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15 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are some of the complications of a DLBT?
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Malposition of tube:
-- Bronchial cuff in R Main Bronchus occluding RUL --- Bronchial cuff herniating over carina Rupture of a thoracic aneurysm Damage to vocal cords during insertion |
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What is Hypoxic Pulmonary Vasoconstriction? (HPV)
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A Compensatory mechanism of increasing vascular resistance in hypoxic areas of the lungs and this diverts some blood flow to areas in most mammals.
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What Are the characteristics of HPV?
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1. Local reaction occuring in hypoxic areas of lung
2. Opposite to a systemic reaction--causing vasoconstriction in response to hypoxia 3. onset/resolution very fast 4. triggered by alveolar hyposia (not arterial) 5. inhibited by: CCB, Volatile anesth., vasodilators(nitrates), 6. augmented by chemoreceptor agonists (almitrine) |
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What is the distribution of blood in the lungs in lateral position, two lung ventilation?
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NONDependent lung: 40%
DEPendant lung: 60% |
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What is the distribution of blood in the lungs in lateral position with OLV?
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HPV results in decreasing CO to the nonventilated lung to 20%:
Nondep. lung: 20% Dep. lung: 80% |
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What factors reduce effectiveness of HPV?
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Shunt Fraction <20% or >80%
Hypervolemia Hypovolemia Excessive TV or PEEP Hypocapnia Acidosis Hypothermia Volative agents >1.5 MAC Vasoactive meds |
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What is the goal of ONE-Lung Ventilation?
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To maintain aadequate arterial oxygenation while providing an adequate surgical field.
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What are the positioning concerns with Lateral Decubiitus Position (LDP)?
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1. Axillary support roll to avoid compression of the nv bundle and forward roll of humeral head.
2. Support of nondependent arm on mayo stand or pillow 3. alignment of head and neck. 4. Careful padding of dep. ear. 5. Eyes! 6. Careful padding to avoid pressure on peroneal nerve at the fibula head of dep. leg 7. careful strapping of the nondependent leg to avoid pressure on peroneal nerve at femoral head. |
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What is the V/Q in the Awake Lateral Position?
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Ventilation: Dependent lung better ventilated (r/t inc contraction of dep diaphragm causes more TV to fill dep lung)
Perfusion: Dependent Lung better perfused. * overall vent and perfusion in dep lung is unchanged and gas exchange remains efficient |
Nagelhaut p634-5
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What is the V/Q in the -anesthetized -Spon Breathing -Lateral Position (closed chest)?
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Ventilation:
1. Nondependent Lung more compliant= better ventilated 2. Dependent Lung= less complaint 3. Total dec in FRC Perfusion: better in dependent lung= V/Q mismatch |
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What happens to the V/Q to a anesth patient in LDP with the addition of Muscle relaxant and PPV?
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with MR-
- diaphrgam relaxes = more noncompliant Dep lung - mediastinum shift= physically impedes dep lung from expansion -abd weight pushes diaph cephalad and impedes dep lung ***Adding PPV with PEEP resotres ventilation to lung and improves V/Q ratio |
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LDP- Open chest- Spon Breathing Pt?
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Mediastinum Shift phenomenom:
impaired ventilation in dep lung due to increased mediastinum shift onto it, -also decreased VR + SNS activation: Pt appears shocky: PALE, HOTN, Dilated pupils |
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Why does the lung collapse when the chest wall is opened?
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1. loss of negative intrapleurel pressure
2. unopposed elastic recoil |
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What is paradoxical Respiration phenomena?
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Lung collapses during inspiration and expands during expiration. (Open side)
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LDP- Open chest- Ventilated (MR)- PPV? How do we improve V/Q?
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Perfusion: not affected much- dep lung still better perfused
Ventilation: diaph movemtn is best in nondendent lung due to loss of resistance and abd pressure-- = greatest ventilation in least perfused lung ***Add Peep to Dep lung only to improve V/Q mismatch |
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