and cause dyspnea, chest discomfort, and hemodynamic instability. In rare cases, a heart defect could allow air to pass from the right‐sided circulation into the arterial flow to the body, leading to stroke or myocardial infarction as an arterial gas embolism. A patient with air embolism requires hemodynamic support, high‐flow oxygen, and prevention of further air embolization. The venous line should be clamped, and the blood pump on the dialysis machine should be stopped. Positioning the affected patient in the left lateral recumbent position (right heart up) may help to stabilize trapped air in the right heart, stopping further embolization. Percutaneous aspiration of air from the ventricle in a patient in extremis may be performed by the EMS physician in the field or by qualified staff on arrival to the ED. Hyperbaric oxygen has been established as a treatment modality once the patient is stable enough for therapy [27].
Uncontrolled hemorrhage from shunt site
Patients undergoing hemodialysis have a high‐capacity vascular structure punctured multiple times weekly, leading to increased risk of bleeding. Grafts and fistulas have high blood flow and pressure compared to peripheral veins. Aneurysms are rare, but can occur, and may rupture catastrophically, causing exsanguination [4, 28]. More common is persistent bleeding after dialysis from the needle insertion site. The patient’s underlying platelet dysfunction, daily use of anticoagulants, and heparin use during dialysis can contribute to difficulty obtaining hemostasis. Typically, hemorrhage from the puncture site will respond to firm digital pressure directly over the bleeding site for 10‐20 minutes. If available, a thin layer of commercially available dressing with hemostatic agents (e.g., QuikClot®, HemCon®) or gauze with topical biological agents (e.g., thrombin, TXA) can also be used with direct digital pressure. Layers of gauze and compressive bandages should be avoided as they serve only to soak up blood and often do not provide the adequate direct pressure needed for hemostasis. Proximal tourniquet application should be used only in life‐threatening circumstances as a last resort, as this may result in permanent damage or loss of the patient’s dialysis access. It should be considered in only critical situations [4, 28].
Disequilibrium syndrome
Patients undergoing hemodialysis are at risk for a neurological manifestation of fluid and electrolyte shifts called disequilibrium syndrome. This syndrome may be severe enough to produce altered consciousness, seizures, or coma, although typically it involves mild symptoms of malaise, nausea, and headaches. This syndrome is a diagnosis of exclusion, as many life‐threatening entities can cause similar symptoms. Thus, the renal patient with the new onset of these features requires prompt evaluation. Treatment is similar to that of cerebral edema with consideration of IV hypertonic therapy and termination of dialysis [4, 30].
Complications of peritoneal dialysis
While electrolyte disturbances can occur, they are typically not as severe as in patients on hemodialysis. As the patient’s dialysis exchange occurs over a longer period, there is less gradient with the dialysate and electrolyte shifts are less abrupt.
The most common and serious complication in peritoneal dialysis is peritonitis, contributing to the cause of death for over 15% of peritoneal dialysis patients. The indwelling abdominal catheter is a nidus for infection. Patients with peritonitis may complain of abdominal pain or nonspecific symptoms of nausea, fatigue, or fever. They may range from being asymptomatic to frankly septic, with guarding of the abdomen and hypotension. Signs of peritonitis for the prehospital clinician include a change in the fluid coming from the catheter during a fluid exchange or purulent drainage from the catheter insertion site [31].
The fluid used for dialysis in peritoneal dialysis often contains high amounts of glucose, drawing water out of the body. In rare cases, patients can absorb the glucose and present with a hyperglycemic, hyperosmolar state and resulting critical illness from the same [32].
Special considerations
The missed dialysis patient
According to one study, the United States has one of the highest rates of missed dialysis treatment at 24% [33]. Younger patients consistently are found to have higher rates of compliance issues. As these patients require dialysis to sustain life, the patient who has missed a session (or several) is at higher risk for deterioration with increased rates of all‐cause hospitalization, all‐cause mortality, cardiovascular mortality, and sudden cardiac death [35].
When a patient who admits to having missed dialysis sessions presents to EMS, the more likely pathophysiology and required treatments can be inferred. Patients with respiratory distress are likely to have fluid overload. Management may be multimodal. Noninvasive positive‐pressure ventilation can be implemented in the awake patient to improve oxygenation [28]. Nitroglycerin is an option to facilitate fluid shifts by increasing venous capacitance. In the setting of uncomplicated fluid overload from dialysis noncompliance, the patient should be hypertensive and tolerate nitrates well [36]. Should the patient be exhibiting signs of cardiogenic shock, consideration should be given to pericardial tamponade [17].
Diuretics such as furosemide can be used in the renal disease patient, provided he or she makes urine. Careful assessment of the patient’s volume status should be made, as giving diuretics to an intravascularly depleted patient can worsen renal function. In the euvolemic or hypervolemic patient, higher than average doses of diuretic will be needed to overcome renal dysfunction [37].
Hyperkalemia
Dialysis‐dependent patients are already at risk for hyperkalemia; those who miss one or more regular sessions incur even more risk. If an ESRD patient presents with arrhythmia (peaked T‐waves, QRS widening, ventricular fibrillation, or ventricular tachycardia) or is unstable with hypotension or cardiac arrest, empiric management of hyperkalemia is warranted [12, 14, 38].
Intravenous calcium is administered for stabilizing the cardiac membrane. This therapy has a duration of action between 30 and 60 minutes, which may necessitate the need for redosing depending on transport times. Calcium gluconate is dosed at 1,000 mg (10 mL of 10% solution) IV over 2‐3 minutes. Calcium chloride can also be dosed at 500‐1000 mg (5‐10 mL of 10% solution) IV over 2‐3 minutes. Both agents require continuous cardiac monitoring and can be repeated after 5 minutes if ECG changes persist or recur [12, 14, 38].
Sodium bicarbonate can help to alkalinize the blood and promote the shift of potassium to intracellular spaces. This is most effectively administered as an isotonic infusion of a bicarbonate solution with concentration 150 mmol/L (typically three ampules in a liter of D5W), being mindful of the potential for fluid overload. Hypertonic formulations, conversely, have been shown to have a neutral effect on potassium as the solute drag that occurs with the hyperosmolar solution counterproductively increases extracellular potassium. The routine administration of hypertonic sodium bicarbonate is no longer recommended in the prehospital setting. There are data that show benefit in its use in hyperkalemic patients with severe acidosis (pH < 7.2) and in those with a contraindication to calcium (e.g., digoxin toxicity), acting to temporarily stabilize cardiac membranes. The dosing is 50 mEq (50 mL of 8.4% solution, commonly distributed as an ampule/needle combination for EMS and code carts) to be given IV over 5 minutes. This can be repeated every 10‐15 minutes if ECG changes persist or recur. Caution should be taken to ensure the IV line is flushed between calcium and sodium bicarbonate doses, as calcium carbonate can form and precipitate [12, 14, 38].
Albuterol can be given in the usual fashion to shift potassium out of the plasma. It is easily administered to the patient and has the advantage of being noninvasive. It can be given as a continuous nebulizer treatment with 10‐20 mg of albuterol solution in 4 mL of saline over 10 minutes. However, the onset of action is not immediate, the potassium level will rebound if not otherwise treated in the next few hours, and tachyarrhythmia is a possible consequence [12, 14, 38].
Regardless of the medication(s) used in the field, the ESRD patient with hyperkalemia will require definitive management, as these therapies serve only to either prevent arrhythmia or temporarily shift potassium from the plasma. The total body potassium