First aid treatment is carried out immediately or very soon after the bite, before the patient reaches a dispensary or hospital. It can be performed by the snake bite victim himself/herself or by anyone else who is present. Unfortunately, most of the traditional, popular, available and affordable first aid methods have proved to be useless or even frankly dangerous. These methods include:
making local incisions or pricks/punctures (“tattooing”) at the site of the bite or in the bitten limb, attempts to suck the venom out of the wound, use of (black) snake stones, tying tight bands (tourniquets) around the limb, electric shock, topical instillation or application of chemicals, herbs or ice packs. Local people may have great confidence in traditional (herbal) treatments, but they must not be allowed to delay medical treatment or to do harm.
As far as the snake is concerned – do not attempt to kill it as this may be dangerous. However, if the snake has already been killed, it should be taken to the dispensary or hospital with the patient in case it can be identified. However, do not handle the snake with your bare hands as even a severed head can bite! The special danger of rapidly developing paralytic envenoming after bites by some elapid snakes: use of pressure-immobilisation Bites by cobras, king cobras, kraits or sea snakes may lead, on rare occasions, to the rapid development of life-threatening respiratory paralysis. This paralysis might be delayed by slowing down the absorption of venom from the site of the bite. The following technique is currently recommended:
Pressure immobilisation method. Ideally, an elasticated, stretchy, crepe bandage, approximately 10 cm wide and at least 4.5 metres long should be used. If that it not available, any long strips of material can be used. The bandage is bound firmly around the entire bitten limb, starting distally around the fingers or toes and
moving proximally, to include a rigid splint. The bandage is bound as tightly as for a sprained ankle, but not so tightly that the peripheral pulse (radial, posterior tibial, dorsalis pedis) is occluded or that a finger cannot easily be slipped between its layers.
Ideally, compression bandages should not be released until the patient is under medical care in hospital, resuscitation facilities are available and antivenom treatment has been started.
Traditional tight (arterial) tourniquets. To be effective, these had to be applied around the upper part of the limb, so tightly that the peripheral pulse was occluded. This method was extremely painful and very dangerous if the tourniquet was left on for too long (more than about 40 minutes), as the limb might be damaged by ischaemia. Many gangrenous limbs resulted!
Unfortunately, most of the traditional, popular, available and affordable first aid methods have proved to be useless or even frankly dangerous. These methods include:
making local incisions or pricks/punctures (“tattooing”) at the site of the bite or in the bitten limb, attempts to suck the venom out of the wound, use of (black) snake stones, tying tight bands (tourniquets) around the limb, electric shock, topical instillation or application of chemicals, herbs or ice packs. Local people may have great confidence in traditional (herbal) treatments, but they must not be allowed to delay medical treatment or to do harm.
Viper and cobra bites Venom
The pressure-immobilisation method as described above will increase intracompartmental pressure and, by localising the venom, might be expected to increase the locally-necrotic effects of viper venoms and some cobra venoms. The use of a local compression pad applied over the wound, without pressure bandaging of the entire bitten limb, has produced promising results in Myanmar and deserves further study.
Transport to Hospital
The patient must be transported to a place where they can receive medical care (dispensary or hospital) as quickly, but as safely and comfortably as possible. Any movement, but especially movement of the bitten limb, must be reduced to an absolute minimum to avoid increasing the systemic absorption of venom. Any muscular
contraction will increase this spread of venom from the site of the bite. A stretcher, bicycle, cart, horse, motor vehicle, train or boat should be used, or the patient should be carried.
Treatment in the Dispensary or Hospital
Rapid clinical assessment and resuscitation
Cardiopulmonary resuscitation may be needed, including administration of oxygen and establishment of intravenous access. Airway, respiratory movements (Breathing) and arterial pulse (Circulation) must be checked immediately. The level of consciousness must be assessed. The following are examples of clinical situations in which snake bite victims might require urgent resuscitation:
• Profound hypotension and shock resulting from direct cardiovascular effects of the venom or secondary effects such as hypovolaemia or haemorrhagic shock.
• Terminal respiratory failure from progressive neurotoxic envenoming that has led to paralysis of the respiratory muscles.
• Sudden deterioration or rapid development of severe systemic envenoming following the release of a tight tourniquet or compression bandage.
• Cardiac arrest precipitated by hyperkalaemia resulting from skeletal muscle breakdown (rhabdomyolysis) after sea snake bite.
• Late results of severe envenoming such as renal failure and septicaemiacomplicating local necrosis.
No comments:
Post a Comment