Respiratory Flashcards
Hypoxemia is
Decreased o2 content in the areterial blood normal values 80-100mmhg
Hypercapnia is
Increased co2 (paCO2) in the blood 35-45mmHg
Hypoxia is
Decreased cellular and tissue oxygenation affecting pH - normal pH is 7.35-7.45
Sa02 is
Bound by Hb apparent on ABG values
Sp02 is
Pulse oximetry, Hb bound oxygen
Pa02 is
Amount of oxygen in the blood
Factors affecting gas exchange
Decreased surface area, thickened resp membrane, solubility of gas, rate of diffusion, pressure gradient between the membranes
Smooth muscle regulates
Diameter of the airways and is lined with ciliated epithelium, cilia beat continuously to move mucus out of the lungs.
Epithelium is
Lined with goblet cells and traps inhaled particles
Shunting of the alveoli is
Obstructed alveolus, no ventilation e.g mucus plug
Dead space of the alveolus
Blood flow obstruction, adequate ventilation often with pulmonary embolism
Protective hypoxic vasoconstriction
Under ventilated lung leads to local vasoconstriction to limit blood flow to affected lung tissue and divert blood to a well ventilated area to continue removal of C02. O2 therapy can cause constricted capillaries to dilate increasing C02 content rapidly and cause pulmonary HTN
Hakdane effect
More desaturated the Hb, the more c02 it carries
Pulmonary oedema is
Hydrostatic fluid is greater than the oncotic pressure = excess lung fluid. Obstructed lymph drainage, blood circulation not moving correctly (LV failure/HTN/AMI/ drugs/ noxious gas inhalation.
Treatment of PO
Diuretics to increase fluid excretion,
Vasodilators (GTN) donates nitric oxide increases smooth muscle cGMP
Inotropic agonist - increase HR to improve contractions
02 therapy
Mechanical ventilation - CPAP
Atelectasis is
Collapse lung due to compression in pleural space or Tumor or absorption (inhaled conc 02 or noxious gas)
Acute resp distress syndrome
Huge inflammatory response causing damage to the capillary membrane allowing fluid to leak into the alveoli. Common cause is sepsis
Asthma
Chronic inflammation causing narrowing of the airways
Asthma is
Often initiated by environmental triggers (extrinsic atopic) leading to dendritic cells presenting the invading toxin to type 2 helper cells (TH2 immune cell subtype) which proliferate against specific allergens by producing cytokines like IL4 = IgE = mast cells leukotrines, prostaglandins and histamines. IL5 = eosinophils = more cytokines and leukotrienes = type 1 hypersensitivity because of IgE
Emphysema can be triggered by
alpha 1 anti-trypsin deficiency which can be caused by smoking
O2 diffusion from alveolus to capillaries occurs because
the PaO2 is less in the capillary than the alveolus - diffusion occurs from a high concentration to a low concentration
Bronchospasm
spreads along an airway, indicates chronic disease
Chronic athsma is identified by
chronic airway remodelling, mucus plugs (hypertrophy of mucus glands) leading to a build up of scar tissue
parasympathetic division of the ANS causes
bronchoconstriction
Classic signs of pneumonia are
Crackles, dullness to percussion due to lung consolidation (fluid), tactile fremitus (vibration of chest when breathing), sharp lung pain, dyspnoea, fatigue, fever, productive cough with yellow sputum (dead neutrophils as pus)
Prednisolone MOA
Corticosteroid that has anti-inflammatory and immunosuppressive mechanisms by decreasing vasodilation and capillary permeability in addition to decreasing leukocyte migration to the area of inflammation
Salmeterol is and MOA
LABA - bronchodilator that stimulates beta 2 actions and therefore cause bronchodilator and increased airflow.
