In the New Testament of the Bible, there is a scene where Jesus resurrects a man by the name of Lazarus back four days after his death. This “miracle” is of course a fictitious event, but nonetheless, the name Lazarus has come to symbolise resurrection after death. For example, there are two actual medical conditions named after Lazarus, both related to death.
The first is called Lazarus phenomenon, where a person who is declared to be clinically dead spontaneously returns to life. This is an extremely rare event that has only been recorded in about 30 cases. In most of these cases, the patients had suffered a cardiac arrest, with all attempts at resuscitation (e.g. CPR, adrenaline) had failed. Sometime after the person was declared clinically dead (usually around 5~10 minutes), the person’s circulatory system would suddenly start on its own and the person would be “resurrected” (quite literally). In one case, a 61 year-old woman was declared officially dead after her heart stopped and her vitals did not return after continuous resuscitation. At the morgue, however, she was found to have a pulse and breathing on her own. She later sued the hospital for the neurological and physical injury caused by oxygen deprivation during her death. There is even a case report of a patient who returned to life two and a half hours after dying (although he died again 3 weeks later).
Of course, the Lazarus phenomenon is not a miracle. In most cases, it is hypothesised that when resuscitation is attempted then stopped, there is a rare chance of the relieving of pressure causing blood to fill the heart, causing a sudden expansion and kickstarting the electrical circuit. Other factors that may influence this is hyperkalaemia resulting from ischaemia and high doses of adrenaline given to the patient during resuscitation having a delayed effect.
Because of this rare “complication” of death, doctors are advised to observe the patient for about 10 minutes after declaring them dead. Just in case.
The second is called Lazarus sign and it occurs not in dead patients, but brain-dead patients. Brain-dead patients are immobile as their higher functions such as cognition and motor functions are destroyed. However, there are rare cases where the brainstem is somehow stimulated, triggering a reflex arc from the spinal cord. This reflex is seen as the patient suddenly raising their arms and dropping them on their chest in a crossed position, much like Egyptian mummies. As the spinal cord is not usually damaged in brain-dead patients, this reflex arc is possible, similar to a knee jerk reflex. The Lazarus sign should not be misinterpreted as a sign that a brain-dead patient is conscious, as it is an involuntary movement. However, it has been mistaken for the resuscitation of a patient, or in some cases, as a miracle.
A person’s body temperature is always maintained between 36.5~37.5°C. This is because enzymes, which are crucial in all physiological reactions in the body, work most efficiently at this temperature. As physiology is essentially a series of chemical reactions, it is heavily dependent on temperature. If the temperature falls, chemical reactions occur slower and vice versa. When body temperature falls below 35°C, metabolism becomes too slow and it poses a risk to the person’s health. This is known as hypothermia.
How does hypothermia affect the body? Hypothermia is categorised into three classes depending on the severity.
- Mild hypothermia (32~35°C) leads to the slowing of bodily functions, tremors and difficulty in walking. The patient’s speech is impeded and other neurological symptoms such as decreased judgement skills and confusion start to appear. Also, blood pressure, pulse and breathing rate rise.
- Moderate hypothermia (28~32°C) causes paralysis of muscles and extreme fatigue (they may complain of being sleepy). As blood (carrying heat) is rerouted to major organs, the skin (especially lips and extremities) become white or purple and very cold. Neurological symptoms worsen with amnesia, memory loss, severe confusion and delusion beginning to show. As sustained hypothermia leads to the tremors stopping, one should not take the lack of tremors as a good sign. Heart rate becomes irregular and arrhythmia may occur.
- Severe hypothermia (20~28°C) leads to chemical reactions becoming so slowed that physiological functions that support life decline dramatically. Heart rate, blood pressure and breathing all lower to dangerous levels and the heart and lungs may stop functioning. As the patient’s major organs begin to shut down, they enter a state of unconsciousness and eventually, clinical death.
As you can see, hypothermia is a highly dangerous situation that can kill. There are some other fascinating facts about hypothermia.
20~50% of hypothermia death cases are associated with paradoxical undressing. This is a strange phenomenon where the person begins to take off their clothes due to confusion and a lack of judgement from the hypothermia. One theory suggests it is related to the cold damaging the hypothalamus (which controls body temperature), causing the brain to think that the body temperature is rising. Whatever the reason, it is extremely dangerous as it worsens the hypothermia.
As explained above, severe hypothermia leads to death. But interestingly, hypothermia also protects organs. This is why organs for transplanting are transported in ice. Similarly, there are examples of people who “died” from hypothermia recovering with no brain damage. Because of this, medical professionals traditionally say: “they’re not dead until they’re warm and dead”. In fact, if there is something wrong with the patient’s circulation and there is risk of damage to their organs (such as in surgery), sometimes the patient’s body temperature is forced down with ice water injections and cooling blankets, known as protective hypothermia.
Blood, which supplies all the cells in the human body with nutrients and oxygen, flows through the vessels due to the pumping of the heart. Thus, blood flow directly transmits the force generated by every heartbeat. As the blood ejected by the heart causes the arteries to “pulse” by stretching and relaxing. As some pulses can be felt over the skin, they are very useful in patient examinations, especially a clinical exam of the cardiovascular system. Although people commonly know how to take a pulse from the wrist or neck, there are many more places a pulse can be taken from.
- Radial pulse: Taken from the inside of the wrist on the side of the thumb.
- Brachial pulse: Taken from the inside of the elbow.
- Carotid pulse: Taken from where the neck meets the jawline, or 2~3cm either side of the Adam’s apple to be precise.
- Apex beat: This measures the heartbeats directly, taken on the left chest between the 4th and 6th ribs (around the left nipple).
- Abdominal pulse: Taken from above the belly button of a lying patient, may be able to see the pulse.
- Femoral pulse: Taken from the middle of the groin.
- Popliteal pulse: Taken from the inside of the knee.
- Posterior tibial pulse: Taken from the inside of the ankle behind the bone.
- Dorsalis pedis pulse: Taken from the back (upper side) of the foot along the middle.
When taking a pulse, you use your second and third fingers (and the fourth if you want) and press lightly on the pulse point. If you press too hard, you may stop the blood flow and obliterate the pulse. As a pulse is measured per-minute, it is often taken for 10 or 15 seconds and multiplied by 6 or 4 respectively. Also, it should be noted whether the pulse has a regular rhythm, and if it is irregular, whether it is regularly irregular or irregularly irregular. If the pulse is over 100 beats per minute, it is called tachycardia, while less than 60 beats per minute is referred to as bradycardia. If it is irregular, it is called an arrhythmia.
An experienced doctor can diagnose different conditions such as an aortic stenosis or atrial fibrillation just from taking the pulse of the patient. Taking a pulse is also a crucial diagnostic tool in traditional Korean and Chinese medicine.