What is the Lake Louise Score and what has it got to do with Kilimanjaro?
The Lake Louise Score is a way of diagnosing whether someone has altitude sickness. Though it’s not perfect, it has been used for more than a quarter of a century now throughout the world, and is a robust and practical tool for researchers to diagnose and to score the severity of AMS.
The score is calculated by asking each climber to fill out a questionnaire. The climber gives a score, between 0 and 3, to several questions on how they are feeling. These individual scores are then added up and a final figure reached.
For example, the first question asks the climber whether he has a headache. If the climber has no headache he or she records a figure of zero; if he or she has a mild headache he or she will write down the number 1; a moderate headache should be recorded as a 2; while a severe, crashing headache should be given a score of 3.
Other questions concern fatigue and weakness; nausea; whether a person has gastrointestinal problems/diarrhoea; and whether the climber is having difficulty sleeping. Again, each of these symptoms are scored from 0-3.
If the total score of the answers to these five questions is between 3 and 5, and there is a score of at least 1 on the headache question, then there are some mild symptoms of AMS and the climber’s health will be monitored closely. If it goes above 5 then the symptoms are more severe and the guide will probably decide that the climber has to descend. A score that suggests that the climber has mild AMS (ie the score is between 3 and 5) does not necessarily mean he must descend. The decision on whether the climber can continue, or should rest, or needs to descend, is the guide’s.
Of course, this system is not perfect, and each climber’s answer is very subjective. For example, what one person describes as a mild headache may, for someone else, feel like a severe one. For this reason, it is just one of the tools used by our crew to check on the health of our climbers…
Other diagnostic tools used by our guides
They will also have with them a pulse oximeter, which they will use daily throughout the trek (and, indeed, before it, at the briefing, to provide them with a baseline reading against which the ‘on-mountain’ readings will be compared). The oximeter clips onto the climber’s finger, and after a short wait a percentage figure is displayed. The procedure is painless, non-invasive and takes just a few seconds. It uses light wavelengths to determine the ratio of oxygenated haemoglobin to deoxygenated haemoglobin; in other words, how well your blood is absorbing oxygen. This is of course a very good indicator of how well the climber is adjusting to the lack of oxygen that he or she can take into the body at altitude.
At sea level the oximeter reading should be near to 100. The guide will note this baseline figure down. He will then continue to test each climber at least once a day and note down the results on a table.
The readings will decrease as the climber ascends – this is normal and expected. But it’s how far it drops that is the concern of the guide, who will use your oximeter score and combine it with the other diagnostic tools to arrive at an opinion as to how well the climber is faring.
Studying the behaviour and physiology of the climber
Our guides are very adept at checking how well each of their climbers is coping on the trek. Just as importantly, they are also very skilled at judging when a climber is capable of continuing, when they need to stop and rest – and when they should head back down the slopes.
A few of our guides were leading climbs before oximeters and other aids were used on Kili, and are used to diagnosing their climbers just by studying them. They will look for changes in the faces and fingers of the climbers to see if there is any evidence of cyanosis (where the lips and fingertips turn bluish, indicating a lack of oxygen in the blood). They may also ask if they can listen to the climber’s breathing using a stethoscope, to listen out for those tell-tale ‘crackles’ that indicate that the climber might have the start of pulmonary oedema (edema).
They will look for changes in the climber’s behaviour, and whether the climber appears muddled, confused or ‘drunk’. If they are concerned about the climber, they may also ask him or her to perform some simple tasks such as walking in a straight line or touching the tip of their nose with their finger. Or will ask them simple questions about themselves, such as their date of birth or family members. The answers provided by the climbers are another piece in the jigsaw puzzle which gradually reveals how well the climber is coping with the altitude.
The above methods, and many others, may be used by our guides to compile a complete picture of the climber’s health and how he or she is coping with the altitude. In short, our guides are required to use every tool at their disposal to ensure your safety.
All that we ask from you in return is that you oblige him by answering any and all questions that he may ask you; that you allow him to use the pulse oximeter; that if he asks you to carry out any simple tests, you undertake those tasks to the best of your ability; and if he asks for permission to examine you, that you let him (these examinations will be peripheral in nature and shouldn’t require the removal of any clothing; if you have a friend with you on the trek and it will make you feel more comfortable if they are with you when you’re examined, do let the guide know).
And, most important of all, after studying your Lake Louise Score, oximeter readings, behaviour and physiology, if he decides that you need to descend, you must do so. The mountain will always be there if you want to come back and try again at a later date – and the guide is only trying to make sure that you’ll be around to attempt another climb, so please let him do his job.
What happens if you need to descend: our rescue protocol
Your guide may decide that the best course of action to guarantee your safety is to send you back down the slopes. Usually this will mean returning to the previous campsite, before deciding on a suitable rendezvous point to meet up with your fellow trekkers who carried on to the summit.
However, the guide may decide that the most appropriate action would be to evacuate you off the mountain altogether. If this is the case, you will be accompanied on your descent either by one of the assistant guides, a summit porter or, if he deems it necessary, by the guide himself. In order to ensure your safety, the guide will probably want you to descend as quickly as possible without risking injury.
While you are descending, the guide will contact our base near Arusha to update them on the situation. As such, by the time you reach the exit gate there should be a car waiting to take you back to your hotel.
Should the hotel you were due to stay in after the trek be full, we will try to book you into a hotel of a similar standard, and then help you to transfer across to the other hotel when a room becomes available. Note that you will need to pay for any extra nights in the hotel that you have; but the transfer from the mountain to the hotel is free.