Monitorización del dióxido de carbono espirado durante la ventilación no invasiva en pacientes con enfermedad pulmonar obstructiva crónica agudizada / Monitoring of the carbon dioxide exhaled during the non invasive ventilation in patients with acute chronic obstructive lung disease

Introducción: La monitorización del dióxido de carbono espirado se utiliza con frecuencia en las unidades de cuidados intensivos, pero su empleo en ventilación no invasiva es escaso. Objetivo: Identificar la asociación entre la presión arterial de dióxido de carbono y el dióxido de carbono espirado, durante la ventilación no invasiva, en pacientes con enfermedad pulmonar obstructiva crónica agudizada. Métodos: Se realizó un estudio observacional, descriptivo, longitudinal y prospectivo de 126 pacientes ingresados con enfermedad pulmonar obstructiva crónica agudizada, tratados con ventilación no invasiva en la Unidad de Cuidados Intensivos del Hospital Provincial Clínico-Quirúrgico Docente Saturnino Lora Torres de Santiago de Cuba, desde enero de 2019 hasta igual mes de 2022, seleccionados por muestreo intencional no probabilístico. Se analizaron variables clínicas, ventilatorias y hemogasométricas, de las cuales se identificaron los valores mínimo y máximo, así como la media, la desviación estándar y la mediana. Se aplicó el coeficiente de correlación de Pearson. Resultados: Los valores promedio de dióxido de carbono espirado fueron 57,83+8,9 y los de presión arterial de dióxido de carbono, de 59,85+9,3. Al analizar la correlación entre las variables se observó correlación positiva entre ambas, para un coeficiente de correlación de Pearson de 0,920. Conclusiones: La monitorización del dióxido de carbono espirado se erige como una variable a considerar en la monitorización de los pacientes con enfermedad pulmonar obstructiva crónica agudizada, tratados con ventilación no invasiva, siempre que se utilice la máscara facial adecuada y se controlen las fugas, con fuerte correlación con la presión arterial del dióxido de carbono.

Introduction: The monitoring of the carbon dioxide exhaled is frequently used in the intensive cares units, but its use in non invasive ventilation is scarce. Objective: To identify the association between the blood pressure of carbon dioxide and the carbon dioxide exhaled, during non invasive ventilation, in patients with acute chronic obstructive lung disease. Methods: An observational, descriptive, longitudinal and prospective study of 126 patients admitted with acute chronic obstructive lung disease was carried out, they were treated with non invasive ventilation, in the Intensive Cares Unit of Saturnino Lora Torres Teaching Provincial Clinical-Surgical Hospital in Santiago de Cuba, from January, 2019 to the same month in 2022, selected by intentional non probabilistic sampling. Clinical, ventilatory and hemogasometric variables were analyzed, of which the minimum and maximum values were identified, as well as the mean, standard and medium deviation. The Pearson correlation coefficient was applied. Results: The average values of carbon dioxide exhaled were 57.83 ± 8.9 and those of arterial pressure of carbon dioxide, 59.85± 9.3. When analyzing the correlation among the variables, positive correlation was observed among both, for a Pearson correlation coefficient of 0.920. Conclusions: The monitoring of carbon dioxide exhaled acts as a variable to consider in the monitoring of patients with acute chronic obstructive lung disease, treated with non invasive ventilation, whenever the appropriate face mask is used and the leaks are controlled, with strong correlation with the arterial pressure of the carbon dioxide.

Capnografia volumétrica para monitoração respiratória de pacientes submetidos a colonoscopia diagnóstica com insuflação de ar comprimido e gás carbônico / Volumetric capnography for respiratory monitoring of patients during routine colonoscopy with room-air and carbon dioxide insufflation

ABSTRACT Background: Capnography and carbon dioxide (CO2) insufflation during gastrointestinal endoscopy under sedation are associated with safety and comfort improvements, respectively. Capnography can provide early detection of apnea and hypoxemia, whereas CO2 insufflation causes lower periprocedural discomfort. This is the first study to report the application of volumetric capnography in colonoscopy. Objective: This study aimed to evaluate the use of volumetric capnography with room air (RA) and CO2 insufflation during routine colonoscopy. Methods: In this prospective cohort study, 101 patients who underwent routine colonoscopy under sedation with volumetric capnography monitoring were included. Insufflation with RA was used to distend the intestinal lumen in group 1 (n=51), while group 2 (n=50) used CO2 insufflation. The primary endpoints were episodes of hypoxia, alveolar hypoventilation, and end-tidal CO2 (EtCO2). The secondary endpoints were tidal volume per minute, consumption of sedation medications, and post-procedure pain using the Gloucester modified pain scale. Results: The number of episodes of hypoxia (SpO2<90%) was similar between the groups: four episodes in Group 1 and two episodes in Group 2. The duration of hypoxia was significantly longer in group 2 (P=0.02). Hypoalveolar ventilation (EtCO2) occurred more frequently in Group 2 than in Group 1 (27 vs 18 episodes, P=0.05). Regarding EtCO2, Group 2 showed higher values in cecal evaluation (28.94±4.68 mmHg vs 26.65±6.12 mmHg, P=0.04). Regarding tidal volume per minute, Group 2 had significantly lower values at the cecal interval compared to Group 1 (2027.53±2818.89 vs 970.88±1840.25 L/min, P=0.009). No episodes of hypercapnia (EtCO2 > 60 mmHg) occurred during the study. There was no difference in the consumption of sedation medications between the groups. Immediately after colonoscopy, Group 2 reported significantly less pain than Group 1 (P=0.05). Conclusion: In our study, volumetric capnography during colonoscopy was feasible and effective for monitoring ventilatory parameters and detecting respiratory complications. CO2 insufflation was safe and associated with less pain immediately after colonoscopy.

RESUMO Contexto: A capnografia e a insuflação de gás carbônico (CO2) durante endoscopia digestiva sob sedação são associados à maior segurança e conforto do paciente, respectivamente. A capnografia pode detectar precocemente a apneia e hipoxemia, enquanto a insuflação de CO2 causa menor desconforto periprocedimento. Relatos da aplicação da capnografia volumétrica em colonoscopias são escassos. Objetivo: Avaliar o uso de capnograifa volumétrica durante colonoscopia diagnóstica com insuflação de ar comprimido e CO2. Métodos: Em estudo prospectivo de coorte, foram incluídos um total de 101 pacientes submetidos a colonoscopia diagnóstica sob sedação com monitoração respiratória por meio de capnografia volumétrica. Insuflação com ar comprimido foi usado para distender o lúmen intestinal no Grupo 1 (n=51), enquanto o Grupo 2 (n=50) utilizou CO2 para insuflação. Objetivos primários foram avaliar episódios de hipóxia, hipoventilação alveolar e CO2 expirado (EtCO2). Objetivos secundários foram avaliar o volume alveolar por minuto, consumo de sedativos e a dor pós-colonoscopia por meio da Escala de Dor Modificada de Gloucester. Resultados: O número de episódios de hipóxia (SpO2 <90%) foi semelhante entre os grupos: quatro episódios no Grupo 1 e dois episódios no Grupo 2. A duração da hipóxia foi significativamente maior no Grupo 2 (P=0,02). A hipoventilação alveolar (EtCO2 ≥25% do valor basal) ocorreu mais frequentemente no Grupo 2 quando comparado ao Grupo 1 (27 vs 18 episódios, P=0,05). Em relação ao EtCO2, o Grupo 2 apresentou valores maiores no momento de aferição cecal (28.94±4.68 vs 26.65±6.12 mmHg, P=0,04). Quanto ao volume alveolar por minuto, o Grupo 2 apresentou valores significativamente menores no momento de aferição cecal quando comparado ao Grupo 1 (2027.53±2818.89 vs 970.88±1840.25 L/min, P=0,009). Não houve ocorrência de hipercapnia durante o estudo (EtCO2 >60 mmHg). Não houve diferença em relação ao consumo de sedativos entre os dois grupos. Imediatamente após a colonoscopia, o Grupo 2 apresentou significativamente menos dor que o Grupo 1 (P=0,05). Conclusão: Em nosso estudo, a capnografia volumétrica durante colonoscopia foi factível e eficaz para monitorar parâmetros ventilatórios e detectar complicações respiratórias, e a insuflação com CO2 foi segura e associada a menor dor imediatamente pós-colonoscopia.

Effects of home-based inspiratory muscle training on sickle cell disease (SCD) patients

ABSTRACT Introduction: Inspiratory muscle training (IMT) has been shown to be an efficient method of improving exercise tolerance and inspiratory and expiratory muscle strength in several diseases. The effects of IMT on patients with sickle cell anemia (SCD) are relatively unknown. Our study aimed to evaluate the effects of IMT on adult SCD patients, regarding respiratory muscle strength (RMS) variables, lung function, exercise tolerance, blood lactation concentration, limitation imposed by dyspnea during daily activities and impact of fatigue on the quality of life. Methods: This was a randomized single-blind study, with an IMT design comprising true load (TG) and sham load (SG) groups. Initial assessment included spirometry, volumetric capnography (VCap) and measurement of RMS by maximal inspiratory and expiratory pressure (PImax and PEmax). The Medical Research Council dyspnea scale and modified fatigue impact scale were also applied and blood lactate concentration was measured before and after the 6-minute walk test. After this initial assessment, the patient used the IMT device at home daily, returning every 6 weeks for RMS reassessment. Both groups used the same device and were unaware of which group they were in. After a period totaling 18 weeks, patients underwent the final evaluation, as initially performed. Results: Twenty-five patients in total participated until the end of the study (median age 42 years). There were no significant differences between TG and SG based on age, sex, body mass index or severity of genotype. At the end of the training, both groups showed a significant increase in PEmax and PImax, improvement in Vcap and in exercise tolerance and dyspnea reduction while performing daily life activities. The same was observed in patients grouped according to disease severity (HbSS and HbSβ0 vs HbSC and HbSβ+), without differences between groups. Conclusion: Home-based inspiratory muscle training benefits outpatients with SCD, including the sham load group. Trial registration:http://www.ensaiosclinicos.gov.br; registration number: RBR-6g8n92.

Lung function and stress echocardiography in pulmonary arterial hypertension: a cross-sectional study

ABSTRACT BACKGROUND: The mechanism of exercise limitation in idiopathic pulmonary arterial hypertension (IPAH) is not fully understood. The role of hemodynamic alterations is well recognized, but mechanical, ventilatory and gasometric factors may also contribute to reduction of exercise capacity in these individuals. OBJECTIVE: To investigate whether there is an association between ventilatory pattern and stress Doppler echocardiography (SDE) variables in IPAH patients. DESIGN AND SETTING: Single-center prospective study conducted in a Brazilian university hospital. METHODS: We included 14 stable IPAH patients and 14 age and sex-matched controls. Volumetric capnography (VCap), spirometry, six-minute walk test and SDE were performed on both the patients and the control subjects. Arterial blood gases were collected only from the patients. The IPAH patients and control subjects were compared with regard to the abovementioned variables. RESULTS: The mean age of the patients was 38.4 years, and 78.6% were women. The patients showed hypocapnia, and in spirometry 42.9% presented forced vital capacity (FVC) below the lower limit of normality. In VCap, IPAH patients had higher respiratory rates (RR) and lower elimination of CO2 in each breath. There was a significant correlation between reduced FVC and the magnitude of increases in tricuspid regurgitation velocity (TRV). In IPAH patients, VCap showed similar tidal volumes and a higher RR, which at least partially explained the hypocapnia. CONCLUSIONS: The patients with IPAH showed hypocapnia, probably related to their higher respiratory rate with preserved tidal volumes; FVC was reduced and this reduction was positively correlated with cardiac output.

Volumetric capnography versus spirometry for the evaluation of pulmonary function in cystic fibrosis and allergic asthma / Capnografia volumétrica versus espirometria para avaliação da função pulmonar na fibrose cística e na asma alérgica

Abstract Objective: To compare the values of the markers for volumetric capnography and spirometry and their ability to classify children and adolescents with asthma, cystic fibrosis (CF), and healthy controls. Methods: This was a cross-sectional study that included 103 patients with controlled persistent allergic asthma, 53 with CF and a healthy control group with 40 volunteers (aged 6 to 15 years), of both sexes. The individuals underwent volumetric capnography and spirometry. Results: Phase III slope (SIII), SIII standardized by exhaled tidal volume (SIII/TV) and capnographic index (SIII/SII) × 100 (KPIv) were different among the three groups assessed, with highest values for CF. The relation between the forced expiratory volume in one second and the forced vital capacity (FEV1/FVC) was the only spirometric marker that presented difference on the three groups. On individuals with normal spirometry, KPIv and FEV1/FVC were different among the three groups. The ROC curve identified the individuals with asthma or CF from the control group, both through volumetric capnography (better to identify CF in relation to the control using KPIv) and through spirometry (better to identify asthma in relation to the control). KPIv was the best parameter to distinguish asthma from CF, even in individuals with normal spirometry. Conclusion: Volumetric capnography and spirometry identified different alterations in lung function on asthma, CF, and healthy controls, allowing the three groups to be distinguished.

Resumo Objetivo Comparar os valores dos marcadores para capnografia volumétrica e espirometria e sua capacidade de classificar crianças e adolescentes com asma, fibrose cística (FC) e controles saudáveis. Métodos Foi realizado um estudo transversal que incluiu 103 pacientes com asma alérgica persistente controlada, 53 com FC e um grupo controle saudável com 40 voluntários (6 a 15 anos), de ambos os sexos. Os indivíduos foram submetidos a capnografia volumétrica e espirometria. Resultados O slope da fase III (SIII), SIII padronizada pelo volume tidal exalado (SIII/VT) e o índice capnográfico (SIII/SII) × 100 (KPIv) foram diferentes entre os três grupos avaliados, com maiores valores para o grupo FC. A relação entre o volume expiratório forçado no primeiro segundo e a capacidade vital forçada (VEF1/CVF) foi o único marcador de espirometria com diferenças nos três grupos. Nos indivíduos com espirometria normal, o KPIv e VEF1/CVF foram diferentes entre os três grupos. A curva ROC diferenciou os indivíduos com asma ou FC daqueles do grupo controle, ambos através da capnografia volumétrica (melhor para identificar a FC em relação aos controles pelo KPIv) e por meio da espirometria (melhor para identificar a asma em relação aos controles). O KPIv foi o melhor parâmetro para distinguir a asma da FC, mesmo em indivíduos com espirometria normal. Conclusão A capnografia volumétrica e a espirometria identificaram diferentes alterações de função pulmonar na asma, na FC e nos controles saudáveis, permitiram que os três grupos fossem diferenciados.

Diagnostic value of volumetric capnography in patients with chronic cough variant asthma

OBJECTIVES: To evaluate the quantitative changes and diagnostic performance of volumetric capnography (VCap) parameters in patients with cough variant asthma. METHODS: This cross-sectional study enrolled 31 patients with cough variant asthma and 30 patients with chronic cough without asthma between November 2010 and March 2012. VCap measurements were recorded at baseline, during the five steps of the histamine challenge, and after bronchodilation with salbutamol. They were then compared between the baseline and histamine challenge, and between the two groups. Receiver operating characteristic curve analysis was performed for different VCap measurements. RESULTS: The slope of phase III (dc/dv3) and the ratio of phase III slope to phase II slope (SR23%) decreased from baseline upon challenge with 1.1 mg histamine in cough variant asthma patients but increased in patients with chronic cough without asthma. Additionally, the change upon challenge with 1.1 mg histamine in dc/dv3 from baseline (S6-S1dc/dv3) in cough variant asthma patients had the largest area under the curve (AUC) (0.814, 95% CI: 0.697-0.931; p<0.001). The AUC for change upon challenge with 1.1 mg histamine in SR23% from baseline was 0.755 (95%CI: 0.632-0.878; p<0.001). At a cutoff of 19.8, S6-S1 dc/dv3 had a sensitivity of 74.2% and specificity of 90.0% and at a cutoff of 40.7, S6-S1 SR23% had a sensitivity of 48.4% and specificity of 96.7%. CONCLUSION: Patients with cough variant asthma exhibit distinct VCap responses for dead space parameters upon challenge with histamine in comparison to patients with chronic cough. VCap parameters like phase III slope and phase III/phase II slope ratio could be used to aid the diagnosis of cough variant asthma.

Respiratory evaluation through volumetric capnography among grade III obese and eutrophic individuals: a comparative study

ABSTRACT BACKGROUND: Excess trunk body fat in obese individuals influences respiratory physiological function. The aims of this study were to compare volumetric capnography findings (VCap) between severely obese patients and normal-weight subjects and to assess whether there is any association between neck circumference (NC), waist-hip ratio (WHR) and VCap among grade III obese individuals. DESIGN AND SETTING: Analytical observational case-matched cross-sectional study, University of Campinas. METHODS: This cross-sectional study compared VCap variables between 60 stage III obese patients and 60 normal-weight individuals. RESULTS: In comparison with the normal-weight group, obese patients presented higher alveolar minute volume (8.92 ± 4.94 versus 6.09 ± 2.2; P = < 0.0001), CO2 production (278 ± 91.0 versus 209 ± 60.23; P < 0.0001), expiratory tidal volume (807 ± 365 versus 624 ± 202; P = 0.005), CO2 production per breath (21.1 ± 9.7 versus 16.7 ± 6.16; P = 0.010) and peak expiratory flow (30.9 ± 11.9 versus 25.5 ± 9.13; P = 0.004). The end-expiratory CO2 (PetCO2) concentration (33.5 ± 4.88 versus 35.9 ± 3.79; P = 0.013) and the phase 3 slope were normalized according to expired tidal volume (0.02 ± 0.05 versus 0.03 ± 0.01; P = 0.049) were lower in the obese group. CONCLUSIONS: The greater the NC was, the larger were the alveolar minute volume, anatomical dead space, CO2 production per minute and per breath and expiratory volume; whereas the smaller were the phase 2 slope (P2Slp), phase 3 slope (P3Slp) and pressure drop in the mouth during inspiration.

Sedation Strategies for Procedures Outside the Operating Room

With the rapid development of diagnostic and therapeutic procedures performed outside the operating room (OR), the need for appropriate sedation care has emerged in importance to ensure the safety and comfort of patients and clinicians. The preparation and administration of sedatives and sedation care outside the OR require careful attention, proper monitoring systems, and clinically useful sedation guidelines. This literature review addresses proper monitoring and selection of sedatives for diagnostic and interventional procedures outside the OR. As the depth of sedation increases, respiratory depression and cardiovascular suppression become serious, necessitating careful surveillance using appropriate monitoring equipment.

Spirometry and volumetric capnography in lung function assessment of obese and normal-weight individuals without asthma / Espirometria e capnografia volumétrica na avaliação da função pulmonar de indivíduos obesos e eutróficos sem asma

Abstract Objective: To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. Methods: Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. Results: At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV1/FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p < 0.05). Volumetric capnography showed that obese individuals had a higher volume of produced carbon dioxide and alveolar tidal volume (p < 0.05). Additionally, the associations between dead space volume and tidal volume, as well as phase-3 slope normalized by tidal volume, were lower in healthy subjects (p < 0.05). These data suggest that obesity does not alter ventilation homogeneity, but flow homogeneity. After subdividing the groups by age, a greater difference in lung function was observed in obese and healthy individuals aged >11 years (p < 0.05). Conclusion: Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV1/FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes.

Resumo Objetivo: Analisar e comparar a função pulmonar de crianças e adolescentes obesos e eutróficos saudáveis, sem asma, pela espirometria e capnografia volumétrica. Métodos: Estudo transversal com 77 indivíduos (38 obesos) entre cinco e 17 anos. Todos fizeram espirometria e capnografia volumétrica. Os obesos repetiram as avaliações após o uso de broncodilatador. Resultados: Na avaliação da espirometria, os indivíduos obesos, quando comparados com o grupo controle, apresentaram menores valores no volume expiratório forçado no primeiro segundo pela capacidade vital forçada (VEF1/CVF) e nos fluxos expiratórios a 75% da CVF e entre 25-75% da mesma (p < 0,05). A capnografia volumétrica demonstrou que os obesos apresentam maior volume produzido de dióxido de carbono e volume corrente alveolar (p < 0,05). Além disso, a relação entre o volume espaço morto e volume corrente, bem como o slope da fase 3 normalizado pelo volume corrente, foi menor nos indivíduos saudáveis (p < 0,05). Esses dados sugerem que a obesidade não altera a homogeneidade da ventilação, mas sim dos fluxos. Ao subdividir os grupos por idade, foi observada maior diferença na função pulmonar entre indivíduos obesos e saudáveis na faixa acima de 11 anos (p < 0,05). Conclusão: Mesmo sem o diagnóstico de asma por critérios clínicos e sem resposta ao uso de broncodilatador, os indivíduos obesos apresentaram menores valores no VEF1/CVF e nos fluxos expiratórios forçados, o que indica a presença de processo obstrutivo. A capnografia volumétrica indicou nos indivíduos obesos maior volume corrente alveolar, sem alterações na homogeneidade da ventilação, o que sugere alteração nos fluxos, sem comprometimento dos volumes pulmonares.

Capnography as a tool to detect metabolic changes in patients cared for in the emergency setting / Capnografia como ferramenta para detectar alterações metabólicas em pacientes atendidos em situações de emergência / Capnografía como herramienta para detectar alteraciones metabólicas de los pacientes atendidos en situaciones de urgência

ABSTRACT Objective: to evaluate the usefulness of capnography for the detection of metabolic changes in spontaneous breathing patients, in the emergency and intensive care settings. Methods: in-depth and structured bibliographical search in the databases EBSCOhost, Virtual Health Library, PubMed, Cochrane Library, among others, identifying studies that assessed the relationship between capnography values and the variables involved in blood acid-base balance. Results: 19 studies were found, two were reviews and 17 were observational studies. In nine studies, capnography values were correlated with carbon dioxide (CO2), eight with bicarbonate (HCO3), three with lactate, and four with blood pH. Conclusions: most studies have found a good correlation between capnography values and blood biomarkers, suggesting the usefulness of this parameter to detect patients at risk of severe metabolic change, in a fast, economical and accurate way.

RESUMO Objetivo: avaliar a utilidade da capnografia para a detecção de alterações metabólicas em pacientes com respiração espontânea, no contexto das emergências e dos cuidados intensivos. Método: pesquisa bibliográfica estruturada aprofundada, nas bases de dados EBSCOhost, Biblioteca Virtual em Saúde, PubMed, Cochrane Library, entre outras, identificando estudos que avaliavam a relação entre os valores da capnografia e as variáveis envolvidas no equilíbrio ácido-base sanguíneo. Resultados: foram levantados 19 estudos, dois eram revisões e 17 eram estudos observacionais. Em nove estudos, os valores capnográficos foram correlacionados com o dióxido de carbono (CO2), em oito com o bicarbonato (HCO3), em três com o lactato, e em quatro com o pH sanguíneo. Conclusões: na maioria dos estudos foi observada uma correlação adequada entre os valores capnográficos e os biomarcadores sanguíneos, sugerindo a utilidade deste parâmetro para a identificação de pacientes com risco de sofrer uma alteração metabólica grave, de uma forma rápida, econômica e precisa.

RESUMEN Objetivo: explorar la utilidad de la capnografía para la detección de alteraciones metabólicas ante pacientes en respiración espontánea, en el ámbito de las emergencias y los cuidados críticos. Método: búsqueda bibliográfica estructurada en profundidad, en bases de datos EBSCOhost, Biblioteca Virtual de la Salud, PubMed, Cochrane Library, entre otras, identificando estudios que evaluaban la relación entre valores de la capnografía y variables implicadas en el equilibrio ácido-base sanguíneo. Resultados: se recopilaron 19 estudios, dos eran revisiones y 17 observacionales. En nueve estudios, se correlacionaron los valores capnográficos junto al dióxido de carbono (CO2), en ocho con el bicarbonato (HCO3), tres con el lactato, y cuatro con el pH sanguíneo. Conclusiones: la mayoría de estudios han obtenido una correlación adecuada entre los valores capnográficos y biomarcadores sanguíneos, sugiriendo la utilidad de este parámetro para la detección de pacientes en riesgo de padecer una alteración metabólica grave, de forma rápida, económica y precisa.

Sedation in colonoscopy by using three different propofol infusion methods and analysis of plasma concentration levels: a prospective comparative study / Sedação em colonoscopia: utilização do propofol em estudo comparativo entre três diferentes modos de administração

ABSTRACT Background: The propofolemia becomes directly linked to the clinical effects of this anesthetic and is the focus for studies comparing propofol clinical use, in different administration methods routinely used in endoscopy units where sedation is widely administered to patients. Aim: To evaluate the effects of three different regimens of intravenous propofol infusion in colonoscopies. Methods: A total of 50 patients that underwent colonoscopies were consecutively assigned to three groups: 1) intermittent bolus infusion; 2) continuous manually controlled infusion; 3) continuous automatic infusion. Patients were monitored with Bispectral IndexTM (BIS) and propofol serum levels were collected at three different timepoints. The development of an original dilution of propofol and an inventive capnography catheter were necessary. Results: Regarding clinical outcomes, statistical differences in agitation (higher in group 1, p=0.001) and initial blood pressure (p=0.008) were found. As for propofol serum levels, findings were similar in consumption per minute (p=0.748) and over time (p=0.830). In terms of cost analysis, group 1 cost was R$7.00 (approximately US$2,25); group2, R$17.50 (approximately US$5,64); and group 3, R$112.70 (approximately US$36,35, p<0.001). Capnography was able to predict 100% of the oxygen saturation drop (below 90%). Conclusion: The use of propofol bolus administration for colonoscopies, through continuous manually controlled infusion or automatic infusion are similar regarding propofolemia and the clinical outcomes evaluated. The use of an innovative capnography catheter is liable and low-cost solution for the early detection of airway obstruction.

RESUMO Racional: A propofolemia está diretamente relacionada com os efeitos clínicos desse anestésico e é foco de diversos estudos comparando os usos clínicos do propofol e os diferentes métodos de administração, como realizado amplamente nos centros de endoscopia. Objetivo: Avaliar os efeitos de três diferentes regimes de infusão de propofol intravenoso em colonoscopias. Métodos: Ao todo 50 pacientes que foram submetidos à colonoscopia foram consecutivamente divididos em três grupos: 1) infusão em bolus intermitente; 2) perfusão contínua controlada manualmente; 3) infusão automática contínua. Os pacientes foram monitorados com Bispectral IndexTM (BIS) e os níveis séricos de propofol foram coletados em três momentos diferentes. Foi necessário a preparação de uma diluição específica de propofol e o desenvolvimento de um cateter de capnografia original manufaturado para a realização do estudo. Resultados: Em relação aos desfechos clínicos, houve diferença estatística na agitação (maior no grupo 1, p=0,001) e pressão arterial inicial (p=0,008). Com relação aos níveis séricos de propofol, os resultados foram semelhantes no consumo por minuto (p=0,748) e ao longo do tempo (p=0,830). Em termos de análise de custo, no grupo 1 o custo foi de R$ 7,00 (aproximadamente US$ 2,25); grupo 2, R$ 17,50 (aproximadamente US$ 5,64); e grupo 3, R$ 112,70 (cerca de US$ 36,35, p<0,001). A capnografia foi capaz de diagnosticar 100% das dessaturações de oxigênio (abaixo de 90%). Conclusão: O uso de propofol em bolus para colonoscopias, por meio de infusão contínua controlada manualmente ou infusão automática são semelhantes quanto à propofolemia e os resultados clínicos avaliados. Além disso, o uso de um cateter de capnografia inovador é solução de baixo custo para a detecção precoce da obstrução da via aérea.

End-tidal capnometry during emergency department procedural sedation and analgesia: a randomized, controlled study / 世界急诊医学杂志（英文）

@#BACKGROUND:This prospective, randomized trial was undertaken to evaluate the utility of adding end-tidal capnometry (ETC) to pulse oximetry (PO) in patients undergoing procedural sedation and analgesia (PSA) in the emergency department (ED). METHODS:The patients were randomized to monitoring with or without ETC in addition to the current standard of care. Primary endpoints included respiratory adverse events, with secondary endpoints of level of sedation, hypotension, other PSA-related adverse events and patient satisfaction. RESULTS:Of 986 patients, 501 were randomized to usual care and 485 to additional ETC monitoring. In this series, 48％ of the patients were female, with a mean age of 46 years. Orthopedic manipulations (71％), cardioversion (12％) and abscess incision and drainage (12％) were the most common procedures, and propofol and fentanyl were the sedative/analgesic combination used for most patients. There was no difference in patients experiencing de-saturation (SaO2<90％) between the two groups; however, patients in the ETC group were more likely to require airway repositioning (12.9％ vs. 9.3％,P=0.003). Hypotension (SBP<100 mmHg or <85 mmHg if baseline <100 mmHg) was observed in 16 (3.3％) patients in the ETC group and 7 (1.4％) in the control group (P=0.048). CONCLUSIONS:The addition of ETC does not appear to change any clinically significant outcomes. We found an increased incidence of the use of airway repositioning maneuvers and hypotension in cases where ETC was used. We do not believe that ETC should be recommended as a standard of care for the monitoring of patients undergoing PSA.

Utility of end-tidal carbon dioxide monitoring in intramuscular ketamine sedation in the pediatric emergency department

PURPOSE: Recently, the use of end-tidal carbon dioxide (ETCO₂) monitoring has been suggested for early detection of hypoventilation over oxygen saturation (S(P)O₂) monitoring. We aimed to determine the usefulness of capnography in monitoring patients sedated using intramuscular (IM) ketamine in the pediatric emergency department (ED). METHODS: This study retrospectively reviewed medical records of patients younger than 16 years who were sedated using IM ketamine and whose ETCO₂ values were documented in the ED. Age, sex, American Society of Anesthesiologists physical status classification (ASA classification), and purpose of sedation were investigated. Vital signs were recorded at pre-sedation, 5 and 10 minutes after sedation, and after recovery. Hypoventilation was defined as S(P)O₂< 95%, ETCO₂≥ 50 mmHg or ≤ 30 mmHg, or increase in ETCO₂≥ 10 mmHg from the baseline without tachypnea. RESULTS: A total of 49 patients were investigated; 42 of them belonged to ASA classification I, and 7 to II. There was no patient with S(P)O₂< 95%, or ETCO₂≥ 50 mmHg, or increase in ETCO₂≥ 10 mmHg from the pre-sedation value. However, 5 patients had an ETCO₂≤ 30 mmHg, and 4 of them (8.2%) had normal respiratory rate and were suitable for hypopneic hypoventilation. Ten patients showed abnormal range of ETCO₂ (normal range, 35-45 mmHg), but did not meet the definition of hypoventilation. No one had clinically serious respiratory events. CONCLUSIONS: During sedation using IM ketamine, 8.2% of the patients had hypopneic hypoventilation without hypoxemia, and they were all younger than 36 months. Capnography for patients sedated using IM ketamine in the ED is useful in detecting hypopneic hypoventilation, and has the potential for preventing clinically serious respiratory events in patients, especially toddlers.

Evaluation of the Efficiency of the Atraumatic Endotracheal Tube in the Pulmonary-Gas Exchange: an Experimental Study

ABSTRACT OBJECTIVE: Mechanical ventilation is frequently necessary, in which case the use of an endotracheal tube is mandatory. The tube has an inflatable balloon in its distal extremity, whose aim is, among other functions, an efficient arterialization. However, serious injuries in the place of contact of the balloon with the trachea can be frequent. Some studies point out that balloons with permanent pressure may reduce this complication. Nevertheless, air scape, expressed by the inspiratory (IV) and expiratory volume (EV) variation (Δ IV-EV), may occur, possibly leading to hypoxemia. Thus, the goal of this study was to verify the efficiency of a modified endotracheal tube on arterializations compared to the traditional endotracheal tube. METHODS: The modified endotracheal tube presents intermittent insufflation, with three drillings in the internal region of the cuff, allowing for insufflation in the inspiratory phase of the mechanical ventilation. Three animals were used for the control group, with a cuff pressure of 30 cmH2O, and seven pigs had the modified endotracheal tube. Each animal was kept under mechanical ventilation (FIO2=0.21) for 6 hours. Arterial and venous gases were measured every three hours (T0; T3; T6). RESULTS: The gases confirmed the lack of hypoxia between the Groups, with a difference in the ΔIV-EV at T0 (P=0.0486). CONCLUSIONS: In this study, the lack of hypoxia showed the efficiency of the modified endotracheal tube. However, new studies are necessary, particularly in diseased lungs, in order to evaluate the real efficiency of the mentioned device on the pulmonary gas exchange.

Adjustable inspiratory occlusion valve in experimental bronchopleural fistula. A new therapeutic perspective

PURPOSE: To assess the efficacy of an adjustable inspiratory occlusion valve in experimental bronchopleural fistula during mechanical ventilation.METHODS:We studied six mechanically ventilated pigs in a surgically created, reproducible model of bronchopleural fistula managed with mechanical ventilation and water-sealed thoracic drainage. An adjustable inspiratory occlusion valve was placed between the thoracic drain and the endotracheal tube. Hemodynamic data, capnography and blood gases were recorded before and after the creation of the bronchopleural fistula as well as after every adjustment of the inspiratory occlusion valve.RESULTS:When compared with the standard water-sealed drainage treatment, the use of an adjustable inspiratory occlusion valve improved the alveolar tidal volume and reduced bronchopleural air leak (p<0.001), without hemodynamic compromise when compared with conventional water sealed drainage.CONCLUSION: The use of an adjustable inspiratory occlusion valve improved the alveolar tidal volume, reduced alveolar leak, in an experimental reproducible model of bronchopleural fistula, without causing any hemodynamic derangements when compared with conventional water sealed drainage.

Correlation of end-tidal carbon dioxide with arterial carbon dioxide among patients in neurosurgical intensive care unit / 中华创伤杂志

Objective To examine the correlation between end-tidal carbon dioxide (PetCO2) and arterial CO2 (PaCO2) among patients admitted in neurosurgical intensive care unit (NICU) and the factors affecting the PaCO2-PetCO2 [P (a-et) CO2].Methods Thirty-two intubated or cut-trachea patients who presented in the NICU were enrolled.Arterial blood gas test was done at seven every morning,and values of PetCO2 were compared with simultaneously recorded PaCO2.The normal gap of P (a-et) CO2 was defined as-5 mmHg to 5 mmHg.Concordance between PaCO2 and PetCO2 was analyzed using the Bland-Altman plot.Parameters between the normal and high P(a-et) CO2 groups were compared to identify the factors affecting the P(a-et) CO2,including Glasgow Coma Scale(GCS),blood pressure (BP),heart rate (HR),respiration rate (RR),body temperature (BT),and pulse oxygen saturation (SpO2).Results Allvalues of PaCO2 and PetCO2 were in accordance with normal distribution (r =0.668,P ＜ 0.01) and concordance between PaCO2 and PetCO2 was 69.8％.Patients who had high P(aet) CO2 showed lower initial GCS,lower instant GCS,BT,as well as pH and higher actual bicarbonate (AB) and PetCO2 than the patients with normal P (a-et) CO2.Correlation between PaCO2 and PetCO2 rapidly declined when positive end expiratory pressure(PEEP) was greater than 5 mmH2O(r =0.229,P ＜ 0.01).Conclusions PetCO2 correlates well with PaCO2 and appears to be a useful monitor of respiratory function of the patients consecutively.Initial GCS,BT,AB and PEEP have an impact on P(a-et) CO2,so those factors should be considered when attempting to monitor the hyperventilation with PetCO2.

Analysis of mean transcutaneous capnography in consecutive patients undergoing polysomnography / Análise da capnografia transcutânea média em indivíduos consecutivamente submetidos à polissonografia

Transcutaneous capnography is a noninvasive method useful for analysis of the behavioral tendency of transcutaneous CO2 pressure (PtcCO2) in patients undergoing polysomnography, to evaluate respiratory sleep disorders. Objective Determine normative PtcCO2 values in normal patients undergoing polysomnography. Method One hundred seventy-nine patients who underwent polysomnography with simultaneous PtcCO2 measurement were assessed by means of a transcutaneous capnograph (TCM4 series from Radiomiter). Results The group classified as normal (N=53) presented a apnea/hypopnea index (AHI) <5 events/per hour of sleep and their age groups varied between 7 and 76 years of age. Conclusion Global mean values of PtcCO2 in the normal group had a Gaussian distribution that varied between 33.1 and 50.0 mmHg (SD 4,363). Such findings allowed the establishment of normative PtcCO2 values for normal individuals. .

A capnografia transcutânea é um método não invasivo útil para análise da tendência comportamental da pressão de CO2 transcutânea (PtcCO2)1,2,3 em pacientes submetidos à polissonografia para análise de transtornos respiratórios do sono. Objetivo Determinar valores normativos da PtcCO2 em pacientes normais submetidos à polissonografia. Método Foram analisados 179 pacientes submetidos à polissonografia com medida concomitante da PtcCO2 através de um capnógrafo transcutâneo. Resultados O grupo classificado como normal (N=53) apresentou índice de apnéia/hipopnéia (AIH) <5 eventos/hora de sono e faixa etária variando de 7 a 76 anos. Conclusão Os valores da média global da PtcCO2 no grupo normal apresentaram distribuição gaussiana variando de 33,1 a 50,0 mmHg (DP 4.363). Tais achados permitiram a criação de valores normativos da PtcCO2 para indivíduos normais. .

SISTEMA DE PULSIOXIMETRÍA Y CAPNOGRAFÍA PARA DISPOSITIVOS MÓVILES ANDROID / A PULSE-OXIMETRIC AND CAPNOGRAPHIC SYSTEM FOR ANDROID MOBILE DEVICES / SISTEMA DE OXIMETRIA DE PULSO E CAPNOGRAFIA PARA DISPOSITIVOS MÓVEIS ANDROID

El monitoreo constante del nivel de saturación de oxígeno y la producción de CO2 es de vital importancia para la supervisión del estado respiratorio del paciente. Este artículo presenta el diseño de un sistema de oximetría de pulso y capnografía que tiene como unidad de procesamiento un chip programable de señales mixtas denominado PSoC (Programable-System-On-Chip), el cual incorpora bloques análogos y digitales configurables, permitiendo que la adecuación de las señales suministradas por los sensores y el procesamiento digital de señales se lleve a cabo en el mismo chip. Se realizó una aplicación en Android para la visualización y registro de las señales biomédicas en una base de datos local, compatible con dispositivos móviles con conectividad wifi. El sistema fue verificado usando un simulador de SpO2 (Saturación parcial de oxígeno), que permitió la calibración de frecuencias cardiacas desde 55 BPM (Beats per Minute) a 145 BPM, así como la curva R con valores de 75% a 100% de SpO2. Se encontró que el error de medición de la frecuencia cardiaca es 1,81%, y 1.33% para la SpO2.

Constant monitoring of oxygen saturation level and CO2 production is vital for monitoring the patient's respiratory status. This paper presents the design of a pulse-oximetric and capnographic system, which core consists of a mixed signal programmable chip, PSoC (Programmable-System-On-Chip), which incorporates a whole analog and digital configurable block system, in order to adequate and process the signals from the sensors all in a single chip. An Android application was also developed, which can display biomedical signals in mobile devices with wireless connectivity, as well as to store information from these signals in a local user database. The microsystem was verified using a SpO2 (oxygen partial saturation) simulator, and heart rates of 55 BPM to 145 BPM were calibrated, as well as the R curve with values of 75% to 100% SpO2. The heart rate measurement error found is 1,81% and 1,33% for the SpO2.

O monitoramento constante do nível de saturação de oxigênio e produção de CO2 é fundamental para monitorar o estado respiratório do paciente. Este artigo apresenta o projeto de um sistema de oximetria de pulso e capnografia cuja unidade de processamento um chips de sinal misto programável chamado PSoC (Programmable-System-On-Chip), o qual incorpora blocos analógicos e digitais configuráveis, permitindo a adaptação dos sinais fornecidos pelos sensores e o processamento digital de sinais será executada no mesmo chip. Foi realizada una aplicação Android para visualização e gravação de sinais biomédicos em um banco de dados local, compatível com dispositivos móveis com conectividade sem fio. O sistema foi testado usando um simulador de SpO2 (saturação de oxigênio parcial), permitindo a calibração da freqüência cardíaca de 55 BPM (batidas por minuto) a 145 BPM, assim como a curva R com valores de 75% a 100% SpO2 . Verificou-se que o erro de medição do ritmo cardíaco é 1,81% e 1,33% para o SpO2.

The usefulness of end-tidal carbon dioxide monitoring during apnea test in brain-dead patients / 대한마취과학회지

BACKGROUND: The apnea test (AT) is essential to confirming the diagnosis of brain death, but critical complications can occur if the AT is maintained over a long period. To minimize the AT period, we used end-tidal carbon dioxide (ETCO2) monitoring because ETCO2 is closely correlated with partial pressure of arterial carbon dioxide (PaCO2). The aim of the present study is to evaluate the usefulness of ETCO2 monitoring during apnea testing. METHODS: We reviewed 61 patients who were pronounced brain dead at our hospital from July 2009 to December 2012. The subjects were divided into two groups: the N-group, in which capnography was not used, and the C-group, in which capnography was used to monitor ETCO2. In the C-group, whenever arterial blood was sampled, the PaCO2 - ETCO2 gradients were calculated and the ventilator setting adjusted to maintain normocapnia prior to apnea testing. RESULTS: Twenty-eight subjects in the N-group and twenty-nine subjects in the C-group were included. The gender ratio, age, and cause of brain death were not different between the two groups. Prior to the AT, the normocapnia ratio was higher in the C-group than in the N-group. During the AT, the total test period was shorter in the C-group. Moreover, systolic blood pressure increased in the C-group and decreased in the N-group during apnea testing. CONCLUSIONS: ETCO2 monitoring during AT allows the PaCO2 level to be predicted, which reduces the duration of the test and stabilizes systolic blood pressure. Thus, with ETCO2 monitoring, the AT can be fast and safe.