Bilateral lung volume reduction surgery

Bilateral lung volume reduction surgery

Patient selection criteria

Inclusion

· progressive, severe dyspnoea that significantly limits quality of life and activities of daily living

· non-smoking for 6 months

· satisfied pulmonary rehab goals ( 6 min walk, motivation)

· acceptable nutritional status 80-120% normal body weight)

Exclusion

· asthma, bronchitis

· significant systemic diseases; diabetes, renal failure

· steroid dependent

· patients resistant to intensive pre-operative pulmonary rehabilitation program

· depression

Exercise tolerance

• 6 minute walk/distance test ( >500 feet)

• dyspnoea index scores (with ADLs)

Chest x-R & CT

• flattened diaphragms, laterally hyperexpanded chest wall, reduced vascular markings and vertical heart position

Physical examination

l hyperexpanded chest

l hyperinflated lungs

l immobile diaphragms

l heterogenous lung tissue ie.target areas of more severe tissue interspersed with less diseased tissue

l elevated shoulders

l ABG with PaCo2 <>

l uncoordinated, thoraco-abdominal breathing patterns

l elevated Hb suggests persistent hypoxia

Pulmonary function studies

l FEV 1(forced expiratory volume in one second) 20-30% of predicted (indexed to height and weight) <15%>35% rehab alone

l FVC(forced Vital capacity) 60% of predicted

l TLC (total lung capacity) 140% of predicted (increased residual volume of trapped gases)

l RV (residual volume) 250% of predicted( limit expiratory reserve, tidal volume and respiratory flow rates)

l increased TGV (thoracic gas volumes)

l increased RAW (resistence to airflow)

Cardiac function evaluation

l right ventricular hypertrophy

l ECG to exclude coronary disease

l right and left catheterisation if suspect pulmonary hypertension (exclude patients with MPAP >35mmHg)

Post-operative care

Hypotension

· Hypovolaemia

Volume restriction due to strict limit of fluid given to prevent pulmonary oedema due to lung tissue manipulation. Peripheral vasodilatation due to sympathetic blockade (decreased: circulating epinephrine, vaso-motor tone, preload, stroke volume and cardiac output.)

Vassopressors and volume expanders only if necessary

· Post-operative bleeding

Serial hematocrit, haemoglobin and coagulation studies and hourly monitoring of drainage

· Hypothermia

Bair hugger warming, radiant heater warming

· Arrhythmias

Treat fluid/electrolyte imbalance (common in first 48-72 hrs)

UWSD management

NB. No suction is applied to chest tubes

l 1hourly checks of UWSD

l observe for bubbling, swinging and draining

l determine which chest drain is bubbling

l immediate chest x-R, then 4-6hrs post-op, then daily (to detect infiltrates or pneumothorax)

l heimlich valves for persistent air leaks as requested by MO (never attach a drainage bag to a Heimlich valve)

l monitor insertion sites for redness, drainage or dislodgment.

l changed weekly (UWSD) daily ( Heimlich valves)

l removal of drains according to MO (as early as 24hrs, but may be a lot longer even post-discharge depending on air leak)

These patients are often claustrophobic and anxious and are best nursed in single rooms with lots of space and very calm staff

Rehabilitation

Discharge 7-10 days

l ROM exercises ( aimed at increasing patient’s level of endurance and overall fitness)

l diaphragmatic breathing and relaxation of shoulders exercises ( aimed at retraining and reconditioning the diaphragm and accessory muscles and improving posture)

l ambulation (SOOB 12hrs post-op, ambulate within room 24 hrs post-op day (treadmill evening of first post-op day in some centres), ambulate in ward day 2; aimed at ambulating independently length of the corridor (300 metres) 3 times daily prior to discharge)

Pain Management

Adequate but not excessive pain control is the goal

l epidural anaesthesia (maximum pain control with minimum respiratory depression usually bupivocaine and fentanyl)

l epidural analgesia (ropivocaine) at 4-10 ml/hr

l panadol for break through pain (often shoulder tip)

l non-steroidal anti-inflammatory drugs 56 hrs post-op

l excessive doses may cause respiratory depression, ineffective airway clearance, potential aspiration and immobility (strictly no CNS depressing drugs)

Sleep and diet

l sleep is essential but over sedation can be disastrous. Judicious use of sedation in consultation with MO

l adequate caloric intake

Patient outcomes

Duration of benefits uncertain. Early studies report 5 years. Recent studies report 3 years.

Improvement of

l pulmonary function(FEV1,FVC,reduced TLC)

l dyspnoea index

l quality of life, energy, physical mobility, ability to perform housework, enjoyment of social life, reduced anxiety levels

l 6 minute walk distance from 150-300 meters

l marked improvement in need for supplemental oxygen