Physio Resp Practical PDF

# Respiration ## Volumes 1. Tidal volume (TV): Volume of air "inspired or expired" in one respiratory cycle at "rest": 500mL 2. Inspiratory reserve volume (IRV): Maximum volume of air inspired by forced inspiration after normal inspiration: 3000mL 3. Expiratory reserve volume (ERV): Maximum volum...

# Respiration ## Volumes 1. Tidal volume (TV): Volume of air "inspired or expired" in one respiratory cycle at "rest": 500mL 2. Inspiratory reserve volume (IRV): Maximum volume of air inspired by forced inspiration after normal inspiration: 3000mL 3. Expiratory reserve volume (ERV): Maximum volume of air expired by forced expiration after normal expiration: 1100mL 4. Residual Volume (RV): Volume of air "Remain" in the lung after forced expiration: 1200mL - Significance: Prevent collapse of the lung. - ↑ elasticity—“emphysema” - Can’t be measured by spirometry. - Measured by helium dilution method. ## Capacities 1. **Inspiratory Capacity (IC):** Maximum volume of air that can be inspired after normal expiration. - IC = TV + IRV = 3500mL. 2. **Functional residual Capacity (FRC):** Volume of air "Remain" in the lung after normal expiration. - FRC = ERV + RV = 2300mL. - Significance: It creates blood between breaths. - Can’t be measured by spirometry. 3. **Vital Capacity (VC):** Maximum volume of air that Can be expired after maximum inspiration. - VC = TV + IRV + ERV = 4600mL. - Clinical significance: "an index of pulmonary function" - Test For lung & respiratory muscles. - Large in: - Male - Athletes - Standing position - Small in: - Female - Pregnancy - Recumbent position 4. **Total lung Capacity (TLC):** Volume of air in the lung after maximum inspiration. - TLC = TV + 1RV + ERV + RV = 5800mL | **Expiration** | **Obstructive lung disease** | **Inspiration** | **Restrictive lung disease** | | :----------------: | :------------------------------: | :---------------: | :------------------------------: | | **Timed vital Capacity** | FVC ++, FEVI < 80% | **FVC ↑** | Fvc ↓, FEV₁ normal or ↑ | | **FEVI** | Marked resistance to air flow | **FEVI** | Damage to lung tissue - Fibrosis, Edema, Collapse | | **Cause** | Asthma, Emphysema, Bronchitis | **Cause** | Fibrosis, edema, Collapse | ## High Altitude Physiology ### Chronic Hypoxia - "Slowly developing" - "Chronic mountain sickness" - P02 + 6 to 40-60mmHg - Symptoms: - Severe fatigue - Tachycardia - Headache - Dyspnea - Nausea - Drowsiness - Compensatory mechanisms: √√ ### Acute Hypoxia - "Rapidly developing" - "Acute mountain sickness" - P02 + 25-40mmHg. - Symptoms: - Alcohol intoxication - Headache - Insomnia - Disorientation - Nausea & vomiting - Irritability - In coordination - Poor mental judgement - Compensatory mechanisms: XX. ### Sudden Severe Hypoxia - P02 sudden ↓ to 20mmHg. - Due to sudden loss of cabin pressure (aircraft) at a height of 30,000 ft. - Loss of consciousness. - Death within 5 min. ### Acclimatization to High Altitudes (Body response to chronic hypoxia) - **Hyperventilation** - **Polycythemia** ~ **Tachy Cardia** + **Angiogenesis** - The most fundamental response to Hypoxia. - **Tachy Cardia** is due to: - **Hypoxia** - **Peripheral chemoreceptors** - **2,3DPG** - **Oxidative enzymes** - **Increased Hyperventilation** - **Increased Erythropoietin** ­- **Increased Peripheral chemoreceptors** - **Increased HR** - **Increased COP** - "Immediate" - **Angiogenesis** “Formation of new capillaries” - **Increased # of mitochondria** - **Increased # of oxidative enzymes** - **Increased Bore marrow** - **Increased Hb affinity of 02** - **Increased 02 delivery to tissues** & **Right shift of 02 dissociation curve.** - **Increased 02 utilization** - **Increased RBCs** - **Increased Hb** - **Increased Hematocrit (60%)** - **Note:** After 2 weeks HR & COP return to normal. ### Pulmonary Hypertension - Occurs 2ry to pulmonary VC caused by alveolar hypoxia (hypoxic pulmonary VC). - Effect: - Better ventilation perfusion in different lung regions - Better gas exchange - **Permanent residents** (Himalayas) are polycythemic, short in stature, have barrel shaped chest & their physical efficiency is almost similar to the sea-level residents. ## Right Ventricular Failure ## Effect of Increased Barometric Pressure - At sea level atmospheric pressure = 1 atm. - Every 10 meters below sea level → ↑ pr. 1 atm. - "Problems associated with exposure to ↑†" barometric pressure. ### During Decent (Compression) - **N2 (Nitrogen Narcosis)** - 80% of inspired air is N2 - N2 highly soluble in fatty tissue (CNS) - ↑ dissolved N2 - delirious effect. - ↑ dissolved N2 - CNS depression. - To avoid N2 narcosis - N2 is replaced by helium. - Helium is less soluble. - **O2 (Toxicity)** - Prolonged exposure >12 hours - O2 toxicity. - **CO2 (Narcosis)** - "Rare" - Seen at greater depth only ### During Ascent (Decompression) - Dissolved gases will diffuse: - From tissues to blood to lung to be expired. - No harmful effect if the ascent is gradual. #### If Decompression is Rapid: - **Deompression Sickness (Caisson’s Disease)** - Rapid escape of gases from "Tissues" to blood in the form of "N2 bubbles" - Block capillaries in Bones - Bone pain - CNS - Paralysis & Convulsions - Coronary myocardial damage - Pulm-Capillaries - choking - ↑↑: Recompression in a pressure chamber, then slow decompression - **Air embolism (SCUBA)** - Decompression - ↑ Pr. outside the lung rapidly - SCUBA tank still giving air under high Pr - Lung suddenly expand - **Rupture of pulm vessels** - **Air pass into vessels** - **Air embolism** ## Abnormal Patterns of Breathing ### Def: - **Eupnea:** normal breathing - **Tachy Pnea:** rapid shallow breathing (↑ rate) - **Hyper Pnea:** Deep breathing - **Hypor ventilation:** ↓ Rate & Depth. - **Apnea:** Stoppage of breathing - **Dyspnea:** Difficult breathing. - **Orthopnea:** Dyspnea on laying down. - **Apneusis:** Maintained inspiration. ### Dyspnea - Def: Difficult breathing. - Awareness of shortness of Breath. - **Notes:** Hyperventilation → Dyspnea - **When ventilation is doubled or tripled:** - Dyspreic index (DI): - BR / MVV - (MVV - PV) / MVV = 94% - BR: Breathing reserve - MVV: Reaximum ventilatory volume. - PV: Pulm ventilation. - (Minute respiratory volume). - Dyspeic index < 70% ### Apnea - Def: Absence of spontaneous breathing. - **Types:** - Apnea Following voluntary hyperventilation. - Apnea with Periodic breathing "Cheyne Stoke's" - Voluntary apnea. - **Cheyne Stokes:** - Physiological Hyperventilation during Sleep. - After voluntary apnea. - **Pathological:** - Children - Brain damage - Congestive HF. - Morphine poisoning - **Causes:** - Circulatory failure - Brain failure - Congestive HF - Morphine poisoning ### Periodic Breathing - Def: Alternate periods of apnea & breathing “Waining & waning”. - **Causes:** - Hyperventilation - Circulatory failure - Brain damage - Congestive HF. - Morphine poisoning ### Mechanisms: - Hyperventilation - ↓ CO2 - ↑ O2 - ↓ CO2 → R.C Apnea - Chemoreceptors - ↑ CO2 → Peripheral chemoreceptors ### Types: - Obstructive - Central infant - New born ### Asphyxia - Def: Prevention of ventilation in alveoli. - **Causes:** - Airway obstruction - Paralysis of respiratory muscles - Choking - Drowning - Strangulation - Eclosed system - Asphyxia, drowning - Co Poisoning ### Effect: - Marked Respiratory pressor response - ↑ MHR & † BP - ↑ HR & ↑ BP → Cardiac arrest - ↓ HR & ↓ BP → Respiratory & cardiac arrest - Acidosis “Diabetic acidosis”??? - Metabolic rate - Hyperthyroidism. ### Artificial Breathing - "Lifesaving" - Mouth to Mouth - Mechanical ventilation - **Causes:** - Airway obstruction - choking - Drowning - strangulation - Asphyxia, drowning or Co poisoning. ### Mechanical ventilation - Intermittent positive pr. - Breathing - Chronic Resp. failure ### Cardiac Dyspnea - Respiratory dyspnea: - Obstructive - Restrictive lung - Ventilation, diffusion & perfusion - Cardiac dyspnea: - LVF → lung congestion - Dyspnea - **Note:** Cardiac dyspnea appears on lying down "orthopnea" & relieved on sitting up: - ↑ LAHV - ↑ lung congestion - ↓ improve circulation - No improvement of orthopnea - Neurogenic dyspnea - Adrenaline apnea - Swallowing apnea - Sleep apnea: - Loss of sensitivity of respiratory neurons to CO2 - "Types" - **Causes:** - Operator gives victim expiratory breath??? - Cyanosis ### Sleep Apnea: - Loss of sensitivity of respiratory neurons to CO2 - **Types:** - Obstructive - Central infant - New born ### Asphyxia: - Def: Prevention of ventilation in alveoli. - **Causes:** - Airway obstruction - Paralysis of respiratory muscles - Choking. - Drowning - Strangulation - Eclosed system - Asphyxia, drowning - Co Poisoning.