Pulmonary function tests
Definition
肺功能测试是一组测量呼吸和肺功能的测试.
Alternative Names
PFTs; Spirometry; Spirogram; Lung function tests; Lung volume; Plethysmography
How the Test is Performed
Spirometry measures airflow. By measuring how much air you exhale, and how quickly you exhale, 肺活量测定法可以评估多种肺部疾病. In a spirometry test, while you are sitting, 你对着一个与呼吸计相连的吸口呼吸. 呼吸量计记录你在一段时间内吸入和呼出空气的量和速率. 站立时,有些数字可能会略有不同.
对于某些测试测量,您可以正常而安静地呼吸. 其他测试要求在深呼吸后强制吸气或呼气. Sometimes, 您将被要求吸入不同的气体或药物,看看它如何改变您的测试结果.
Lung volume measurement can be done in two ways:
- 最准确的方法叫做身体体积脉搏图. 你坐在一个看起来像电话亭的透明密闭盒子里. 技术人员会让你用一个嘴吸气和呼气. 盒子内压力的变化有助于确定肺容量.
- 当你通过一根管子呼吸氮气或氦气一段时间后,也可以测量肺容量. 通过测量与管子相连的腔室中的气体浓度来估计肺的体积.
To measure
How to Prepare for the Test
Do not eat a heavy meal before the test. Do not smoke for 4 to 6 hours before the test. 如果你需要停止使用支气管扩张剂或其他吸入药物,你会得到具体的指导. 您可能需要在考试前或考试中吸入药物.
How the Test will Feel
因为这个测试包括用力呼吸和急促呼吸, 你可能会有短暂的呼吸急促或头晕. You also might have some coughing. 你通过一个紧密的嘴呼吸,你会有鼻夹. 如果你有幽闭恐惧症,在封闭的测试亭进行测试的部分可能会感到不舒服.
按照指示使用呼吸计的呼吸口. 牙套周围密封不良可能导致结果不准确.
Why the Test is Performed
Pulmonary function tests are done to:
- 有助于诊断某些类型的肺部疾病,如
asthma ,bronchitis , andemphysema -
Find the cause of
shortness of breath - 测量工作中接触化学物质是否会影响肺功能
- Check lung function before someone has surgery
- Assess the effect of medicines
- Measure progress in disease treatment
- 测量对心血管疾病治疗的反应
Normal Results
正常值是基于你的年龄、身高、种族和性别. Normal results are expressed as a percentage. 如果一个值大约小于预测值的80%,通常被认为是异常的.
不同实验室的正常值范围可能略有不同, 基于稍微不同的方法来确定正常值. 与您的十大赌博平台排行榜谈谈您的具体测试结果的含义.
在肺功能检查后,您的报告上可能会出现不同的测量结果,通常包括:
- Diffusion capacity to carbon monoxide (DLCO)
- Expiratory reserve volume (ERV)
- Forced vital capacity (FVC)
- Forced expiratory volume in 1 second (FEV1)
- Forced expiratory flow 25% to 75% (FEF25-75)
- Functional residual capacity (FRC)
- Maximum voluntary ventilation (MVV)
- Residual volume (RV)
- Peak expiratory flow (PEF)
- Slow vital capacity (SVC)
- Total lung capacity (TLC)
What Abnormal Results Mean
异常结果通常意味着你可能有胸部或肺部疾病.
Some lung diseases (such as emphysema, asthma, chronic bronchitis, 感染会使肺部含有过多的空气,需要更长的时间才能排空. 这些肺部疾病被称为阻塞性肺疾病.
其他肺部疾病会使肺部疤痕累累,体积变小,导致肺部空气太少,无法将氧气输送到血液中. Examples of these types of illnesses include:
- Extreme overweight
- 肺纤维化(肺组织瘢痕或增厚)
Sarcoidosis andscleroderma
肌肉无力也会导致检测结果异常, even if the lungs are normal, that is, similar to the diseases that cause smaller lungs.
Risks
There is a small risk for
References
Bhakta NR, Kaminsky DA. 肺功能测试:生理学和测试原理. In: Broaddus VC, Ernst JD, King TE, et al, eds. 默里和纳德尔的呼吸医学教科书. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 31.
Scanlon PD. Respiratory function: mechanisms and testing. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 79.
Wald O, Izhar U, Sugarbaker DJ. Lung, chest wall, pleura, and mediastinum. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL,编辑. Sabiston Textbook of Surgery. 21st ed. Philadelphia, PA: Elsevier; 2022:chap 58.
Review Date: 12/06/2021