High Altitude Medicine on Himalayan Treks and Expedit - PDF document

High Altitude Medicine on Himalayan Treks and Expeditions* MS, FICS, FAIS, FIAGES, Consultant Gastro-Intestinal and Laparoscopic Surgeon, since 1984, Pune. Founder Member of B.J. Medical College Mountaineering Club, Pune, till 1978; Hon. Life Member and Medical Adviser since 2001, South Calcutta Mountain Lovers Association, Kolkata. Founder Secretary (2002 to 05), Chairman (2006 to 14), Indian Medical Association Trekking Club, Pune. Hon. Local Secretary of Pune section. The Himalayan Club, Mumbai. He has undertaken 25 high altitude trekking and mountaineering expeditions in Vol.69 No.4. April 2016 50 uration, hypoxia and acclimatisation at these altitudes. Table 5 summarises the e�ect of high altitude on various systems of body. At heights more than 8000 m, the available oxygen in the air is so low that it is not su�cient to support the human life. Yet there are a group of people, who are permanent residents at these levels. They are mostly Tibetans and even Ethiopians and Americans. These native residents have in fact no adverse e�ects at such high levels. There are physiological and genetic adaptations in these people. In an article by Yi X a population genomic survey was done to study the heritable adaptations of ery of genes involved in adaption to extreme altitudes including EPAS1 gene which shows evidence of the strongest natural selection observed at any human gene. In ., the functional analysis of genes such as EG+-1 and // 1 was done. This study supports the mechanism of high altitude adaptation and illuminates the complexity of hypoxia response pathways Table 1 showing summary of various altitudes areas 51 Acclimatisation ing oxygen levels at higher elevations; in order to avoid Adequate acclimatisation is essential for safe travelling in the mountains. At altitudes above 3000 m individuals should climb no more than 300 m per day with a rest day every third day. nyone su�ering

symptoms of acute mountain sickness should stop, and if symptoms do not resolve within 24 hours descend at least 500 m. Table 2 summarises the mechanism of Pre-Acclimatisation Pre-acclimatisation is when the body develops tolerance to low oxygen concentrations before ascending to an altitude. (t signi�cantly reduces risk because less time has to be spent at altitude to acclimatise in the traditional way. Additionally, because less time has to be spent on the mountain, less food and supplies have to be taken up. . it has been shown that there is a signi�cant reduction in the incidence of ,2 Since the protocols and the data with respect to altitude sickness di�er, there is no general consensus about the standard way to perform Although some bene�cial e�ects have been demonstrated, it is not possible to draw �rm conclusions from the few available fects of preacclimatisation at simulated altitude on the reduction of acute mountain sickness (AMS) incidence and performance loss at high altitude. For the present, 1-4 Table 2 showing the summary of the mechanism of Acclimatisation h of daily exposures for 1-5 weeks to simulated altitudes of about 4,000 m seem to initiate ventilatory and autonomous nervous system adaptations to high altitude with the potential to reduce AMS development.High Altitude Sickness (HAS)It refers to a spectrum of conditions due to failure of acclimatisation during a rapid ascent to higher altitudes (4800 to 11,200 ft or more) due to progressive oxygen de�ciency (low p.) i.e., hypoxia causing excessive water tors for developing HAS are:In altitudes above 10000 ft / 3000 m (the probability Daily ascent is more than 1000 feet / 300 m for more than 3 consecutive daysPhysical exertion in form of carrying load more than 25% of body weight, climbing for more than 10 hours in a day, inadequate food and �uids, inadequate rest Consumption of alcohol, tobacco o

r addicting drugs Failure of acclimatisation during initial ascent causes AMS (a mild and non-risky condition) and if it remains undiagnosed and/or left untreated for few days, and then it worsens into HACE or HAPE. HACE and HAPE pose Prevention dict the development of HAS which can be undertaken Fig. 2. AMS Prevention Instruction poster on Everest Base Camp trek Fig. 3. Altitude sickness warning – Indian Armyprior to trek or expedition. However, those found un�t (or positive) in stress test or un�t in cardio respiratory functions are likely to develop HAS. Hence, they are de ,2 is a pathological e�ect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 (8,000 ft). If left undiagnosed or untreated it can develop tude a�ained, amount of physical activity and individual susceptibility. The sign and symptoms are given in �gure 5. Table 3 summarises the treatment and care to be taken post treatment. Please refer to Fig. 2 for the poster placed at the Everest Base Camp Trek informing the climbers on how to prevent AMS and Fig. 3 for the poster placed by the Indian Army alarming the altitude sickness Edema (HACO) - - - - - - - - - Fig. 1. 3 Forms of high altitude sickness (HAS) Gradual ascent above 10,000 ft / 3000 m – climb slowly and steadily. Average daily ascent of 1000 to1500 ft / 300 to 450 m for 2 to 3 consecutive days and rest at same altitude on every 3If ascent exceeding 2000 ft / 600 m is inevitable on any climatisation. If reaching directly above 10000 ft / 3000 m by vehicle or �ight, stay resting at same altitude for at least 1 day and consider using preventive dose of Acetazolamide 250 mg once daily 1 day before and few days after. ‘Climb high and sleep low’ principle: altitude of night camp should be lower than the highest point reached during day’s total climb whenever possible

.Adequate hydration - Minimum 4 liters per day - waAdequate nutrition - Minimum 3000 kcal per day - Adequate rest and Sleep - Minimum 10 hours per day - slightly head up. Pillars of AMS Treatment: If you feel unwell at high altitude, it is Acute Mountain Sickness (AMS) until proven otherwise! Don’t ascribe your symptoms to change in food or weather.: -ever ascend with symptoms of ,2! Don’t hide symptoms due to ego, shame or peer pressure. : If your symptoms are worsening to HACE or HAPE, descend immediately till you feel well! This means descend even at night, in bad weather or adverse terrain and also abandon summit a�empt. Fig 4. 3 golden rules of High Altitude Sickness as laid down by Dr.David Shlim at CIWEC Clinic in Kathmandu, Nepal.Table 3 shows the treatment and care to be taken * Please refer to Figure 6 for details of medicines to be carried in the First Aid and Medicine Box.† Please refer to Figure 9 for useful equipments to carry during Table 4: Injuries / wounds during trekking 54 ,2 scoring system developed by The +ake +ouise ft Fig. 5. Portable Hyperbaric ChamberFig. 6. Gamow Bag Fig 7: Signs and symptoms of AMS, HAPE and HACE Fig. 8. First Aid and Medicine Box HAPE HACE Relief Valve Windows Tie-down Straps Zipper Optional Intake Valve Sphygmomanometer Intake Valve behaviour Antiseptic liquid -ame, address, age, sex. height, weight, temper-ature, pulse rate, respiratory rate, blood pressure, oxygen saturation. Any healthy individual from 10 to 100 years can participate depending upon �tness and stamina. s regards other parameters like weight, height, pulse rate, respiratory rate, blood pressure, they should be within Pathological laboratory tests and their normal values:Platelet count 1.5 - 4.5 lacs. 4rine routine – -ormal Blood urea – 20 to 40 mg% Blood sugar – %asting 70 -110 mg% and /ost meals 120 2tress Test – -egative for exercise induced ischaemia.Bruce /rotocol - person is ask

ed to walk, then jog and �nally run on a moving belt with progressively in Portable and foldable stretcher designed by Godbole. (4 /ersons can safely carry an injured or ill person weighing up to 100 kg on unfolded stretcher) High Altitude Cerebral Edema (HACE)It is a medical condition in which the brain swells with �uid because of the physiological e�ects of travelling to a high altitude. (t is a life threatening form of altitude sickness which develops if AMS is undiagnosed or remains untreated. It occurs when the body fails to acclimatise while ascending to a high altitude. It appears to be a vasogenic Edema, �uid penetration of the blood–brain barrier, although cytotoxic Edema, cellular retention of �uids, may also play a role. H CE can present with a wide variety of neurologic manifestations and these symptoms resolve with descent. The persistence of neurologic symptoms after descent suggests intracranial lesion. The sign and symptoms are given in �gure 7. Table 3 summarizes the Treatment ticle by 2hlim D1 et al the authors have reported three cases of previously unsuspected Generally, ,2 precedes H CE. In patients with iting, headache that does not respond to non-steroidal anti-in�ammatory drugs, hallucinations, and stupor.In some situations, however, AMS progresses to HACE even without these symptoms. HACE is generally preventable by ascending gradually with frequent rest days -ot ascending more than 1,000 m (3,300 ft) daily and not sleeping at a greater height than 300 m (980 ft) more than the previous night is recom High Altitude Pulmonary Edema (HAPE)nary Edema (�uid accumulation in the lungs) that occurs in otherwise healthy mountaineers at altitudes typically above 2,500 meters (8,200 ft) leading to hypoxia (+ess oxygen in blood) and hypercarbia (More carbon-dioxide in blood). (t is usually rare. (t occurs in about 1 – 2 % of climbers above 10,000 feet

/ 3000 m. It is usually preceded by AMS for 1 to 2 days. Throat infections or chest infections turn out to be predisposing factors and hence it mimics pneumonia. There is a high mortality rate unless diagnosed and treated urgently by medical a�endant. The sign and symptoms are given in Figure 8. Table 3 • /ositive stress test means appearance of abnormal ECG changes indicating ine�ciency of heart to cope with stress of exercise and that person is un�t for high altitude trek due to high chances of heart a�ack. • -egative stress test means absence of abnormal ECG changes during test period till speci�c target heart rate is achieved and that person is �t for high altitude trek. ll such �t persons are classi�ed by author into 4 broad categories based on duration of exercise tolerance or ‘stamina’ – 1) < 5 minutes – /oor stamina 2) 5 to 10 minutes – verage stamina and performance on trek 3) 10 to 15 minutes – Good stamina and performance on trek 4) >15 minutes – Excellent stamibetes mellitus or hypertension, • /ersons with these conditions may trek to altitude with at least • (nevitable extra risk may be covered by extra premium insur• Those with diseases of heart, lungs, brain, liver & kidneys are not advised to participate in very • Doses of medicines should be • Carry double stock of required • Take medical information note from treating physician & give a • Every day on trek, write down in diary doses of medicreasing speed and upward gradient till speci�c target heart rate is achieved or abnormal ECG (Electro-cardio-gram) changes appear whichever occurs earlier. 57 Table 5: E�ect of high altitude on various systems of our body 5 days Diarrhoea coloured coloured catheterisation of oestrogen trekkinmg poles re-hydrate promptly • 1eport any symptoms promptly to leader or medical • (n case of any health problem,

descend immediately to the nearest medical facility, accompanied by another • Don’t run. 6alk at constant steady speed.• Don’t walk for more than 10 hours a day.• Don’t carry more than 25% of your body weight as • Don’t swim in any water body/ pond / river.• Don’t drink un boiled / un �ltered water.• Don’t eat excess of non vegetarian food.• Don’t consume alcohol, tobacco and addicting drugs in ,ountaineering is ge�ing popular as a sport in (ndia as well as all over the world. More and more individuals, both men and women of all age groups from various �elds of career (e.g. doctors, engineers etc.) are moving to mountaineering as a hobby or even out of interest and/or curiosity to undertake the expedition. This article will surely help the amateur climbers as a primary guide to ing modules conducted by various institutes prepare the individual for undertaking such expeditions. Mountaineering can be compared to a coin with two sides. .ne side of the coin is the fun and adventurous aspect and the other side will be the danger aspect. Dr. Godbole quotes, “,ountain is an enemy to be conquered by any available means & possible methods so as to create titude then it is likely to result in a competitive spirit. This spirit will drive the climber into speedy ascents and miscalculation in the risks and will become overcon�dent in his moves. This will result in more chances of ge�ing altitude sickness and related risks. Instead one should have an a�itude of a pilgrim. Dr. Godbole quotes here rightly, “,ountain is a divine face of nature to be worshiped like god who may allow mountaineer to ascend & descend safely!” This a�itude of climber is likely to result in realistic goals, calculated risks and humble persistent actions. This in turn will result in less chance of altitude sickness and related risks to reach the desired goal within the time frame safely and i

n a healthy state. Finally, mountaineering can be considered as a good example of team spirit. It is always advised to climb in pairs or groups rather than solo trekking because the later is maximally prone to problems and risks. “-on-/hysician ltitude Tutorial”. (nternational Society for Mountain Medicine. Archived from the Peacock AJ. ABC of oxygen: oxygen at high altitude. ,uza, 21; %ulco, C2; Cymerman, . ltitude cclimatisation Guide. rmy 1esearch (nstitute of Environmental ,edicine. (42 1(E,). ,ar 2004 Jackson SJ, Varley J, Sellers C. Incidence and predictors of acute mountain sickness among trekkers on Mount Kilimanjaro. High Alt Med Biol. 2010;11(3):217-22.*üpper TE, 2chö� 5. /reacclimatisation in hypoxic chambers for high altitude sojourns. Sleep Breath. Burtscher ,1, Brandstä�er E, Ga�erer H. Preacclimatisation in simulated altitudes. Sleep 8i 7, +iang 8, Huerta-2anchez E. 2equencing of 50 human exomes reveals adaptation to high altitude. 2imonson T21, 8ang 8, Hu� CD et al. Genetic evidence for high-altitude adaptation in Tibet. Science. The +ake +ouise Consensus on the De�nition and 0uanti�cation of ltitude (llness” in 2u�on )1, Coates G, Houston C2 (Eds), Hypoxia and ,ountain Medicine. Queen City Printers, Burlington, Vermont, 2hlim D1, -epal *, ,eijer H). 2uddenly symptomatic brain tumors at altitude. Ann Emerg Med. 1osenberg, Gary (2012). ,olecular /hysiology and ,etabolism of the -ervous 2ystem (5 ed.). .xford 4niversity /ress. (2B- 978-0-19-539427-6.Bärtsch P, Swenson E. Acute High-Altitude Illnesses. The -ew England )ournal of ,edicine. 2013;386 (24): 2choene 1. (llnesses at High ltitude. Chest. (mray C, 6right , ndrew 2, 1obert 1. cute Mountain Sickness: Pathophysiology, Prevention, and Treatment. Progress in Cardiovascular Diseases. 6ilson ,, -ewman 2, (mray C. The Cerebral E�ects of scent to High ltitudes. +ancet -eurology. 58 Vo