This presentation is the property of its rightful owner.
Sponsored Links
1 / 70


  • Uploaded on
  • Presentation posted in: General

ANAESTHESIA WITH CONCURRENT RESPIRATORY DISEASES MODERTOR BY- DR SUCHIT KHANDUJA DR GIAN CHAUHAN JR ANAESTHESIA. Preoperative Preparation. General assessment- This involves history, examination and investigation .

Download Presentation


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Anaesthesia with concurrent respiratory diseases




Preoperative preparation

Preoperative Preparation

General assessment-This involves history, examination and investigation.

History. Ask about symptoms of wheeze


Sputum production,


Chest pain

Exercise tolerance,

Orthopnoeaand paroxysmal nocturnal dypsnoea

Anaesthesia with concurrent respiratory diseases

  • Diagnosis of chronic chest complaints such as asthma or bronchiectasis is often known.

  • Present medication and allergies are noted, and a history of smoking sought.

  • Previous anaesthetic records may be available and can help in planning care.

Anaesthesia with concurrent respiratory diseases

Examination. Inspect for

  • Cyanosis

  • Dyspnoea

  • Respiratory rate

  • Asymmetry of chest wall movement

  • Scars, cough and sputum colour.

Anaesthesia with concurrent respiratory diseases

Percussion and auscultation of chest may suggest

  • Areas of collapse and consolidation,

  • Pleural effusions,

  • Pulmonary oedema or infection. 

  • Corpulmonale may be evident as peripheral oedema and raised jugular venous pressure

  • Enlarged lymph nodes in the neck may suggest lung cancer.

Anaesthesia with concurrent respiratory diseases

Investigations. Leucocytosis may indicate active infection, and polycythaemia chronic hypoxaemia.

ABG should be performed in patients who are dyspnoeic with minimal exertion and the results interpreted in relation to PIO2.

Preoperative hypoxia or carbon dioxide retention indicates the possibility of postoperative respiratory failure.

May require a period of assisted ventilation on the Intensive Care Unit.

Anaesthesia with concurrent respiratory diseases

  • Pulmonary function tests, provide baseline pre-operative measurements.

  • Chest clinic has charts to compare these results against those predicted for the patients age, sex and weight.

  •  The results are also compared against the patient's previous records to assess current disease control.

Anaesthesia with concurrent respiratory diseases

  • FEV1.0 (Forced Expiratory Volume in 1 second) and FVC (Forced Vital Capacity) are commonly measured. A reduction in the FEV1.0:FVC ratio indicates obstructive airways disease. (The normal is 0.75 (75%) or more). A reduction in FVC occurs in restrictive lung disease.

  • An FEV1.0 or FVC less than 70% of predicted, or an FEV1.0:FVC ratio less than 65%, is associated with an increased risk of pulmonary complications.

Anaesthesia with concurrent respiratory diseases

  • Chest X-rays may confirm effusions, collapse and consolidation, active infection, pulmonary oedema, or the hyperinflated lung fields of emphysema.

  • ECG may indicate P-pulmonale, a right ventricular strain pattern (dominant R waves in the septal leads) or right bundle branch block.

Anaesthesia with concurrent respiratory diseases

  • In patients with poor respiratory function premedication (if used) must not cause respiratory depression.

  • Opiates and benzodiazepines can both do this

  • Are best avoided if possible, or used with caution.

  • Humidified oxygen may be administered .

  • Anticholinergic drugs (e.g. atropine) may dry airway secretions and may be helpful before ketamine .

Specific respiratory problems

Specific Respiratory Problems

Coryza (common cold)

  • Typically, children experience six to eight URIs per year

  • May be even more frequent among young children attending nursery school or day care

  • 30%–40% of URIs are caused by rhinoviruses;

  • Other viruses—including coronavirus, respiratory syncytial virus, and parainfluenza virus—contribute significantly to the etiology of the disease.

Anaesthesia with concurrent respiratory diseases

  • Patients may present with undiagnosed infections including croup (laryngotracheobronchitis), influenza, bronchiolitis, herpes simplex, pneumonia, epiglottitis, and strep throat.

  • Most viral URIs are self-limiting

  • May produce airway hyperreactivity that persists for several weeks after infection.

  • Viral invasion of the respiratory mucosa may render the airway sensitive to secretions or potentially irritant anesthetic gases.

Anaesthesia with concurrent respiratory diseases

  • Viral invasion of the respiratory mucosa may render the airway sensitive to secretions or potentially irritant anesthetic gases.

  • Bronchial hyperreactivity resulting from viral infections may be neurally mediated.

  • Atropine, for example, has been shown to block airway hyperreactivity.

  • Viral infections increase the response of airway smooth muscle to tachykinins .

  • De Soto et al. (9) found that children with symptoms of a URI had a significant increase in the risk of postoperative arterial oxygen desaturation and laryngospasm.

Anaesthesia with concurrent respiratory diseases

Independent risk factors for adverse respiratory events in children with active URIs include

Use of an ETT in a child <5 yr old.

Prematurity (<37 wk).

History of reactive airway disease.

Paternal smoking.

Surgery involving the airway,

Presence of copious secretions.

And presence of nasal congestion.

Preoperative assessment

Preoperative Assessment

Child is presenting for an emergent procedure

  • Presence of a URI should be elicited

  • Will alert the anesthesiologist for complications

  • Modification of the anesthetic management to reduce any risk.

Anaesthesia with concurrent respiratory diseases

Children for elective procedures with suspected URI

  • Require careful preoperative assessment

  • Detailed history and physical exam to be done.

  • Lungs should be auscultated to exclude any lower respiratory tract involvement,

  • A chest radiograph should be considered if the examination is questionable.

  • Patient should be evaluated for fever, dyspnea, productive cough, sputum production, nasal congestion, lethargy, and wheezing.

Anaesthesia with concurrent respiratory diseases

  • Nasal congestion, sputum production, and a history of reactive airway disease were identified as predictors of adverse respiratory events

  • Confirmation of URI by a parent found to be a better predictor of laryngospasm than symptom criteria .

  • Children with congenital heart disease can have URI confused with CHF.

Anaesthesia with concurrent respiratory diseases

Should be able to undergo surgery ….

  • Children presenting with uncomplicated URI

  • Who are afebrile with clear secretions and appear otherwise healthy

  • Those with noninfectious conditions

Anaesthesia with concurrent respiratory diseases

Should be postponed for surgery……

Children with more severe symptoms—including

  • Mucopurulent secretions

  • Productive cough

  • Fever >38°C

  • Lethargy

  • Signs of pulmonary involvement

  • If a bacterial infection is suspected

    Their elective surgery postponed for a minimum of 4 wk or more(if bact. Infection is suspected)



  • Analysis of nasopharyngeal swabs or aspirates for viral isolation

  • Measurement of white blood cells counts

  • The chest radiograph is also of little utility

Anesthetic management

Anesthetic Management

  • Directed at minimizing secretions and avoiding stimulation of a potentially sensitive airway.

  • Airway be suctioned (under deep anesthesia) to remove excess secretions

  • Ensure that the patient is adequately hydrated

  • Humidification may also be important in children with URIs, particularly for long cases.

Anaesthesia with concurrent respiratory diseases

  • Anticholinergicsglycopyrrolate or atropine may be useful in reducing secretions and attenuating vagally-mediated hyperreactivity.

  • Bronchodilator premedication has also been suggested

  • Preop treatment with corticosteroids and salbutamol minimized intubation-evoked bronchoconstriction more effectively than inhaled salbutamol alone.

Anaesthesia with concurrent respiratory diseases

  • Use of an ETT should be avoided

  • ETT is likely the airway of choice for surgery of the oropharynx and neck, major thoracic and abdominal surgery, and operations lasting more than a couple of hours.

  • LMA, is a safe alternative for some procedures

  • Complications in children with mild URIs was similar between sevoflurane and halothane.

  • Sevoflurane provided a more rapid recovery profile

Anaesthesia with concurrent respiratory diseases

  • Can prefer to extubate under deep anesthesia to avoid reflex constriction of the airways.

  • Also can extubate when the patient is awake, believing that a patient with intact reflexes is in a better position to clear secretions and respond to the tactile stimulation of ETT removal.



  • Asthma causes hyper-responsive airways with oedema, inflammation and narrowing due to smooth muscle spasm.

  • Characteristically reversible, unlike chronic obstructive pulmonary disease

  • Elective cases should not be undertaken unless asthma is well controlled

  •  In poorly controlled asthma a short course of steroids is often effective in improving control of the disease.

  • Patients on preoperative steroids will need extra perioperative supplementation if they are taking more than the equivalent of 10mg of prednisolone a day.

Preoperative assessment1

Preoperative assessment

  • Assessed by the frequency and severity of attacks

  • Hospital and intensive care admissions seen

  • Examination may reveal expiratory wheezes, use of accessory muscles or an over-distended chest.

  • Peak expiratory flow rates (PEFR) pre- and post-bronchodilator should be measured

Anaesthesia with concurrent respiratory diseases

  • Blood gas analysis is usually reserved for severe disease (breathlessness on minimal exertion).

  • Before surgery, patients should be free of wheeze

  • PEFR greater than 80% of the predicted or personal best value

  • Severe asthmatics may require their inhalers being changed to nebulisers.

  • Inhaled steroid dose may have to be increased or oral steroids commenced (Prednisolone 20-40mg daily) one week prior to surgery 

Perioperative management

Perioperative management

  • Consider converting inhaled beta 2 agonists such as salbutamol to the nebulised form

  • Give nebulisedsalbutamol (2.5-5.0mg) with premedication.

  • Avoid aspirin or NSAIDs and any other allergens known to the patient.

  • If applicable local or regional anaesthesia used alone will avoid the problems of general anaesthesia. 

  • If  general anaesthesia is required, the addition of regional techniques can reduce operative volatile anaesthetic and post operative opioid requirements and the likelihood of respiratory complications.

Anaesthesia with concurrent respiratory diseases

  • Ketamine and all the volatile agents are bronchodilators.

  • Avoid thiopentone

  • Airway manipulation should be kept to a minimum

  • Controlled ventilation with the use of neuromuscular blocking drugs will be needed for major or long procedures

  • Atracurium and tubocurare,high dose opoids should be avoided as they release histamine.

  • Deriphylline with b2 adrenergic agonist and halothane should be carefully used together.

  • Capnograph must be carefully noted for signs of bronchospasm.

Anaesthesia with concurrent respiratory diseases

  • Residual neuromuscular blockade must be fully reversed

  • Extubation can occur when spontaneous ventilation is resumed and oxygenation is adequate.

  • Deep extubationdec. chances of laryngospasm.

  • Extubation induced laryngospasm can be blunted by lidocaine 1-2 mg/kg prior to extubation.

Postoperative care

Postoperative care

  • Adequate analgesia is vital.

  • Humidified oxygen is continued for up to 72 hours following major abdominal or thoracic surgery together with regular physiotherapy until the patient regains mobility.

  • Maintenance of hydration with intravenous fluids is required until oral intake is sufficient.

  • Usual anti-asthmatic medications are resumed immediately

  • May require intravenous steroids to temporarily replace oral

  • Nebulised bronchodilators to replace inhalers if the patient cannot take a deep breath

  • Failure to ensure adequate postoperative oxygenation and ventilation may require admission to an intensive care area.

Anaesthesia in patients with chronic obstructive pulmonary disease

Anaesthesia in patients with Chronic Obstructive Pulmonary Disease

  • Chronic obstructive pulmonary disease (COPD) is a very common respiratory disorder that affects many people across the world.

  • Long term survival of patients with severe COPD undergoing any type of surgery is poor (47% 2 year mortality)

  • Significant risk of postoperative morbidity, especially pulmonary complications

Pathophysiology of copd

Pathophysiology of COPD

  • Inflammatory disease of the lungs that is characterised by airflow limitation that is not fully reversible

  • Complicated by significant systemic manifestations and co-morbidities.

  • Usually secondary to inhaled noxious particles or gases

  • Most common of which worldwide is cigarette smoke

Anaesthesia with concurrent respiratory diseases

  • The lung pathology in COPD is a combination of inflammatory small airways disease(obstructive bronchiolitis) and parenchymal destruction (emphysema).

  • The small airways disease leads to obstruction and air trapping

  • The loss of lung parenchyma decreases gas transfer, reduces the pulmonary capillary bed and worsens VQ mismatching.

  • Reducing the parenchymal support of the walls of the small airways contributes to the airflow limitation.

Anaesthesia with concurrent respiratory diseases

  • Causes hypoxaemia and sometimes hypercarbia.

  • Direct result of COPD can be corpulmonale

  • Respiratory and skeletal muscle wasting and weight loss can occur

  • Co-morbid diseases, especially cardiovascular are more prevalent

Clinical features of copd

Clinical Features of COPD

  • Dyspnoea

  • Wheeze

  • Cough with or without sputum production.

  • Onset of COPD is insidious

  • Most patients are symptomatic either with cough or progressive dyspnoea long before they present to medical services.

Anaesthesia with concurrent respiratory diseases

  • Diagnosis of COPD should be considered in all patients over forty years old with a significant smoking history (>10 pack years) with some symptoms.

  • Mainstay of treatment of COPD is bronchodilation both for maintenance and for exacerbations.

  • β-agonists and anticholinergics (ipratropium bromide and tiotropium bromide) are used; the latter are proposed to have an additional effect of relieving air trapping.

Anaesthesia with concurrent respiratory diseases

  • Long term inhaled steroids are usually only indicated in patients with severe COPD and repeated exacerbations or who have co-existent asthma.

  • Oral steroids are beneficial in the treatment of exacerbations.

Preoperative assessment2

Preoperative assessment

History and examination

  • Establish exercise tolerance, particularly hills and stairs

  • Enquire about frequency of exacerbations, hospital admissions and previous requirements for invasive and non-invasive ventilation.

  • A smoking history is vital

Anaesthesia with concurrent respiratory diseases

  • Cough and particularly sputum production has been shown to be an independent risk factor for postoperative pulmonary complications in COPD.

  • Clear history regarding co-morbid conditions is vital.

  • Symptoms and signs of active infection should be sought including green or purulent sputum, increased dyspnoea, wheeze and signs of consolidation.

  • Nutritional status should be assessed

  • Patients with both high and low BMI have increased risk.



  • Chest X-ray is useful to exclude active infection and occult malignancy

  • The presence of extensive bullous disease highlights the potential risk of pneumothorax.

  • ECG may reveal right heart disease (right ventricular hypertrophy or strain).

  • Spirometry is used to clarify diagnosis and assess severity

Anaesthesia with concurrent respiratory diseases

  • GOLD Classification of COPD (based on post bronchodilator FEV1)

  • Stage I: Mild FEV1/FVC <0.70

  • FEV1 ≥ 80% predicted

  • Stage II: Moderate FEV1/FVC < 0.70

  • FEV1 50 - 80% predicted

  • Stage III : Severe FEV1/FVC <0.70

  • FEV1 30 - 50% predicted

  • Stage IV: Very Severe FEV1/FVC 0.70

  • FEV1 <30% predicted or FEV1 < 50%

    predicted and chronic respiratory failure

Anaesthesia with concurrent respiratory diseases

  • Simple exercise tests such as stair climbing and the 6 minute walk test are safe and simple to perform

  • Arterial blood gas measurement is useful: PaCO2 > 5.9 kPa and PaO2 <7.9 kPa (on room

    air) are both associated with a worse prognosis.

Preoperative optimisation

Preoperative optimisation

  • • Smoking cessation

  • Current smokers are at far greater risk of developing postoperative pulmonary complications.

  • should be stopped at least eight weeks before surgery in order to obtain maximum benefit

Anaesthesia with concurrent respiratory diseases

  • Optimal drug treatment.

  • Almost all patients with COPD benefit from at least one dose of nebulised bronchodilator preoperatively

  • High doses of nebulised β-agonists can cause or exacerbate tachyarryhthmias and cause hypokalaemia. Nebulisedanticholinergics can increase sputum viscosity

Anaesthesia with concurrent respiratory diseases

Treatment of infection/ exacerbation

  • Current infection or exacerbations are a contraindication to anaesthesia.

  • Should be treated with both β-agonist andanticholinergic therapy, preferably in nebulised form, and a short course of systemic steroids.

  • Prophylactic antibiotics over the operative course may be beneficial

Anaesthesia with concurrent respiratory diseases

  • Physiotherapy

  • Preoperative physiotherapy is important in sputum producing COPD patients to clear any retained sputum that may cause intraoperative bronchial plugging or pneumonitis.

  • Pulmonary rehabilitation, may also have a role

Principles of perioperative anaesthetic management

Principles of perioperativeanaesthetic management

Airway and ventilation

  • Bronchospasm may occur on induction, during airway instrumentation and on extubation.

  • May need aggressive administration of bronchodilators to prevent or treat acute hypoxaemia and hypercarbia

  • Avoidance of endotracheal intubation, if possible, may reduce the risk of bronchospasm.

  • Extubation should be carried out with the patient awake and sitting up.

Anaesthesia with concurrent respiratory diseases

  • V/Q mismatch increases under general anaesthesia and in the supine position

  • Combined with atelectasis, this leads to worsening hypoxaemia

  • Pronounced if the patient is obese or is in the Trendelenburg or lithotomy position.

  • Supplemental oxygen and positive pressure ventilation may be necessary.

Anaesthesia with concurrent respiratory diseases

  • Sputum plugging can be caused by excessive sputum production

  • May lead to lobar collapse

  • Saline nebulisation, endobronchial suctioning, and physiotherapy to clear the sputum plug are the treatment strategies.

  • Inadequate analgesia and insufficient postoperative physiotherapy can lead to retained secretions and hence infections

  • Postoperative chest infection must be promptly diagnosed and treated with antibiotics.

Anaesthesia with concurrent respiratory diseases

  • Pneumothorax is more likely in patients with COPD

  • Mechanical ventilation should be carefully set to minimise high airway pressure and avoid breath stacking

  • The respiratory rate should be low .

  • Postoperatively, patients may require increased monitoring and continued ventilatory support.

  • Residual effects of general anaesthesia and sedation may result in hypoventilation causing hypercarbia and hypoxaemia.

Anaesthesia with concurrent respiratory diseases

  • Some will require regular arterial blood gas monitoring and further ventilatory support (non-invasive or invasive).

  • Some will require regular arterial blood gas monitoring and further ventilatory support (non-invasive or invasive).

  • In these patients high inspired oxygen levels may suppress respiratory drive causing hypoventilation and hypercarbia.

  • Patients at such risk should be placed in ICU/HDU.

Cardiovascular issues

Cardiovascular issues

  • Some patients with COPD develop corpulmonale

  • In these patients adequate oxygen therapy is required along with diuretics and digoxin.

  • Fluid balance is crucial

  • Central venous pressure monitoring may be useful

  • Presence of tricuspid valve incompetence may not reflect the true right sided filling status.

Postoperative care1

Postoperative Care

  •  Patient with underlying respiratory disease is at increased risk of postoperative pulmonary complications.

  • Particularly so in smokers, or after upper abdominal or thoracic surgery.

  • Airway is vulnerable for up to 24 hours, and hypoventilation can occur for up to 3 days.

  •  If there are problems the patient will need to go to the HDU or ICU

Anaesthesia with concurrent respiratory diseases

Oxygen therapy

  • Following minor surgery hypoxia may occur for the first hour or two after surgery

  • Oxygen should therefore administered until the patient is fully awake and recovered from the anaesthetic.

  • After major surgery hypoxia can occur for up to for 3 days, particularly at night.

  • Precipitated by opoids

  • Patient with chest disease or ischaemic heart disease, at risk.

  • Oxygen (2-4L/ min by nasal cannulae) should be given

Anaesthesia with concurrent respiratory diseases

  • Some patients with very severe COPD depend on hypoxia to maintain ventilatory drive

  • All affected patients will have had severe COPD for many years.

  • The inspired oxygen concentration shold be monitored

  •  Repeat arterial blood gas estimations carried out to guide the level of oxygen treatment tolerated by the patient

Anaesthesia with concurrent respiratory diseases

Pain Relief

  • Effective analgesia reduces the incidence of postoperative respiratory complications.

  • Opioids may be required for 48-72 hours after major surgery

  • Intravenous opioid boluses can be titrated against pain in the recovery room

  • If available, patient controlled analgesia (PCA) systems allow the patient to titrate opioid requirements to their pain

  • The combination of opioids with rectal or oral drugs, such as paracetamol or non-steroidal anti- inflammatory agents (NSAIDs), gives particularly good analgesia whilst reducing opioid side effects.

Anaesthesia with concurrent respiratory diseases


  • Teaching patients in the preoperative period to participate with techniques to mobilise secretions and increase lung volumes in the postoperative period, will reduce pulmonary complications.

  • Methods employed are coughing, deep breathing, early mobilisation, and chest percussion and vibration together with postural drainage.

Anaesthesia with concurrent respiratory diseases

Steroid supplementation

  • Brittle asthmatic or severe COPD patient may benefit from a course of prednisolone (20-40mg daily) the before surgery.

  • Patients who have received a course of steroids in the 6 months before surgery, or who are on maintenance therapy of greater than 10mg of prednisolone a day, are presumed to have adreno-cortical suppression

  • Perioperative steroid supplementation will be required.

Anaesthesia with concurrent respiratory diseases

  • Intravenous hydrocortisone 100mg 8 hourly is given starting with the premedication.

  • Over the next 5 days this is tapered to their normal daily 

  • Intravenous steroids must replace oral whilst these cannot be taken.

Anaesthesia with concurrent respiratory diseases

Prophylaxis of venous thromboembolism

  • Prophylactic measures should begin before surgery in those at risk and continued until early mobilisation

  • Regular subcutaneous heparin and anti-embolism stockings are commonly used.

Bronchiectasis and cystic fibrosis

Bronchiectasis and Cystic Fibrosis

Prior to surgery therapy is maximised using 

  • Course of intravenous antibiotics, physiotherapy,

  • Nebulised bronchodilators

  • An extra 5-10mg/day of oral prednisolone, if taking long term steroids. 

  • Elective surgery is postponed if respiratory symptoms are present.

  • Postoperatively continue intravenous antibiotics and regular physiotherapy until discharge. 

  • Adequate nutrition is resumed as early as possible



  • The patient with active pulmonary tuberculosis may be wasted, febrile and dehydrated.

  • Production of sputum and haemoptysis may cause segmental lung collapse and blockage of the endotracheal tube.

  • Humidification of anaesthetic breathing systems is therefore important

  • Inspired oxygen concentration will have to be increased

Anaesthesia with concurrent respiratory diseases

  • Appropriate intravenous fluids are given to rehydrate the patient.

  • Anaesthetic equipment must be sterilised after use to prevent cross infection of tuberculosis to other patients. 

Anaesthesia with concurrent respiratory diseases

Restrictive pulmonary disease

  • Intrinsic, such as pulmonary fibrosis related to rheumatoid arthritis or asbestosis

  • Extrinsic-caused by kyphoscoliosis or obesity. 

  • Oxygenation may be impaired at the alveolar level and because of poor air supply to it

  • Steroids are the usual treatment for fibrotic disease.

Anaesthesia with concurrent respiratory diseases

Intrinsic Disease

  • The anaesthetist should be alerted early. 

  • Preoperatively obtain spirometry, arterial blood gases, lung volume and gas transfer measurements

  • A reduced PaO2 indicates severe disease

    The chest physician may suggest an increase in steroid dose.

  • Steroid supplementation will be required over the operative period

  • Postoperatively, supplemental oxygen is given to keep SpO2>92%, and respiratory infection is treated early.

  • High tidal volumes must be avoided to prevent bulla formation and pneumothorax.

Anaesthesia with concurrent respiratory diseases

Extrinsic Disease

  • The restrictive deficit here leads to rapid, shallow breathing, often relying on diaphragmatic movement 

  • Poses problems for breathing and sputum clearance postoperatively

  • Blood gases remain normal until disease is severe and PaCO2 rises.

  • Postoperatively, vigorous physiotherapy and adequate analgesia are vital. 

  • May require ICU or HDU care if Postoperative hypoxia, fatigue or carbon dioxide narcosis occurs.

Regional anaesthesia

Regional anaesthesia

  • Regional anaesthesia avoids many of the respiratory problems

  • Provides good postoperative analgesia

  • Decreases requirement of opoids and inhalational agents if given concomitantly with GA

  • Most blocks can safely be performed with or without sedation.

  • Interscalene block should be avoided as the resultant phrenic nerve palsy may further compromise respiratory function.

  • Blocks above level of T5 should be avoided.

Anaesthesia with concurrent respiratory diseases


  • Login