Assisting natural mechanisms

If you are going to operate on a patient you have to cut him, and if you cut him he bleeds, so you have to control this bleeding. He can also bleed from an injury (55.1). The body has excellent mechanisms for controlling bleeding, so that your task is mostly to assist them. The main mechanisms are the cascade of enzymic reactions which make his blood clot, and the ability of the muscular walls of his arteries to contract.

If you fail to control bleeding adequately he dies, so watch the blood he loses. The loss of a given volume of blood is much more serious in a child (3-1), than it is in a fit adult, who can usually lose a litre without the need to replace it by blood, whereas a small child can easily bleed to death from what might seem to be a very small loss.

The most generally useful ways of controlling bleeding are pressure and haemostats, but there are also special methods for particular parts of the body, such as the scalp (63.9), the dura (63.9), the gut (9.3) and the liver (66.7).

Pressure is the simplest and most valuable way to control bleeding. If you press on a tissue, the walls of its vessels will come together, and where their edges are cut, clot will start to form. When you release the pressure you will probably find that bleeding has stopped, or that only the arteries will continue to spurt at you, and these you can tie off. Press with a gauze pack. Some surgeons use warm saline packs, but there is no evidence that these are any better than cold or dry ones, and they are certainly less convenient. ''Hot packs' are therefore going out of fashion. If pressure is to succeeed, you must press for long enough[md]this is normally at least 5 minutes by the clock, which is one reason why every theatre should have a method of recording time. If the tissue behind the bleeding area is firm, as when you press a bleeding scalp against the patient's skull (63-19), pressure is even more effective. In an emergency you can control bleeding from a patient's uterus by pressing her aorta against her spine through her abdominal wall (19.11a).

A variation of this method is to pack a wound at the end of an operation and to remove the pack not more than 24 hours later, as with a bleeding liver (66.7), or after a sequestrectomy (7.6). Very occasionally, you may need to pack the uterus (19.11a).

Fig. 3-1 BLOOD LOSS IN ADULTS AND CHILDREN. A, and B, when you operate on a child, make an accurate ''blood balance sheet'. In a major operation measure the blood he loses by weighing the blood-soaked swabs on a balance. Replace blood he has lost with an equal volume of blood as soon as possible. This should be HIV free or from a close relative. C, the balance sheet for an adult need not be nearly so accurate. A fit adult, such as a mother having a Caesarean section, can tolerate a blood loss of up to a litre or even a litre and a half, before you need to give her blood, rather than Ringer's lactate or saline. You can usually measure the blood she loses in a sucker bottle. When an adult needs blood, he needs at least two units. The transfusion of a single unit is useless. A haemostat (artery forceps) can be used to grasp a bleeding vessel, particularly an artery which is spurting blood at you. You can then tie it.

Raising the bleeding part will lower the pressure in its veins, and and so minimize bleeding. This is valuable if a patient is bleeding from a limb, or the venous sinuses of his brain (a rare and difficult emergency), when the level of his head in relation to the rest of his body is critically important (63.9). But there is a risk of air embolism if a rigid vascular channel, such as a sinus, is raised above the level of the heart.

Adrenalin, added to the local anaesthetic solution, or to saline used to infiltrate the tissues, will minimise capillary and venous bleeding, when scar tissue is dissected for plastic surgery (58.25), or during the repair of a vesicovaginal fistula (18.18). Never use adrenalin in the penis, or the distal parts of a limb such as a finger or toe, or in an intravenous forearm block, because it may constrict the vessels so much that the part becomes gangrenous. You can also use an adrenalin soaked pack in a bleeding nose (25.6).

A vessel can be sutured, either to repair a break in its wall, or to anastomose it end-to-end (55.6). If a limb is severely injured, this may save it.

Bone wax can be packed into the bleeding edge of the skull into the diploe (63.9), or into the marrow of a bone, if the bleeding area is not too big.

Haemostatic gauze (''Surgijel') will eventually stop bleeding from the oozing cut surface of the liver (66.7), or the surface of the brain (63.9). Unlike ordinary gauze it is slowly absorbed. It is expensive and rarely indicated. A substitute is to cut a piece of muscle, hammer it flat, and use this (63.9).

The clotting power of the blood can be restored. When you have given a patient many units of blood, the citrate in it will lower his blood calcium and prevent his blood clotting. So don't forget to give him 10 ml of 10% calcium gluconate after every fourth unit of blood. The only other thing you may be able to do when his blood fails to clot is to give him fresh blood, but this may be impractical. You are unlikely to have individual clotting factors to give him, except, if you are fortunate, fibrinogen (19.11a).

Arteries and veins can be formally exposed, clamped and tied high above a bleeding lesion. You will only need to do this on unusual and desperate occasions. The classical sites for doing it are the external carotid (3.3) (rare), the third part of the subclavian (rare, 3.4), the internal iliac (for obstetric haemorrhage, much the most important, 3.5), the external iliac (rare), the femoral (uncommon, 3.7) and the popliteal artery (rare, 3.8).

A tourniquet will control bleeding from the distal part of a limb: (1) You can use a pneumatic tourniquet to control bleeding during an operation as described in Section 3.9. This is very valuable, and for many operations it is essential, because it enables you to operate in a bloodless field (3.9). (2) A tourniquet can be used as a first aid measure. This is so dangerous that many surgeons consider that first aid workers should never use one, but should rely on direct pressure instead (55.1).

The common mistakes are: (1) To panic when there is severe bleeding. (2) Not to apply pressure when this is indicated, or not to apply it for long enough. (3) To grasp wildly with a haemostat in a pool of blood, to fail to grasp the bleeding vessel, and perhaps to injure some important structure. (4) Not to apply the special methods for special sites.

GAUZE, haemostatic, surgical, ''Surgijel' or equivalent, 5 packs only.

A STORY ABOUT BLEEDING. A surgeon went to an international meeting on prostatectomy. He got bored and said to a friend ''I am having a bit of trouble with my waterworks, whom should I see?'' ''Go to Mr. X'' he was told, ''he is the best in town''. So our surgeon visited Mr. X and said ''Could you show me your method of prostatectomy?'' The answer was ''Yes certainly, but my only secret is, that I drink more tea than the others!''. So it proved. At the end of the operation when the prostatic bed was bleeding, Mr. X just put in a monster pack, and had a leisurely cup of tea. When he and his assistant rescrubbed and came back 20 minutes later, the pack was taken out and there were no bleeding points to tie off! LESSONS When you control bleeding by pressure or with a pack sufficient time (5 minutes by the clock) is all important.

SOME USEFUL METHODS See elsewhere for the special methods described above.

GAUZE PACKS will control oozing. Press dry gauze onto the bleeding area, or wring out gauze or any piece of cloth in hot water, and press this on the wound. If the operation is difficult, and you need a rest, this may be the time to go out to the changing room for a break and a cup of tea, while your assistant applies pressure. This will make sure that pressure is applied for the necessary time.

When you come back, instead of finding the whole area pouring blood, you will probably find one one or two tiny bleeders, which you can pick up in mosquito forceps and tie off. Because fewer ligatures are needed, there will be less chance of sepsis.

DRY FIRM PRESSURE PACKS can be used to compress a large bleeding vessel against something solid such as the spine (18.17).

PACKING A WOUND at the end of an operation is sometimes necessary. If, for example, you remove sequestra under a tourniquet, you can pack the wound tight, and remove the pack 24 or 48 hours later (63.7). Don't leave a pack in longer than 48 hours, or it will promote sepsis, and there may be severe bleeding when you remove it.

LEAVING CLAMPS IN THE WOUND. Very ocasionally, if you are inexperienced and desperate, you may have to clamp a vessel, and send the patient back to the ward with the handle of the haemostat protruding from the wound under a dressing. Remove it cautiously 24 hours later and close the wound. This is indeed a measure of desperation. It may be useful for a bleeding cervix (18.15, 19.11a, M 22.2) and for a bleeding renal pedicle (67.2). Most experienced surgeons have never had to do it.

Fig 3-2 HAEMOSTATS. If you can see a bleeding vessel, you can usually grasp it with these locking forceps, which are one of the great inventions of surgery.