Tag: disease

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 Science & Nature

Vision

Posted on by Jinavie

Consider this: if you see something that is not there, or not see something correctly, is that due to a problem in your eyes or your brain? An interesting anatomical fact is that the eyes are part of the brain. They originally evolved from the brain and drifted further and further forwards, connected to the brain by the optic nerves. If you lift a brain out from the skull, the eyes would be pulled backwards too. But technically speaking, eyes are distinct organs by themselves that have merely originated from a portion of the brain. It does not think or make decisions by itself. Just like a camera, an eye records things as it sees it and transmits it to the brain via the optic nerve via electrical signals. The brain then processes the signals in the occipital lobe, located at the back of the head (this is why you “see stars” when you bang the back of your head).

This means that vision can be altered anywhere along the pathway. If you have cataracts, where the lens of the eye becomes clouded, you lose portions of your visual field. If you have a large pituitary gland tumour, it presses on the optic nerve and causes double vision (diplopia) or vision loss. If you have a stroke in the occipital lobe, you can lose your vision. The brain’s role in producing vision can easily be demonstrated in the form of optical illusions. The eye merely records and transmits what it sees, but the brain becomes confused by what information it receives and tries to make sense of it. In the process, we experience bizarre illusions such as static images moving by themselves.

Because of this intricate pathway, some pathologies present with fascinating symptoms. A condition called Anton’s blindness (or Anton-Babinski syndrome) causes a patient to “see” despite being blind. Patients with Anton’s blindness are adamant that they can see perfectly clearly, and will even describe what they are seeing. However, what they “see” is completely different to what the object actually looks like. For example, if the patient looked at a blonde woman wearing a yellow blouse and a red skirt, they may describe her as a brunette woman wearing a blue shirt and black jeans.

The reason for their blindness is that their occipital lobe was damaged (usually by a stroke), leading to an inability to process the information from the eyes. Although the eyes are pristine and record what they see in perfect detail, the brain is incapable of interpreting the signals. The brain then goes on to confabulate, where the brain fills the gap by conjuring up false information. This makes Anton’s blindness quite hard to pick up on as the patient will not complain of it. It is only found when someone pays close attention to the patient and notices subtle cues like the patient bumping into furniture or talking in the direction where they think a person is at (even after they move). Ergo, the patient adamantly believes that they can see as their brain thinks it is seeing things (even though it is not receiving the information from the eyes properly).

Seeing is not believing. You see what you believe.

Posted in Psychology & Medicine

Clubbing

Posted on by Jinavie

Among the thousands of signs and symptoms in the field of medicine, there is one that every doctor and medical student knows since the development of medicine. Clubbing is an easily noticeable sign in a patient’s fingers that can have wide implications on their health.

Clubbing is essentially when the angle (gap) between the fingernail bed and finger disappears. The formal definition is much more complicated, such as “the loss of the normal <165° angle, or Lovibond angle between the nailbed and the fold”, but for all intents and purposes the simple definition is sufficient.

To see if a patient has clubbing, the physician carefully studies the fingers against light. There are a few ways to check for clubbing but the most popular methods are holding the fingers out straight and holding them parallel to the ground, checking the angle between the nailbed and finger, or the Schamroth’s window test. The latter test is done by holding two opposing fingers (such as the left and right index fingers) against each other nail to nail. The fingers are then held against the light so that the light can shine through the “window” that is made. If the window is not seen, the test is positive and the patient has clubbing.

What does clubbing suggest? Clubbing was first noticed by Hippocrates, the father of Western medicine, who observed that people with clubbing tended to grab their chest and fall dead. This is one of the most common associations to clubbing – a congenital cyanotic heart defect such as tetralogy of Fallot or patent ductus arteriosus. Other common associations are related to the lungs, such as lung cancer (one of the most common causes) and various other lung diseases such as interstitial lung disease, tuberculosis and other chronic infections. There are also a myriad of other diseases associated to clubbing, including but not limited to: Crohn’s disease, ulcerative colitis, cirrhosis, celiac disease, Graves disease and certain types of cancers (lung, gastrointestinal and Hodgkin’s lymphoma mainly). Clubbing can also be idiopathic, where there is no apparent cause for the clubbing and the person just has it (possibly just born with it).

Despite knowing about clubbing for over 2000 years, we still do not know the exact reasons for clubbing. There are theories that it is related to a fall in blood oxygen content leading to vasodilation in the peripheries. As the pathophysiology is not clear and so many diseases are associated with it, when clubbing is found in the patient the physician should investigate the related organ systems (heart, lungs, GI mainly) to narrow down the possible cause of it. As many of the causes (such as lung cancer) carry a rather morbid prognosis, it is quite important to notice whether the patient has clubbing when doing a physical examination.

Posted in Psychology & Medicine

Symptom Reporting

Posted on by Jinavie

Some people always complain of symptoms, claiming that they are sick, while some people never seem to complain even if they have a whole list of symptoms. Why is there a difference in symptom reporting between people? For example, women are more likely to recognise symptoms and report them compared to men. This is because men are generally under the social pressure of needing to appear strong and healthy, so they become stoic and less sensitive to pain and disease. Women are usually more sensitive to internal bodily changes and worry more about their health.

According to a psychological theory called the competition for cues hypothesis, there are two signals that compete for attention when we recognise symptoms. The first is bodily changes, i.e. internal cues, while the other is external stimuli from what happens around us. Awareness of symptoms follows a ratio between these two signals: if there is a strong internal cue such as severe pain, we notice symptoms more quickly, while if there are many distractions, we may not notice the symptom. For example, according to a study people can run faster when listening to music and running through a forest with plenty to see. This is because music and the scenery distract the runner from internal cues. As we can only process a certain amount of information at a given moment, the more distractions there are the less sensitive we become to signals from inside our body.

Another factor that affects symptom reporting is illness labelling. The more information we have about a disease, the more we search for those symptoms. For example, if you yawn or scratch yourself, people around you will do the same. This is because they see you yawning and subconsciously believe that they should yawn too. This can be a powerful effect, as seen in mass hysteria. This strange phenomenon occurs when a person observes a sick person and their brain believes they are sick too, beginning to show symptoms despite being healthy. A similar example is seen in medical student disease, where medical students, with their extensive knowledge of diseases, match their own symptoms to symptom lists of rare diseases. For example, they might think that their high blood pressure is due to a phaeochromocytoma or renal artery stenosis, rather than just hypertension.

However, the opposite can occur where people fail to notice important symptoms and suffer serious consequences as a result. For instance, not all cases of heart attacks (myocardial infarction) cause unconsciousness and a patient may believe they are fine when only chest pain occurs. Failure to get treated as soon as possible at a hospital may result in ventricular fibrillation, leading to sudden death.

Posted in Psychology & Medicine

Sudden Death

Posted on by Jinavie

Unlike diseases such as tuberculosis or cancer, some disease processes are known to kill a human being within an hour of onset. Other than the obvious causes such as decapitation, massive bleeding or any other trauma-related injuries, these diseases tend to be cardiac or respiratory in origin.

A common example is coronary artery disease, where the blood vessel providing blood to an area of the heart becomes completely blocked by stenosis (narrowing, often by atherosclerosis) or a clot. This results in immediate ischaemia (lack of oxygen) to heart muscles, which causes cell death. This produces scar tissue which disrupts the electrical activity of the heart, which may lead to a condition called ventricular fibrillation where the heart beats in an uncontrolled, erratic manner. When in VF, the heart effectively becomes useless as it cannot coordinate proper pumping function. Blood circulation stops and the patient goes in to multiple organ failure (the brain goes first) within a very short time. Although it can kill within a short time, early identification and treatment may be able to prevent VF from occurring and save the patient’s life. If VF does occur, it is crucial to begin CPR or use a defibrillator if available.

VF can also occur in other situations. For example, there is a genetic condition called long QT syndrome which predisposes the patient to spontaneous arrhythmias (electrical abnormalities in the heart). Even becoming too excited can sometimes set off a VF in some LQTS patients, thus they require an implantable cardioverter-defibrillator (ICD) to shock their heart back in to normal rhythm every time they develop an arrhythmia.

Some other causes of sudden death include: aortic dissection (tearing of the aorta that may cause massive internal bleeding), pulmonary embolism (a clot obstructs blood flow in the lung, stopping circulation), commotio cordis (a blow to the heart at a certain moment in the heart rhythm triggers VF), ruptured brain aneurysm (ballooning of an artery in the brain), anaphylaxis (severe allergic reaction that cuts off airflow to the lungs) and poisoning (various mechanisms, mainly related to disrupting cellular function).

Death can strike swiftly, even from within your body.

Posted in Psychology & Medicine

Stroke

Posted on by Jinavie

A stroke is caused by a disruption in the supply of blood to the brain, which leads to cell death as oxygen is required. There are two types: ischaemic (where a clot cuts off blood supply to an area of the brain by blocking an artery) or haemorrhagic (when a blood vessel ruptures and leaks blood instead of delivering it to tissue). The most common cause of a stroke is a clot that made its way up to carotid arteries into the brain until it wedges in small vessel. There are many risk factors for blood clots, such as smoking, high cholesterol levels, atrial fibrillation and long distance flights.

Because the brain is always in high demand of oxygen (taking 20% of the total oxygen available), strokes can produce devastating effects within minutes. 5 minutes of oxygen deprivation can lead to irreversible cell death, a principle that is also used in cases of shock, where the blood pressure is too low to supply organs, or cardiac arrest. Therefore, it is crucial to recognise a stroke early so that an ambulance may arrive and deliver clot-busting medication such as streptokinase.

The FAST mnemonic is an effective way of remembering the common signs of a stroke. It is also useful in reminding people to respond fast.

  • F – Facial weakness: Is the person’s smile crooked? Disrupted brain function causes facial weakness on the opposite side. The weakness is usually seen around the mouth or eyes.
  • A – Arm weakness: Can the person keep both arms outstretched? This is related to motor function of the brain.
  • S – Speech difficulty: Is the person’s speech slurring or are they having problems understanding speech? This is a combined result of impaired motor function and speech centres of the brain.
  • T – Time to act: Call an ambulance. NOW.

Posted in Psychology & Medicine

Tetanus

Posted on by Jinavie

Tetanus is an infectious disease caused by a soil-borne bacteria called Clostridium tetani. Patients are often infected soil entering the blood through deep wounds, such as a cut. The bacteria produces a toxin called tetanospasmin which leads to the characteristic symptoms of tetanus involving muscle.

The term tetanus actually refers to a state where skeletal muscle remains contracted and cannot relax due to maximum signalling from the nervous system. Tetanus is associated with some distinct symptoms involving tetanised muscles.

Tetanus starts in the face in the form of lockjaw (jaw clamps shut and cannot be opened) and sardonic risus sardonicus. Risus sardonicus, also known as sardonic grin, is a contorted, malicious-looking smile that is caused by spasms of muscles in the face. A good portrayal of the grin is seen in the Joker’s face from the Batman comic book series.
The disease then progresses to cause stiff neck, spasming of chest and leg muscles and difficulty swallowing. 

A dramatic symptom is opisthotonos, where the patient experiences extremely painful contractions of back muscles causing them to arch their back against their will. Along with lockjaw and risus sardonicus, it is a characteristic sign of tetanus and has been known for centuries. Before it was attributed to tetanus, people used to think the person was possessed by a demon due to the agonised screams and involuntary spasming of the body.

The disease is especially devastating in infants and can be spread to the fetus within the womb. This is because babies do not have a developed passive immune system that can combat the infection. Neonatal tetanus carries a mortality rate of over 90% and is responsible for 15% of all neonatal deaths.

Tetanus is a preventable disease through immunisation. Immunisation is done by injecting an inactive form of the toxin (i.e. cannot cause disease), inducing a reaction by the immune system. This essentially “teaches” the immune system to defend the body against tetanus. By completing a course of three doses and receiving occasional booster shots throughout life, tetanus can be prevented. Pregnant women must be immunised against tetanus to prevent neonatal tetanus (the babies receive scheduled immunisations soon after birth too).

This is one example of how immunisation can effectively prevent fatal diseases in a population.

Posted in Psychology & Medicine

Kuru

Posted on by Jinavie

European explorers who visited the island of Papua New Guinea in the 1950’s noticed that the Fore tribe suffered from a strange disease. The patient would initially have headaches, joint pains and tremors. They then show signs of weakness and are unable to stand.  The shaking of limbs, a classic symptom of the disease, becomes progressively worse as the disease progresses (“kuru” is a Fore word for “to shake”). In the late stages, the patient shows other neurological symptoms such as uncontrollable laughter and emotional instability. By this point, their tremors and ataxia (lack of coordination) is so severe that they cannot sit without support. They may also suffer from inability to speak or swallow, become unresponsive to their surroundings, develop ulcers on the skin and become incontinent (cannot hold urine/faeces). Within 3 months to 2 years after the symptoms develop, the patient dies.

Kuru is exclusive to the Fore tribe and medical researchers were puzzled by the nature of this disease. It is incurable and takes more than 10 years to develop (from the time of infection). In 1961, Dr Michael Alpers discovered that kuru was spread due to a certain cultural behaviour within the tribe – cannibalism. The Fore tribe had a tradition of eating the corpse of a deceased tribe member at the funeral as to return their life force back in to the tribe. Of course, this involved the consumption of the brain as well.

It was discovered that kuru is caused by a strange pathogen known as a prion. Prions are misfolded pieces of proteins that cause disease by converting the body’s proteins into “wrong” proteins. These new prions then convert more proteins until the body is filled with deposits of such proteins. Prions mainly affect the brain and cause spongiform encephalopathy – meaning that the brain becomes sponge-like and full of holes. The most famous example of prion disease is mad cow disease.

After colonists took over Papua New Guinea, cannibalism was banned and kuru faded away. This was proof that cannibalism was what spread the prion from one victim to another. It was also discovered that women and children had a higher incidence as men would have priority in choosing what part of the body to eat first. As with lions, the men always chose muscles first and women and children would often finish the organs such as the brain. As prions are indestructible, it cannot be treated, cured or prevented (other than not eating brains). It also means that it transmits perfectly from a dead patient to an unsuspecting victim who is feasting on the infected brain.

A disease that causes the brain to disintegrate, causing limb shaking and inability to walk, spread by the ingestion of brains. Is it possible that zombies are caused by eating brains and not the other way around?

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Posted in Psychology & Medicine

Munchausen’s Syndrome

Posted on by Jinavie

Some people are known to overreact regarding their health, such as a hypochondriac thinking that she has kidney failure because her urine looks slightly frothier. However, some people far surpass the level of hypochondrias to the level of psychiatric disease.
Münchausen’s syndrome patients are known to exaggerate or create symptoms so that the doctor would pay attention to them. When the doctor investigates, treats and sympathises with the patient they gain satisfaction from all the attention they are receiving.
Although this may sound like hypochondrias, Münchausen’s is far more serious.

A Münchausen’s patients are known to cause symptoms just to get attention from others. For example, a common manoeuvre used is the injection of insulin to induce a hypoglycaemic seizure. When their symptoms are “treated”, the patient will most likely invent another factitious disease to be treated for a longer time. They will also seek out many different doctors when the attending doctor catches on to their act. In fact, a Münchausen’s patient will do almost anything to prolong medical care, even accepting unnecessary and risky procedures such as surgeries.

The key difference between Münchausen’s syndrome and hypochondriasis is that the patient is aware that they are not actually sick (hypochondriacs actually believe they are sick). The fundamental basis for Münchausen’s syndrome is the desire for attention. Thus, the main risk factor for developing Münchausen’s is childhood experience of seeing someone close (typically a family member) suffering a debilitating disease. For example, if a girl sees her sister suffering from leukaemia and receiving all the attention of everyone around her, she may develop feelings of jealousy and later try to duplicate the scenario. As a patient, the person feels safe and comfortable and this feeds their addiction to medical care.

As Münchausen’s patients are very proficient liars and act completely like an actual patient, doctors must rule out any diseases before suspecting that their patients have a psychiatric problem. However, some signs such as the patient being overly keen on receiving procedures such as biopsies or continuously developing random symptoms may indicate Münchausen’s.

Interestingly, a similar condition called Münchausen’s syndrome by proxy also exists, where a caregiver (e.g. mother) convinces a doctor that the person they are caring for (e.g. child) are sick. Unfortunately, as these patients actually cause illness in the child, it is considered a form of child abuse. Common “symptoms” include: growth problems, asthma, allergies, vomiting, diarrhoea, seizures and infections. This may lead to the child developing Münchausen’s syndrome in the future.

Posted in Psychology & Medicine

Korsakoff’s Syndrome

Posted on by Jinavie

It is a well-known fact that excessive drinking leads to a so-called “blackout”. This form of memory loss is common in normal people and cannot be seen as a major illness. However, there is another disease that can be caused by excessive drinking called Korsakoff’s syndrome. Strictly speaking, this is not caused by alcohol but due to a thiamine (vitamin B1) deficiency and is commonly found in alcoholics and malnourished patients (it has also been reported to be caused by mercury poisoning and after centipede bites in Japan).

The six characteristic symptoms of this syndrome are: anterograde (cannot form new memories) and retrograde (cannot remember old memories) amnesia, confabulation, lack of detail in conversation, lack of insight and apathy.

Korsakoff’s syndrome patients show a very peculiar behaviour. As stated before they suffer from both anterograde and retrograde amnesia so not only can they not remember the past but they cannot make new memories either. Ergo, the brain uses information from its surroundings and attempts to recreate the lost memories, the result being confabulation. Confabulation is essentially what happens when the brain tries to fill in blanks in memories with false information. Confabulation is seen in everyday life too with healthy people but in the case of Korsakoff’s patients the effects are significantly more profound. For example, if you ask a patient what she did yesterday, she may look at your horse-print tie and claim she was horse-riding. If you ask the same question an hour later without your tie and instead holding a book with a photo of a Ferris wheel on the cover, she’ll state that she was at the amusement park. As one of the leading causes of amnesia and confabulation, Korsakoff’s should be suspected in any alcoholic or very underweight patient who keeps changing their stories around. 

As previously explained, the disease is caused by thiamine deficiency – therefore, the treatment is administering thiamine. But if the syndrome has persisted for a long time, the brain injury may be permanent. Also, treating the underlying alcoholism and malnutrition is important. 

If the thiamine deficiency is prolonged, it may lead to another disease called Wernicke’s encephalopathy. This is known as Wernicke-Korsakoff’s syndrome and in addition to the above symptoms, the patient may also experience confusion, tremors, nystagmus, paralysis of eye muscles, ataxia, coma and can eventually lead to death. All because of a deficiency of a single vitamin.

Who said nutrition is not important?

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(NB: Dory from Finding Nemo is one of the most accurate portrayals of amnesia in films)