Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Egans 47 Weaning
Egans Ch. 47 Discontinuing Ventilatory Support
| Question | Answer |
|---|---|
| Weaning success is defined as | effective spontaneous breathing without any mechanical assistance for 24 hours |
| Medical (ICU) patients | Often have coexisting problems and usually take more time to complete weaning than surgical patients |
| The minimum VC and spontaneous tidal volume are | 10 to 15 ml/kg IBW and 5 to 8 ml/kg respectively |
| Vital capacity | is effort dependent and requires proper teaching and coaching for accurate measurements |
| For successful weaning outcomes, the QS/QT should be | < 20% (pulmonary shunt) |
| QS/QT calculation | Qs/Qt = (PAO2 - PaO2)0.003/(CaO2 - CVO2) + (PAO2 - PaO2)0.003 |
| On 100%, every 50 mmHg difference in P(A-a)O2 | approximates 2% physiologic shunt |
| P(A-a)O2 should be _____ while on 100% | < 350 mmHg |
| PaO2/FiO2 index should be | .200 mmHg |
| Vd/Vt ratio should be | < 60% |
| F/Vt should be | < 100 cycles/L (very accurate) |
| a/A ratio is better | > 0.8 |
| PO.1Max | Pressure max < 6% |
| Basic Methods for Discontinuing Ventilatory Support | Increasing periods of spontaneous breathing IMV or SIMV PSV Single daily spontaneous breathing trials (SBT) |
| SBT and PSV are _____ _____ than other methods | more effective |
| define weaning | gradual reduction in the level of ventilatory support |
| define discontinuing ventilatory support | overall process of removing the patient from the ventilator regardless of method |
| Need for Mechanical Ventilation | Apnea - drug overdose, trauma, cardiac arrest, pneumonia, ARDS, COPD, Neuromuscular Impending failure Severe oxygenation problems |
| Ventilator work load refers to | demand of ventilatory muscles |
| Ventilator work load is determined by | 1) Level of ventilation needed 2) Compliance of lung & thorax 3) Resistance to flow in airways 4) Imposed WOB (ventilation) |
| Increased Demand & Level of Ventilation Required is determined by | 1) Metabolic rate (sepsis) 2) CNS drive 3) Ventilatory deadspace |
| Decreased compliance | Atelectasis, pneumonia, fibrosis, pulmonary edema, and ARDS Decreased thoracic compliance: obesity, ascites, abdominal distension, & pregnancy |
| Increased resistance | Bronchospasm, mucosal edema, and secretions Artificial airways: ET and trach tubes Other factors: circuits, demand flow systems, inappropriate vent flow or sensitivity settings |
| Ventilatory capacity | CNS drive - most have increased except neuromuscular and drug induced Ventilatory muscle strength Ventilatory muscle endurance |
| Factors reducing ventilatory drive | Decreased PaCO2 Metabolic alkalosis Pain Electrolyte imbalance Narcotics, sedatives Fatigue Neurologic or Neuromuscular disease |
| Respiratory muscle strength is influenced by | age, sex, muscle bulk and overall health |
| Controlled ventilation can lead to | ventilation muscle atrophy |
| Ventilatory muscle endurance is a | fuction of energy supply vs demand |
| Ventilatory demand is related to | the amount of work performed and is a fuction of minute ventilation (Ve), compliance, and resistance |
| Once ventilatory muscles fatigue, they must be | rested for 24 hours to recover |
| Factors considered for successful weaning | Ventilatory workload vs capacity Oxygenation status Cardiovascular status Psychological factors |
| Careful pt evaluation is required to determine? | which patients are ready to be removed quickly, which may need a prolonged ventilatory phase, and which are not ready for discontinuation of ventilatory support |
| Patients receiving support for 72 hours or less | often can be removed quickly from the ventilator |
| Patients who need longer than 72 hours of support | may require a more structured approach for weaning |
| Current guidelines recommend pts requiring > 24 hours of M.V. | be carefully assessed to determine all causes of ventilator dependence |
| Considerations for discontinuing vent support | 1) reason for instituting m.v. 2) pts baseline functional status 3) vent workload vs vent capacity 4) oxygenation status 5) cardio status 6) overal organ systems 7) duration of critical illness 8) duration of m.v. 9) psychological factors |
| Patient evaluation criteria | 1) evidence of rev of condition that caused the need for m.v. 2) oxygenation: PaO2 > 60 on < 40 - 50%; PEEP of 5 - 8 cm H2O or less; PaO2/FiO2 ratio > 150 - 200; pH > 7.25 |
| Patient evaluation criteria for hemodynamics | Absence of acute myocardial ischemia Absence of marked hypotension Adequate Bp without vasopressor treatment |
| Patients must be able to initiate ? | inspiratory effort and breath spontaneously |
| Weaning Indices | PaO2/FiO2 ratio > 150 - 200 (PAO2-PaO2) < 350 mmHg MIP (NIF) > -20 to -30 cmH2O VC > 10 - 15 ml/kg MVV > 20L or 2 x Ve (f/Vt) < 105 b/min/L PO.1 < 6 cmH2O |
| Ventilation evaluation | Presence of palpable scalene muscle use on inspiration; Irregular ventilation pattern; palpable abdominal muscle tension during expiration; inability to alter breathing pattern |
| Patients having none of the ventilation evaulation signs have | 90% chance of success |
| Patients having one or two signs of ventillation evaluation | will need continued support |
| Patients having three or more signs of ventillation evaluation | indicate pt is unstable |
Created by:
stephnpc
Popular Respiratory Therapy sets