Artificial pulmonary ventilation in patients with COPD

Patogenesis

• COPD is characterized by chronic inflammation of the airways, lung parenchyma and pulmonary vasculature.
• Accumulation of macrophages, T Ly (CD8+), neutrophils.
• Mediators.
• Oxidative stress.
• Imbalance between the system of proteinases and antiproteinases.
• Muscle dysfunction – muscle microdisruption, oxidative stress, glucocorticoid therapy.

Etiology

• Smoking.
• Socioeconomic position.
• Enviromental factors.
• Recurrent respiratory infections.
• Lung disease at a young age.
• Bronchial hyperreactivity.
• Profesion.
• Alpha 1 protease inhibitor deficiency.

Pathophysiological changes

• Dry DC.
• Expiratory flow obstruction.
• Loss of lung elasticity
• V/Q abnormalities.
• Hyperinflation.
• Weakening of respiratory muscles.
• Abnormal „respiratory drive“.
• Pulmonary hypertension.

Clinical presentation

1. Chronic brochitis – the presence of cough for more than 3 months (exclusion of other causes - TU, etc.)
   • These individuals are usually obese, bulbous protrusion dominates.
   • Dyspnea is less in comparison to the emphysematic type, patients are cyanotic, tend to have polyglobulia and show signs of decompensated cor pulmonale.
     • They are referred to as "blue bloaters" - the bloated, swollen, blue type (also "blue bubble").
2. Emphysema – abnormal expansion distal to the terminal bronchioles, associated with destruction of the alveolar wall without signs of fibrosis.
   • Patients tend to have a large emphysematic chest, they are usually asthenic.
   • However, significant shortness of breath is not accompanied by polyglobulia or cyanosis. .

   Some authors refer to this type of patients as "pink puffers" - pink type (or "pink puffer"). Patients are short of breath but have pink skin.

Diferential diagnosis

• Bronchial ashtma.
• Cardiac failure.
• Bronchiectasis.
• TB.
• Obliterative bronchiolitis.
• Diffuse panbronchiolitis.

Treatment

• Intravenous or oral administration of corticoids is recommended as part of the treatment of hospitalized patients.
• An oral dose of 30–40 mg prednisolone/day for 7–10 days is considered effective and safe

→ longer administration does not increase the treatment effect and is associated with a higher risk of side effects (hyperglycemia, muscle atrophy).

• Administration of antibiotics is recommended for:

• Patients with the simultaneous occurrence of three so-called cardinal symptoms - increased shortness of breath, increased amount of sputum and purulent nature of sputum.
• Diseases requiring artificial pulmonary ventilation (including non-invasive ventilation).

• Manual or mechanical chest vibration may be beneficial in patients with high sputum production (more than 25 ml/d) or in patients with lobar atelectasis.
• There are no data demonstrating the beneficial effect of inhalation administration of secretolytics.
• Pulmonary rehabilitation may be beneficial in the recovery phase from an acute exacerbation of COPD.
• Before discharge, the initiation of treatment with a proven effect on the number of exacerbations and hospitalizations of patients with COPD should be considered

→ administration of long-acting inhaled bronchodilators.

→ administration of inhaled corticoids and their combinations.

Total or partial respiratory insufficiency?

• pCO₂ indicator of adequacy of ventilation!!!
• pO₂ ndicator of lung oxygenation function!!!

→ Partial insufficiency = hypoxia → Global insufficiency = hypoxia + hypercapnia.

• If a patient with hypoxic (partial) respiratory insufficiency is given oxygen, relief will occur.
• A patient will global insufficiency accumulates CO₂ in such a way that CNS loses sensitivity to its increased level and breathing depends only on the presence oflack of oxygen – hypoxia → pif we give more oxygen (more than approx. 2-4 l/min) we can alleviate the hypoxia that was holding breathing and the patient will stop breathing!

!!!! → herefore, it is important in the first phase, using the examination according to Astrup, to distinguish what kind of hypoxia is involved

pH shows the degree of compensation, in an acute exacerbation CO₂ is high (can be chronic) and pH is low.

Links

Related articles

• COPD

References

• Incomplete citation of lecture. 

 PETR, Vojtíšek. Chronická obstrukční plicní nemoc [lecture for subject Modul UPV, specialization intesive care unit nursing – specializační studium Vyšší odborná škola zdravotnická a Střední škola zdravotnická]. Ústí nad Labem. 2012-12-16. 

• PAVEL, Dostál, et al. Základy umělé plicní ventilace. 2. edition. Praha : Maxdorf, 2005. ISBN 80-7345-059-3.