COPD Flashcards
Risk factors for COPD?
Cigarette smoking, passive smoking, ambient air pollution, hyperresonpsive airways, respiratory infection, occupational factors, alpha 1 antitrypsin deficiency
COPD vs. Bronchitis
COPD: Pink Puffer (emphysema, PaO2 >60, normal PaCO2) Thin Anxious, purse lips Accessory muscles Dyspnea Scant secretions Markedly diminished breath sounds With resp infx right -sided heart compromise CXR- hyperinflation low diaphragm
Emphysema: Blue Bloater (bronchitic, PaO2 45) Overweight Cyanosis dusky appearance Cough Copious secretions Diminished breath sounds R-sided heart failure / cor pulmonae CXR- increased broncho-vascular markings
Signs of increased risk on the H/P?
Exercise intolerance Chronic cough Dyspnea Absent breath sounds or wheezing Prolonged exhalation
Respiratory Preparation Maneuvers Dilate the Airway/Treatment Bronchospasm
Sympathomimetics 3,5 cAMP production bronchodilation
PDE Inhibitors- Inhibit breakdown of 3,5 cAMP
Steroids-decrease mucosal edema
Cromolyn-Mast cell stabilization
What preop treatment interventions may be warranted?
Benefit to stop smoking 8 wks preop however no smoking after midnight (to decrease COHb).
Antibiotics for evidence of respiratory infection
Oxygen for hypoxemia and/or evidence of increased pulmonary vascular resistance
Bronchodilators to address reversible component, if present
Hydration
What should the preop evaluation include for this patient?
Counsel pt regarding: post op complications Atelectasis Hypercapnea Hypoxemia Retention of secretions Bronchospasm Explain need for post op ventilation
What is the goal for the anesthetic management of patients COPD
Patients with obstructive disease are at risk for both intraoperative post-operative pulmonary complications
GOAL: Minimize the risk of postop respiratory failure.
Volatile agents will blunt airway reflexes and reflex bronchoconstriction but consider the CV effects
Regional anesthesia may offer benefits for surgery of the extremities and lower abdomen (not above T-6).
Judicious use of opioids – prevent and/or treat postop pain but avoid respiratory depression.
What is the anesthesia plan regarding induction
REGIONAL:
– Good choice extremity surgery, +/- lower abdominal; consider that patient can not tolerate additional IV sedation
levels >T6 should be avoided as they need their accessory muscles!
GENERAL:
No specific agent ‘ideal”-consider co-morbidities
Volatile agents produce brochodilation and are rapidly eliminated
Consider prolonged respiratory effects
use short acting NMB
titrate opioids carefully –resp depression
consider less tolerance for respiratory depressant effects of all drugs
Adjunctive IV administration of opioids and lidocaine prior to airway instrumentation will decrease reactivity
Maintenance
ETT bypasses natural airway humidification : need to use humidifier and low flows
Ventilation
Tidal volumes adjusted to keep airway pressure
Emergence
Post-operative respiratory status is the priority issue
Adequate pain control (pain free breathing and improved coughing)
Consider prolonged mechanical ventilation– adjust vent using ABG guidance
Advantages and disadvantages of using N2O
ADVANTAGES:
decrease dose of volatile anesthetic and (quick on, quick off).
DISADVANTAGES:
potential to diffuse into airspaces quicker than nitrogen can exit, potentially leading to bullae rupture and tension pneumothorax.
Also nitrous is usually given in concentrations between 50 and 70% - this limits the concentration of oxygen that can be administered.
Effects of surgery on the VC and FRC?
- VC decreases 40% after upper abdominal surgery and can take up to 14 days to return to normal
- FRC decreases 10% to 15% in supine, healthy spontaneously breathing subjects
- General anesthesia decreases FRC another 5% to 10%
- FRC requires 3 to 7 days to recover after upper abdominal procedures
Patients with pre-operative FEV1/FVC ratio less than 0.5 or with a pre-op PAC02 greater than 50 will likely need post-op mechanical ventilation
Post-op mechanical ventilation should be to maintain
Pa02 60-100
Pa02 to maintain ph 7.35-7.45
Patient with COPD benefit from the following anesthetic considerations pre-operatively in order to prevent post-operative pulmonary complications
Receive bronchdilation therapy Chest physiotherapy Deep breathing maneuvers Forced oral fluids >3 L per day Smoking cessation for 2 months pre-op
Post anesthetic management
Post-op Pulmonary problems are primarily restrictive
Decreased lung volumes
Consider abdominal impingement on movement of diaphragm
Abnormal resp pattern with shallow breathing with rapid respirations
Consider surgical site-this is an important risk factor for development of of Post-operative pulmonary complications
Describe Exubation in the COPD patient
Post-op ventilation is not a complication
an expected result of anesthesia and surgery in patients with moderate to severe COPD
Patients should be counseled about possible prolonged post-op ventilation with possible need for tracheostomy
Encourage lung expansion maneuvers decrease the risk of atelectasis by increasing lung volumes
Deep breathing
Chest PT
Incentive spirometry
