Obstructive lung disease Flashcards
Preoperative pulmonary testing is indicated for which of the following patients?
A. A patient with a baseline NaHCO3 35 mEq/L
B. A patient undergoing a planned pneumonectomy
C. A patient with hypoxemia on room air (PaO2 < 60 mmHg)
D. A patient with suspected pulmonary hypertension
E. All these patients should undergo preoperative pulmonary testing.
E.
What is obstructive lung disease?
pulmonary conditions characterized by airflow limitation
can be inside the lumen, bronchial wall, or peri bronchial region- reversible vs. non-reversible
Orthostatic sleep apnea is a
mechanical obstruction of breathing that occurs during sleep when pharyngeal muscles relax
Risk factors for OSA include:
occurs in 24% of males & 9% of females
obesity is most significant precipitating factor
increasing incidence in pediatric cases
OSA is an independent risk factor for
increased morbidity
With OSA obstructed airways lead to
chronic hypoxemia and hypercarbia
results in inflammatory state, other pathologies such as atherosclerosis, HTN, stroke, insulin resistance and diabetes; Low FRC
Clinical features of OSA include
hallmark of OSA is habitual snoring, fragmented sleep, and daytime somnolence
Patients with OSA present with comorbidities related to
obesity, hypoxemia
systemic & pulmonary hypertension, ischemic heart disease, and CHF
Diagnosis of OSA can be done through
polysomnography- records the number of abnormal respiratory events/ Hr (the apnea plus hypo apnea index, AHI)
If a patient has OSA, there is no evidence that
delaying a case will improve outcomes
For AHI & OSA diagnosis,
> 5 associated with sleep-related symptoms
15 is diagnosis for moderate OSA
30 severe OSA
What does STOP BANG stand for?
Snore loudly daytime Tiredness Observed stop breathing High blood Pressure BMI> 35kg/m^2 Age> 50 years Neck circumference >40 cm Gender- male
FEV1 is the
volume of air forcefully exhaled in one second (80-120% of predicted value)
FVC is the
volume of air forcefully exhaled after a deep inhalation (3.7L females, 4.8 L in males
The normal FEV1 to FVC ratio is
75-80%
The most clinically useful test of lung function includes
spirometry
FEV 25-75% is
measurement of air flow at midpoint of a forced exhalation
The Maximum voluntary ventilation (MVV) is the
maximum amount of air that can be inhaled and exhaled in 1 minute
males 140-180 and females 80-120 L/min respectively
The diffusing capacity or DLCO is
the volume of carbon monoxide transferred across the alveoli into the blood per minute per unit of alveolar partial pressure
normal value is 17-25 mL/min/mmHg
a single breath of 0.3% CO and 10% helium is held for 20 seconds
The “common cold” results in
22 million doctor visits annually
-infectious (viral or bacterial) nasopharyngitis accounts for 95%
Diagnosis of acute upper respiratory infection is based on
signs & symptoms- non-productive cough, sneezing, and rhinorrhea
bacterial infections more serious and include- fever purulent nasal damage, productive cough and malaise, patient may present with tachypnea and wheezing
Pediatric patients with acute upper respiratory infection are at higher risk for
complications when actively sick, have history of reactive airway disease, ETT intubation, and airway surgery
The urgency of surgery should be determined to decide the case should be cancelled or not
If a case is cancelled due to acute upper respiratory infection it should not be rescheduled for
six weeks
The anesthetic management for acute upper respiratory infection includes
hydration, reducing secretions, limited airway manipulation, and LMA vs. ETT
Adverse respiratory events with acute upper respiratory infection include:
bronchospasm, laryngospasm, airway obstruction, postoperative croup, desaturation
Asthma is a
reversible airway obstruction characterized by: bronchial hyperreactivity, bronchoconstriction, and chronic inflammation of the lower airways
The development of asthma is due to
multifactorial- genetic or environmental
Describe the pathophysiology of asthma.
activation of the inflammatory pathway leads to infiltration of airway mucosa with:
-eosinophils, neutrophils, mast cells, T cells and B Cells
inflammatory mediators include: histamine, prostaglandin D, and leukotrienes
airway edema results and there is thickening of the basement membrane
simultaneous edema and repair
Signs and symptoms of asthma include
episodic disease with symptom-free periods with acute exacerbations- episodes may last minutes to hours but patiently completely recovers
phases of daily attacks with some degree of obstruction
Clinical manifestations of asthma include
wheezing, productive and nonproductive cough, dyspnea and chest discomfort leading to air hunger, eosinophilia
Status asthmaticus is an
asthma exacerbation that persists despite treatment
Diagnosis of asthma is dependent on
symptoms- wheezing, chest tightness, shortness of breath, airflow obstruction that is partially reversible with bronchodilators AND
pulmonary function testing
Patients with asthma have these changes on a pulmonary function test
FEV1 less than 35% of normal
downward “scooping” of expiratory limb of loop
Increase in FRC, but TLC remains within normal limits
DLCO is uncahnged
Arterial blood gases for patients with asthma are
normal in mild disease
hypocarbia and respiratory alkalosis are common- reflects neural reflex changes in lungs, not hypoxemia
For patients with severe asthma obstruction, the arterial blood gases are associated with
PaO2 less than 60 mmHg
rises in PaCO2 noted when FEV1 is less than 25%- fatigue in accessory muscles contributes to hypercarbia
Discuss the chest radiograph appearance for patients with asthma.
may be normal
-with severe asthma they may have hyperinflation or hilar congestion due to mucus plugging and pulmonary hypertension
The EKG of patients with asthma may show
right ventricular strain associated with increased pulmonary pressures
T wave inversion in right precordial leads (V1-4) and inferior leads (II, III, and aVF)
Status asthmaticus is a
life threatening emergency in which bronchospasm does not respond to treatment
Treatment of status asthmaticus includes:
IV corticosteroids, supplemental oxygen, IV magnesium sulfate to cause relaxation, oral leukotriene inhibitor, and administration of B2 agonists- metered dose inhaler, nebulizer, injection (IV or subcutaneous)
For patients with status asthmaticus who are resistant to treatment, think
airway edema and secretion
The treatment of patients with asthma is focused on
treating inflammation and bronchospasm
Drugs that are used to treat asthma include:
corticosteroids- beclomethasone long-acting bronchodilators- salmeterol; combination- Symbicort and Advair Leukotriene modifiers- singular Anti-IgE monoclonal antibody- omalizumab Methylxathines- theophylline mast cell stabilizer- cromolyn
For patients with asthma who have PFT’s performed,
it an be useful in determining treatment response
FEV1 is greater than 50% of normal= symptom free
For patients with asthma, it is important to investigate this in the preoperative period.
preoperative history- assessment of disease severity & treatment effectiveness
includes:
severity and characteristics of asthma- used of accessory muscles, active wheezing?
previous ICU admission or intubation required?- two or more in the past year?
eosinophil counts (inflammatory process)
PFT results- FVC <70% or Fev1/FVC <65% increases perioperative risk
presence of coexisting diseases
Should also assess for additional preoperative therapy
The optimal anesthetic for an asthmatic patient is
regional because there is less manipulation of the airway
Induction for asthmatics includes
continue all meds until time of surgery- stress dose of steroids only if systemic therapy in last six months
deep induction- propofol vs. ketamine
IV or trans-tracheal lidocaine injection
sufficient volatile to suppress reactivity of airways= sevoflurane less pungent and has bronchodilation effects
avoid histamine releasing drugs- narcotics and paralytics
Perioperative anesthetic considerations with asthma include
adjust I;E ratios to prevent air trapping
adequate fluid administration
avoid anticholinesterase drugs
light anesthesia vs. bronchospasm- administer b2 agonist, deepen anesthetic, consider steroids and/or magnesium, administer neuromuscular blocking agent
_____ extubation may be considered for asthmatics
Deep extubation as long as you know that the patient is sufficiently breathing on their own
COPD is the
non-reversible loss of alveolar tissue and progressive airway obstruction
COPD will be the
third leading cause of death by 2030
Risk factors for development of COPD include:
cigarette smoking, occupational exposures, pollution, recurrent respiratory infections, low birth weight, alpha 1-antitrypsin deficiency
Emphysema is characterized by
enlargement of air spaces distal to the terminal bronchiole with destruction of walls
loss of alveoli and damage to capillaries
small airways are thin, tortuous, and atrophied
A bullae is
one large alveolar sac
Centriacinar emphysema is
more common in the apex
Panacinar emphysema has
no regional preference but might be seen more in the lower lobes
Paraseptal emphysema runs along
specific regions of the lungs
Chronic bronchitis is a disease characterized by
excessive sputum production
expectoration of sputum most days for at least 3 months for 2 successive years
Hallmark findings of chronic bronchitis include
hypertrophy of mucus glands of large bronchi
inflammatory changes in small airways
granulation of tissue, smooth muscle increases
peri bronchial fibrosis
The diagnosis of COPD is via
spirometry- can only be definitively determined with this
PFTs in COPD patients will reveal
a decrease in FEV1/FVC ratio- decrease <70% of predictive not reversible with bronchodilators
decrease in FEV25-75
Increase in FRC and TLC- increase in RV
Severity determined by GOLD spirometry criteria
GOLD is used to determine
the severity of COPD and stands for global initiative for chronic obstructive lung disease
The treatment for COPD is
designed to relieve symptoms and slow disease progression
smoking cessation, long-term oxygen administration- relief of arterial hypoxemia with supplemental oxygen is more effective than any known drug therapy
Exercise training program
Smoking cessation for patients with COPD significantly lowers
disease progression and decreases mortality by 18%
Long-term oxygen administration for patients with COPD includes
2 lpm nasal cannula
PaO2 <55 mmHg
HCT >55%
evidence of cor pulmonale
Drug treatments for patients with COPD include
long-acting B2 agonists (not albuterol)
inhaled corticosteroids
long-acting anticholinergic drugs- help dry out secretions– abitropium
It is recommended that additional pharmacological treatment for COPD patients includes
vaccinations, diuretics, systemic corticosteroids, and theophylline
Lung volume reduction surgery can be performed for patients with
severe cases of COPD
The mechanism of improvement for lung volume reduction surgery for patients with COPD includes
increase in elastic recoil
decrease in amount of hyperinflation
improved diaphragmatic and chest wall movement
decrease in abnormal V/Q
Anesthetic considerations for patients receiving lung volume reduction surgery includes
double-lumen tube, avoidance of nitrous oxide, avoidance of excessive pressure ventilation
Preoperative anesthetic considerations for the patient with COPD include:
a preoperative history with
smoking history- smoking associated with numerous comorbidities
current medications- continued through morning of surgery
oxygen use
exercise tolerance
frequency of exacerbations- most recent and its course
use of non-invasive positive pressure ventilation
Clinical signs in COPD are more predictive
of pulmonary complications
Factors that contribute to postoperative complications for patients with COPD include
active clinical signs and symptoms
Age >60
ASA III or IV
current smoker- greater than 60 pack/year smoking history
Cardiovascular involvement- right ventricular function should be assessed by echocardiography
low albumin <3.5 g/dL
surgical factors
Factors that determine the need for preoperative pulmonary function testing include.
hypoxemia or need for home oxygen with no known cause
NaHCO3 >33 mEq/L
PaCO2 >50 mmHg
history of respiratory failure due to persistent problem
severe SOB attributed to disease
planned pneumonectomy
difficulty assessing pulmonary status through clinical means
differential diagnosis needed
need to determine response to bronchodilators
pulmonary hypertension
Risk reduction strategies for the COPD patient include
Smoking cessation- at least 6 weeks prior to surgery is best; immediate cessation is not recommended
nutritional status- malnutrition increases risk of pleural leaks after lung surgery
regional anesthesia- peripheral nerve blockade carries little risk of pulmonary complications
except for intrascalene blocks which can cause ipsilateral phrenic nerve palsy
For general anesthesia in COPD patients,
volatile agents are useful
avoid nitrous oxide
careful with use of benzodiazepines and opioids
For COPD patients undergoing general anesthesia and receiving volatile agents, it is useful because
they are rapidly eliminated
have bronchodilation effects- desflurane can cause irritation
For COPD patients undergoing general anesthesia, nitrous oxide should be avoided because
it attenuates HPV and increases V/Q mismatch
Use of benzodiazepines and opioids in patients with COPD can prolong
ventilatory depression
For COPD patients requiring mechanical ventilation,
provide humidification avoid dynamic hyperinflation of the lungs- hemodynamically unstable patients; differential diagnosis is tension pneumothorax Vt 6-8 mL/kg PIP <30 cmH2O FiO2 titrated to maintain SpO2 >90%
Patients with COPD who are mechanically ventilated may develop
air trapping or auto PEEP
positive pressure ventilation is applied without sufficient expiration leading to an increase in intrathoracic pressure and a decrease in venous return
it increases pulmonary artery pressure
results in right heart strain
Expiratory outflow obstruction disorders include
bronchiectasis, cystic fibrosis, primary ciliary dyskinesia, bronchiolitis obliterans, tracheal stenosis
Postoperative considerations for the COPD patient include
lung expansion maneuvers, early ambulation, and neuraxial anesthesia
For COPD patients needing continued mechanical ventilation, it is necessary to
maintain SpO2 >90%, PaCO2 to maintain pH of 7.35-7.45, postoperative trial of BIPAP
Patients with COPD who suffer a bronchospasm could occur due to
light anesthesia or airway manipulation during induction
Bronchospasm treatment includes
figure out why deepen anesthetic deliver a short-acting bronchodilator suction secretions IV steroids epinephrine if neede
For patients who develop air trapping, the capnography will
show sloped carbon dioxide concentration
expiratory flow does not reach baseline before next breath
Bronchiectasis is the
irreversible airway dilation and collapse resulting from inflammation due to chronic infections- pseudomonas is the most common organism cultured
With bronchiectasis, ____ may occur
significant hemoptysis; 200 mL over 24 hour period
In patients with bronchiectasis, resultant airway collapse
increases susceptibility for recurrent infections- once established nearly impossible to eradicate
The diagnosis of bronchiectasis is done through
history of chronic cough with purulent sputum
diagnostic imaging of CT confirms disease presence and location
Signs and symptoms of bronchiectasis include
hemoptysis, dyspnea, wheezing, pleuritic chest pain, and finger clubbing
Anesthetic considerations for the patient with bronchiectasis include:
detailed patient history- severity, most recent exacerbation, home medications need to be taken day of surgery
elective procedure should be delayed until patient is optimized
If the patient with bronchiectasis has general anesthesia, these considerations are important.
frequent suctioning
double lumen tube
avoid nasal intubations
Cystic fibrosis is an
autosomal recessive disorder that affects a single gene on chromosome 7
- prevents chloride transport and movement of salt and water in and out of cells
Cystic fibrosis transmembrane conductance regulator
Cystic fibrosis results in
abnormally thick sputum production outside of epithelial cells
Cystic fibrosis leads to damage of
lungs (bronchiectasis, COPD) sinusitis pancreas (DM) liver (cirrhosis) GI tract (ileus) Reproductive organs (azoospermia)
The primary cause of morbidity and mortality for the cystic fibrosis patient is
chronic pulmonary infection
The diagnosis of cystic fibrosis is via
sweat chloride concentration >70 mEq/L
clinical manifestations of chronic purulent sputum production, malabsorption with response to pancreatic enzyme therapy, bronchoalveolar lavage high in neutrophils, COPD common in most adult patients
The presence of normal sinuses is strong evidence that
CF is not present
Treatment of CF is direct at
alleviation of symptoms and includes clearance of airway secretions correction of organ dysfunction nutrition prevention of intestinal obstruction -gene therapy is currently being investigated
Primary ciliary dyskinesia is a
congenital impairment of ciliary activity in the respiratory tract epithelial cells and sperm cells
Primary ciliary dyskinesia includes these issues:
Karategener’s syndrome which is a triad of:
chronic sinusitis, bronchiectasis, situs inversus- seen in half of patients, patients may also develop decreased fertility
Anesthetic considerations for patients with cystic fibrosis include:
elective procedures delayed until patient is optimized- controlling infection and removing secretions
vitamin K treatment- absorption of fat-soluble vitamins
General anesthesia with volatile agents- increased oxygen concentration, relaxation of smooth airway msucles
AVOID anticholinergic medications
awake extubation
adequate pain control
Anesthetic considerations for the patient with primary ciliary dyskinesia include
regional anesthesia preferred preoperative focus- pulmonary infection & organ inversion reverse position of ECG leads left internal jugular vein cannulation right uterine displacment avoid nasal pharyngeal airways
Bronchiolitis obliterans is a disease of
the small airways and alveoli in children from respiratory syncytial virus (RSV)
In adults, bronchiolitis obliterans may result from
viral pneumonia, collagen vascular disease (rheumatoid arthritis), Silo filler’s disease (inhalation of nitrogen dioxide), and graft vs. host disease following transplantation
Bronchiolitis Obliterans Organizing Pneumonia shares features of
interstitial lung disease and bronchiolitis obliterans
Treatment is usually ineffective and includes corticosteroids and bronchodilators
Tracheal stenosis occurs following
prolonged intubation or over-inflation of the endotracheal tube cuff
Tracheal stenosis results in
ischemia of tracheal mucosa resulting in scarring- may not appear for several weeks after intubation
becomes symptomatic in the adult when tracheal diameter decreases to <5 mm- dyspnea prominent even at rest, must use accessory muscles in all phases of breathing
Flow loops display flattened inspiratory and expiratory curves
The treatment for tracheal stenosis is
tracheal dilation is a temporary measure- balloon or surgical dilators, lasering of scarred tissue
tracheobronchial stent can be short or long-term solution
tracheal resection with anastomosis is the best treatment
Anesthetic considerations for the patient with tracheal stenosis include
translaryngeal intubation
volatile agents to ensure maximum inspired oxygen concentration
helium, if available will decrease the density of gas mixture and improve flow through the narrowing
