March 5, 2009
March 7: Anaesthesia Day
Pain manager
For years, anaesthetic drugs have enabled patients to undergo painless surgeries. Now anaesthetists take their skills beyond the operating theatre. DHANY OSMAN reports
Many a patient who has benefited from experiencing little or no pain while undergoing surgery or childbirth can thank an often overlooked field of medicine: anaesthesia.
Since becoming available over 150 years ago, anaesthetic drugs have meant that patients can undergo longer and more complicated surgeries, minus the trauma of excessive pain.
Today's anaesthesiologists, or anaesthetists, practise a range of subspecialties, like obstetric and paediatric anaesthesia.
Outside the operating theatre, these specialists play vital roles in areas like post-operative and chronic pain management.
'More anaesthesiologists are also helming medical committees that look into safety standards, infection control, resuscitation, disaster management and hospital planning,' said Dr Naville Chia, the current president of the Singapore Society of Anaesthesiologists (SSA). He is a consultant with the anaesthesia department at Alexandra Hospital.
This Saturday is Anaesthesia Day here and the SSA aims to inform the public about the uses of anaesthesia and the available options, as well as address some common misconceptions.
'Some people still think we're not doctors and this may lead to trust issues,' Dr Chia added.
So what exactly does anaesthesia involve and how safe is it?
Meaning 'without sensation' in Greek, the medical practice of anaesthesia primarily involves the use of drugs to numb either the whole body or certain parts of it so operations can be done without the patient experiencing any trauma, pain or discomfort.
Sprays, ointments or injections are used in local anaesthesia (LA) to numb small areas of the body, where the nerves rest closer to the skin surface.
Regional anaesthesia (RA), applied for operations to deeper parts of the body, involve the injection of anaesthetic drugs to the nerve clusters that relay signals from that area to the brain.
Examples include spinal and epidural 'blocks' used during childbirth or lower-body surgeries.
In epidural anaesthesia, the drugs are delivered via a catheter that is inserted into the patient's epidural space (a part of the spine). Such patients are sometimes given sedatives as well, to keep them relaxed but still awake during the procedures, said Dr Chia.
'With regional anaesthesia, you may feel some sensation but you don't feel pain,' he added.
There is, of course, general anaesthesia (GA), in which a patient is put in a carefully monitored unconscious state, which may be necessary for certain surgeries. GA is usually done intravenously with anaesthetic drugs, although anaesthetic gas can sometimes be used as well.
Said Dr Chia: 'The choice between regional and general anaesthesia is dependent upon patients' consent. If they would rather be asleep during surgery, we will usually comply.'
Today, there is also monitored anaesthetic care (MAC) for those undergoing minor surgery. This sedates the patient and keeps him calm during the procedure.
Patient-controlled analgesia (PCA) is also available to help patients manage their post-surgical pains. Using a device that intravenously delivers the analgesic agent - usually morphine - patients can activate a dose of pain-relief when necessary.
A variation of this method, called patient-controlled epidural analgesia (PCEA), is also available to help women experiencing a prolonged labour process.
Risks and side-effects
Experts agreed that the risks involved in today's use of anaesthesia are minimal, especially given the many precautionary measures taken before, during and after surgery.
At Changi General Hospital (CGH), nearly all patients scheduled for surgery go through a full evaluation at its Pre-Anaesthesia Assessment Clinic (PAAC). 'The aim of the PAAC is to evaluate a patient's fitness for surgery, so as to reduce anaesthesia and surgical risks,' said Dr Yong Chee Seng, chief consultant of the anaesthesia department at CGH.
Within the operating room, anaesthetists carefully monitor a patient's vital signs, provide adequate pain relief and ensure an adequate 'depth' of anaesthesia.
All this is done to ensure safe and smooth surgery, he added.
As for the nightmare scenario of a patient waking up, or becoming aware, during surgery, doctors said that such an occurrence is rare.
Dr Chia said quoted incidences fall between 0.1 and 0.2 per cent.
After a GA-assisted operation, patients may often feel disoriented, nauseous or tired but this is to be expected and is part of the normal recovery process, doctors said.
MYTHS DEBUNKED
Dr Yoong Chee Seng, chief consultant at Changi General Hospital's anaesthesia department, addresses some common myths about anaesthesia: Severe pain is inevitable after surgery
Today, severe post-operative pain can be treated with pain medication and other forms of anaesthesia. Hospital staff should be alerted before the pain becomes more serious and debilitating.
No pain, no gain
It was believed that pain was a necessary part of the healing process. In fact, severe pain can cause distress and suffering, hamper recuperation and increase post-operative complications.
Modern forms of pain relief can help patients experience little or no pain while at rest and tolerable pain when moving about, even after major surgery.
Pain medications are addictive
The truth is that, when properly prescribed, pain medications such as morphine and other opioids very rarely lead to addiction.
Pain medications have significant side effects
While some pain-relief medications can cause nausea, vomiting and sleepiness, these symptoms are reduced with time and can be treated with other medications.
Taking too many pain medications is unhealthy
With current thinking centred on providing 'balanced pain relief', patients are treated with a few different medications concurrently. This lessens the side effects of each medication as lesser amounts of each is needed.
Epidural and nerve blocks can lead to nerve damage or paralysis
Epidural and peripheral nerve blocks are excellent ways to provide post-operative pain relief and help to reduce the amounts of nauseating pain medications which a patient is given.
The risk of major permanent nerve injuries or paralysis is very low and lies somewhere between one in 10,000 cases and one in 100,000 cases.
Beyond the operating room
Women's anaesthesia
This sub-specialty provides pain relief for women before and after major surgery, as well as during childbirth.
Special attention is given to pregnant women as they are more prone to breathing problems while under anaesthesia, said Dr Alex Sia, head of the women's anaesthesia department at KK Women's and Children's Hospital (KKH).
Women are also more prone to nausea and vomiting during surgery so care has to be taken in choosing a suitable method of anaesthesia for them and in monitoring their condition throughout the procedure.
With Singaporean women becoming more aware of their options, Dr Sia said that about 45 per cent of women at KKH now opt for epidural anaesthesia to help reduce their labour pains.
For those undergoing Caesarean sections, regional anaesthesia can also be given to allow women to witness their child's delivery.
The advent of patient-controlled computer-assisted technology for epidural pain management has also made it easier for women in labour to 'customise' their pain relief to their needs, said Dr Sia. This technology will be implemented at KKH later this year.
Paediatric anaesthesia
This sub-field deals with the anaesthetic needs of young patients before, during and after surgery.
When anaesthetising young children, special attention must be paid to the amount of drugs given. This is usually measured in proportion to a child's size and body weight, said Dr Pua Hwee Leng, an anaesthesiologist in private practice.
Children may be frightened at the sight of the needles used to administer the drugs intravenously, so anaesthetic gas is often used to lull them to sleep first, Dr Pua added.
The masks used may be scented with chocolate or strawberry aromas, to put the tots at ease. In some situations prior to the surgery, parents are allowed into the operating room to calm the child.
Anaesthetists also help to minimise side effects like pain, nausea and disorientation felt post-surgery, said Dr Pua.
Acute and chronic pain services
Beyond the operating theatre, anaesthesiologists also provide pain-relief services for those recovering from surgery.
This is usually provided via oral or intravenous drugs like opioids that are carefully administered by doctors or nurses. Epidurals or 'nerve blocks' - which block sensation to certain areas of the body - may also be used.
'Good pain relief also helps to prevent complications like lung infections and blood clots,' said Dr Yoong Chee Seng, chief consultant of the anaesthesia department at Changi General Hospital (CGH).
Dr Yoong added that providing adequate pain relief also helps patients to participate better in post-operative physiotherapy and other rehabilitation exercises.
Some anaesthesiologists now provide chronic pain management services too, he said.
Gas masks used may be scented with chocolate or strawberry aromas to put tots at ease.
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