Cystic Fibrosis

Question 1

What is the definition of CF ??

Answer 1

Is a multisystem, autosomal recessive disease and is the commonest lethal genetic disease in Cucasian.

The disease caused by mutations in single gene - the CF transmembrame regulator(CFTR) gene on chromosome 7 .

Question 2

Tell me about the CFTR gene

Answer 2

The CFTR is a chloride (cl-) channel found at the apical found at the apical border of epithelial cells, which line most of the exocrine glands.

All mutations causing CF lead to abnormal Cl− conductance through the CFtR channel. this results in loss of Cl− transport and a disturbance of the sodium (na+)/ Cl− balance needed to maintain a normal thin mucus layer. In CF, the mucus is viscid and is less well cleared by thecilia.

Question 3

What are the clinical manifestations of CF ?

Answer 3

1- progressive lung disease (frequent LRtI, chronic hypoxaemia, and cor pulmonale)

2-nasal problems (chronic sinusitis and nasal polyps)

3-hepatobiliary system disease due to obstruction of bile ductules (focal biliary cirrhosis, portal hypertension, multinodular biliary cirrhosis),

4-meconium ileus, recurrent abdominal pain,

5-pancreatic exocrine insufficiency and CF-related diabetes, infertility, and osteoporosis.

Question 4

General considerations

Answer 4

• Patients with severe disease are best managed in a major centre with multidisciplinaryinput.
• neonates may present for surgical treatment of meconiumileus.
• nasal polypectomy, enteral feeding, or vascular access device placement are commonly performed as elective surgical procedures for CF patients.
• Almost all patients with CF have symptoms of bronchiectasis (see E p. 106).
• the perioperative complication rate in CF is ~10% (mostly pulmonary), but half of this is for minor ear, nose, and throat (Ent) procedures.
• Day-case surgery is uncommon in CF patients; however, it is possible in patients with stable disease and a good baseline functional status.

Question 5

Preoperative assessment

Answer 5

• gain a history of therapy, medications, and exacerbations.
• Exclude or treat active chest infection.
• Ascertain the patient’s functional ability.
• note details of the non-respiratory components.
• Always inform the patient’s physician of an admission to a surgicalward

Question 6

Investigations

Answer 6

• FBC, U&Es, coagulation study, LFts, and blood glucose should be performed.
• Respiratory assessment tests include CXR, baseline ABg analysis, and spirometry.
• Spirometry generally shows an obstructive pattern, with a decrease in FEV1 and the FEV1/FVCratio.
• In advanced disease, an ECg and echocardiogram are useful to diagnose cor pulmonale.
• A6MWt forms part of the pre-lung transplant work-up in many centres. the results of this may be available when patients present for non-transplant surgery.
• CPEt may prove to be a useful indicator of physiological reserve.

Question 7

Conduct ofanaesthesia

Answer 7

• Consider placing an arterial line to facilitate frequent ABg analysis.
• Consider using cardiac output monitoring in patients with cor pulmonale who present for major surgery.
• For short or non-abdominal or non-thoracic procedures, an LMA with a spontaneously breathing patient may minimize the adverse effects of gA on respiratory mechanics.
• An Ett, however, allows bronchial toilet and improved control of gas exchange

. • Avoid nasal intubation, where possible, due to the high incidence of nasal polyposis.

• keep airway pressures as low as possible when using positive pressure ventilation. Monitor for pneumothorax.

• Use humidifiedgases.
• Short-acting drugs should be used, wherever possible, to facilitate rapid emergence.
• Patients are often cachectic, so careful positioning and padding is important.
• Consider a regional anaesthetic technique, where appropriate, to avoid airway manipulation and to optimize post-operative analgesia.

Question 8

Post-operativecare

Answer 8

• Aim to minimize the risk of development of a post-operative respiratory tract infection.
• Aim to extubateearly.
• Ensure nMB is fully reversed.
• For patients who use home non-invasive ventilation, ensure that the patient’s own equipment is available immediately post-operatively

. • Chest physiotherapy should be resumed as early as possible.

• It is appropriate for patients with advanced disease to be monitored in a high dependency setting.
• For patients with FEV1 <1L, PaO2 <9.3kPa, or PaCO2 >6.6kPa, consider a period of post-operative ventilation.
• Eighty per cent of CF patients have pancreatic malabsorption. Maintaining adequate nutrition after surgery is essential, as is the advice of an experienced dietitian.