Asthma

Question 1

What is asthma

Answer 1

It’s a disorder of variable severity which cause symptoms from airway obstruction,inflammation and hyper responsiviness

Question 2

Symptoms

Answer 2

Shortness of breath
Wheeze
Cough
Sputum production

Question 3

How can you differentiate it from COPD

Answer 3

• presence of childhood symptoms
• diurnal variation
• specific trigger factor
• abscence of smoking
• response to previous treatment

Question 4

Preoperative assessment

Answer 4

• Key indicators of severe disease: history of frequent exacerbation, hospital visits and most important prior tracheal intubation to manage sever attack.
• Documents any allergies/ drug sensitivities esp the eefect of NSAIDs/aspirin
• aAsk about trigger factors and recent rep infection
• The type, dose, frequency and degree of benefit of therapy
• Examination should focus on detecting of acute bronchospasm, active lung infection( which should defer surgery), chronic lung disease and RHF
• Advise patients to stop smoking at least 2 months prior to surgery
• viral infection is a potent triggers of asthma so postpone elective if symptoms suggests URTI
• There is an association with nasal polyps in atopic patient

Question 5

Treatment options before surgery

Answer 5

Based on the level of severity of the disease:::

1- patient with mild asthma (peak flow >80% of predicted or minimal) rarely require extra ttt prior to surgery. Consider adding short acting Beta2 agonist just prior to surgery.

2- Moderately controlled patients should add inhaled corticosteroids to thier beta2 agonist 1 wk prior to surgery.

3- poorly controlled asthma (>20% variability in PEFR) may need to add oral corticosteroids such prednisolone 20-40mg daily for 1 wk.

Question 6

Investigations

Answer 6

1- serial home measurements of peak flow are more informative than single reading. Measure the response to bronchodilator and look for “early morning dip” which suggest that the comtrol isn’t optimal
2- spirometry helps to detect the chronic residual effect of acute asthma and to stratify the severity of the disease.
**Results of peak flow &spirometry compared with predicted values based on age, gender and height

3-Blood gases only necessary in ptnt with severe disease (poorly controlled, frequent hospital admissions previous ICU admissions)
4- ECG may show right atrial or ventricular hypertophy, acute strain, right axis deviation and RBBB
5- CXRs reveals flattened diaphragm if the lung is hyper inflated and imp to evulate for pulmonary congestion, edema.

Question 7

Conducts of anaesthesia

Answer 7

THE GOAL os TO AVOID Brochospasm
1~ for major surgery start chest physiotherapy preop
2~Conider premedication with anticholenergic to dry out secretions and suppress upper airway vagal responses.
3~ Add neubilized salbutamol2.5 mg to premedication
4~Consider the need to arterial line intraop in high risk to facilitate frequent ABGs
5~When asthma os poorly controlled, regional technique are ideal for peripheral surgery. Spinal generally safe provided the the patient can lie flat comfortably
6~Where GA is necessary, use short acting anaesthic agenents.short acting analgesic (remifentanyl) are appropriate for procedures with minimal postop painor when reliabl regional block present.
7~ intubation may provoke bronchospasm. Consider potent opiid cover. Only instrument the airway when the patient is deeply anaesthestised . LA to the cord maybe helpful
8~ ventilator strategies such as limiting peak inspiratory pressure and Vt with increasing I:E ratio.
9~ Avoid histamine releasing drug(morphine,atracurium,mivacurium)
10~ Inspired Air should be humidified to avoid airway irritation. Stimulating maneuver should be avoided as suctioning or only when the patient is deep.
11~ Reversal pf using acetylcholine esterase inhibitor should be used with caution d.t their muscarinic effect
12~ prophylactic use of antiemetic or antacids should be considered to avoid aspiration which can trigger severe bronchospasm

Question 8

Postoperative Care

Answer 8

-Patient with sever disease with upper-abd or thoracic surger should be admitted to ivu postop.
-In acute brochospasm at the end of operation, or of the patient has difficult airway, traumaor full stomach, consideration should be given to a period of post-op mechanical ventilation to allow time for airway to recovery.
-Ensure all usual medications are prescribed posop
- Following major thoracic or abd surgery, good pain control is important and thoracic epiduralthe best choice
- if PCA consider fentanyl other than morphine
-prescribe O2 for the duration of epidural or PCA
- prescribe regualr neubilizer therapy
- Review the dose of steroid daily
- Avoid Nsaid in poorly controlled asthma
-If there is increasing dyspmea or wheeze postop, consider other possible contributions ( PE, LV failure)
Also consider fluid overload