Design and application of a central venous pressure measurement tool / 中华危重病急救医学

Central venous pressure (CVP) reflects the comprehensive condition of effective blood volume, cardiac function and vascular tone. Clinical monitoring of CVP can indirectly understand and evaluate the dynamic changes of blood volume in patients, and provide a reference for patients to venous fluid. At present, the traditional manual measurement method is widely used for measurement, which has some shortcomings such as zero shift, cumbersome operation (requires two health care workers to cooperate). In order to overcome the above problems, the author invented a new fixable CVP measurement tool and obtained the national utility model patent (ZL 2021 2 1451705.7). The tool is mainly composed of a base plate, a movable frame and a measuring department, etc. When used, the base plate is placed into the back of the patient and pressed and fixed, the movable frame is adjusted, the zero point is found, and the measurement data is read from the measuring department. It has the advantages of simple and convenient operation, small measurement error, wide applicability (different body types) and so on, which is suitable for clinical promotion.

Subjective method for tracheal tube cuff inflation: performance of anesthesiology residents and staff anesthesiologists. Prospective observational study / Insuflação de balonete de tubo traqueal por método subjetivo: desempenho de médicos residentes e especialistas em anestesiologia. Estudo prospectivo observacional

Abstract Background and objectives: Poor monitoring of tracheal tube cuff pressure may result in patient complications. The objective method of using a manometer is recommended to keep safe cuff pressure values (20‒30 cm H2O). However, as manometers are not readily available, anesthesiologists use subjective methods. We aimed to assess appropriateness of a subjective method for attaining cuff pressure and the expertise level of manometer handling among anesthesiology staff and residents in a university teaching hospital. Methods: Prospective observational study, recruiting participants that performed tracheal intubation and the subjective method for tube cuff inflation. Patients with difficult airway, larynx and trachea anatomic abnormality and emergency procedures were not included. Up to 60 minutes after tracheal intubation, an investigator registered the cuff pressure using an aneroid manometer (AMBU®) connected to the tube pilot balloon. Results: Forty-seven anesthesiologists were included in the study - 24 residents and 23 staff. Mean (SD) and medians (IQR) measured in cmH2O were, respectively, 52.5 (27.1) and 50 (30‒70). We registered 83% of measurements outside the recommended pressure range, with no difference between specialists and residents. The level of expertise with the objective method was also similar in both groups. Pressure adjustments were performed in 76.6% of cases. Conclusion: The subjective method for inflating the tracheal tube cuff resulted in a high rate of inadequate cuff pressures, with no difference in performance between anesthesiology specialists and residents.

Resumo Justificativa e objetivos: O controle inadequado da pressão dos balonetes dos tubos traqueais pode resultar em complicações. A técnica objetiva com uso de manômetro é a recomendada para manutenção de valores seguros de pressão (20-30 cm H2O). Mas como ese instrumento é pouco disponível, os anestesiologistas recorrem a técnicas subjetivas. O objetivo deste estudo foi avaliar a adequação da técnica subjetiva para obtenção das pressões dos balonetes e o nível de experiência com uso do manômetro entre médicos especialistas e residentes de anestesiologia de um Hospital Universitário. Método: Estudo observacional prospectivo, com participantes que realizaram intubação traqueal e técnica subjetiva para insuflação dos balonetes. Pacientes com via aérea difícil, anormalidades anatômicas de laringe e traqueia, risco de broncoaspiração e os casos de emergência não foram incluídos. Até 60 minutos após a intubação, um investigador registrava a pressão do balonete utilizando um manômetro aneroide (AMBU®) conectado ao balonete guia do tubo. Resultados: Quarenta e sete anestesiologistas foram incluídos no estudo - 24 residentes e 23 especialistas. As pressões (cm H2O) média (DP) e mediana (IQR) encontradas foram, respectivamente, 52,5 (27,1) e 50 (30-70). Da amostra, 83% estavam fora da faixa adequada de pressão, sem diferença entre especialistas e residentes. O nível de experiência com a técnica objetiva também foi semelhante entre os grupos. Correção da pressão foi realizada em 76,6% dos casos. Conclusões: A técnica subjetiva para insuflar os balonetes dos tubos traqueais resultou em alta prevalência de pressões inadequadas, sem diferença no desempenho entre especialistas e residentes.

A design and study of a novel electronic device for cuff-pressure monitoring / 中华危重病急救医学

Objective To design a novel electronic device for measuring the pressure in the cuff of the artificial airway; and to study the advantage of this device on continuous and intermittent cuff pressure monitoring. Methods ① a portable electronic device for cuff pressure measurement was invented, which could turn pressure signal into electrical signal through a pressure transducer. Meantime, it was possible to avoid pressure leak from the joint and the inside of the apparatus by modified Luer taper and sophisticated design. If the cuff pressure was out of the normal range, the apparatus could release a sound and light alarm. ② Six traditional mechanical manometers were used to determine the cuff pressure in 6 tracheal tubes. The cuff pressure was maintain at 30 cmH2O (1 cmH2O =0.098 kPa) by the manometer first, and repeated every 30 seconds for 4 times. ③ Study of continuous cuff pressure monitoring: We used a random number generator to randomize 6 tracheal tubes, 6 mechanical manometers and 6 our products by number 1-6, which has the same number of a group. Every group was further randomized into two balanced groups, one group used the mechanical manometer first, and the other used our product first. The baseline pressure was 30 cmH2O, measurement was performed every 4 hours for 6 times. Results When traditional mechanical manometer was used for cuff pressure monitoring, cuff pressure was decreased by an average of 2.9 cmH2O for each measurement (F = 728.2, P = 0.000). In study of continually monitoring, at each monitoring point, the pressure measured by electronic manometer was higher than the mechanical manometer. All the pressures measured by mechanical manometer were dropped below 20 cmH2O at 8th hour, and there was no pressure decrease below 20 cmH2O measured by electronic manometer in 24 hours by contrast. In study of intermittent monitoring, the same result was found. The pressure was dropped significantly with time when measured by mechanical manometer (F = 61.795, P = 0.000), the drops below 20 cmH2O began at 8th hour; but when measured by electronic manometer, all the value stayed unchanged around the baseline in 24 hours (F = 0.511, P = 0.796). Conclusions Compared with traditional mechanical manometer, cuff pressures monitored by our novel electronic manometer were steadier in both continuous and intermittent monitoring. The device is compact and convenient, and can provide a good solution for continuously monitor of the tracheal cuff pressure.

Análise da resistência do incentivador respiratório em indivíduos jovens / Resistance analysis of incentive spirometry in young individuals

A inspirometria de incentivo técnico na fisioterapia, que promove o aumento da resistência nas vias aéreas, é comumente utilizada na recuperação e reabilitação da função pulmonar. O estudo teve por objetivo investigar a resistência gerada através da pressão inspiratória máxima (PImáx) no momento da execução da terapêutica do incentivador respiratório a fluxo, nos níveis do equipamento R0,R1, R2, R3 em 71 voluntários de ambos os sexos, idade entre 18 e35 anos. Foram divididos em subgrupos, utilizando índice de massa corpórea (IMC) como variável determinante, obtendo-se subgrupos masculinos G1 (IMC = 22,48m/kg2; n = 10) e o G2 (IMC = 26,71m/kg2; n = 20) e os subgrupos femininos G3 (IMC = 20,86 m/kg2;n = 26) e o G4 (IMC = 25,15 m/kg2; n = 15). Foram realizadas três mensurações de PImáx, e após cada medida o voluntário identificava o nível de esforço pela escala de percepção subjetiva de esforço (PSE)de Borg. A estatística aplicada foi descritiva e inferencial, análise de Cluster, teste t, Post Hoc de Bonferone e Kolmogorov-Smirnov. Conclui-se que a intensidade gerada pelo inspirômetro de incentivo é de leve a moderada para os níveis 1, 2 e 3, podendo atingir intensidades superiores a 80% em indivíduos com sobrepeso.

Incentive spirometry is a physical therapy technique that promotes resistance in the air track has been commonly used in therecovery and rehabilitation of pulmonary functions. The present study investigated the resistance generated through maximum inspiratory pressure during therapy sessions with flow-oriented incentive spirometry, the equipment operating on levels R0, R1,R2, R3 in 71 volunteers from both genders, aging between 18 and 35. They were divided into subgroups, utilizing body mass index(BMI) as the determinant variable, obtaining male subgroups G1(BMI = 22.48m/kg2; n = 10) and G2 (BMI = 26.71 m/kg2; n =20) and the female subgroups G3 (BMI = 20.86 m/kg2; n = 26)and G4 (BMI = 25.15 m/kg2; n = 15). Three MIP measurements were obtained, after which the volunteer identified the effort level by Borg’s Rating of Perceived Exertion (RPE). Statistics applied were descriptive and inferential, Cluster analysis, T test, Post HocBonferone and Kolmogorov-Smirnov. This study concluded that the intensity generated by incentive spirometry is light to moderate on levels 1, 2, and 3, possibly reaching intensity higher than 80% forover-weight individuals.

Repercussão da hemodiãlise na função pulmonar de pacientes com doença renal crônica terminal / Impact of hemodialysis on lung function in patients with chronic renal

Pacientes com doença renal desenvolvem frequentemente complicações pulmonares como edema, derrame pleural e infecção. Método: A avaliação respiratória deu-se através de exames de espirometria, manovacuometria, oximetria e gasometria, antes e depois de sessão de hemodiálise (HD). As variáveis espirométricas foram analisadas em porcentagens de valores de referencia com o objetivo de eliminar efeitos da idade, altura e sexo. Resultados e Discussão: Avaliaram-se 33 pacientes (51,5% mulheres) com média de idade 42,8 +- 14,2 anos, em tratamento no Hospital das Clínicas de Porto Alegre. A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1) e o pico de fluxo expiratório (PFE) apresentaram um aumento significativo após sessão de HD, o que determinou um aumento no número de espirometrias normais, passando de 12 (36,4%) para 17 (51,5%). A força muscular também apresentou aumento significativo. A oximetria permaneceu inalterada após HD, o que pode ser explicado pelos resultados da gasometria, pois, após HD, houve um aumento substancial no PH e nos níveis de bicarbonato, caracterizando quadro de alcalose metabólica. Observou-se, também, queda na pressão parcial de oxigênio e aumento na pressão parcial de dióxido de carbono, provavelmente na tentativa de restabelecer o valor do PH. Conclusões: Mesmo sem apresentar sintomas respiratórios, pacientes renais crônicos apresentam alterações na função pulmonar que melhora após tratamento com HD.

Patients with kidney disease often develop complications such as pulmonary edema, pleural effusion, and infection. Method: The respiratory evaluation was made through examination of spirometry, manometer, pulse oximetry and blood gases before and after hemodialysis session (HD). Spirometric variables were analyzed as percentages of reference values ​​in order to eliminate the effects of age, gender and height. Results and Discussion: We evaluated 33 patients (51.5% women) with mean age 42.8 + - 14.2 years, treated at the Hospital das Clinicas de Porto Alegre. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) showed a significant increase after HD session, which led to an increase in the number of normal spirometry results, from 12 ( 36.4%) to 17 (51.5%). Muscle strength also increased significantly. Pulse oximetry remained unchanged after HD, which can be explained by the results of blood gas analysis, since, after HD, there was a substantial increase in pH and bicarbonate levels, characterizing a condition of metabolic alkalosis. There was also a drop in partial pressure of oxygen and increased partial pressure of carbon dioxide, probably in an attempt to restore the value of PH. Conclusions: Even without respiratory symptoms, chronic renal failure patients show changes in lung function improves after treatment with HD.

Intraocular Pressure Assessment in Vitrectomized Gas-filled Eyes

We assessed the accuracy of Goldmann or Schi-(phi)tz tonometric readings in the gas filled vitrectomized eyes. We performed pars plana vitrectomy with or without lensectomy in 8 rabbit eyes, and in 6 enucleated porcine eyes. Fluid-air exchange was done at the end of the procedure. Intraocular pressure was measured using Goldmann tonometer and Schi-(phi)tz tonometer and was compared with true pressure which was monitored by manometer with indwelling catheter in the intravitreal cavity. Goldmann and Schi-(phi)tz tonometry always showed lower presure value than manometeric one(P0.05).

Design and application of digital manometer for air-pocket in manual air-way / 医疗卫生装备

This paper discusses the design of a special digital manometer for air-pocket in manual air-way. Integrated silicon pressure sensor MPX5010 with high precision and sensitivity is adopted in the device. It can not only measure and display air pressure of air-pocket,but also give the alarm for excessive pressure,thus providing a timely and convenient way for clinician to control air-pocket pressure,which ensures the safety and precision for clinic.