This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
The proper quantity of food for a nutrient enema for an adult is 4 to 8 ounces; for a young child, 2 to 3 ounces, given every 4 or 6 hours.
Upon withdrawing the tube, if there is danger that the injection will not be retained, a soft compress or folded towel should be pressed up firmly against the anus for twenty minutes or half an hour.
The retention of the enema is aided by placing the patient in a proper position. He should lie, if possible, upon the left side, with the hips raised high upon a pillow, and the injection should be given very slowly and carefully. The "Sims " gynaecological position is the best, but with the hips more elevated.
The question of how many injections can be given must depend upon the irritability of the rectum. It can never be used like the stomach, and it is advisable to begin by ordering an enema only once in six hours. If the rectum is in good condition the number may be increased to one every four, or even every three hours. In exceptional cases or for emergencies small injections, not exceeding one and a half ounce, may be given once in two hours; but if repeated at such brief intervals, they are almost certain to excite irritation.
When it is important that nutrient enemata should be continued for some time, the exact condition of the rectum should be ascertained by the physician, and the most minute directions should be given to the nurse. The matter is not infrequently left to an attendant, who is wholly ignorant of the proper conditions to be observed, and failure is sometimes reported when a little intelligent attention bestowed upon details would overcome all difficulties.
As already stated, many cases have been recorded in which patients have been nourished exclusively by nutrient enemata for several weeks, and it is an important fact that the rectum may acquire a certain degree of toleration for them. For the first few days they may be rejected, but when correctly prepared and administered they will soon be successfully retained. But it is only in the most favourable cases that rectal alimentation can be long continued without eventually producing irritation and mucous diarrhoea, and in the majority of instances this is likely to occur after two or three weeks. The enemata must then be discontinued, but may, if necessary, be resumed again after a brief interval. Queirolo, of the University of Pisa, has fed typhoid-fever patients exclusively by nutrient enemata four times a day with success, his idea being to avoid putting anything into the small intestine capable of fermenting or producing toxins, but this practice is not in accord with modern views of the disease.
The presence of haemorrhoids is a serious drawback when the use of rectal feeding becomes imperative, and care should be exercised not to irritate or inflame them by the passage of the catheter or nozzle of the syringe. In such cases it is necessary to use only a very soft and flexible catheter, and to allay irritation by the topical application of a 2-per-cent solution of cocaine.
Whenever nutrient enemata are employed for a long time the rectum should be thoroughly evacuated and cleansed, at least once a day, by flushing with a copious injection of warm soapsuds and water, amounting to two or three pints, immediately after which a food enema should be given.
The cleansing enemata may be given through a double or single catheter. If a double catheter is preferred, a larger quantity, two or three quarts, of water may be advantageously given, and a few grains of common salt should be added to each injection. If the rectum is irritable, and much mucus coats its inner surface, it may be well to add boric acid to the water in saturated solution. The injection washes out any particles of waste matter or remains of a previous nutrient injection, cleanses the mucous surface, stimulates its circulation, and prepares it for better absorption.
Opium, while it prevents peristaltic action and favours retention of the enema, may also tend to interfere with its absorption. It is consequently to be avoided, if possible, but when irritation of the rectum exists it becomes necessary to inject a little laudanum. Ordinarily, three to four minims is sufficient, but ten, or even twenty, may be required in some cases. This dosage must not be often repeated. Its effect, of course, should be watched, and it must not be given too freely. If nutrient enemata are constantly employed it is sometimes found that a larger dose injected by a small hard-rubber syringe half an hour or an hour before giving an enema allays the irritation more completely than if the opium is given in one of its constituents. Injected by itself, the quantity of opium is so small that it is not ejected, but is absorbed, and its local action is obtained before the larger bulk of fluid in the enema is injected. In other cases it is sufficient to give the laudanum in very small quantity, five or six minims with each enema.
Instead of laudanum, the deodorised tincture of opium or McMunn's elixir may be used.