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What is paroxysmal nocturnal dyspnoea?

PND is the sudden development of dyspnoea during the early hours of night occurs two three hours after retiring to bed. The patient awakens from sleep due to failing of severe suffocation and choking sensation. After getting up from bed the patient with either sits in bed with legs hanging by the side of bed or may rusts to the open window with the hope that coal air will relieve his symptoms.
This may be accompanied with dry repetitive cough due to interstitial oedema. Where the alveate are free of oedema.
This attack may progress and severe sweating can occur along with dyspnoea and subsides in 30 minutes. Sometimes it may progress to acute pulmonary oedema.
Significance of PND
PND occur due to acute left heart failure can be LAF or LVF (LAF left atrial failure, LVF – left ventricular failure. Acute onset dyspnoea with wheeze and repetrated productive cough are seen in cardiac asthma. It is characterised by wheeze due to bronchospasm which is more in night. Acute pulmonary oedema is the severe stage of cardiac asthma with leaking of fluid into the alveolar.
Causes of PND
PND is caused by left atrial or left ventricular failure
Clinical examination findings in PND
  • Patient is usually anxious and pale with sweating and an hunger
  • Central cyanosis may be present
  • Tachycardia is present
  • Blood pressure may be high
  • Jugular venous pressure is elevated 
  • S3 gallop may occur
  • Auscultation of lung filed reveal vescular breath sound with prolonged expiration. Rhonchi and legs may be heard.