Lungs Physiology
• 2 Pleural, 1 attached to outside of lungs and 1 attached to inside of ribs.
• Space between the 2 pleural is negative to
... [Show More] atmosphere
• When inhale becomes more positive and atmosphere more negative. Exhaling is passive
• Most of lower lobes are posterior, must listen to lungs posteriorly
• Breath sounds
o Bronchial: High pitched & loud, normal in tracheal & larynx
o Bronchovesicular: Moderate pitched & amplitude, normal over major bronchi
o Vesicular: Low pitched & soft, like wind through trees, normal in lower lung fields where smaller bronchioles & alveoli are.
Pulmonary Emboli (P 603)
• Occlusion of portion of pulmonary artery by a blood clot – from venous circulation – lower extremities or heart.
• Causes ventilation-perfusion mismatch (V/Q) – Ventilated alveoli no longer perfused due to clotted artery.
• Risk Factors
o Venous stasis (w/prolonged immobility); Central venous catheters; Surgery (NPO, dehydrated, immobilized pts); Obesity; Advanced age; Hypercoagulability (Platelets >400K and not enough fluids; sticky blood); Hx of thromboembolism.
o Greatest r/f in the young is the combo of smoking and hormone based contraceptives.
• Nursing Assessment Findings
o Respiratory Classic Manifestations (Hypoxia drives all s/s)
Dyspnea (sudden onset); Chest pain (sharp & stabbing); Apprehension, restlessness; Feeling of impending doom; Cough; Hemoptysis (blood in sputum).
o Respiratory Signs
Pleural friction rub (scratching sounds from pleura rubbing together & pain on deep inspiration); Tachypnea; Crackles (or normal); S3 or S4; Diaphoresis; Low grade fever; Petechiae over chest and axillae; Decreased arterial oxygen saturation (SaO2)
o Many pts w/ a PE do not have “classic” sx (i.e. hypoxia), but instead have vague sx resembling the flu (n/v & general malaise)
o Cardiac Manifestations
Decreased tissue perfusion: tachycardia, JVD, Syncope (loss of consciousness), Cyanosis, & Hypotension.
o In patients with r/f for PE, JVD (RSHF), syncope (decreased blood flow to brain), cyanosis (severe hypoxia) and hypotension together, NEED RAPID RESPONSE TEAM CALLED. HAVE HELP ON WAY B4 O2 APPLIED
o When pt has sudden onset of dyspnea, chest pain, and/or hypotension, immediately notify Rapid Response Team. Reassure pt. and elevate HOB. Prepare for O2 therapy and ABG analysis
o Saddle Emboli – Embolism at split of pulmonary artery that blocks both branches to the lungs
• Medical Dx
o Chest X-ray – May show PE if large but will help r/o other things
o CT scan – Most often used to dx PE
o TEE (Transesophageal Echocardiography) – See if there are clots in the atria
o Ventilation Perfusion scan (V/Q)
Considered if pt is allergic to contrast dye done w/CT scan
Radioactive substance to see if air is getting into the alveoli; injected into blood to look at clot and can also detect pneumothorax. Done 2x
o ABGs
Respiratory Alkalosis FIRST from hyperventilation
THEN Respiratory Acidosis from shunting
• Shunting of blood from the right side of the heart to the left side w/o picking up O2 from lungs – causes PaCO2 level to rise resulting in respiratory acidosis.
LATER Metabolic Acidosis & lactic acid buildup from tissue hypoxia
Even if ABGs & Pulse Ox shows hypoxemia it is not enough to dx PE alone as PE is not the only cause of hypoxemia.
• Medical Management
o GIVE O2, IV FLUIDS, INOTROPES (DOBUTAMINE/MILRINONE)
Oxygen therapy to maintain O2 sat at 95% or patient baseline
Hypotension - Tx w/ IV fluids (isotonic) & Inotropes (Dobutamine/Milrinone, make heart contract more forcefully); vasopressors (norepi, epi, dopamine) when hypotension persists after fluids.
o Anticoagulation w/ Heparin drip – Goal is PTT 1.5-2.5 x normal (60-70 sec) = 90-175 sec
Minimize growth of existing clots and prevent new ones
Antidote Protamine Sulfate
Do not use w/salicylates (Aspirin)
o Convert to Warfarin when stable – On 3rd day of Heparin use, overlap – INR target 2-3 (0.9-1.2 normal)
Antidote – Vit K – phytonadione (Mephyton)
Teach pts to avoid foods high in K (leafy dark green vegis, herbs, spring onions, Brussel sprouts, broccoli, cabbage, asparagus, potatoes, & winter squash).
o Enoxaparin or dalteparin
o Fibrinolytic (tPA) to tx massive PE or hemodynamic instability
Antidotes – clotting factors, FFP, & aminocaproic acid (Amicar)
Dissolve the clot itself
o Embolectomy – surgical removal of the embolus – When tPA can’t be used or for massive PE w/shock
o Inferior Vena Cava Filter – to prevent [Show Less]