incremento); caso 3 - 168 (40%)) versus (caso 2 e 4 - 60 metros, com incrementos de 9% e 14%, respectivamente) e maior número de degraus (caso 1- 28 (23% de aumento); caso 3- 37 (34%)) versus (caso 2 ­ 2 (2% incremento); caso 4 - 15 (21%)). CONCLUSÃO: A RCPM apresentou efeitos positivos, com incremento da capacidade funcional e melhora da QV, além da redução dos sintomas durante o esforço, particularmente nos pacientes submetidos ao TIAI.

INTRODUCTION: Exercise-induced oxyhemoglobin desaturation in post-COVID-19 patients appears to be associated with reduced diffusion and lung volumes, greater dyspnea and low functional capacity, being related to higher mortality and worse prognosis. Cardiopulmonary and metabolic rehabilitation (CPMR) is relevant, as it aims to restore functionality, exercise tolerance and quality of life (QoL). OBJECTIVE: To verify the effects of CPMR in patients who presented exercise-induced oxyhemoglobin desaturation after hospital discharge due to COVID-19 and also to observe the difference between moderate-intensity continuous training (MICT) and high intensity interval training (HIIT) on effort tolerance, symptoms and QoL. METHODS: This is the report of a series of 4 cases who were hospitalized for COVID-19 and who, after hospital discharge, presented exertion-induced oxyhemoglobin desaturation during the 6-minute step test (6MST). Patients were assessed using spirometry at rest, measurement of inspiratory muscle strength, 6MST, 6-minute walk test (6MWT), quadriceps and biceps brachii maximum repetitions test, and answered the SF-36 QoL questionnaire. Submitted to a training protocol containing training of the inspiratory muscles and resistance training for large muscle groups, additionally, 2 patients underwent CMIT (with 60-80% of heart rate reserve) and 2 HIIT (with 40% of HR reserve in the off, for 4 minutes and 80 to 100%, in the on phase, for 2 minutes) on a treadmill for 30 minutes, finally, after 3 months, they were reassessed. RESULTS: There was an increase in effort tolerance, inspiratory and peripheral muscle strength, in addition to an improvement in QoL and a reduction in symptoms in all patients after CPMR, but there were greater increments in patients submitted to HIIT compared to CMIT in the distance covered in meters (case 1 - 156 (23% increment); case 3 - 168 (40%)) versus (case 2 and 4 - 60 meters, with increments of 9% and 14%, respectively) and greater number of steps (case 1 - 28 (23% increase); case 3- 37 (34%)) versus (case 2 ­ 2 (2% increment); case 4 - 15 (21%)). CONCLUSION: CPMR had positive effects, with an increase in functional capacity and improvement in QoL, in addition to a reduction in symptoms during exertion, particularly in patients undergoing HIIT.

Factores asociados a bajo rendimiento cognitivo en adultos con sospecha de apnea obstructiva del sueño / Factors associated with low cognitive performance in adults with suspected obstructive sleep apnea

La apnea obstructiva del sueño (AOS) se ha asociado a deterioro cognitivo. OBJETIVO: Identificar factores asociados a bajo rendimiento cognitivo (BRC) en adultos con sospecha de AOS. MÉTODO: Se realizó evaluación cognitiva empleando la Evaluación Cognitiva de Montreal (MoCA); se consideró BRC un puntaje inferior a 21. El diagnóstico de AOS fue mediante poligrafía respiratoria de 5 canales, según índice de apnea-hipopnea (IAH). Se evaluó también calidad de sueño, síntomas depresivos, entre otros. RESULTADOS: En 91,5% de 320 pacientes consecutivos se confirmó el diagnóstico de AOS. El promedio de MoCA fue 20,6 puntos. El grupo con BRC tenía mayor edad, menor escolaridad; mayor frecuencia de hipertensión arterial y diabetes mellitus, y desaturaciones de la oxihemoglobina de mayor magnitud. No hubo diferencias de gravedad según IAH entre ambos grupos. COMENTARIO: Los pacientes con BRC presentan factores de riesgo asociados a deterioro cognitivo, y mayor magnitud de desaturaciones de la oxihemoglobina.

Obstructive sleep apnea (OSA) has been associated with cognitive decline. OBJECTIVE: To identify factors associated with low cognitive performance (LCP) in adults with suspected OSA. MATHOD: Cognitive evaluation was performed using Montreal Cognitive Assessment (MoCA), and scores lower than 21 were considered LCP. The diagnosis of OSA was made using 5-channel respiratory polygraphy, according to the apnea-hypopnea index (AHI). Sleep quality, depressive symptoms, among others, were also evaluated. RESULTS: In 91.5% of 320 consecutive patients the diagnosis of OSA was confirmed. The MoCA average was 20.6 points. The group with LCP was older, less educated, were more likely to have hypertension and diabetes mellitus, and with more severe oxyhemoblobin desaturations. There were no differences in severity according to AHI between both groups. COMMENT: Patients with LCP have risk factors associated with cognitive impairment, besides more severe oxyhemoglobin desaturations.

Evaluación de la Saturación Venosa de Oxígeno (SvO2) desde la teoría de los sistemas dinámicos / Evaluation of SvO2 from the Theory of Dynamic Systems

Introducción: La evolución de un sistema dinámico se puede caracterizar a partir de la construcción de atractores caóticos. Objetivo: Desarrollar una metodología de evaluación de la saturación venosa de oxígeno, fundamentada en los sistemas dinámicos, para pacientes en Unidad de Cuidados Intensivos. Metodología: Se seleccionaron 10 pacientes con diferentes patologías de la Unidad de Cuidados Intensivos Postquirúrgicos, y registró la saturación venosa de oxígeno durante su tiempo de estancia. Con base en estos valores se construyeron atractores caóticos en el mapa de retardo y se evaluaron los valores mínimos y máximos ocupados por el atractor. Resultados: Se halló que la saturación venosa de oxígeno tiene un comportamiento caótico; los valores máximos y mínimos de los atractores en el mapa de retardo variaron entre 22,10 mmHg y 93,70 mmHg. Conclusiones: Se plantea una nueva metodología capaz de caracterizar el comportamiento de la variable monitorizada para la evaluación del paciente crítico(AU)

Introduction: The evolution of a dynamic system can be characterized from the construction of chaotic attractors. Objective: To develop a methodology based on dynamic systems, for the evaluation of venous oxygen saturation of patients in the Intensive Care Unit. Methodology: 10 patients with different pathologies of the Post-surgical Intensive Care Unit were selected, and recorded venous oxygen saturation during their time of stay. Based on these values, chaotic attractors were constructed on the delay map and the minimum and maximum values occupied by the attractor were evaluated. Results: It was found that venous oxygen saturation has a chaotic behavior; the maximum and minimum values of the attractors on the delay map varied between 22.10 mmHg and 93.70 mmHg. Conclusions: A new methodology is proposed capable of characterizing the behavior of this monitored variable for the evaluation of the critical patient(AU)

Rattlesnake Crotalus molossus nigrescens venom induces oxidative stress on human erythrocytes

Background Globally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes. Methods Human erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0-640 μg/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination. Results Low concentrations of venom (<10 μg/mL) generates oxyhemoglobin release by hemolysis, whereas higher concentrations produced a hemoglobin shift of valence, producing methemoglobin (>40 μg/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 μg/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm−1) and lipid peroxidation (2960, 2920 and 1740 cm−1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom. Conclusions Crotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.(AU)

Successful Extubation After Weaning Failure by Noninvasive Ventilation in Patients With Neuromuscular Disease: Case Series

OBJECTIVE: To report successful cases of extubation from invasive mechanical ventilation at our institution using pulmonary rehabilitation consisting of noninvasive ventilation (NIV) in neuromuscular patients with experience of reintubation. METHODS: Patients who experienced extubation failure via the conventional weaning strategy but afterwards had extubation success via NIV were studied retrospectively. Continuous end-tidal CO₂ (ETCO₂) and pulse oxyhemoglobin saturation (SpO₂) monitoring were performed. Extubation success was defined as a state not requiring invasive mechanical ventilation via endotracheal tube or tracheotomy during a period of at least 5 days. RESULTS: A total of 18 patients with ventilatory failure who initially experienced extubation failure were finally placed under part-time NIV after extubation. No patient had any serious or long-term adverse effect from NIV, and all patients left the hospital alive. CONCLUSION: NIV may promote successful weaning in neuromuscular patients with experience of reintubation.

Spontaneous Low-Frequency Cerebral Hemodynamics Oscillations in Restless Legs Syndrome with Periodic Limb Movements During Sleep: A Near-Infrared Spectroscopy Study

BACKGROUND AND PURPOSE: Periodic limb movements (PLM) during sleep (PLMS) are associated with cortical and cardiovascular activation. Changes in cerebral hemodynamics caused by cortical activity can be measured using near-infrared spectroscopy (NIRS). We investigated oscillatory components of cerebral hemodynamics during PLM and different sleep stages in restless legs syndrome (RLS) patients with PLMS. METHODS: Four female RLS patients with PLMS, and four age- and sex-matched normal controls were included. PLM and sleep stages were scored using polysomnography, while the spontaneous cerebral hemodynamics was measured by NIRS. The phase and amplitude of the cerebral oxyhemoglobin concentration [HbO] and the deoxyhemoglobin concentration [Hb] low-frequency oscillations (LFOs) were evaluated during each sleep stage [waking, light sleep (LS; stages N1 and N2), slow-wave sleep (stage N3), and rapid eye movement (REM) sleep]. In RLS patients with PLMS, the cerebral hemodynamics during LS was divided into LS with and without PLM. RESULTS: The cerebral hemodynamics activity varied among the different sleep stages. There were changes in phase differences between [HbO] and [Hb] LFOs during the different sleep stages in the normal controls but not in the RLS patients with PLMS. The [HbO] and [Hb] LFO amplitudes were higher in the patient group than in controls during both LS with PLM and REM sleep. CONCLUSIONS: The present study has demonstrated the presence of cerebral hemodynamics disturbances in RLS patients with PLMS, which may contribute to an increased risk of cerebrovascular events.

Subarachnoid Hemorrhage Showed Only on T2-Weighted Magnetic Resonance Imaging

We present the case of a 28-year-old pregnant woman with subarachnoid hemorrhage who was initially unable to undergo a CT scan and exhibited interestingly high signal intensities only on T2-weighted MRI without any signal change on fluid attenuated inversion recovery and gradient-echo imaging. These findings could be explained by a combination of factors that increase the signal intensity with elevations in the concentrations of protein and oxyhemoglobin due to massive bleeding and with the decreased fluid void signal inferred by the presence of hydrocephalus.

Prevalence and Predictors of Nocturia in Patients with Obstructive Sleep Apnea Syndrome / 수면정신생리

OBJECTIVES: Several studies suggest that nocturia may be related to obstructive sleep apnea syndrome (OSAS). The mechanism by which OSAS develops nocturia has not been determined. The present study aimed to determine the prevalence of nocturia among adults with OSAS and to identify factors that may be predictive in this regard. METHODS: Retrospective review of clinical and polysomnographic data obtained from patients evaluated at the sleep clinics of the St. Paul's Hospital between 2009 and 2012. The urinary symptoms were assessed on the basis of the International Prostate Symptom Score (IPSS). Pathologic nocturia was defined as two or more urination events per night. OSAS was defined as apnea-hypopnea index (AHI) > or =5. A multivariate analysis using logistic regression was performed to examine the relationship between polysomnographic variables and the presence of pathologic nocturia, while controlling for confounding factor. RESULTS: A total of 161 men >18 years of age (mean age 46.7+/-14.1), who had been referred to a sleep laboratory, were included in the present study. Among these, 27 patients with primary snoring and 134 patients with obstructive sleep apnea were confirmed by polysomnography. Nocturia was found in 53 patients with OSAS (39.6%) and 8 patients with primary snoring (29.6%). The AHI was higher in patients with nocturia than in those without nocturia (p=0.001). OSAS patients with nocturia had higher arousal index (p=0.044), and lower nadir oxyhemoglobin saturation (p=0.001). Multiple regression analysis showed that age (beta=0.227, p=0.003), and AHI (beta=0.258, p=0.001) were associated with nocturia, and that the presence of pathologic nocturia was predicted by age (OR 1.04 ; p=0.004) and AHI (OR 1.02 ; p=0.001). CONCLUSION: Nocturia is common among patients with OSAS. The strongest predictors of nocturia are age and AHI in patients with OSAS.

A Case of Pulmonary Thromboembolism Complicating Acute Overdose of Benzodiazepines

Acute pulmonary thromboembolism (PTE) is a major medical problem in many hospitalized patients with medical and surgical conditions, and venous thromboembolism is responsible for up to 15% of all in-hospital deaths. However, PTE complicating acute intoxication has been reported only rarely, and prophylaxis for venous thromboembolism is not routinely incorporated into the management of acute poisoning in emergency departments or general wards. We describe here a case of pulmonary thromboembolism that developed within 48 h of acute benzodiazepine overdose. A 47-year-old female patient was brought to the emergency department by ambulance. She had been found unconscious, and empty packages of medications prescribed by her psychiatrist and an empty bottle of liquor were found. The estimated drugs and amounts were alprazolam 22.5 mg, diazepam 150 mg, flunitrazepam 7.5 mg, fluoxetine 150 mg, and propranolol 600 mg. Approximately 40 hours after initial presentation, she complained of dyspnea and pulse oxymetry indicated 84%. Her arterial pH was 7.41, pCO2 41.6 mmHg, pO2 46.8 mmHg, and oxyhemoglobin saturation was 83.4%. The serum D-dimer concentration was 2.78 mcg/dL, and computed tomography of the chest showed acute PTE in the right upper lobar and segmental pulmonary arteries and both lower segmental pulmonary arteries. When caring for patients with sedative drug overdose, a high level of suspicion of PTE is required, and appropriate diagnostic and therapeutic measures might be undertaken when PTE is suspected. In addition, appropriate prophylaxis for venous thrombosis should be considered.

Correlation between LIFG and autonomic activation during stressful tasks: a functional near-infrared spectroscopy (fNIRS) study / 华中科技大学学报（医学）（英德文版）

It remains unclear whether language tasks in one's first (L1) or second (L2) language can cause stress responses and whether frontal, autonomic and behavioral responses to stressful tasks are correlated. In this study, we studied 22 Chinese subjects whose L2 was English and measured the cerebral blood oxygenation in their frontal lobe by using functional near-infrared spectroscopy (fNIRS) as participants engaged in a mental arithmetic task (MAT) and verbal fluency tasks (VFTs) in L1 (Chinese) and L2 (English). To examine the activated cortical areas, we estimated the channel location based on Montreal Neurological Institute (MNI) standard brain space by using a probabilistic estimation method. We evaluated heart rate (HR) changes to analyze autonomic nervous system (ANS) functioning. We found that the MAT and VFTs induced greater increases in HR than did the control (Ctrl) task. Furthermore, subjects developed greater increases in HR in the MAT and VFTL2 than they did in the VFTL1. Compared with the Ctrl task, the MAT and both VFTL1 and VFTL2 produced robust and widespread bilateral activation of the frontal cortex. Interestingly, partial correlation analysis indicated that the activity in the left inferior frontal gyrus (LIFG) [Brodmann's area (BA) 47] was consistently correlated with the increases in HR across the three tasks (MAT, VFTL2, and VFTL1), after controlling for the performance data. The present results suggested that a VFT in L2 may be more stressful than in L1. The LIFG may affect the activation of the sympathetic system induced by stressful tasks, including MATs and VFTs.

The Optimal Pulse Oxygen Saturation in Very Low Birth Weight or Very Preterm Infants

PURPOSE: To determine the effect of changing practice guidelines designed to avoid hyperoxia or hypoxia in very low birth weight or very preterm infants. METHODS: We analyzed a database of <1,500 g birth weight or <32 weeks of gestation infants who were born and admitted to the neonatal intensive care unit of Chungnam National University Hospital from January 2007 to July 2010. First, we defined the relationship between arterial partial pressure of oxygen (PaO2) and pulse oxygen saturation (SpO2). When we evaluated 96 pairs of PaO2 and SpO2 measurements, oxygen saturation was 90-94% at a PaO2 of 43-79 mmHg on the oxyhemoglobin dissociation curve, according to pulse oximetry. Based on this observation, a change in practice was instituted in August 2008 with the objective of avoiding hypoxia and hyperoxia in preterm infants with targeting a SpO2 90-94% (period II). Before the change in practice, high alarms for SpO2 were set at 100% and low alarms at 95% (period I). RESULTS: Sixty-eight infants the met enrollment criteria and 38 (56%) were born during period II, after the change in SpO2 targets. Demographic characteristics, except gender, were similar between the infants born in both periods. After correcting for the effect of confounding factors, the rates for mortality, severe retinopathy of prematurity, and IVH attended to be lower than those for infants in period II. No difference in the rate of patent ductus arteriosus needed to treat was observed. CONCLUSION: A change in the practice guidelines aimed at avoiding low oxygen saturation and hyperoxia did not increase neonatal complication rates and showed promising results, suggesting decreased mortality and improvements in short term morbidity. It is still unclear what range of oxygen saturation is appropriate for very preterm infants but the more careful saturation targeting guideline should be considered to prevent hypoxemic events and hyperoxia.

A Case of Aluminum Phosphide Poisoning

Aluminum phosphide is commonly used as a rodenticidal agent in agricultural workplaces. However, reported cases of aluminum phosphide poisoning in Korea are rare. Upon contact with moisture in the air, aluminum phosphide releases highly toxic phosphine gas (PH3). PH3 is readily absorbed through lung epithelium and into the bloodstream. Phosphine may cause denaturing of oxyhemoglobin and enzymes important to respiration and metabolism, and also may effect cellular membranes. There are numerous complications associated with acute aluminum phosphide poisoning including gastrointestinal, respiratory, and cardiac toxicities. We report the case of a 46-year-old man who suffered from respiratory and cardiac toxicities after unintentional aluminum phosphide exposure. More intensive education for prevention is recommended.

Evaluation methods for the efficacy of neoadjuvant chemotherapy for breast cancer / 癌症

With the widespread clinical application of neoadjuvant chemotherapy, it has become an essential part of combination therapy for patients with breast cancer. However, a rapid, accurate, and effective approach for assessing the therapeutic efficacy of neoadjuvant chemotherapy is unavailable. Routine physical examinations cannot provide effective clinical evaluation. Although imaging techniques play an important role in evaluating the therapeutic effect of neoadjuvant chemotherapy, this is limited because it only detects morphologic changes. Blood oxygen detection for breast diseases is an emerging diagnostic technique that has distinctive merit in assessing the efficacy of chemotherapy. Biologic markers are becoming more important in assessing the effect of neoadjuvant chemotherapy for patients with breast cancer. This review summarizes the principles and the current applied practice of these approaches to evaluate the effect of neoadjuvant chemotherapy for patients with breast cancer.

The development of a wearable pulse oximeter sensor and study of the calibration method / 生物医学工程学杂志

The paper first analyses the principles of measurement of the two-wave oximeter and their limitations in technology. We propose to filter off motion interference from pulse oximeter signal using an algorithm based on the Beer-Lambert law that requires a three-wave probe (660 nm, 850 nm, and 940 nm). Based on the new algorithm, this paper describes the design principle of the circuitry and the software flowchart. Also, we study the calibration method of the pulse oximeter sensor and discuss the results in this paper.

Effect of smoking habits on sleep

To evaluate the effect of smoking habits on sleep, data from 1492 adults referred to the Sleep Institute were accessed and divided into 3 categories of smoking status: current, former and non-smokers. Categories of pack-years (<15 and greater than or equal to 15) defined smoking severity. The association of smoking status and smoking severity with sleep was analyzed for sleep parameters, especially apnea and hypopnea index (AHI) greater than or equal to 5, more than 5 percent of total sleep time (TST) spent with oxyhemoglobin saturation (SaO2) <90 percent, and arousal index. The arousal index was higher among current (21 plus or minus 17) and former smokers (20 plus or minus 17) than non-smokers (17 plus or minus 15; P < 0.04). Former smokers had a higher percent of TST at SaO2 <90 percent than non-smokers (9 more less 18 vs 6 more less 13; P < 0.04). Former smokers with pack-years greater than or equal to 15 compared to <15 exhibited higher AHI (22 plus or minus 24 vs 16 plus or minus 21; P < 0.05) and arousal index (22 plus or minus 19 vs 18 plus or minus 15; P < 0.05). Current smokers with pack-years greater than or equal to 15 compared to <15 exhibited higher arousal index (23 plus or minus 18 vs 18 plus or minus 16; P < 0.05) and percent of TST at SaO2 <90 percent (11 plus or minus 17 vs 6 more less 13; P < 0.05). Smoking status and pack-years were not associated with AHI greater than or equal to 5 on logistic regression analysis, but current smokers with pack-years greater than or equal to 15 were 1.9 times more likely to spend more than 5 percent of TST at SaO2 <90 percent than non-smokers (95 percentCI = 1.21-2.97; P = 0.005). The variability of arousal index was influenced by gender, AHI and current smokers with pack-years greater than or equal to 15 (all P < 0.01). Smoking habits seem to be associated with arousal and oxyhemoglobin desaturation during sleep, but not with AHI. The effect was more pronounced in current than former smokers.

Efeitos da tosse manualmente assistida sobre a mecânica do sistema respiratório de pacientes em suporte ventilatório total / Effects of manually assisted coughing on respiratory mechanics in patients requiring full ventilatory support

OBJETIVO: A tosse manualmente assistida (TMA) consiste na compressão vigorosa do tórax no início da expiração espontânea ou da fase expiratória da ventilação mecânica. Tendo em vista a utilização rotineira da TMA na unidade de terapia intensiva, a proposta deste estudo foi analisar os efeitos dessa técnica no comportamento da mecânica do sistema respiratório de pacientes submetidos a suporte ventilatório total. MÉTODOS: Foram estudados 16 pacientes intubados, sedados e submetidos à ventilação mecânica controlada, sem participação interativa com o ventilador. A mecânica do sistema respiratório e a saturação periférica de oxigênio foram mensuradas antes e após a aplicação de TMA e após a aspiração traqueal. Foram realizadas 10 aplicações bilaterais da técnica por paciente, com intervalos de 3 ciclos respiratórios entre cada aplicação. RESULTADOS: Os dados evidenciaram a diminuição da pressão resistiva e da resistência do sistema respiratório e aumento da saturação periférica de oxigênio após a aplicação da TMA associada à aspiração traqueal. Não foram evidenciadas alterações das pressões de pico, platô e complacência do sistema respiratório após a aplicação da TMA. CONCLUSÕES: A TMA foi capaz de alterar a mecânica do sistema respiratório, mais especificamente aumentando as forças resistivas através do deslocamento de secreção. A técnica pode ser considerada eficaz e segura para pacientes em pós-operatório imediato. A associação entre TMA e aspiração traqueal mostrou-se benéfica, alcançando os objetivos propostos: deslocamento e remoção de secreção das vias aéreas.

OBJECTIVE: Manually assisted coughing (MAC) consists of a vigorous thrust applied to the chest at the beginning of a spontaneous expiration or of the expiratory phase of mechanical ventilation. Due to routine use of MAC in intensive care units, the objective of this study was to assess the effects of MAC on respiratory system mechanics in patients requiring full ventilatory support. METHODS: We assessed 16 sedated patients on full ventilatory support (no active participation in ventilation). Respiratory system mechanics and oxyhemoglobin saturation were measured before and after MAC, as well as after endotracheal aspiration. Bilateral MAC was performed ten times on each patient, with three respiratory cycle intervals between each application. RESULTS: Data analysis demonstrated a decrease in resistive pressure and respiratory system resistance, together with an increase in oxyhemoglobin saturation, after MAC combined with endotracheal aspiration. No evidence of alterations in peak pressures, plateau pressures or respiratory system compliance change was observed after MAC. CONCLUSIONS: The use of MAC alters respiratory system mechanics, increasing resistive forces by removing secretions. The technique is considered safe and efficacious for postoperative patients. Using MAC in conjunction with endotracheal aspiration provided benefits, achieving the proposed objective: the displacement and removal of airway secretions.

[ effect of upper airway obstructive surgery on respiratory symtoms and Spo2]

The obstruction of the upper respiratory tract [URT] is one of the most important reasons patients' recurrent referral to the ENT clinic. Adentonsilar hypertrophy is almost common reason of the upper respiratory tract obstruction, and it will cause some changes in lung volumes and also in blood gases. The purpose of this study was to determine the effects of tonsillectomy on respiratory symptoms and arterial blood oxygen saturation. In a clinical trials study, in a pre and post operative manner, 62, 2-14 years old children were imposed to adentonsilectomy in an easy sampling way. The respiratory symptoms such as: snoring, dyspnea, feeling airway obstruction, mouth breathing and oxygen saturated hemogolobin condition [Spo2], prior to surgery and one month after operation, has been studied and recorded. The results were compared with paired t-test. In a preoperative manner, 80% of patients had mouth breathing symptom and mouth dryness which were reduced to 10% after surgery. Spo2 measurement had no significant difference before and after surgery, and, it was in a normal range. The correction of respiratory obstruction due to adenotonsilar hypertrophy does not make any changes in arterial blood oxygen. The surgery which is used for correction of these obstruction, will just improve the clinical respiratory symptoms such as snoring and mouth breathing

A nondestructive method to measure the oxygen binding and releasing properties of biodegradable polymers microcapsules intented for blood substitutes / 生物医学工程学杂志

P50 is an important parameter reflecting the binding and releasing oxygen properties of blood substitutes. In this study, based on the strong penetrating property of near infrared light and the mechanism involved in the pulsatile oxygen meter in clinic as well as on the ability for penetrating biodegradable polymers and detecting bovine hemoglobin encapsulated within the microcapsules, we have made an airproof and equilibrium apparatus to measure oxygen saturation and oxygen partial pressure. Subsequently, we have obtained the oxygen dissociation curve and P50 of the microcapsules loaded bovine hemoglobin in the light of oxyHemoglobin and deoxyHemoglobin with different spectrum in the near infrared region. The above-mentioned apparatus and method are not destructive to the microcapsules, and the process is simple and nondestructive. So it is practical to take in-situ measurements of the oxygen binding and releasing property of biodegradable polymer microcapsules intented for the blood substitute.

Obese obstructive sleep apnea patients with tonsil hypertrophy submitted to tonsillectomy

The physiopathology of obstructive sleep apnea-hypopnea syndrome (OSAHS) is multifactorial and obesity has been shown to be one of the main factors correlated with its occurrence. In obese patients with anatomical alterations of the upper airways it is often difficult to predict success for surgical correction since obesity is a limiting factor. Therefore, the aim of the present study was to evaluate the results of tonsillectomy in a specific group of patients, i.e., obese OSAHS patients with tonsil hypertrophy. Seven OSAHS patients with moderate obesity with obstructive palatine tonsil hypertrophy were submitted to tonsillectomy. All patients were submitted to pre- and postoperative appraisal of body mass index, otorhinolaryngology examination and polysomnography. Patients' average age was 36.4 ± 10.3 years and average preoperative body mass index was 36.6 ± 6.3 kg/m². Postoperative weight did not differ significantly from preoperative weight (P = 0.27). Average preoperative apnea and hypopnea index (AHI) was 81 ± 26/h and postoperative AHI was 23 ± 18/h (P = 0.0005). Average preoperative minimum oxyhemoglobin saturation (SaO2 min) was 69 ± 14 percent and the postoperative value was 83 ± 3 percent (P = 0.038). In relation to AHI, 6 (86 percent) of the 7 patients studied showed a reduction of 50 percent in relation to preoperative level and of these, 4 (57 percent) presented AHI of less than 20 percent. Only one patient presented a reduction of less than 50 percent in AHI, but even so showed improved SaO2 min. Tonsillectomy treatment for OSAHS in obese patients with obstructive palatine tonsil hypertrophy caused a significant reduction in AHI, with improvement in SaO2 min. This procedure could be eventually considered as an option of treatment for obese OSAHS patients with significant tonsil hypertrophy when continuous positive air pressure therapy is not possible as the first choice of treatment.