Oxygen 88-92% target

Hypoxic respiratory drive theory

In some COPD patients, chronic CO₂ retention occurs due to poor ventilation.

Over time, the brain becomes less sensitive to high CO₂ levels.

Instead, the body relies on peripheral chemoreceptors, which detect low oxygen (hypoxia) to trigger breathing.

This is known as the hypoxic drive

Ventilation/perfusion- hypoxic pulmonary vasoconstriction

In COPD patients hypoxic pulmonary vasoconstriction occurs due to low oxygen levels in the alveoli. The alveoli are damage due to emphysema, leading to areas with poor oxygenation. The pulmonary arterioles redirect blood flow to better ventilated alveoli to optimise gases exchange. if oxygen levels are raised to high, the body reduces hypoxic pulmonary vasoconstriction and blood continue to flowing poorly alveoli which worsening ventilation perfusion mismatch leading co2 retention.

Haldane effect –

n COPD, chronic hypoxia leads to increased deoxygenated haemoglobin.

This enhances CO₂ binding to haemoglobin in the blood, but when given high levels of oxygen, O₂ displaces CO₂ (due to the Haldane effect), leading to sudden CO₂ retention and hypercapnia.

This is one reason oxygen therapy must be carefully controlled in COPD patients.

Decrease in GCS

Salbutamol agonist 2.5-5mg

Does – 2.5-5mg

How – salbutamol bind to the beta 2 receptors and relaxes the smooth muscles in the bronchi and causes bronchi dilation increasing gaseous exchange

Therapeutic use – relief from acute bronchospasm or wheezing

Side effect – headache, muscles spasms, increased heart rate bet1 activation

Precautions – salbutamol can cause tachycardiac because it can bind to beta 1 adrenergic receptors which creates stimulation which increase heart rate

ipratropium bromide

does – 5mg

how- blocks muscarinic receptors M1,M3 on the smooth muscles of the airways in the lungs. It prevents bronchoconstriction resulting in bronchodilation lasting around 4-6 hours.

Therapeutic use – relaxes the smooth muscles of the bronchi opening airway and improving airflow. Also reduces mucus production by block m3 receptors

Side effect – dry mouth, cough, nausea

Precaution – renal dysfunction, mild tachycardia

Prednisonle

Does- 30mg

How – steroid for inflammatory. It reduces the release of pro-inflammatory cytokines il1,il6, macrophages and neutrophils. Which reduces bronchial inflammation, airway hyperresponsiveness and mucus production, causing immunosuppressive effects.

Therapeutic use – reducing bronchial inflammation

Side effect- high levels blood sugar, mood changes

Precautions – can increase infection due to the immunosuppressive effect it causes

Co-amoxiclav/benzypencicllin

How – inhibits bacterila cells wall synthesis by binding to penicillin biding protein. This weakness the bacterial cells wall and leading to cell death

Therapeutic use – respiratory infection

Side effect – diarrhoea, nausea, abdominal pain, rash

Precaution – penicillin allegery avoid, renal impairment

Clarithromycin

How – bind to the 50s ribosomal subunit of bacterial, which prevents elongation of polypeptide chain stopping bacterial protein growth. Reduces pro-inflammatory cytokine.

Therapeutic use – stops bacterial growth and kills bacterial and reduces inflammation

Side effect- headache, abdominal pain

Precaution – can increase bleeding risk by intercating with warfarin

Ibuprofen

Dose 400mg

How – COX enzymes produces prostaglandis which create pain, inflmaation and fever. It reduces both cox1,cox2 production. This reduces inflammation and reduces pain and fever

Therapeutic use – analgesic, anti inflammatory,

Side effects – gastric ulcers, gastrc irritation

Precaution – can lead to acute kdney injury,

Amlodipine

Does 5mg

How – calcium channel blocker, blocks the calcium entry into vascular smooth muscles cells. This reduces intrcellular calcium levels, leading to smooth muscle relation and vasodilation. Imrpvoing oxygen delivery to the heart also reduces blood pressure

Therapeutic use – hypertension, angina, coronary artery disease

Side effect – peripheral edema, hypotension,

Precaution – can worsen fluid retention

Bendroflumethiazide

Does 2.5

How – is a thiazed diuretic acting on the distal convoluted tubule of the nephron. It blocks the sodium co transposter cells reabsorpting water and sodium.this increases sodium and water execration

Threaputci use – dierutic, hypertension edema

Side effect – hypokalemia muscles weakness, hypercalcemia nausea

Preactuion – electrolyte imbalance, reanl imapriemtn

N/saline intravenous fluid

Does 500ml

Therapeutic uses- crystalloid solution used to restore fluid and electrolyte balance such as sodium, isotonic solution which is similar to plasma and stays within the extracellular space, restore blood volume

Common side effects – hypernatremia high levels of sodium, oedema

Precaution- patient with kidney disease and heart failure, can lead to fluid overload and electrolyte imbalance

How the drug works - Normal saline (0.9% sodium chloride) is a crystalloid solution commonly used for intravenous (IV) administration. It is composed of 0.9% sodium chloride in water, which is isotonic with respect to plasma, meaning its osmolality is similar to that of the body’s extracellular fluid.