Hypodermoclysis (Subcutaneous Hydration)
Hypodermoclysis is a well-tested, safe, inexpensive, and easy method for hydrating adult and pediatric patients which was used from the late 19th century until IV hydration became common in the mid-20th century.47,48 Hypodermoclysis is used acutely if starting an IV is difficult and for chronic hydration in patients who cannot take sufficient oral fluids due to nausea and vomiting, intestinal obstruction, neurological disease, or a diminished level of consciousness. In at least one case, it was used in a wilderness setting to resuscitate an adult in shock from gastrointestinal bleeding.49
The advantages of this method are that it has a relatively low cost, is easy to administer without skilled personnel, and is generally more comfortable for the patient than having an IV. In addition, it does not cause thrombophlebitis, generally does not cause local or system infection, and can be stopped and restarted at any time without fear of the needle clotting or the system failing.50
This method can be slower (~1 mL/min) than IV hydration, and can be used to administer only those medications that can be given subcutaneously. However, these include potassium chloride (up to 40 mmol or mEq/L), opiates (hydromorphone requires only a very small volume, although morphine also works), antiemetics (such as metoclopramide, lorazepam, diphenhydramine, dexamethasone, or promethazine), and sedative/anxiolytics (such as lorazepam and midazolam). Other medications that have been reported to be successfully given via hypodermoclysis—but using an infusion pump—include atropine, haloperidol, hydroxyzine, methadone, methotrimeprazine, metoclopramide, octreotide, phenobarbital, and scopolamine.51,52 In some countries, it is not unusual to give other medication classes through this route: antipsychotics (levopromazine; UK), antibiotics (ceftriaxone, amikacin; France), and other analgesics (tramadol, demerol/pethidene, buprenorphine; Switzerland, Germany, UK, France).53
Clean the skin with antiseptic and insert a 23- to 25-gauge butterfly needle or other small-gauge needle for injection into a subcutaneous site at a 45- to 60-degree angle, with the bevel up. These needles fit onto the end of standard IV tubing. If the needle is too deep (e.g., in the muscle), the infusion causes pain. If blood appears, a vessel has been entered; apply pressure and select another infusion site.51
Generally, infusion sites are the medial or lateral abdominal wall, along the iliac crest, in the anterior chest wall below or lateral to the breast, around the scapula, or in the anteromedial or anterolateral thigh. The abdominal wall and iliac crest areas are said to cause the least discomfort.54 In extremely agitated patients, the inter- or sub-scapular area can be used to prevent them from pulling at the needle.51 Typical sites for needle placement in infants and children are shown in Fig. 11-2.
Sites for hypodermoclysis needle placement in infants and children.
Attach intravenous tubing to the needle and secure it with an occlusive clear plastic dressing, if available. Normal (0.9%) saline (NS) is most commonly used, although 0.45% saline and 5% dextrose in 0.45% saline (D5 half normal) have also been used, often at two infusion sites. The infusion rate is typically 1 mL/min/site (1.5 L/day/site), 1 to 2 L overnight, or 500 mL over 1 to 2 hours three times a day (tid). Hypotonic (e.g., glucose in water) and hypertonic (e.g., glucose in NS) solutions should not be given subcutaneously, since the body must convert the administered fluid pool into its normal fluid and electrolyte composition before it can be absorbed.55,56 Hypotonic solutions, including 5% dextrose in water (D5W), have caused hyponatremia; blood and colloids are ineffective via this route.57
In infants and children, infuse no more than 200 mL/injection site. In premature infants during the neonatal period, fluid should not exceed 25 mL/kg body weight at no more than 2 mL/min.58
Ideally, you should change the needles and tubing every 1 to 4 days. Change the site after each liter of fluid, and sooner if there are signs of local reaction.54 Families and nonclinical caregivers can be instructed how to provide this therapy at home.
Although it is uncertain whether it is effective, if available, hyaluronidase is often used to reduce local edema and pain and to increase the fluid absorption rate. In adults, add 150 to 300 units to each liter of infusate or inject 75 to 150 units combined with 1 mL of anesthetic at the infusion site.54,59 For infants and children, add up to 30 units of hyaluronidase to each 200 mL of infusate.58
Check the infusion site for evidence of edema or infection. Edema can often be relieved by massaging the area. Infection at the infusion site is rare, although at remote locations without professional medical supervision, a significant number of abscesses, presumably resulting from poor cleansing of the injection sites, have been noted.50 Observe all patients for signs of fluid overload.
Rectal hydration (proctoclysis) can be used to instill fluids into children or adults who do not have profuse diarrhea. Use rectal hydration in patients who cannot tolerate hypodermoclysis because of generalized edema, pain on injection, or bleeding disorders.60
This method of fluid administration was popular into the 1930s, but its use declined with the development of IV technology.54 Recently, rectal hydration has been used in the terminally ill, but it may also be of value in survival situations, for postoperative patients, and in those with mild dehydration where other routes of hydration are not available. It is safe, inexpensive, and so easy to use that it is generally administered by relatives to homebound patients.54,60
Place the patient on his side with the buttocks raised on two pillows or folded blankets. Gently insert a well-lubricated 22-Fr NG tube or a large Foley catheter 10 to 40 cm into the rectum. Do not force the tube, since the primary danger is perforating the bowel. After taping the tube to the buttocks, attach a longer length of tubing (e.g., IV tubing) and an IV bag, enema bag, or a funnel. Elevate the bag, clamp the tube, and add the fluid to the bag. Use this to infuse warm NS, standard oral rehydration fluid, or tap water (take care to limit the amount, especially in children). Sodium and potassium may be added to the fluid.61 Note that infusing cool fluid often causes the patient to immediately expel it.
Start the infusion at 100 mL/hr and increase it to a maximum of 400 mL/hr, or until fluid leak from the rectum appears. Another method is to start by infusing 200 mL of fluid over 15 to 20 minutes. (If more than 400 to 500 mL is administered faster than over 20 minutes, reflex abdominal cramping will expel it.) Then clamp the catheter and leave it in place. Instill another 200 mL every 4 hours, delivering up to 1200 mL/24 hr in an adult. After the infusion of a desired total daily volume of fluid, the catheter is removed; it can be reinserted daily for weeks or more at a time.54,60,62
In children, insert the smallest available catheter to minimize local irritation. Place it 8 to 12 cm beyond the anal sphincter. Begin instilling fluid at 1 drop/second.63
Complications include discomfort, leakage, tenesmus, and stool production (enema effect). If there is stool production after an infusion, decrease the infusion rate.
One successful method for using proctoclysis for resuscitation employed a surgical glove with one fingertip cut off, which was secured to the end of a 14-Fr urethral catheter with waterproof tape. The glove supposedly acted as a "reservoir," although it also probably caused some added discomfort. Unlike other methods, these clinicians inflated the catheter bulb and then pulled down to seat it against the rectum. They administered 1 L of double-strength ORT and then 2 L of standard ORT over a 3-hour period. Oral rehydration followed.49
Rectal drips can be valuable in cases when maintenance or perioperative fluids are needed. Post-operatively, this can often be done for 2 or 3 days. One suggestion is to instill up to 2.5-L tap water into the (adult) anesthetized patient over 2 to 3 minutes at the end of the operation. Two hours later, begin a slow rectal drip of tap water or other appropriate solution at the rate of 2.5 L/24 hours.64
Using tap water conserves sterile fluids if they are scarce. Better than plain tap water is to add 0.5 teaspoon of sodium chloride/L and 0.25 teaspoon of potassium citrate/L for maintenance fluids. Replace gastric losses with an equal quantity of saline (1 level teaspoonful of salt/L tap water) that contains 20 mmol of potassium per liter.65
Intraosseous (IO) infusion is one of the quickest ways, both in children and in adults, to establish access for the rapid infusion of fluids, drugs, and blood products in emergency situations.66–68 However, in some cultures, almost any other method, including intraperitoneal infusion, is preferable to IO infusion.6
Placing an IO needle and beginning the infusion generally takes less than 1 minute; this is much faster than placing an IV in critical situations, especially in infants/small children or in any patient in shock or in cardiac arrest.67,69 Standard practice is to use an IO needle in resuscitation situations when venous access cannot be obtained after either three attempts or within 90 seconds of starting the procedure, or when the clinicians do not believe they can quickly get venous access.
Since the marrow cavity is contiguous with the venous circulation, the IO route can be used to infuse fluids and medications, and to take blood samples for crossmatch. Any fluid, blood product, or medication (except for cytotoxic agents, such as chemotherapeutic drugs) can be given through the IO route. The onset of action and drug levels during cardiopulmonary resuscitation (CPR) using the IO route are similar to those given intravenously.68
Intraosseous infusion is contraindicated when (a) there is a femoral fracture on the ipsilateral side and the lower extremity will be the site of needle placement, (b) the tibia (or other bone where the needle will be placed) is fractured, or (c) osteomyelitis exists in the bone to be used.68
Intraosseous infusion is also contraindicated in patients with osteogenesis imperfecta or osteopetrosis, with an infection or burn overlying the infusion site, with a bleeding diathesis, and who have already had multiple IO needles or attempts at the same site.
Ideally, IO infusions are done through a special IO needle or a bone marrow aspiration needle with an obturator. Alternatively, use any needle with a stylet. A large-gauge spinal needle and stylet can be cut down to a 3-cm length, beveled, sharpened, resterilized, and packaged in advance for IO use.70,71
In emergencies or situations of scarcity, use a standard 14- to 20-gauge butterfly/injection/IV needle; all connect to syringes and standard IV tubing. Using smaller-gauge or longer needles, however, risks their being too fragile or flexible to penetrate the bony cortex. Occasionally, when using such a needle without an obturator, the lumen becomes plugged with bone. If aspiration or running fluid under pressure does not clear the obstruction, another needle can immediately be placed in the same hole—although this may be more difficult than it sounds.
Common sites for IO placement are the proximal anteromedial tibia (1 to 3 cm below the tibial tuberosity on the anteromedial surface) or distal anterior femur in children, the anterior-superior iliac spine or above the medial malleolus (adult or child), and the sternum (in adults with special equipment).
The thickness of the bone precludes the use of the tibia or distal femur in children, and almost always in adults. However, the area just above the medial malleolus has proven to be easy to use in both pediatric and adult patients (Fig. 11-3). Enter the bone at a 90-degree angle (perpendicular) to the skin.67 Using the sternum has the potential for lethal injuries, so avoid this site unless a sternum-specific needle, or an IO drill, is used.
Intraosseous needle insertion at ankle: pediatrics or adult. (Reproduced with permission from Iserson.67)
Use aseptic technique and a sterile needle. Placing a bone marrow needle without using a sterile technique increases the chance of osteomyelitis and cellulitis. Clean the skin. In awake patients, inject a small amount of local anesthetic in the skin and continue to infiltrate down to the periosteum. Hold the insertion site firmly to stabilize it. Do not put your hand behind the insertion site; it could get stabbed with the needle.
Insert the needle with a pressing and twisting (or "drilling") motion until you feel a "give" as the needle passes through the cortex.
Remove the obturator (if there is one) and attach a 5-mL syringe to aspirate a blood sample—both to confirm placement and to draw a sample for analysis. (A larger syringe may not be able to generate sufficient negative pressure.)
Another method to confirm needle placement is that the needle remains upright without support, although this may not be as obvious in infants because they have softer bones than older children or adults. Also, with correct placement, fluid flows freely through the needle without swelling of the subcutaneous tissue.68
Even if blood cannot be aspirated (which occurs about one-third of the time), attach IV tubing or a syringe and infuse solution, generally 0.9% saline or the equivalent, under pressure. If it flows easily, the needle is in the correct location. Pressure can be applied to the system by putting a 3-way stopcock on the IO needle and using a syringe to push the fluid. This is especially useful if the IV solution is in a bottle, which cannot be pressurized.
If no blood can be aspirated, the needle may be blocked with marrow. To unblock the needle, slowly inject 10 mL of NS. Check that the limb does not swell and that there is no increased resistance. If the tests are unsuccessful, remove the needle and try another site. (If using extremities, use a more proximal site.)
Secure the needle if necessary with adhesive tape or, if the needle is longer than the short IO needle, clamp the needle where it enters the skin and tape it to the patient. Daniel Tsze, MD, of Brown University, has used tongue depressors to stabilize it. Break one tongue depressor in half (width-wise), and then make a "sandwich" of the two halves with the IO needle in between. The tongue depressor edges are against the skin (Fig. 11-4). Apply tape circumferentially. (Personal written communication, received June 5, 2007.)
Securing the intraosseous needle using tongue depressors and tape.
Complications are rare, the most common being local skin or bone infections, fluid extravasation, tibial fracture (especially in neonates), and compartment syndrome. The most common complication is putting an IO needle distal to a fracture or a prior IO infusion site: the infused fluid leaks out.68
Intraperitoneal instillation of saline is a simple, safe, and effective technique to rehydrate adult and pediatric patients with ongoing fluid losses when the patient cannot tolerate oral or NG fluid administration or when local personnel, for whatever reason, cannot easily establish an IV.6,72,73 It is most commonly used in children up to 3 years old (and older, if they are small for their age).
The procedure can be repeated and also may be used for continuous rehydration in postoperative patients.74 Benefits of using this technique when resources are limited are that (a) it can be done in 5 to 10 minutes once a day using only one health care worker, and (b) it lessens the discomfort and the danger of over-hydration from IV infusion.
Intraperitoneal rehydration is useful for the mild to moderately dehydrated child. The procedure itself is fast (<10 minutes) and usually permits the child to return home for the next 24 hours. The patient normally returns the next day to assess whether the procedure must be repeated. However, the method does not allow fluid to be absorbed fast enough (it takes about 4 hours to be absorbed) to be the only method used for resuscitating those who are severely dehydrated. The other drawbacks are that it uses expensive IV fluids and it must be done aseptically, using sterile equipment.75
The child can be restrained or mildly sedated, if necessary.73 Lay the patient supine and palpate (or ultrasound) the abdomen to be certain that the liver, spleen, and bladder are not distended; if these organs are enlarged, they can be perforated by this procedure.
Use a 16-gauge needle to transfuse blood or an 18-gauge needle to administer fluids. Optimally, use a catheter-over-needle (typical IV catheter), although a hypodermic needle will also work. Try to use a catheter that is at least 18-gauge; smaller ones have a tendency to kink, so may need to be held in place or readjusted several times during the infusion. Leaving the needle in the catheter (pulled back so that the needle tip is within the plastic) may not be an option, since the IV tubing may not connect to it.
After thoroughly cleansing the overlying skin, pinch a fold of skin in the midline; use local anesthetic if needed. Insert the needle either 2 cm below or 2 cm above the umbilicus in the midline. Alternatively, since the abdominal wall is generally lax in dehydrated (and especially emaciated) children, insert a thumb into the umbilicus pointing cephalad, pinching and lifting the abdominal wall between the thumb and index finger (Fig. 11-5). Apply traction and push the needle obliquely and cephalad through the abdominal wall (Fig. 11-6). Some clinicians hold the needle vertically; others insert it at an angle. In part, this depends upon the thickness of the abdominal wall. Note that introducing the needle midway between the umbilicus and the symphysis pubis, which was once advocated, has resulted in severe hemorrhage from puncture of the iliac arteries.76
Pinch abdominal wall and lift.
Push needle through abdominal wall.
If an ultrasound machine is available, use it to guide needle entry. For additional safety, as soon as the needle enters the subcutaneous tissue, the fluid line is opened so that entering into the peritoneal cavity is marked by free flow of fluid—effectively pushing away any bowel. Run fluid "wide open," using gravity. Once the needle is in the abdominal cavity, the fluid will flow very fast; the fluid pushes any bowel loops out of the way of the needle. If the catheter kinks because of its small caliber (larger sizes may not be available), lift the umbilicus so that the catheter is clear of any bowel obstructing its flow. Use the initial "pinch" to both grab and lift the umbilicus. The technique is so safe that technicians and nurses have repeatedly performed this procedure independently.73
Fix the needle with adhesive tape. Cover it with gauze, if available.
Infuse crystalloids after the bottle or bag has been carefully warmed in an oven or hot water bath. Blood can be warmed using the rapid admixture method described in Chapter 17, Transfusion. Since many infants and children with emaciation and dehydration are also relatively hypothermic, the warm fluid also helps that condition.6
For blood, give 20 to 25 mL/kg as fast as possible, usually over 5 to 15 minutes. For fluids, give 40 to 70 mL/kg as fast as possible.77 If the child is still in the medical facility and remains dehydrated, administer another intraperitoneal bolus 4 hours later.75
Infants weighing 12 pounds (5.45 kg) usually tolerate about 235 mL (0.5 pint; 43 mL/kg) of fluid. Children weighing 20 pounds (9.1 kg) usually tolerate about 473 mL (1 pint; 52 mL/kg). Any discomfort they experience stems from abdominal distention. Adding hyaluronidase does not seem to be of any benefit. The rate of fluid absorption varies, although fluid overload does not seem to occur.6
After infusing the fluid, remove the needle. Keep a child in a half-sitting position, preferably on mother's lap, for about 2 hours after infusion. Note that even if the needle pierces the intestine (which is rare), it will not cause any harm but may cause some rectal blood to appear.77
In children <15 years old, infuse hypotonic crystalloids; in adults, administer isotonic solutions (e.g., 0.9% saline).6 Other solutions that have been used include half-strength Darrow's solution with glucose (sodium, 61 mmol; potassium, 17 mmol; chloride, 52 mmol; lactate, 27 mmol; glucose, 50 g; and calories, 200/L), lactated Ringer's solution (Na+, 130 mEq/L; K+, 4 mEq/L; Ca++, 3 mEq/L; Cl–, 109 mEq/L; lactate, 28 mEq/L), normal (0.9%) saline (Na+, 154 mEq/L; Cl–, 154 mEq/L), and 0.45% saline (28 mEq KCl/L).55,78 Table 11-7 shows the composition of standard IV fluids.
Table 11-7 Composition of Standard IV Fluids ||Download (.pdf)
Table 11-7 Composition of Standard IV Fluids
Electrolyte Concentration (mEq/L)
Normal (0.9%) saline
Dextrose 5%; 0.45% normal saline
Ringer's lactate (Hartmann's solution)
Half-strength Darrow's solution
Note that hypotonic solutions, such as half-strength Darrow's, while suitable for children who are primarily dehydrated, should not be used for other forms of shock.78 Blood transfusion through this route is beneficial for the treatment of chronic anemia, rather than for resuscitation due to acute blood loss (i.e., shock).79,80
Do not perform this technique on children with ascites, distended and tympanitic abdomens, cellulitis over the abdomen, or who may have adhesions from infection (e.g., tuberculosis) or prior surgery.11,76 If there is concern about adhesions from prior abdominal surgery or injury, insert the needle under ultrasound guidance or using a semi-open technique as is done for peritoneal lavage. Also consider other hydration methods, including IO infusion.