Procedures and Emergency Medical Techniques for Nonhuman Primates
The basic emergency triage procedures for nonhuman primates are identical to the triage of other small mammals. The basic triage examination consists of a survey of the respiratory, cardiovascular, urinary, and neurologic systems to identify life-threatening abnormalities. Blood sampling, intravenous catheterization, and FAST scans should be included in the preliminary evaluation. Sedation may be needed on more alert animals to perform diagnostic tests and treatments.
Normal Vital Parameter Reference Ranges
On larger primates weighing 1 kg or more, the saphenous or femoral vein is an ideal site for IV catheter placement. Size of the catheter can range from 26-gauge to 18-gauge, depending on the size of the vessel and the patient. The median cubital vein or the cephalic vein in the front limb can also be used. In an extreme emergency, a cut down over the femoral vein allows visualization and quick placement of the IV catheter. In smaller primates (<1 kg), intraosseous placement of catheters is recommended. The tibia (inserted through the tibial crest) or the femur (inserted into the greater trochanter) can be accessed for this purpose. As with all intraosseous catheters, survey radiographs should be taken to ensure proper placement. After placement of the catheter, it is important not only to place an E-collar on the patient but also to wrap all four limbs in bandages. Nonhuman primates are strong and dextrous and will remove the IV catheter by chewing or pulling if this is not done.
The femoral vein and artery are the preferred site for blood sample collection in nonhuman primates. If tolerated, these samples can be collected on awake and restrained patients. If sedation is needed, the dissociative drugs (eg, ketamine), can be used.
Larger New World primates may be intubated using typical small-animal techniques via visualization with a laryngoscope. As with all small mammals, it is important to measure correct endotracheal tube length, because the oral cavity and neck is shorter than in the dog and cat. Cuffs should not be over- or underinflated.
Old World primates such as macaques have cheek pouches and can have food stored in them. Care must be taken to check for and remove any food or debris from these pouches as soon as the patient loses jaw tone. This will reduce the chance of aspiration under general anesthesia. Small primates (<1 kg) and prosimians may be intubated with noncuffed avian endotracheal tubes. Typical sizes are 2 mm and 2.5 mm. If these are unavailable, red- rubber tubes may be adapted and used.
Surgical monitoring should include ECG, blood pressure, temperature, pulse oximetry, and capnography. In the smaller animals, a Doppler monitor with a human pediatric cuff can be used (easily on the tail) for both systolic blood pressure and auditory heart rates.
Pain should always be part of the emergency assessment. Inadequate pain control can cause increased stress on the cardiovascular and respiratory systems. Suggested analgesic and opioid drug doses are included in the table ( Nonhuman Primate Therapeutics a).