Transcript Perioperative Management of Pulmonary Disease

By Dave Telles
Diplomate of the American Board of Oral and Maxillofacial Surgeons
Introduction
 preoperative assessment - a major consideration in patients
who undergo a surgical procedure
 thorough assessment – of underlying pulmonary disease
helps to minimize the risk for perioperative complications
 Complications range from –
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minor atelectasis, dyspnea
Cough
increased sputum production
severe pneumonia and respiratory failure requiring prolonged
mechanical ventilation.
 PPCs can have a serious impact on morbidity and mortality
and can prolong a hospital stay by an average of 1 to 2
weeks
PFTs
Pre-op
 Patient-related risk factors
 1. Smoking – risk declines after 8 wks of cessation
 2. Underlying lung condition
 3. General health status
 4. Age
 5. Obesity
 Procedure-related risk factors
 1. Site of surgery
 2. Type of surgery—open versus laparoscopic
 3. Duration of surgical procedure
 4. Type of anesthesia
Abg
 Arterial blood gas analysis is not done routinely.
 It is required if significant lung dysfunction is
suspected.
 Arterial carbon dioxide tension (Paco2) > 45 mm Hg
indicates significant alveolar hypoventilation and
chronic respiratory failure
 known to be associated with increased respiratory
complications
Pulmonary HTN
 a significant and independent predictor of hospital
mortality in elderly patients undergoing cardiac
procedures
 in pregnant women, pulmonary hypertension carries a
high risk for maternal death, approximately 30% to
50%
 Pts w/ moderate to severe portopulmonary
hypertension (mean pulmonary artery pressure greater
than 35 mm Hg) and underwent liver transplantation
had a mortality of up to 50%
Pulmonary HTN
 severe pulmonary hypertension and a cardiac shunt,
systemic hypotension results in an increased right-toleft shunt
 predisposes to development of acidosis
 lead to further decreases in SVR
 Pulmonary vascular resistance may increase due to
hypoxia, hypercapnia, endogenous catecholamines or
Valsalva maneuvers.
 May require Pulm artery cath for hemodynamic
monitoring
Periop Pulm Complication
 risk for developing pulmonary insufficiency
postoperatively ranges from 5% to 80%
 Factors that affect ventilation during post-op
 1. Low tidal volume leading to alveolar collapse and
development of atelectasis
 2. Decrease in residual volume, functional residual
capacity, and vital capacity
 3. Reduced lung compliance
 4. Postoperative hypoxemia resulting from shunting
and atelectasis
Periop Pulm Complication
 Alveolar collapse begins within 1 hour and progresses
rapidly to produce significant transpulmonary
shunting
 Maximal inflation deep breathing exercises at regular
intervals help in returning the postoperative lung
function toward normal
 recumbent position -- superior lobes of the lungs are
ventilated
 perfusion is preferential to the dependent lobes leading
to shunting of blood
 results in hypoxemia.
Periop Pulm Complication
 1. Aggressive fluid resuscitation leading to increased
hydrostatic pressure
 2. Injury to the capillary membrane as a result of
endotoxins released from tissue injury and
microemboli
 3. Left ventricular dysfunction with a resultant
increase in left atrial pressure leading to transcapillary
transudation
 4. Poor nutrition with loss of proteins resulting in low
oncotic pressure
Effect on anesthesia on respiration
 intubation and inhalation gases impair mucociliary
transport  increase in secretions
 may persist for 2 to 6 days postoperatively
 ET intubation -- can cause bronchospasm by reflex
stimulation of the airways
 Prolonged anesthesia and surgery -- impair the function of
lung inflammatory cells
 Kotani et. Al. -- shows that anesthetic agents (isoflurane
and propofol) modulate alveolar macrophage function
intraoperatively – may increase susceptibility to infection
 Supresses normal cough reflex and glottic closure
Vent perfusion mismatch
 induction of anesthesia, there is more ventilation to
the nondependent areas of the lung
 increasing the alveolar dead space
 increase in ventilation perfusion mismatch
 Causing Shunting of blood
 accentuated by areas of atelectasis
Post-op Pulm Complications
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1. Exacerbation of COPD or asthma
2. Hypoxemia
3. Aspiration
4. Atelectasis
5. Upper airway obstruction
6. Postobstructive pulmonary edema
7. Pneumonia
8. Pleural effusion
9. Pulmonary embolism
10. Tracheal lacerations or rupture
11. Bronchospasm
Asthma / COPD Exacerbation
 If peak expiratory flow rate is less than 80% of predicted,
use of systemic steroids during the perioperative period is
recommended.
 Wheezing should be controlled with the use of inhaled bagonists
 Patients treated chronically with prednisone in doses of 20
mg daily for more than 3 weeks in the previous 6 months
may exhibit suppression of adrenal hypothalamic axis -may require a maintenance dose
 on 5-mg daily or less of prednisone should not have
suppression and steroids may be discontinued as indicated.
Hypoxemia
 Postoperative hypoxemia is defined as an arterial oxygen
saturation of less than 90% or Pao2 of lessthan 75% of the
preoperative value
 Factors
 anesthesia-induced hypoventilation and the loss of upper
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airway muscle tone
Volume overload
inability to clear secretions
upper airway edema
Aspiration
pulmonary embolism
Intrinsic lung conditions
Aspiration
 RFs
Reduced consciousness, resulting in compromise of the cough reflex
and glottic closure
 Neurologic defects, resulting in dysphagia
 Surgery involving the upper airways
 Esophageal disorders, and gastric reflux
 Mechanical disruption of the normal anatomy of the glottis as a result
of tracheostomy, endotracheal intubation, and nasogastric feeding
 Local pharyngeal anesthesia given during procedures e.g.
bronchoscopy and upper endoscopy
 Feeding gastrostomy
 Recumbent position
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 Complications
 Chemical Pneumonitis
 Fulminant ARDS
Atelectasis
 Most common problem encountered during post-op
period
 Tx
 Lung expansion maneuvers
 adequate pain control
 pulmonary toileting
 Use of mucolytic agents, such as N-acetylcysteine,
neither decreases sputum production nor the
incidence of atelectasis or pneumonia
Strategies to reduce post-op Pulm
Complications
 Preoperative
 Smoking cessation preferably 8 weeks before surgery
 Treatment of bronchospasm
 Optimization of airway obstruction in OSA
 Anticoagulation in venous thromboembolism (VTE)
 Treatment of upper respiratory tract infection
 Patient education
 Correction of electrolyte imbalance
Strategies to reduce post-op Pulm
Complications
 Intraoperative
 Type of anesthesia: preferably spinal or epidural
 Shorten duration of operations to less than 3 hours
 Preferably laparoscopic surgeries
 Avoidance of long-acting
 neuromuscular blockers
 Postoperative
 Lung expansion maneuvers
 Adequate pain control
 Deep vein thrombosis (DVT) prophylaxis
 Early ambulation
Smoking Cessation
 Adding nicotine replacement therapy or bupropion to
behavioral support increases 6-month success rates on
average by 8% to 9%
 Studies show that 1 in 5 smokers who want to make an
attempt to quit is successful if given appropriate
therapy
COPD
 Arterial blood gas analysis also is helpful in assessing
the presence and severity of hypercapnia, which can
complicate oxygen therapy.
 Pts with hypoxemia – supplemental oxygen should be
supplied at the lowest level necessary to maintain a
Po2 of at least 60 mm Hg or an oxygen saturation of
90% or greater
 At risk for retaining CO2
OSA
 Nasal CPAP should be used for at least 2 weeks before
surgery.
 Postsurgery CPAP
 used even when patients are awake to decrease edema
 prevent rapid eye movement rebound
 May require temparory tracheotomy
 Initial post-op monitoring erc in ICU
Lung Expansion Maneuvers
 Deep breathing exercises
 Incentive spirometry prevents the development of
atelectasis.
 Intermittent positive pressure breathing is not more
effective than incentive spirometry or deep breathing
exercises
 CPAP is effort independent
 found as effective as deep breathing exercises or
incentive spirometry
What information is obtained from
spirometry?
What information is obtained from
spirometry?
 provides timed measurements of expired lung volumes
 possible to interpret more than 15 different measurements
from spirometry alone
 Forced vital capacity (FVC), forced expiratory volume in 1
second (FEV1), FEV1/FVC ratio, and flow between 25% and
75% of the FVC (MMF25-75)
 most clinically helpful indices obtained from spirometry
 spirometry demonstrates airflow limitations, it does not
determine its cause
 e.g., airway obstruction versus decreased alveolar elastic recoil
versus decreased muscle strength
 effort dependent and requires a motivated patient
Pneumothorax
 Hyperresonance of affected hemithorax
 Decreased or absence of breath sounds
 Tracheal deviation to the other side of pneumothorax
 Respiratory distress
 Hypotension
 Tachypnea
 Hypoxia
 Distended neck veins (this could be absent if your
patient is hypovolemic