Sleep Study

What is a Sleep Study?

It is a multiple-component test that electronically transmits and records specific physical activities while an individual sleeps. The recordings become data that are analyzed by a qualified physician to determine whether or not a sleep disorder is present, including OSA (Obstructive Sleep Apnea). OSA is diagnosed when there are more than 5 episodes of apnea lasting at least 10 seconds in one minute during the entire sleep period.

Too much stress experienced over a sustained period of time, with insufficient coping strategies can result in ‘wear and tear’ to the body. Over the longer term, both emotional and physical wellbeing can be affected. Inability to contain your inner tension may also result in collateral damage to interpersonal relationships and work performance.

• Equipments used in a Sleep Study
• How is a Sleep Study conducted?

Equipments used in a sleep test

The equipments used in a sleep test include:

• A. Surface electrodes on the face and scalp that will send
• B. Belts placed around the chest and abdomen to measure breathing frequency
• C. ECG (electrocardiogram) to record heart rate and rhythm
• D. ensor at the nostrils to record airflow
• E. Bandage-like probe on the finger to measure the amount of oxygen in the body
• F. Microphone to record snoring activity

How is a Sleep Study conducted?

• The sleep study is done overnight and it can be done in hospital or home setting. Qualified sleep technicians will be involved in setting up the equipments.
• The sleep physician upon completion of the sleep study will prepare a detailed report. It provides useful diagnostic information about sleep related breathing disorders, movement disorders in sleep and other less common conditions like seizures in sleep and other abnormal behaviours during sleepy.

For Appointments, pls call: +65 6311 4710

Chronic Cough

Do you have a cough that is persistent and irritating?

Coughing is a natural reflex to clear the irritants for the airways and the lungs. However if a cough lasts for >8 weeks, you are suffering from chronic cough.

It can affect your sleep, interfere with your work and social life. You may be anxious and worried too. Occasionally you may have chest pain, giddiness and tiredness as a result of the chronic cough.

It is a common symptom and there are various causes of chronic cough. Some of the causes can be serious and life-threatening and therefore, it is important to see a doctor for further evaluation.

• Common causes of chronic cough
• Tests and Diagnosis

Common conditions that can cause chronic cough include:

• Asthma

It is the common cause of chronic coughing in the population. It may present with wheezing, chest tightness and shortness of breath. In cough-variant asthma coughing is the only symptom.

Upon contact with certain chemicals or cold air, the cough may become worse and this is referred to as hyperactive airways disease. Inhaled steroids are effective in reducing the inflammation in the airway and improving the cough. Inhaled bronchodilators like salbutamol may also prescribed.

• Postnasal drip

Excess mucus produced from an allergy reaction, common cold or a sinus infection, can accumulate at the back of the throat. This can cause irritation and inflammation that result in persistent coughing and need to clear the throat. Antihistamine, decongestant and nasal steroid spray are commonly prescribed.

• Gastro-Esophageal Reflux Disease (GERD)

Symptoms associated with GERD include frequent heartburn or a sour taste in the mouth, but half of the patients do not always present with these symptoms. Blood pressure medications Angiotensin-converting enzyme (ACE) inhibitors used to treat hypertension are known to cause chronic cough (up to 20%). The cough usually begins within hours of the first dose to months after the initiation of therapy. Once the drug is ceased, the cough will subside within 1-4 weeks.

The constant irritation from the acid reflux in the esophagus, throat and even in the lungs can lead to chronic coughing. Medications given will be mainly to reduce acid production in the stomach. Patient will be advised not to eat 2-3 hours before bedtime and avoid certain foods that can worsen the cough.

• Blood pressure medications

Angiotensin-converting enzyme (ACE) inhibitors used to treat hypertension are known to cause chronic cough (up to 20%). The cough usually begins within hours of the first dose to months after the initiation of therapy. Once the drug is ceased, the cough

• Chronic Bronchitis

Chronic productive cough is one of the symptoms of chronic bronchitis. The inflammation of the bronchial airways causes congestion, breathlessness and wheezing of the lungs. It is not uncommon in current or ex-smokers as a result of long term cigarette smoking. Known as chronic obstructive pulmonary disease – COPD, a spirometry- simple lung function test, is useful to confirm the diagnosis. Treatment will include smoking cessation and use of bronchodilator inhalers.

Other causes of chronic cough include lung cancer, pulmonary tuberculosis, bronchiectasis and chronic lung infection or inflammation.

Tests and Diagnosis
The initial step in the evaluation is a medical history and physical examination by a respiratory physician.

• Lung imaging

Chest x-ray is useful to check for lung cancer, pulmonary tuberculosis, lung scarring and other abnormal lung structures A more detailed imaging test as CT scan provide more detailed views of the lungs and it may be requested if the chest x-ray showed abnormalities.

• Lung function tests

These simple, noninvasive tests evaluate how the lung is functioning. It is useful in diagnosing asthma, COPD and restrictive lung diseases. There are 3 components to pulmonary function testing: spirometry, lung volumes and diffusion capacity.


1. Spirometry is the most basic test. Spirometry measures how much air you can quickly breathe into and out from your lungs. This test is done by having you take a deep breath and blow hard into a tube connected to a machine. Most patients can perform this test easily in the outpatient setting with coaching from a trained technician. Sometimes a methacholine challenge test is done to check for hypersensitivity of the airway. Spirometry is useful to diagnose COPD and asthma.

2. Lung volumes measures how much air your lungs can hold, and there are two ways for the measurement to be done- the nitrogen washout technique and the body plethysmography technique. Lung volumes are useful to diagnose restrictive lung diseasees like pulmonary fibrosis.

3. Diffusion capacity measures how well your lungs put oxygen into and remove carbon dioxide from your blood. It involves breathing in a very small amount of carbon monoxide and measuring the amount that is transferred from the alveoli to the capillary. This test is useful to follow up lung fibrosis and scarring.

Exhaled nitric oxide
This is a simple non invasive test that takes 5 minutes. Nitric oxide content is measured from a patient’s exhalation breath. When exhaled nitric oxide is raised, there is likely an eosinophilic inflammation in the airways that can occur in asthma and eosinophilic bronchitis.

Bronchoscopy
Bronchoscopy is a technique of visualizing the inside of the airways, inserting a small scope into the airways. This allows the doctor to check the patient’s airways for bleeding, tumors, infection or inflammation. This test is commonly done in the endoscopy room. Specimens may be taken from inside the airways or lungs.

For Appointments, pls call: +65 6311 4710

Skin Prick Test

What is a Skin Prick Test?
The skin prick test is a very common test to identify whether a certain substance causes the allergies in a person.
Many common food products, animal allergens and household allergens can be tested. Allergens such as dust mites,
house dust and cockroach are commonly found at home and are can be taken to minimize the contact.

Pets are also a source of allergens especially cats and dogs that can be easily identified and radily avoided.
Some common food allergy in children include egg, fish and nuts.

• Allergy
• Is the Skin Prick Test safe?
• How is a Skin Prick Test conducted?

Allergy

Allergy is not an uncommon medical problem. We are seeing more children with food allergy and more adults with allergic rhinitis and asthma in Singapore

• An allergy is an abnormal reaction by a person’s immune system against an usually harmless substance. It maybe something you ate, inhaled or touched that causes the allergic reaction.
• A person without allergies would have no reaction to this substance, but when a person who is allergic encounters the trigger, the body reacts by releasing chemicals which cause allergy symptoms. These symptoms can range from running nose, rashes, watery itchy eyes, asthma attacks, urticaria to life-threatening anaphylactic shock.

Is the Skin Prick Test safe?

Skin prick testing is generally safe and reliable for adults and children. It is considered to be the most convenient and least expensive to determine the allergen that one is allergic to.

How is a Skin Prick Test conducted?

During the skin prick test, a very small amount of certain allergens is introduced to the skin by pricking on the surface on the skin (forearm or back of the person) using disposable pricks.


Allergens Tray

After the pricking is done, reaction will occur within 15 minutes if there is allergy. It will be a little swelling at the spot where the allergen was introduced, associated with itchiness and redness around the same area.
The swelling will subside in about 2 to 3 hours’ time.

Positive reaction from the prick

Patients are advised to see a doctor before doing the test as there are certain medications like antihistamine to withhold to ensure accuracy of the test.
Pregnant ladies are not advised to do the test.

For Appointments, pls call: +65 6311 4710

OSA & SLEEP STUDY

Obstructive Sleep Apnea (OSA) & Sleep Study (Polysomnography)

Obstructive sleep apnea (OSA) describes a medical condition that is characterized by intermittent
episodes of absence of breathing (apnea) caused by complete obstruction of the upper airway passages during sleep. Narrowing of the air passages at the back of the throat occur in certain group of individuals.

Complete closure of these passages can occur during sleep as a result of further relaxation of the tissue at
the back of the throat.

During these episodes of apnea, which last from 10-90 seconds, reduction of oxygen level in the body develops until the apnea is terminated by an arousal, which restores the airway patency. This cycle of events is repeated multiple times during sleep in individuals with OSA, resulting in fragmented sleep.

• How common is this condition?
• What are the consequences of OSA?
• When do we suspect OSA?
• How is OSA diagnosed?
• What is a sleep study?
• Can OSA be treated?

How common is this condition?

OSA is an under-recognized and under-diagnosed condition worldwide. It is estimated that OSA affects up to 25% of the adult population. A study showed that 93% of women and 82% of men with moderate to severe OSA are not diagnosed.

What are the consequences of OSA?

Excessive daytime sleepiness is a major consequence of OSA. It can result in:

• Poor concentration and memory
• Affect job and school performance
• Affect relationships
• Poor quality of life
• Increased risk of motor vehicle accidents

Oxygen starvation occurs during sleep and it increases the risk for:

• Hypertension
• Heart failure and heart attacks
• Heart rhythm, abnormalities
• Strokes
• Increased lung pressures (pulmonary hypertension)
• Death

OSA is also associated with increased total cholesterol and triglycerides, increased insulin resistance and systemic inflammation.

When do we suspect OSA?

We suspect OSA in individuals with the following symptoms:

• Excessive daytime sleepiness
• Gasping and choking during sleep
• Poor concentration at work or school
• Loud habitual snoring
• Hypertension

Obesity is the most important risk factor for OSA. OSA is present in about 45% of obese individuals. It was also found to be moderately prevalent (46%) among obese children.

How is OSA diagnosed?

OSA is suspected based on symptoms and physical examination. The diagnosis of OSA is confirmed further by a sleep study (polysomnography) that is interpreted by a sleep physician.

What is a sleep study?

It is a multiple-component test that electronically transmits and records specific physical activities while an individual sleeps. The recordings become data that are analyzed by a qualified physician to determine whether or not a sleep disorder is present, including OSA. OSA is diagnosed when there are more than 5 episodes of apnea lasting at least 10 seconds in one minute during the entire sleep period.

The equipments used in a sleep test include:

• Surface electrodes on the face and scalp that will send recorded electrical signals from the brain, eyes and muscles to the measuring equipment
• Belts placed around the chest and abdomen to measure breathing frequency
• ECG (electrocardiogram) to record heart rate and rhythm
• Sensor at the nostrils to record airflow
• Bandage-like probe on the finger to measure the amount of oxygen in the body
• Microphone to record snoring activity

The sleep study is done overnight and it can be done in hospital or home setting. Qualified sleep technicians will be involved in setting up the equipments.
The sleep physician upon completion of the sleep study will prepare a detailed report. It provides useful diagnostic information about sleep related breathing disorders, movement disorders in sleep and other less common conditions like seizures in sleep and other abnormal behaviours during sleep.

Can OSA be treated?

Treatment of OSA is based on severity of OSA and individualized approach. Mild OSA can be treated with weight loss, better sleep hygiene, sleep posture, reducing alcohol consumption and dental devices.

The most effective treatment will be the use of continuous positive airway pressure (CPAP) machine where air pressure is used to keep the upper airway passages continuously open during sleep. Removing the obstruction will improve the sleep and reverse the hypertension, cardiac problems and metabolic abnormalities associated with OSA.

Occasionally, surgery involving the upper airway and jaw may be indicated in certain individuals.


For Appointments, pls call: +65 6311 4710

Spirometry

What is a Spirometry?

Spirometry is one of the commonest lung function tests performed in a respiratory clinic.

Lung function tests are used to assess how well you move air in and out of your lungs and well oxygen enters your body.

Spirometry is used to measure the rate at which the lung changes volume during forced breathing maneuvers. In simple terms, it measures how much air you can quickly breathe into and out from your lungs.

This test is done by having you take a deep breath and blow hard into a tube connected to a machine. Most patients can perform this test easily in the outpatient setting with coaching from a trained technician.

It is useful for diagnosing and monitoring respiratory conditions such as chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis. Spirometry can also detect early airflow obstruction in smokers who may have few or no symptom. In certain group of patients, it is also used to determine fitness for surgery and anesthesia.

Our spirometry test uses the flow sensing technique to detect the air flow.
Most spirometers display the volume-time curve and flow-volume loop graphs:

I. A volume – time curve



II. A flow – volume loop


In order to get an accurate result, before performing spirometry:

• Withhold some inhalation medications for 4 -24 hours (according to doctor’s advice)
• Do not smoke for at least 4 hours
• Do not exercise strenuously for at least 1 hour
• Do not wear tight clothing that may restrict the chest movement
• Do not drink alcohol for at least 4 hours
• Do not eat a large meal for at least 1-2 hours

Patient is seated comfortably for the test. A disposable mouthpiece is attached to the spirometer for the patient to perform the maneuver. Patient will be coached on the whole procedure before performing the test. Take a deep breath in through the mouth until the lungs are full. Blow into the mouthpiece as hard, fast and long as possible, until the lungs feel empty.

The procedure has to be repeated a few more times to get consistent results. A breathing medicine (bronchodilator) is sometimes given to find out how much better the patient might breathe with this type of medicine. The procedure usually takes 30 minutes to complete this test.

For Appointments, pls call: +65 6311 4710

Chronic Obstructive Pulmonary Disease (COPD)

What is COPD?

COPD is a chronic degenerative disease of the lungs whereby the airways become irreversibly narrowed and the lung’s ability to function is compromised. It is characterized by two common disease processes:

1. Emphysema
Air sacs form in the lungs in COPD from loss of elasticity. As a result, the air is trapped and there is difficulty in bringing air in and out of the lungs.

2. Chronic bronchitis The airways become swollen and filled with mucus
In 2008, COPD was the 8th leading cause of death and 7th leading cause for hospital admissions in Singapore.

• What causes COPD?
• What are the symptoms of COPD?
• How can COPD be diagnosed?
• How is COPD treated?

What causes COPD?

The main cause of COPD in Singapore is smoking, including second hand smoking.

What are the symptoms of COPD?
The symptoms of COPD may be quite similar to asthma:

• Chronic cough
• Breathlessness
• Wheezing and/or chest tightness
• Mucus and sputum production

As the condition progresses, one’s activities such as walking, doing household chores and grocery shopping can be severely limited by the breathlessness.
However, in the early stages, the disease can be completely asymptomatic until there is substantial lung damage (>50% of lung damage before symptoms occur).

How can be COPD diagnosed?

Spirometry (a lung function test) is the gold standard for diagnosing COPD.

Spirometry is performed in the clinic, and is a simple breathing test using specialized equipment that will allow the lung specialist to diagnose COPD as well as other types of lung conditions like asthma.

How is COPD treated?

COPD is usually treated with a combination of:

• Inhalers
• Oxygen therapy
• Lung rehabilitation and chest physiotherapy

It is of prime importance for smokers to quit smoking to prevent/delay the progression of COPD. This can be done under professional guidance of a lung specialist, with the usage of medications to quit smoking.
Regular physical exercise as well as vaccinations against pneumococcus and influenza are highly recommended, as they may cause severe lung infections in COPD patients.