Editor’s note: Hypodermoclysis is a medical procedure. Proper setup, sterile technique and fluid administration precautions should be reviewed with your medical practitioner.
“Volume shock” is the term for inadequate tissue perfusion and oxygenation due to low blood volume. Severe bleeding is the most obvious cause, but it is much more common aboard ship to go into shock as a result of dehydration. You don’t take in enough fluid to replace abnormal losses due to diarrhea, vomiting or excessive sweating. Prolonged sea sickness is the obvious example.
The body compensates for dehydration by making more efficient use of the remaining fluid and trying to reduce fluid loss. The skin becomes pale as blood vessels constrict, the heart beats faster, and sweating and urine production is reduced. The patient feels weak, dizzy and sick. This state of compensated volume shock can go on for a while, but the compensation mechanisms will ultimately fail, and the patient will be in serious trouble.
The treatment for volume shock is to stop fluid loss and replace fluid volume. This is a lot easier said than done, especially if the rough weather continues, the vomiting won’t stop and the patient refuses to eat or drink anything. The ideal treatment is to start an IV and infuse a couple of liters of normal saline. This is what we do in the clinic, and what many offshore sailors and professional mariners would like to be able to do aboard ship.
Unfortunately, starting and maintaining an IV under adverse conditions is not easy. Learning on latex training arms and well-hydrated classmates is not adequate preparation for the sea motion of a small boat or the collapsed veins of your dehydrated crewmember. Even an experienced nurse or paramedic would have trouble in this situation.
For the inexperienced user, hypodermoclysis is a much easier, safer and more reliable technique for fluid replacement. Fluid is infused into the space under the skin from where it is absorbed into the blood. Inserting the needle and catheter into a vein is not required. The needle is placed under the skin on the back, chest, abdomen or thighs. There is much less risk of blood clots, infection and blood vessel inflammation. The needle can be left in place for days, if necessary, or just used to infuse a bolus of fluid and removed.
Infusion rates are much slower than with IV therapy, but up to three liters of fluid can be given over 24 hours. This is more than enough for most cases of sea sickness or dehydration from other illness. Ashore, the technique is often taught to unskilled caregivers responsible for patients that are managed at home. The other major users of hypodermoclysis are veterinarians. Since their patients rarely tolerate IV therapy, the vets bolus the cat or dog with normal saline in several sites. The critter is then free to go while the fluid is absorbed over time.
The same fluid bags and tubing are used as with IV therapy, but we use a butterfly needle rather than an IV catheter to penetrate the skin. The technique is very easy, but it is a medical procedure for which you need some training. A nurse in your doctor’s office should be able to demonstrate in just a few minutes.
There is also a kit made specifically for hypodermoclysis by Norfolk Medical Products. It includes tubing with a flow meter and an adhesive pad with two 25-gauge needles designed to penetrate the skin, but no further. The high-flow version of the Aqua-C Hydration System will deliver up to three liters of fluid per day. It is easy, simple and safe, and a good alternative when IV skills are limited.
Fluids like normal saline and the administration sets and needles are prescription items in the U.S. Your doctor may be willing to provide you with the material and training in the office. The Aqua-C system is available by prescription from pharmacies.
While IV fluid replacement remains the gold standard in the hospital, hospitals remain notoriously clean, well-lit, dry, warm and immobile. It should come as no surprise that the techniques and equipment used by veterinarians and home health care nurses are more appropriate for a vessel at sea. Hypodermoclysis provides a good alternative for the offshore voyager who has little opportunity to maintain medical skills and no way to provide a stable treatment environment.
Jeffrey Isaac is a physician’s assistant with a particular interest in remote and extreme environments. He is a senior instructor with Wilderness Medical Associates, a licensed captain and an experienced bluewater sailor.