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The Physics and Physiology of Falling
Lim Ju Boo
BSc, PG Dip Nutr, MSc, PhD (Med) MD (IU), FRSH, FRSMed, DSc
A Scientific Poser
I read a very interesting answer the other day coming from Captain Lim in his website when someone wrote to him enquiring what happens when a passenger is thrown out from a plane flying at 35,000 feet? I believe Captain Lim gave a very accurate answer to that question. The question was so interesting that I could not help thinking of the possible physics and physiology occurring to a human body falling from such a tremendous height. Allow me to fill in the details where Captain Lim left out.Before I start elaborating on the answer Captain Lim gave, let me straight away tell you I do not know the answer with absolute certainty. The reason is very simple. I have never seen a person falling off from an aircraft before, let alone has a study or a scientific experiment been done to study him as he falls to his death. Neither do I not know of any sane person who would conduct such a bizarre experiment either.
In the absence of any account documented in the literature, whatever discussed here is entirely, and personally my own. I conjure up a scientific hypothesis, based on other indirect existing observations, and established facts. Knowledge can only come from a study. All scientific experiments on humans are governed by professional ethics, and scientists do not go round murdering people just to gather some scientific facts. Hence I do not know of any experiment being done where a person is being pushed out of a plane at 35,000 feet just to observe what happens to him during the fall. I do not think they have done this even to an animal. The only other way to study such an effect is through controlled experiments using a parachute. But the psychological and physiological effects on a parachutist who knows he is undergoing an experiment, and who knows he is safe, and will land safely, is entirely different from one who accidentally fell off from a plane without a parachute. Furthermore, it is from a height more than three times higher than those attempts by a parachutist
The scenarios are totally, and entirely different. There is just no comparison. As I am not a parachutist, I do not know if there had been any one attempting to jump from a height of over 10 km, where the air is so thin, and where the temperature is a forbidden – 55 0 C. I do not think a parachute could open effectively at such great heights where the air is very thin. A parachute can only work when air rushes into it to unfold it. When the air is so rarified at that attitude, one can hardly breath. The parachutist will be knocked unconscious within 30 seconds before he could even open his parachute. So what I am attempting here is to construct a scenario using intelligent guesses based on existing knowledge, and observations in physics, medicine and physiology. Some indirect experiments may already been conducted by NASA scientists but some of the results are kept in very tight wrap, and the rest of the scientific world is kept in the dark.
The Scenario
Now, let us imagine a picture of a human passenger falling off a jet liner flying at 35,000 feet. That’s 10,668 metres or 10.67 km up in a hostile environment where the temperatures are down to the tune of – 55 0 C. The atmospheric pressure their registers only 8.89 inches of mercury, whereas the normal atmospheric pressure at sea level is 29.9 inch of mercury. What happens then? Thanks to Capt KH Lim who assures us that, that will never happen as the aircraft doors are shut tight by air pressures within the cabin, and it can never be opened unless the pressure is released by the Captain on landing. That’s assuring enough! But let us examine a hypothetical situation where the plane burst open due to an onboard explosion. Hopefully this will not be another Satanic act by another madman onboard. Let us assume the passengers are all thrown out. What happens?
Let us look at the haemodynamics first. This means its effects on the physics and dynamic of blood circulation. We assume the passengers were not killed or injured by the explosion, but were merely falling down, and begins to accelerate downwards. It will continue to accelerate until air resistance, and drag brake it to a maximum velocity. This is called the terminal velocity. Once the terminal velocity is reached, no matter how fast that speed is, it will have no effect on the haemodynamics. The danger lies not because of the maximum (terminal) velocity, but from the acceleration as the body plunges faster and faster towards the ground. As I said, I have not seen or studied the effects of a human body plunging downwards to earth before, let alone from such great height, so the scenario I construct here are only based on theoretical scientific principles on to expect.
Circulatory Dynamics :
First of all, I do not anticipate much changes to the haemodynamics since the acceleration is only 1 G (one unit of gravitation force). This is from the natural pull of the Earth’s gravity. During the fall, the casualty if conscious, will only experience the feeling of weightlessness and free floating, and this may not have a very profound effect on the circulatory system. This feeling of weightlessness will soon disappear the moment the terminal speed is reached, and there is no more acceleration. The victim will feel as if he was riding on a very fast roller coaster, or in a very fast car. But suppose now we imagine a situation where the passenger didn’t fall out of the plane, but was actually diving downwards together with the plane at a tremendous acceleration of let’s say 4-5 G (4-5 times greater than the pull of natural Earth’s gravity). This probably is achievable by a very fast plane accelerating downwards at a rate greater than the natural gravity of Earth.
What happen then? Ah ! that make a great difference. Suppose now he plunges downwards head first, and legs up. The acceleration that mimics tremendous gravitation pull downwards will act like a centrifugal force, similar to the water being spun outwards from wet clothes against the drum in a washing machine. This will cause all the blood to pool towards the legs, leaving no or little blood going to the head (brain). The casualty will immediately suffer a syncopal event (faints) or a ‘black out’ due to low cerebral perfusion of blood and oxygen. This gives rise to an event called transient cerebral ischaemia leading to a “black out”. The black out is similar to one caused by hypoxia (lack of oxygen), but not exactly the same as the cabin partial oxygen pressure is still maintained. But both are due to lack of sufficient oxygen perfusion into the brain, although the mechanism causing it is different.
Of course a number of other factors can also cause faints (syncope). It is not just from falling off a plane into a hostile environment where the oxygen tension is very low. In fact anything that causes the blood flow to the brain to be compromised, will result in a faint. For instance, if the vagus nerve (the 10th cranial nerve – the longest and the principal component of the parasympathetic division of the autonomic nervous system) is over-stimulated, it will cause the heart to slow down, thus reducing the blood flow to the brain. In medicine, we call this phenomenon “(vaso) vagal attack” brought about by factors such as fear, pain, stress, and shock as Captain Lim pointed out.
This event result in vaso- dilation, and a corresponding drop in blood pressure. This event temporary de-stabilizes blood pressure, affect circulatory dynamics, and the blood supply to the brain. I have quite a number of patients (predominantly females) who came to me complaining about their frequent ‘blackouts’ Most of these are young patients who are tall, and have low haemoglobin (Hb) levels, a feature among young menstruating women. Their frequent momentary faints were due to sudden change in their positions from lying down to standing up. That sudden change in the position, coupled with their low Hb which carries vital oxygen to the tissues, causes a sudden drop in blood pressure as the heart pumping ability (cardiac efficiency and output) is unable to cope with the sudden change in position against gravity.
This phenomena is called postural hypotension. This affects sufficient blood going to the brain. On a number of other occasions I have elderly patients with the same problem. But they were normotensive (normal blood pressures), meaning they were also not hypotensive (low blood pressure). On further investigations, I found they were diabetic, a disease that damages the nerves (neuropathy), which in turn controls blood pressure among other functions. Some of them with frequent faints were also taking antihypertensive, or vasodilator drugs, all of which may affect blood flow to the brain (cerebral insufficiency). Syncopes & Heart Disease
Other cases though I have not come across, were those with vertebrobasilar insufficiency or those with Stokes-Adams Syndrome. They affect cerebral perfusion because of cardiac arrhythmia (irregularities in the heartbeat), which in turn is caused by heart block (interruption to electrical impulses to the heart muscles to contract rhythmically). Heart block or auriculoventricular block, is a medical term to mean an interruption to the transmission of electrical impulses from the sinoatrial nodes (SA node or “pacemaker”) onwards to the atrioventricular (AV) nodes. Ultimately, the electrical impulses enters the muscles of ventricles to contact rhythmically (alternately) with the auricles via specialized conducting systems (AV bundle, or the Bundle of His) before distribution to a network of fibres in the ventricles. If there is any interruption to this electrical transmission it will cause the heart to beat irregularly (arrhythmia). The P-R interval in the ECG tracing is prolonged.
There are many types of ‘heart block - branch bundle block, etc, and the severity (degrees) of heart block, but we will not go into that. Heart block here does not mean that the coronary vessels were blocked by cholesterol e.g. atherosclerosis, although heart block may be an indirect result of “hardening” (sclerosis) of the Bundle of His caused by interference of blood supply to the heart. This affects subsequent electrical transmission through the network of ventricular fibres (Purkinje fibres) through the damaged myocardium (heart muscles). The Bundle of His is a sheath of insulating connective tissues, also called the atrioventricular bundle, which extends from the atrioventricular node from the atrium across the fibrous skeleton of the heart to the ventricles. It acts as the main transmission wire to conduct electrical impulse across the heart from the atrium to the ventricles. However, these are separate pathologies, and have no relationships to ‘faints’ caused by hypoxia in an environment where the oxygen tension is very low. We are not discussing a subject on medicine or physiology here, although it is good to know that there are many other factors that can cause a person to faint, and not just the fright of falling off a plane.
Captain Lim has correctly pointed out that a person can be unconscious from sudden (nervous / emotional ) shock of falling. But as I said earlier, the likelihood of a casualty fainting due to a mechanical cause (not emotional shock) such as blood being pulled away from the head (if he accelerates head first) is unlikely as the acceleration is only 1 G. This is just not great enough to destabilize haemodynamics or induce any profound physiological changes. In fact a person falling from a great height merely feels the sensation of weightlessness (I guess) during the initial stages of acceleration, but once the terminal velocity is reached, he probably feels he is riding on a fast vehicle. This is my guess, as I have not experienced it myself.
Acceleration & Shifting Parameters
In the event of a tremendous acceleration experienced by a falling (human) body such as a pilot in a plane nose diving down at a fantastic speeds with the victim inside, and if the position the body is such, that the legs go first and head last towards the direction of the dive. A lot of blood will start to pull towards the head causing tremendous cerebral congestion due to pooling of blood towards the brain This also results in lesser venous return from the brain. The result can be even more disastrous than a mere faint. The casualty instead, may run the very heavy risk of suffering a hemorrhage in the brain – a CVA (Cerebral Vascular Accident) or stroke. One of the vessels may burst open due to increased intracranial / intravascular pressures. In the actual situation of a body falling off a plane, it is very unlikely that he will black out (head downward first) due to this particular mechanical reason, or run a risk of a CVA event (legs downward first) as the acceleration is too small, and the time too short to elicit an effect. He would by then achieved a terminal velocity.
In fact with the air drag and air resistance, the acceleration due to earth’s gravity is even less than the standard 9.81 metres per second per second. The rate of acceleration is less at very high altitudes since the force of attraction between the body and the Earth’s gravitational pull falls off inversely as the square of their distance. As the body falls nearer and nearer towards Earth, the pull (force) becomes greater and greater , and thus the acceleration will no longer be constant at 9.81 m / sec /sec. Acceleration (a) is directly proportion to pull or force (F). . F = ma, where m (mass) is constant. In truth this is not so.
Remember air is always there. It will slow down all the acceleration until a terminal velocity is reached. The very slightly greater acceleration achieved nearer Earth will be cancelled out by the vastly increased in air drag due to higher air density at lower heights. In fact (I guess) the air resistance will be a much greater factor in slowing down the speed of fall than the mild increase in speed due to a change in acceleration as the body plunges down towards Earth. Capt Lim mentioned about terminal velocity of 130 mph (11440 feet / min = 190.67 feet / sec = 58.1 metres per second). The question I like to address now is, how far the drop would have to be before the body reaches this terminal velocity of 58.1 m / sec ? I made an assumption that this will be reached after the body has dropped 565 feet (172.2 metre) to terminal velocity I calculated this out from Newton’s equations on motion. But this is only true had the body fallen through a vacuum without any resistance. It is also correct if the acceleration had been constant. This is not true in practice. There is air up there, albeit thin to offer considerable resistance and drag. As the body falls, the air density gets higher and higher. The density of the air affects the drag. But density will also depend on the humidity and the temperature.
Hence the drag will depend on all these factors. To add to the difficulty of calculating acceleration, drag and final speed these parameters keep on changing at varying altitudes, in fact every second, and a fraction of a second. The denser air at lower heights may even have a mild braking effect on the terminal velocity, and the braking effect is even greater if the body drops into the sea where the density of salt water is even higher than fresh water. It is very hard to determine what these changes would be, as the parameters are continuously shifting. With variables changing all the time, it is almost impossible to apply standard equations to come with some final conclusion. It is of course possible to apply calculus to evaluate small increments over time, but how are we to know what the values would be to enable them to be substituted into the equations.
Then again, the drag will also depend on the shape and size of the falling body. If a passenger stretch out his legs and arms the drag will be greater against the air resistance. He will take a longer time, and also greater distance to fall before he arrives at the terminal velocity. But if the passenger /victim curls up like a ball, or put his arms and legs by his sides and drop vertically down, the effect is the other way round – faster. All these parameters are very difficult to determine and calculate. I suppose one way is to use a super-computer to simulate these changes in order for us to arrive at the correct distance traveled before the body arrives at the terminal velocity of 130 mph (58.1 metres per second). So I have assumed the air up at 35,000 feet (10.668 km) is almost ‘vacuum’ and then applying Newton equations to arrive a drop of 565 feet before reaching terminal velocity of 130 mph. I guess it should not differ very much from the actual figure since the air density up there is near “vacuum”. This means the drop is from 35,000 - 565 feet = 34,435 feet (10,495.8 metres) before terminal velocity.
Hypoxia & Oxygen Saturation
Then as Captain Lim correctly said, the passenger will be unconscious after 30 seconds. In other words, at 10,700 metres (about 35,000 feet) where the air pressure is only 260 hPa (normal at sea-level = 1013 hPa), and a density of only 0.41 kg / m3, the oxygen partial pressure will drop to 21/100 X 260 = 54.6 hPa. At that partial pressure of oxygen, the oxygehaemoglobin dissociation curve showed that the haemoglobin is only about 82 % saturated with oxygen. This is well below the safe level of at least 95 % saturation recommended by the American College of Chest Physicians and the National Heart, Lung and Blood Institute for a person to stay conscious.
Oxygen saturation (SaO2) level below 90 % will result in hypoxaemia (hypoxia), and unconsciousness. A SaO2 level of 82 % at that height feet (35,000 feet), the “useful consciousness” last only 30 seconds from severe hypoxia as rightly pointed out by Captain Lim. If he is a parachutist at that height (God-forbids), he better get his parachute opened before 30 seconds, or else…….? He will remain unconscious until he reaches 10,000 feet when there is sufficient air. The time taken at 130 mph or 11440 feet / min = 190.67 feet / sec will be 128.15 seconds (2 minutes 8 sec) before he reaches that height. He will probably have another 52.5 seconds more to go before he crashes into the ground towards a certain death, provided there is no updraft of air currents to delay the death. All in, he will take 180 seconds – exactly 3 minutes since achieving a terminal velocity of 130 mph at a height of 34,435 feet.
Further Effects of Hypoxia
Captain Lim pointed out that the environment outside at 35,000 feet is very hostile. That’s very correct, and I support it. The temperature is in the region of – 55 0 Celsius, and the atmospheric pressure is very low – 260 hPa, and air density is only 0.14 kg / m3. The normal air pressure at sea level is 1013 hPa (29.92 inches of mercury), and the density 1.2 kg / m3. Briefly, when a passenger is thrown out from the plane into such an environment he will stay conscious for only 30 seconds or less. A want of oxygen will cause him to become hypoxic within less than a minute. A hypoxic person for want of oxygen will cause him to loss consciousness. Hypoxaemia sets in when the oxygen partial pressure (PaO2 < 59 mm Hg (7.8 kPa). This will cause an oxygen saturation level in the blood (haemoglobin) to be less than 90 % (SaO2 < 90 %).
Even at between 8,000 to 10,000 feet, let alone at 35,000 feet a person will begin to experience ‘mountain sickness’ For instance at 14,000 feet above sea level, the atmospheric pressure is around 450 mm Hg (mercury). The partial oxygen pressure is proportionately reduced to (20.96/100) multiplied by 450 = 94 mm Hg (20.96 is the percentage of oxygen in the air at sea level). Compare this with 160 mm Hg (partial pressure) of oxygen at sea level. The oxygen pressure in the alveolar air (in the lungs) and arterial blood therefore, is only between 55-60 mm Hg. The oxygen saturation level (SaO2) of the blood (haemoglobin) at this altitude is around 82 %, as compared to the normal saturation of about 97.5 % or a little higher. The blood when it reaches an oxygen saturation of lower than 97.5 percent will show signs of headache, nausea, vomiting, dyspnoea (breathing increases in depth and rate - breathing difficulty), and cyanosis (blue face, blue lips, blue finger tips etc) sets in.
Other clinical presentations include emotional outburst like crying, laughing, quarrelsomeness, or hilarity. Clinical features also include sense of exhilaration, foolhardiness, boisterousness or stubbornness, blurred vision etc, etc. At least at this attitude (around 10,000 feet) we can still remain conscious or regain consciousness, although a little hypoxic (oxygen hunger/ want / insufficiency). Capt Lim pointed out that the victim may regain conscious by the time he falls to 10,000 feet. This is true if he still breathing. Normally in an unconscious person, especially if his brain is already compromised by hypoxia, he will stop breathing all together. Remember my calculation showed it took a good 128.15 seconds to drop from 34,435 feet to 10,000 feet at a terminal velocity (provided it does not change) of 190.67 feet per second. 128.15 second is a jolly good 2 minutes 8 seconds. The brain cannot be derived of oxygen when a person is not breathing for more than 3 minutes. Brain stem death automatically sets in. He will not breath anymore when there is brain stem death, even when artificially ventilated. In short, if he is unconscious and not breathing at the same time, it is unlikely he will breathe again even if he falls to 10,000 feet where the air is slightly life-supporting.
Haematological Response
However, there may be a chance that he may still breath all the way down. In fact a lack of oxygen and a rise in carbon dioxide levels in the blood (hpercapnia / hypercarbia), may stimulate chemo-receptors in the carotid body to increase breathing depth and respiration rate (hypernea). There are many other reflex and chemoreflexes such as the Hering-Breur reflex, carotid sinuses and carotid bodies that will be stimulated into action, and force the victim to breath. We shall not go into all those feedback mechanisms. The heart rate also increases to compensate. So there is a chance he may continue to breath even if hew is unconscious.
If this altitude is stabilized as for mountain dwellers, these clinical symptoms gradually disappears as the body gets acclimatized. This it does among other things, by increasing the red blood cell count from 6.5 million to 8.5 million, as well as homoestatic adjustments to the circulatory and respiratory mechanisms. At much higher altitudes like at 35,000 feet, it is completely impossible to breathe unless with supplemental oxygen, and even then, it has to at increased pressure, since the oxyhaemoglobin dissociation curve clearly slows that oxygen supply itself is not sufficient. It has to be given at a pressure. The oxygen saturation of haemoglobin can only be improve with increasing partial oxygen pressure. Any undergraduate chemistry student will tell us that the solubility of gasses in a solution increases with pressure, albeit the chemistry of oxygen combined with haemoglobin is more complex than gasses dissolving inside a solution. Only 100 % supplemental oxygen delivered under pressure on a demand system can effectively ventilate the lungs to provide full SaO2 levels.
At 35,000 feet the atmospheric pressure is only 26 kPa (195 mm Hg), and the partial oxygen pressure is only (20.96/100) X 195 = 40.87 mm Hg (5.45 kPa) or about slightly over 20 % that at sea level. If we look at the oxy-haemoglobin dissociation curve at this partial pressure, the haemoglobin is apporoximetly only 75 % saturated with oxygen. I only made the best estimate here since the oxy-haemoglobin dissociation curve is not stable, as it is affected by carbon dioxide levels (Bohr Shift), myoblobin levels, carbon monoxide as well as other factors. So I have to consider all these physiological and biochemical variations as well to come out with the best data. The SaO2 is measured by the pulse oximeter. At that altitude the SaO2 about 75 % when the PaO2 is 40 mm Hg I wonder how the jet engines breathe at this cruising height ? I believe (my guess only), it does this by compressing the air within the turbines to an acceptable pressure and oxygen density before firing the kerosene. That’s where you can have sufficient carbon dioxide and pressure to make your Nescafe in my previous article. Joking only.
As indicated by Captain Lim, a person losses consciousness within 30 seconds, and this could be partly due to the hypoxic condition, and partly due to extreme fright and shock. On the other hand, under very low hypoxic environments, the spleen – a reservoir for blood where blood is held in the pulp of the spleen (spleen parenchyma) will contract forcing more blood into the circulation. It is an emergency response by the body under sudden hypoxaemic conditions. In fact the spleen has a very large concentration of slightly immature red blood cells or recticulocytes than in the general circulation. This can be drawn upon to augment the blood volume when an emergency situation arises. The reticulocytes normally constitute only about 0.5 % of the total amount of red blood corpuscles (RBC) in circulation. But the bone marrow, the site of erythropoiesis (RBC formation) can be stimulated by low oxygen tension.
Under such condition, the immature reticulated cells (reticulocytes) are poured into the general circulation by 10 fold. However, the spleen will respond by contracting only under certain conditions. They are : a rise in the environment temperature (but it is just the opposite outside at – 55 0 C), strenuous muscular exercise, emotional excitement, carbon monoxide poisoning, haemorrhage, and rarified atmospheres. But the immediate response by the spleen among all other factors, is a very low oxygen tension in the blood. This itself may offset the liability of a falling person to faint due to the hypoxic condition. Furthermore, the extremely cold condition at -55 o C will immediately shut down the peripheral circulation (blood circulation beneath the skin), and drive the blood deeper into the vital organs such as the brain. That itself may override the tendency to faint. So there is an interplay of several factors that contradict each other.
The outcome becomes very unpredictable. It is very unlikely that the bone marrow may respond by discharging additional reticulocytes (matutred RBC) into the circulation when the fall is so short - 2-3 minutes. Even the emergency discharge of immature RBC like megaloblasts, erythroblast, and normoblasts from the bone marrow – the site where RBC are manufactured (site of erythopoiesis) takes time, and I do not know or can envisage the bone marrow will be able to do this within 200 seconds or so. The spleen may respond by contracting within less than a minute under such an emergency situation. The actual response time can only be determined by an actual study from a falling human body, and not by inference constructed through our observation under more stabilized and controlled conditions. Often, the basis of our understanding in medicine or physiology depends on this knowledge. So which factor overrides the other to bring out the optimal response and best results will depends entirely on the actual physical and physiological conditions prevailing at the time of the fall. This can only be derived from an actual study, and nothing less. Sorry I do not have such data from any study anywhere, and this is probably the best I can theoretically construct in this article.
In Summary
It is extremely difficult to predict precisely what are the physiological changes that will take place when a human body suddenly falls from such great heights as 35,000 feet. That’s 10.7 km up. The scenario is entirely different from someone jumping down from a plane 10,000 feet with the safety of a parachute latched on. He does this without any fear. The continuously changing parameters – temperature, air pressure, air density, oxygen partial pressures and oxygen saturation of the blood, and perhaps even velocity and directions of fall are changing so very rapid during the descend that it is almost impossible to know whether the body has time to adjust these physiological changes.
This is unlike a mountain dweller who lives in lesser dense air, but he is given time to adjust and acclimatize, such as seen by an increasing the red blood cell count. The same thing applies for an air-plane that suddenly looses cabin air-pressure. The pilot can bring the plane down to a lower altitude, say 10,000 feet, stabilize it there, provide supplemental oxygen through a face mask and head for the nearest airport. That will also give ample time for a human body to react, such as causing the spleen contract to discharge more blood into the circulation. But would these homeostatic and protective mechanisms become operative during severe short-term events ?
Does the body have time to react to such rapid and continuous events? The answer is nobody knows. No murderous / suicidal scientific studies of this sort has ever been conducted by any ethical scientist. What was described by this author are based on his existing knowledge, the best of scientific logic and reasoning only. They may be different in actual situations. Your guess is as good as mine. However, whatever the physiological and biochemical changes are, ultimately we must all admit the passenger will crash into the ground, and DEATH IS INSTANTENEOUS. But before that happens the above would probably the scenario of physiological events But once again, I congratulate Capt KH Lim on his very brief, but correct explanation on the possible events when a human body falls from 35,000 feet. That must have been the most probable answer to a dilemma that has never been studied before – at least not that I know of.A Hind-thought in First Aid
After writing the above article, I thought about some of the procedures taught in first-aid In first-aid, when a casualty faints, the method is to lie the casualty with the head downwards and legs elevated to encourage the blood to gravitate towards the head This is the standard method is called the “Trendelenburg’s Position” This position is applicable under normal situation on Earth. But in this case, when a casualty suffers a syncope (fainting) because he falls downwards towards Earth with head downwards first, the method to apply (if that can be applied when a casualty is plugging rapidly down, unless he is in a enclosed cabin of an aircraft together with the rescuer), is to do the opposite of the Trendelenburg’s Position. The casualty should be encouraged to stand up (feet down and head up in the direction of the fall) instead. I hope there are first-aiders, paramedics and even doctors reading this. Please note this.
Do not follow what the medical emergency manual or first-aid book, or first-aid trainers tell you as the situation here is entirely different. We are not stationary standing on solid ground any more. First-aiders need to use their brains to think analytically. Use scientific logic to analyse, and not merely follow what the manual, the text book or what the lecturer tell us. Throw away all those instructions if we think they are contradictory to sound scientific principles. Use our brains and scientific logic to reason out the approach to take. Sometimes I only wish first-aiders learn a little more on anatomy and physiology first, so that they can understand why certain procedures are adopted, instead of doing things blindly just because the manual says it should be “like this or like that” Hopefully trainer’s would not teach them merely for the sake of passing an examination, but intelligently.
A lot of students do this sort of things. In unusual and complicated situations, certain standard procedures cannot be applied. That’s where a scientifically trained or a medically trained mind who can logic out intelligently, comes to the rescue. Under unusual conditions he is able to override all those textbook knowledge and instructions. A different alternative procedure, so long it is scientific, will need to be applied. Just about 3 weeks ago I was on the way to the toilet somewhere, and I happened to pass by a group of advanced first-aiders, and Basic Medical Technicians who were practicing the Heimlich manoeuvre on a mannequin called “Choking Charlie” . This is a procedure where a rescuer stands behind a ‘café coronary syndrome’ (universal sign of choking) victim to try to dislodge the foreign body – usually food from the victims windpipe by smartly and rapidly compressing the diagram inwards and upwards.
This principle works only if there is sufficient tidal volume of air in the lungs so that this normal “tidal volume” of about 500 dl of air may be used to force out the lodged body. The total lung capacity is about 5,200 dl (cc), which includes Inspiratory Capacity (3,000 dl), Expiratory Reserve Volume (1,000 dl), Vital Capacity (4,000 dl), and Residual Volume (1,200 ml). So I casually asked them (on my way to the toilet) what would they do if the victim is a lady in the late stage of her third trimester – advanced stage of pregnancy. Probably we can’t even put our arms around her bloated abdomen to compress even though the baby is in the pelvic cavity below the abdomen.
Similarly, if the casualty is an accident victim at the same time, and is also suffering from Pneumothorax (a rupture of a subpleural bleb). This is caused by chest injuries where air enters the chest cavity causing one or both lungs to collapse In such case, there is not sufficient air in the lungs for the Heimlich procedure. What would they then do under such a situation I asked ? They were stunned when this question was put to them.. They stared blankly at me, because all these complications are not given in their first-aid manual. Neither do I suspect their trainers taught them how to deal with these unusual emergencies. I looked at their blank faces for several seconds, and they also stared at me before I entered the toilet. I told them when they were ready with the answers, let me know They never gave me the answer of course after I came out from the toilet..
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