Tag: medicine

Posted in Psychology & Medicine

Triage

Posted on by Jinavie

In dire times such as wars, natural disasters and pandemics, we hear news of healthcare professionals setting rules to limit medical treatment provided to certain groups of people. This can come across as shocking to people as it seems unfathomable that a hospital would not do everything within its power to save a life. However, this is a well-known and commonly practised principle in medicine known as triage.

Fundamentally, triage is a system used to prioritise who should receive what level of medical care when. The word triage comes from the French verb trier, which means “to sort“. Modern triage was first designed by a French surgeon named Dominique Jean Larrey, who served in the Napoleonic Wars. Larrey categorised wounded soldiers into one of three groups:

  1. Those who would likely die no matter what treatment they received
  2. Those who would likely live no matter what treatment they received
  3. Those whose quality of life may benefit from immediate treatment

He advised battlefield medics to quickly assess what group a wounded patient would fall under and to focus on the last group. For example, if a soldier had superficial cuts and not heavily bleeding, they would be able to transport themselves back to base. A soldier who is not breathing or lost two or more limbs would be unlikely to survive despite acute surgery (especially with where medicine was at in those times). In other words, medical care would be focussed on those who would likely survive and benefit from urgent medical care, such as the patient who is needing an amputation to stop life-threatening bleeding from an injured limb.

This may sound cruel, but it is the unfortunate reality of healthcare. Ideally, we would like to give the best care to every patient, but we live in a world of scarcity, where resources are finite and limited.

Therefore, we rely on utilitarianism, where we ask “what is the most amount of good we can do with these finite resources?”.

Modern triage is more complicated than Napoleonic times, especially in the emergency department. However, in the case of emergency situations involving mass casualty, triage returns to its simple, original form.

Let us imagine a city struck by a massive earthquake. There are tens of thousands of people with varying severity of injuries. How do we prioritise who will be taken to hospital, need on-site treatment, or left to die or find their own way to hospital?

Physicians and nurses will quickly assess a patient and their vital signs to categorise them using coloured tags, such as red for needing emergency treatment, green for does not need treatment, or black for deceased or likely to die. This is because without triage and prioritisation, the available medical resources will quickly be exhausted and no further care will be deliverable.

If multiple doctors and nurses stop triaging and focus on one patient needing complex surgery, tens or even hundreds of potentially salvageable lives could be lost. If non-urgent injuries are all taken to hospital, the hospital will be overwhelmed and will not be able to provide care to those who are critically ill. If a patient with a non-survivable injury is operated on and taken to the intensive care unit (ICU), they will have lost the opportunity to use those resources on a patient with a better chance of survival.

As harsh as it sounds, saving ten people with moderate injuries who would die without treatment is preferred over the one person who has a less than 10% chance of surviving with maximum medical care. This may be as black-and-white as choosing to not rescue a person with an obviously unsurvivable injury such as decapitation, but it may be as complicated and ethically challenging as deciding if an elderly patient with a lung infection should be intubated and ventilated (breathing machine), fully knowing that a younger, healthier patient with the same infection may need that ventilator to survive, but with a much higher chance of survival and restoring their quality of life.

Triage is a classic example of when the rational solution to a problem such as scarcity challenges ethics and emotions. It may sound as if doctors are playing god when they are declining ICU level of care for an elderly patient, but we must also consider that they have a duty to provide the most effective care for all of society, not just the one patient. These kind of ethical dilemmas are an everyday occurrence in the medical field and can cause significant guilt, anger, pressure and resentment for the healthcare provider.

To simulate the weight of triage, consider the following scenario. Following an explosion in your neighbourhood, you respond to a scene with four patients:

  1. Your 28-year old co-worker with heavy bleeding from a laceration of their leg
  2. Your 83-year old mother who is bleeding from their head and unresponsive, breathing very irregularly and poorly
  3. Your neighbour’s 8-year old child who is not breathing despite straightening their airway and applying rescue breaths
  4. Your 45-year old who is screaming in pain from a broken arm but not bleeding and able to walk
    You have the capability to treat and transport one patient. Who do you choose?

As much as we would like the save the life of our loved ones or a young child first, the principles of triage dictate that the first patient demands the most immediate response.

Triage does not account for emotional connections, personal biases or even justice necessarily. It is a cold, hard rule system that we use so that we can separate our emotions and instincts out amongst a horrific situation.

The algorithm for the START triage system – a widespread system used in many modern mass casualty scenarios
Posted in Psychology & Medicine

Holistic Medicine

Posted on by Jinavie

At face value, medicine appears to work on a relatively simple model. You gather information through history taking, clinical examination and investigations such as lab tests and imaging. Then, you narrow down the differential diagnosis to the single most likely diagnosis. Lastly, you treat the diagnosis as per the recommended treatment guidelines.

But if you ask anyone who works in healthcare, they will all know that is not the whole truth. There are so many other factors and variables that play in to the management of a patient that the model above does not address.

For example, you may diagnose a skin infection and prescribe antibiotics, but the person may not have enough disposable income to pay for the medications. You may come up with a plan for the patient to come in to clinic in a week’s time for a review, but they may not have transport or someone to look after their children so that they can come in. You may diagnose that there is nothing medically wrong with the patient, but they may still be worried that they have a serious condition that killed their father.

In medicine, you do not treat the disease; you treat the patient. It is easy to get so focussed on the clinical picture that the overall context is lost. This leads to incomplete care, which causes a variety of issues ranging from patient dissatisfaction to recurrent presentations.

Although it may seem difficult and time-consuming to pay attention to these extra details, it almost always pays off in one way or another. Addressing a patient’s troubled social situation may reduce the number of times they present to hospital, saving significant costs. The doctor taking the time to reassure the patient that their symptom is not concerning for a significant illness may let the patient sleep comfortably at night. Talking through the patient or their family’s concerns and questions might make the worst day of their lives slightly more tolerable.

This approach is useful outside of the hospital too. When you face a problem, regardless of the type, instead of trying to come up with a quick fix to patch it up, try to consider the context of the problem. You may discover that there is a deeper, more fundamental cause of the problem that needs fixing.

Posted in Science & Nature

Brace Position

Posted on by Jinavie

A word you never want to hear during a flight is “brace, brace”. It is used as an instruction from the flight crew to the passengers that there is an impending crash landing and everyone should assume the brace position. It is covered in the safety instructions at the start of every flight.

The brace position varies for each country and airline, but the general principle is to bend forward, putting your head either on your lap or against the headrest of the seat in front of you, having your feet flat on the ground and covering your head with both of your hands.

The purpose of the brace position is to maximise your chance of survival in the event of a crash landing. A typical passenger jet travels at around 900km/h. When a plane crashes, extreme amounts of force are exerted on the plane chassis and its contents. The following is a non-exhaustive list of potential sources of injury for a passenger:

  • Inertia and two-point seat belt (only across the waist) results in “jack-knifing”, where the body folds over at high speeds. This can cause catastrophic injury to abdominal organs and the spine.
  • Head and neck injury against the seat in front, resulting in anywhere between a concussion to bleeding in or around the brain. Even if the head injury is survivable, being knocked out or confused after a concussion reduces your chances of escaping the crashed plane before collapse, fires or explosions.
  • Whiplash injury of the neck.
  • Limb injury from flailing.
  • Injury from falling debris.

The brace position has been optimised over the last 20-30 years to reduce the risk of all of the above types of injuries, with multiple studies confirming that it is effective in reducing crash mortality.

Another positive news is that the risk of dying from a plane crash is extremely low. Your risk of dying on a flight is 1 in 60 million – far, far lower than the risk of dying from a car accident, being hit by a bus, a brain aneurysm or even being hit by lightning. Thanks to rigorous research, improved design and numerous safety features such as brace position, you have a 95% survival chance in an airplane crash, and even in serious crashes, the survival chance is 76%. 

Of course, the minute percentage of plane crashes that result in fatalities tend to be non-survivable in the first place, but we cannot postpone death forever.

Posted in Psychology & Medicine

Analgesic Ladder

Posted on by Jinavie

Quite possibly the most common condition that a physician needs to treat is pain. Being the main way for the body to communicate that there is something wrong, pain can take various forms to make us suffer physically. The best way to make this pain go away is to treat the underlying cause, but often the cause is unclear and we need to manage the symptoms first.

Just as there are many kinds of pain, there are numerous different types of analgesics, or painkillers. Doctors and nurses take into account various factors to decide which analgesia to use, how much to give and how often to give it. For example, opioids (e.g. morphine) are one of the most effective pain-reliefs, but it comes with many adverse effects such as vomiting, constipation, drowsiness, slowing of breathing and potentially death. To facilitate this, the World Health Organisation created the concept of the “Analgesic Ladder”, establishing some simple rules to guide appropriate analgesia administration.

The ladder has been adapted to accommodate for new research and advancing pain-relief methods, but the general principle remains the same.

First, simple non-opioid medications should be given orally and regularly. Almost always, the first-line analgesia is paracetamol (acetaminophen in USA). It is an effective pain-relief, especially when it is taken regularly four times a day, while being extremely safe as long as it is not taken above the maximum dosage (4 grams/day). As effective as it is, people often neglect to take it regularly as directed, or take it too late when the pain has progressed to a severe level, hence the common misunderstanding that it is weak.

The next step of non-opioid medications are non-steroidal anti-inflammatories (NSAIDs), such as ibuprofen or diclofenac. These medications work particularly well for musculoskeletal pain, muscle aches from viral illnesses and simple headaches. However, they are prone to causing stomach upsets, ulcers and kidney dysfunction. They can also exacerbate asthma in some patients. It should be taken in conjunction with paracetamol as they have a synergistic effect. Because of its gastrointestinal side effects, it is recommended to be taken after meals.

When paracetamol and NSAIDs are ineffective at easing the pain, a weak, oral opioid such as codeine or tramadol is added in. These medications are powerful, but often have undesirable side effects such as nausea and vomiting, constipation, confusion and agitation.

As we step up the ladder, we introduce stronger opioids. This includes oral options such as sevredol and oxycodone, to intravenous options such as IV morphine and fentanyl. As effective as these medicines are, they must be used with caution given the significant adverse effects such as opioid narcosis, where a patient can stop breathing or enter a coma.

Other than opioids, there are various other options of pain relief that may be explored as adjuncts. Neuropathic pain from nerve damage is notorious for being opioid-resistant, so medications such as gabapentin or tricyclic acids (traditionally an antidepressant) may be used. Ketamine is sometimes used as it has analgesic properties. A PCA (patient-controlled analgesia) pump with morphine or fentanyl may be more effective to optimise the timing of doses. Long-acting opioids such as methadone may be considered. Lastly, nerve blocks with local anaesthesia, such as epidurals, are often used in conjunction to reduce the need for opioids.

Pain is an extremely useful evolutionary tool as it allows as us to avoid harm, but it can create just as many problems. The analgesic ladder helps health professionals better manage pain so that patients do not have to suffer as much while they are being investigated and treated.

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Posted in Psychology & Medicine

Voodoo Death

Posted on by Jinavie

We inherently fear death. Much of what we do biologically is struggling against death. We eat and drink to sustain ourselves. We feel pain to avoid things that may eventually kill us. Even moments before our death, our brain will flash our life before our eyes to grasp at any past experiences that may help us survive.

Because of this, we are also inherently neurotic. Some fear flying in a plane because they can imagine the plane crashing and burning, even knowing that flying is safer than a car ride. Childhood traumas where we thought we might die cause long-lasting damage to how we behave and think as an adult.

The most interesting example of how the fear of death can affect us is the phenomenon of voodoo death.

American physiologist Walter Cannon published a paper in 1942 studying cases of “voodoo death” – where healthy people (usually from tribal societies) suddenly passed away after being cursed. Voodoo death starts when a person is cursed or condemned to die by a medical person, such as a witch doctor or shaman. The victim and those around them must believe that the curse will actuall kill them (due to the culture or tradition). The victim’s family may even prepare a funeral. The victim loses all hope that they can survive the curse. They then die, even though their body shows no signs of physical ailment.

For example, the Australian Aborigines are known to have practised “boning”, where a witch doctor would point a vexed bone at an enemy, causing the victim to immediately convulse and die. A Nairobi woman passed away within 24 hours of finding out that the fruit she ate was sacred and she committed a great sin. A Maori man, who was told he should never eat wild game meat, died a day after finding out that he had accidentally eaten wild game meat – even though he had eaten it 2 years ago.

Voodoo death is not only limited to pre-modern societies. In the 1990’s, there was a documented case where a patient was diagnosed with terminal metastatic oesophageal cancer. After saying his goodbyes to his family as were his last wishes, he swiftly passed away. On autopsy, they discovered that the cancer had not actually spread that much and was not the cause of death.

There are many theories as to what may cause voodoo death. The traditional thought was that intense fear and stress stimulates the release of catecholamines such as adrenaline, inducing a massive fight-or-flight response, as seen in broken heart syndrome. The surge of adrenaline causes the heart to beat too fast and too strongly, until it gives out and causes cardiac arrest.

However, more recent studies showed that animals that die from stress exhibit signs of the opposite happening – that is, the parasympathetic nervous system (responsible for the common type of fainting spells called vasovagal syncope) is overactive. Because the parasympathetic nervous system has the opposite effect to the sympathetic (fight-or-flight), it can cause the heart to slow to the point of stopping.

This parasympathetic overactivity may be triggered by a sense of absolute hopelessness, essentially causing the body to “give up” on life. On a related note, the hopeless victim will likely not be eating or drinking much while under extreme emotional duress, so dehydration and catatonia may play a role as well.

Voodoo death is an excellent example of how much power the mind has over the body. Ironically, the fear of death itself can cause death.

Posted in Psychology & Medicine

Heartbeat Hypothesis

Posted on by Jinavie

When you compare the lifespans of mammals, it is common to see that larger animals live longer than smaller animals. Another observation is that smaller mammals almost always have a much higher basal heart rate. For example, a mouse has a basal heart rate of about 600 beats per minute (bpm), but only lives 3 years on average. An elephant has a basal heart rate of 30bpm, but lives up to 60 years. If you do the maths, it turns out that the total heartbeats per lifespan is surprisingly similar between the two species (0.94 billion beats). It has been noted that amongst mammals, there is a clear inverse correlation between heart rate and lifespan.

This observation led to the popularisation of a factoid that the heart can only beat a limited number of time before it eventually fails.

Unfortunately, there has been very limited evidence to support this theory. It is medically true that a heart under more strain for a long period of time, such as with high blood pressure, has a tendency to develop more diseases such as cardiomyopathy and heart failure. However, there are too many other variables to consider. For example, exercise temporarily raises your heart rate but improves your overall cardiovascular health and lowers your basal heart rate.

It is much more likely that death from aging is related to the basal metabolic rate. Metabolism produces free radicals, which are elements with free electrons that can damage cells. Therefore, the higher the metabolic rate (such as in mice), the faster the damage accumulates and results in death.

That being said, consider the other implication of the so-called heartbeat hypothesis. Our hearts beat faster in response to many stimuli: exercise, excitement, fear, anxiety, fun and love. If the hypothesis is true, that would mean that intense emotions could make our hearts tire out faster and hasten our inevitable demise.

Could falling in love be detrimental to our physical health? Thankfully, this has never been shown to be true, with many studies showing that happily married couples tend to outlive single people.

Even if it were true, would you give up on the idea of love to live a few more years? What kind of life would be worth living without any highs or lows? Perhaps when we fall in love, experience heartache or become overwhelmed with happiness, we are making the voluntary choice of quality, not quantity, of life.

Posted in History & Literature

Night Vision

Posted on by Jinavie

During World War II, the British Royal Air Force boasted an impressive accuracy in intercepting Nazi German bombers despite the cover of darkness at night. The British air ministry reported that their fighter pilots ate a large amount of carrots to boost their night vision. Since then, it has become public knowledge that carrots help you see better in the dark.

Unfortunately, this is false. The British air force were not actually using carrots to help see better in the dark; they were using a revolutionary new technology called radar to spot enemy war planes from a far distance. The carrot propaganda was spread to hide this fact from the Germans.

The carrot myth sounds plausible as carrots contain a large amount of beta-carotene, which is converted into vitamin A in the body. Vitamin A is a key chemical required for vision, in the form of retinal. It is true that vitamin A deficiency can cause night blindness. However, the dose of vitamin A required to improve your night vision is so high that it cannot be achieved by simply eating a lot of carrots.

Posted in Psychology & Medicine

Fried Rice Syndrome

Posted on by Jinavie

Food poisoning is most often caused by the bacteria Staphylococcus, which produces a toxin that stays on food even when it is properly prepared. The body senses the toxin and promptly tries to rid itself of the toxins, resulting in heavy vomiting 1-2 hours after eating the spoiled food.

Many different germs can cause food poisoning, among which one of the most interesting is Bacillus cereus. B. cereus is found on many different foods, but it is commonly associated with a type of food poisoning called fried rice syndrome. It creates spores that can survive if food is not improperly cooked (as in not hot enough or cooked for long enough), as the temperatures are not high enough.

Unlike infections such as gastroenteritis where the bacteria are killed by heat during cooking, spores are quite resistant to short periods of reheating, such as microwaving. This means that if the spores were not killed when the rice was first cooked, it stays around even after refrigeration and reheating. The bacteria grow from the spore and start producing a toxin called cereulide. One to five hours later, the person who eats this tainted rice develops severe vomiting and nausea.

Fortunately, like most food poisonings, fried rice syndrome is easily treated with supportive management. The body does most of the work by decontaminating itself through vomiting. The important part is staying hydrated by keeping up with fluid loss. Most food poisoning cases resolve on their own within 24 (miserable) hours.

Posted in Psychology & Medicine

Synaesthesia

Posted on by Jinavie

What colour do you associate with the letter “E”? What sound do you hear when you feel the fluffiness of cotton? These sound strange to most people as we experience the senses in distinct ways. However, for 4% of the population, this is a completely normal experience.

Synaesthesia (“joined sensation”) is the neurological phenomenon where two or more senses are coupled together. This creates two kinds of synaesthesia: projection, where you physically sense something (such as seeing a purple circle when hearing piano music), and association, where you associate the sense with another sense (“that sounds quite orange”).

The most common form of synaesthesia that is reported is grapheme-colour synaesthesia, where certain people perceive letters and numbers as different colours. However, there are various kinds of synaesthesia, such as chromesthesia, where people associate sounds with colours (previously called “coloured hearing”). In fact, almost every combination of senses have been described, with some individuals experiencing multiple senses at the same time.

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The exact origin and mechanism of synaesthesia are yet to be fully explained. The most likely explanation is that in the brain of synaesthetes, the neural pathways for the various senses cross-over more than they should, causing the simultaneous activation. There are already some cross-overs between these pathways, as evidenced by various sensory illusions that the average person can enjoy. For example, a ventriloquist can fool the audience into thinking the puppet is talking as we hear speech and see the puppet’s mouth moving.

An alternative explanation is that there may be an element of ideasthesia – where concepts are paired with sensory experience. This would mean that synaesthetes are experiencing sensations due to the idea something represents, not because of the original sensory stimulus.

For example, when a synaesthete describes that the word “tree” tastes like brie cheese, it might not be the sound of the word, but rather the concept of a tree that triggers the sensation. We actually see examples of this in day to day life in the form of metaphors. We describe a wine having a round taste or a person being sweet.

There is much to learn about the phenomenon, but synaesthesia has already deepened our understanding of how we perceive the world, process it and commit it to memory through the use of associations and mnemonics.

Posted in History & Literature

Factoid

Posted on by Jinavie

Factoids are commonly known as trivial tidbits of knowledge and fact. This is actually incorrect. Factoids actually mean pieces of false information that have circulated and become popular to the point that they are accepted as facts. This makes factoids ironic in the sense that the definition of a factoid itself, is a factoid.

Here are several examples of common factoids.

“Vikings wore horns on their helmets”. 

There is no evidence of this ever happening and all Viking helmets found in archaeology are hornless. It is likely a myth originating from dramatisation of the Vikings in opera.

“Medieval people thought the Earth was flat”.

It has been common knowledge that the Earth is spherical even since ancient Greek times. Greek astronomer Eratosthenes even calculated the Earth’s circumference to within 5-15% error margin of the actual circumference in 240BC.

“Napoleon Bonaparte was short”.

Napoleon’s height was recorded as 5 feet 2 inches, but this is in fact French feet. This converts to 5 feet 7 inches, which is taller than the average height for French males at the time.

“The low life expectancy in the Middle Ages meant people usually died around their 30’s”. 

The low life expectancy of the past was mostly due to the high infant mortality, meaning people who survived into adulthood lived much longer, fuller lives.

“You need to drink eight glasses of water to stay healthy”. 

There is no agreed upon amount of water a person should drink in medical literature. The current consensus is that drinking water when you feel thirsty is fully sufficient to avoid dehydration.

“Carrots help you see in the dark”.

Vitamin A is indeed used by the body to synthesise chemicals used in vision, but having more does not improve your vision. This was a myth propagated by Great Britain during World War 2 to mask the fact that they were using radar for accurate nighttime bombings.

“Evolution is a theory, meaning there is insufficient evidence to confirm it”. 

This is a complete misunderstanding shared by many people against evolution. The word “theory” in science means a concept or set of principles that best explains an observed phenomena, not a hunch as it is often used in common English. For example, gravity is a theory, as well as germ theory (that microorganisms cause infectious diseases).

“Chameleons can change the colour of their skin to match their surroundings”.

Chameleon’s skin colours change based on their mood, not the colour of their surroundings. Cuttlefish, on the other hand, can perfectly mimic and blend in to their surrounding environment.

“Adding oil when boiling pasta stops sticking”.

The oil floats to the top and does nothing to prevent sticking. Adding oil after draining the water will help.

“Searing meat seals in the juices”.

Searing can actually make meat drier on average. It does, however, add more flavour by adding a brown crust due to the Maillard reaction.

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