Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo (USP) Sao Paulo, SP 05508-000, Brazil.
Biomedical Engineering Laboratory - University of Sao Paulo (USP) Sao Paulo, SP 05508-010, Brazil.
Exp Biol Med (Maywood). 2021 May;246(9):1094-1103. doi: 10.1177/1535370221993095. Epub 2021 Feb 18.
Assessment of respiratory mechanics extends from basic research and animal modeling to clinical applications in humans. However, to employ the applications in human models, it is desirable and sometimes mandatory to study non-human animals first. To acquire further precise and controlled signals and parameters, the animals studied must be further distant from their spontaneous ventilation. The majority of respiratory mechanics studies use positive pressure ventilation to model the respiratory system. In this scenario, a few drug categories become relevant: anesthetics, muscle blockers, bronchoconstrictors, and bronchodilators. Hence, the main objective of this study is to briefly review and discuss each drug category, and the impact of a drug on the assessment of respiratory mechanics. Before and during the positive pressure ventilation, the experimental animal must be appropriately sedated and anesthetized. The sedation will lower the pain and distress of the studied animal and the plane of anesthesia will prevent the pain. With those drugs, a more controlled procedure is carried out; further, because many anesthetics depress the respiratory system activity, a minimum interference of the animal's respiration efforts are achieved. The latter phenomenon is related to muscle blockers, which aim to minimize respiratory artifacts that may interfere with forced oscillation techniques. Generally, the respiratory mechanics are studied under appropriate anesthesia and muscle blockage. The application of bronchoconstrictors is prevalent in respiratory mechanics studies. To verify the differences among studied groups, it is often necessary to challenge the respiratory system, for example, by pharmacologically inducing bronchoconstriction. However, the selected bronchoconstrictor, doses, and administration can affect the evaluation of respiratory mechanics. Although not prevalent, studies have applied bronchodilators to return (airway resistance) to the basal state after bronchoconstriction. The drug categories can influence the mathematical modeling of the respiratory system, systemic conditions, and respiratory mechanics outcomes.
呼吸力学评估从基础研究和动物模型扩展到人类的临床应用。然而，为了将这些应用于人类模型，首先研究非人类动物是可取的，有时甚至是强制性的。为了获得更精确和可控的信号和参数，所研究的动物必须进一步远离其自主通气。大多数呼吸力学研究使用正压通气来模拟呼吸系统。在这种情况下，有几类药物变得相关：麻醉剂、肌肉阻滞剂、支气管收缩剂和支气管扩张剂。因此，本研究的主要目的是简要回顾和讨论每类药物，以及药物对呼吸力学评估的影响。在正压通气之前和期间，实验动物必须适当镇静和麻醉。镇静可以减轻研究动物的疼痛和不适，麻醉平面可以预防疼痛。有了这些药物，就可以进行更可控的操作；此外，由于许多麻醉剂会抑制呼吸系统的活动，因此可以最大限度地减少动物呼吸努力的干扰。后一种现象与肌肉阻滞剂有关，肌肉阻滞剂的目的是最大限度地减少可能干扰强迫振荡技术的呼吸伪影。通常，在适当的麻醉和肌肉阻断下研究呼吸力学。在呼吸力学研究中，支气管收缩剂的应用很普遍。为了验证研究组之间的差异，通常需要挑战呼吸系统，例如通过药理学诱导支气管收缩。然而，所选的支气管收缩剂、剂量和给药方式会影响呼吸力学的评估。虽然不常见，但已有研究应用支气管扩张剂在支气管收缩后使气道阻力（气道阻力）恢复到基础状态。药物类别会影响呼吸系统的数学模型、全身状况和呼吸力学结果。
