Transcript Respiratory Insufficiency, Sleep
Respiratory Insufficiency Sleep Apnoe Hypopnoe Syndrome (SAHS)
Classification of respir. insuff.
1. Progression in time - acute - chronic 2. Pathophysiology - type I (hypoxemia=PaO2<60 Hgmm) - type II (hypoxemia + hypercapnia=PaCO2>50 Hgmm) 3. Pathomechanism -
V/Q mismatch
- hypoventilation - limited diffusion - right-left shunt 4. Etiology - airway - lung parenchyma - lung vasculature - chest wall and pleura - neuromuscular
Alveolar gas equation: P A (mmHg) = (P B -47) x F I O 2 – 1.2 x P a CO 2 102 = 150 48
P CO2 = V CO2 V A
The causes of hypoventilation Site of abnormality
Central Brain stem Spinal cord Peripheral nerves Neuromusc. Junction Upper airway Chest wall Respiratory muscles
Disease
Primary hypoventilation sy, barbiturat, opiat Encephalitis, haemorrh., trauma Cervical trauma, poliomyelitis Guillain-Barré-sy, bilat.n.phrenicus paresis Myasthenia gravis Trachea stenosis Kyphoscoliosis, trauma Muscular dystrophies
Diminished diffusion
• Transit (contact) time: 0.75 s • Equilibration: 0.25 s • Exercise + diminished diffusion: PaO2<60 Hgmm • PaCO2 : no change or decreases • Causes: alveolitis fibrotisans, sarcoidosis, pneumoconiosis, connective tissue diseases, drugs, irradiation, alveolar cell cc, Goodpasture-sy, CHF
Right-left shunt
• Anatomic: lung (a-v malformation), heart (ASD, VSD, Eisenmenger-sy) • Functional: V/Q=0; ARDS, atelectasia, oedema, haemorrhagia • Hypercapnia: no or rarely • Hypoxemia: cannot be corrected by 100% O2
Ventilation-perfusion mismatch
• “Functional shunt”, most frequent cause of hypoxemy • COPD, ILD, pulmonary embolism • Regional differences in airway resistance and lung compliance • Hypercapnia: only in severe cases (blue bloater) • Hypoxemia: correctable with small incraese in FIO2
Symptoms of hypoxemia és hypercapnia HYPOXEMIA
Cyanosis Tachycardia Hypertension Headache Agitation Dezorientation
HYPERCAPNIA
Warm, wet skin Tachycardia Hypertension Headache myosis, papilla oedema Agitation Dezorientation, sleepiness Loss of consciousness Fibrillation, bradycardia Tremor Pathologic reflexes Convulsions, retina bleeding Loss of consciousness Brain damage Coma
Diseases leading to resp. insuff.
Airway Lung parenchyma Hyperpermeability (ARDS) Pulmonary vascular Heart failure with cyanosis Neuromuscular Trauma (head, neck) Ptx, pleurisy Chest wall(deform., trauma) Drug overdose (sedatives)
Type I
+ + + + + + +
Type II
+ + + + + +
Oxigen supplementation in chronic resp. insuff.
NOTT: Ann Intern Med, 1980 BMC: Lancet, 1981 only way to prolong survival
Indication
: (stable condition) • PaO2 < 55 mmHg or SAT < 88% • 55 mmHg < PaO2 < 60 mmHg with pulmonary hypertension, polyglobulia or right heart failure
Aim
: PaO2 ≈ 60 mmHg vagy SAT ≈ 90 %
CAVE:
CO2 retention in COPD (max.1-2 L/min)!
Dosage
: > 15 h/day
PaO
2
< 55 Hgmm PaO
2
> 55 Hgmm
ARDS
Shock Infection Hematologic Inhalation Ingestion Embolism Metabolic Other
The causes of ARDS
Trauma, haemorrhagia,acut hypovo lemia (severe burning of the skin) Pulmonary - extrapulm. sepsis DIC, abundant transfusion NO2, NH4, Cl, SO2, gases, O2-tox.
(FIO2 >0.5), gastric acid aspiration Paraquat, barbiturat, aspirin, narcotics, lidocain, hydrochlorotiazid fat, air, cell aggregate Diabetic ketoacidosis, uremia Pancreatitis, height , irradiation, aspiration, drawn in water, re-exspansion
Diagnosis of ARDS
• Acute onset (1-3 days) • One or more risk factors • Chest X-ray: new, bilateral, snow flake – like infiltrates • Exclusion: heart failure, fluid overdose, chronic lung disease • Hypoxemia not corrected with O 2 : - mild: PaO 2 /F I O 2 200-300 mmHg - moderate: 100-200 mmHg - severe: < 100 mmHg
Non-invasive ventilation (NIV) in global respiratory insufficiency - BiPAP
Sleep apnoe-hypopnoe syndrome (SAHS)
• Dg: apnoe >5/h , >30/sleep period, SAT decrease: minimum 4% • Apnoe: > 10 s • Arousal (EEG) defraction of sleep • Apnoe index: Number of apnoe/h:<5 - mild: 5-15 - moderate: 15-30 - severe: >30
Types of SAHS
• Central (kb. 5%) • Obstructive • Mixed
Risk factors: -
obesity - alcohol - sedatives
Symptoms of SAS
• Daytime sleepiness • Morning headache, tenebrosity • Change in personality • Strong hoarsness • Movements during sleep • Enuresis nocturna • Impotency • Hypertonia, arrhythmias • Right heart failure
Score: 0 – 24 Upper limit of normal: 9 Normal : 5.9 ± 2.2
SAS: 16 ± 4.4
Diagnosis of SAS (poliszomnográfia)
• EEG • EOG • EMG • EKG • ABG, pulzoximetry • Detection of airflow • Detection of breathing movements, leg movements • Voice recording • Video
Therapy of SAS
• •
Change in life style nCPAP, BiPAP
•
Medroxiprogesteron (Provera)
•
Surgery
• Acetazolamid (Diamox, Fonurit) • Almitrin • Protryptilin