Combined forced oscillation and fractional-order modeling in patients with work-related asthma: a case–control study analyzing respiratory biomechanics and diagnostic accuracy

Background Fractional-order (FrOr) models have a high potential to improve pulmonary science. These models could be useful for biomechanical studies and diagnostic purposes, offering accurate models with an improved ability to describe nature. This paper evaluates the performance of the Forced Oscillation (FO) associated with integer (InOr) and FrOr models in the analysis of respiratory alterations in work-related asthma (WRA). Methods Sixty-two individuals were evaluated: 31 healthy and 31 with WRA with mild obstruction. Patients were analyzed pre- and post-bronchodilation. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC). To evaluate how well do the studied models correspond to observed data, we analyzed the mean square root of the sum (MSEt) and the relative distance (Rd) of the estimated model values to the measured resistance and reactance measured values. Results and discussion Initially, the use of InOr and FrOr models increased our understanding of the WRA physiopathology, showing increased peripheral resistance, damping, and hysteresivity. The FrOr model (AUC = 0.970) outperformed standard FO (AUC = 0.929), as well as InOr modeling (AUC = 0.838) in the diagnosis of respiratory changes, achieving high accuracy. FrOr improved the curve fitting (MSEt = 0.156 ± 0.340; Rd = 3.026 ± 1.072) in comparison with the InOr model (MSEt = 0.367 ± 0.991; Rd = 3.363 ± 1.098). Finally, we demonstrated that bronchodilator use increased dynamic compliance, as well as reduced damping and peripheral resistance. Conclusions Taken together, these results show clear evidence of the utility of FO associated with fractional-order modeling in patients with WRA, improving our knowledge of the biomechanical abnormalities and the diagnostic accuracy in this disease.

Biomechanical Impacts of Forward Head Posture on the Respiratory Function

Introduction: Forward head posture (FHP) is a very common problem among the working population. Being one of the most subconscious function in humans, respiratory function utilizes both the diaphragmand external intercostal muscles for quiet breathing. However during labored breathing, many other muscles will be recruited, and mostly these muscles have attachments in the cervical, thoracic ribcage,and even lumbar vertebrae. By the nature of attachments of these muscles on the cervical vertebra and thoracic cage, it is then plausible that FHP would affect the respiratory function. Methods: Thorough searches were done through international journals for the last ten years regarding the topic of FHP and its impacts to the respiratory biomechanics. Discussion: Previous studies have reported how prolonged FHP will result in kyphotic posture, reducing the mobility of ribcage, and modifies all respiratory muscular attachments such as sternocleidomastoids, intercostals, and to a certain extent, the diaphragm. All these result in a restrictive lung disorder, signified by reducing spirometry values, such as Forced Vital Capacity, Sniff Nasal Inspiratory Pressure, and Peak Flow Rate. Conclusion: Forward head posture disturb the respiratory biomechanics.

Combined forced oscillation and fractional-order modeling in patients with work-related asthma: a case-control study analyzing respiratory biomechanics and diagnostic accuracy

Background Fractional-order (FrOr) models have a high potential to improve pulmonary science. These models could be useful for biomechanical studies and diagnostic purposes, offering accurate models with an improved ability to describe nature. This paper evaluates the performance of the Forced Oscillation (FO) associated with integer (InOr) and FrOr models in the analysis of respiratory alterations in work-related asthma (WRA). Methods Sixty-two individuals were evaluated: 31 healthy and 31 with WRA with mild obstruction. Patients were analyzed pre and post bronchodilation. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC). To evaluate how well do the studied models correspond to observed data, we analyzed the mean square root of the sum (MSEt) and the relative distance (Rd) of the estimated model values to the measured resistance and reactance measured values. Results and discussion Initially, the use of InOr and FrOr models increased our understanding of the WRA physiopathology, showing increased peripheral resistance, damping, and hysteresivity. The FrOr model (AUC=0.970) outperformed standard FO (AUC=0.929), as well as InOr modeling (AUC=0.838) in the diagnosis of respiratory changes, achieving high accuracy. FrOr improved the curve fitting (MSEt=0.156±0.340; Rd=3.026±1.072) in comparison with the InOr model (MSEt=0.367±0.991; Rd=3.363±1.098). Finally, we demonstrated that the bronchodilator use increased dynamic compliance, as well as reduced damping and peripheral resistance. Conclusions Taken together, these results show clear evidence of the utility of FO associated with fractional-order modeling in patients with WRA, improving our knowledge of the biomechanical abnormalities and the diagnostic accuracy in this disease.

Combined forced oscillation and fractional-order modeling in patients with work-related asthma: a case-control study analyzing respiratory biomechanics and diagnostic accuracy

Background Fractional-order (FrOr) models have a high potential to improve pulmonary science. These models could be useful for biomechanical studies and diagnostic purposes, offering accurate models with an improved ability to describe nature. This paper evaluates the performance of the Forced Oscillation (FO) associated with integer (InOr) and FrOr models in the analysis of respiratory alterations in work-related asthma (WRA). Methods Sixty-two individuals were evaluated: 31 healthy and 31 with WRA with mild obstruction. Patients were analyzed pre and post bronchodilation. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC). To evaluate how well do the studied models correspond to observed data, we analyzed the mean square root of the sum (MSEt) and the relative distance (Rd) of the estimated model values to the measured resistance and reactance measured values. Results and discussion Initially, the use of InOr and FrOr models increased our understanding of the WRA physiopathology, showing increased peripheral resistance, damping, and hysteresivity. The FrOr model (AUC=0.970) outperformed standard FO (AUC=0.929), as well as InOr modeling (AUC=0.838) in the diagnosis of respiratory changes, achieving high accuracy. FrOr improved the curve fitting (MSEt=0.156±0.340; Rd=3.026±1.072) in comparison with the InOr model (MSEt=0.367±0.991; Rd=3.363±1.098). Finally, we demonstrated that the bronchodilator use increased dynamic compliance, as well as reduced damping and peripheral resistance. Conclusions Taken together, these results show clear evidence of the utility of FO associated with fractional-order modeling in patients with WRA, improving our knowledge of the biomechanical abnormalities and the diagnostic accuracy in this disease.

Recruitment Maneuver in Elderly Patients with Different Peripheral Chemoreflex Sensitivity during Major Abdominal Surgery

The goal of the study was to evaluate the effect of a recruitment maneuver on respiratory biomechanics, oxygenation, and hemodynamics in patients suffering from chronic heart failure with different peripheral chemoreflex sensitivity. The study was conducted in 115 elderly patients which underwent major abdominal surgery under general/epidural surgery. Peripheral chemoreflex sensitivity (PCS) was evaluated with breath-holding duration (BHD) during breath-holding test. All patients were divided into two groups: group H had a high PCS (BHD = 38 seconds or less,n=49); Group M had a middle PCS (BHD more than 38 seconds,n=66). Recruitment maneuver improved oxygenation and respiratory biomechanics in all cases. However, cardiac output decreased by an average of 18%–31% in group H compared to 18%–28% in group M. SVR either remained unchanged or decreased by up to 14% of the initial value in group H, while, in group M, it had a tendency to increase, which was 24% of the initial value. So, recruitment maneuver is an effective method to improve oxygenation and biomechanical properties of the respiratory system but in patients with increased peripheral chemoreflex sensitivity it associates with the risk of hemodynamic disturbances.