cohort. In the acutely ill patient, management is similar, including oxygen and nitrates. High‐flow nasal or face mask oxygen, noninvasive positive‐pressure ventilation, or intubation and ventilation may be required for worsening respiratory distress. Focused point of care ultrasound can provide information regarding the nature of cardiac contractility or pericardial effusion from uremia. Ultimately, dialysis may be required to offload fluid and facilitate return to baseline hemodynamic and pulmonary function [4, 11]. The availability of emergent dialysis must be considered by the EMS clinician when deciding on the most appropriate destination for the patient.
Potassium
Perhaps the most well‐known and feared complication of renal failure is that of hyperkalemia. The healthy kidney excretes 95% of the daily potassium intake [12]. Fatal arrhythmias are most likely to occur with serum levels over 9 mEq/L [13]. Hyperkalemia is associated with poor outcomes in both the general population and in patients with renal disease. It has been found to be an independent predictor of inpatient mortality [14]. Nonetheless, a patient with CKD can often tolerate higher levels of potassium than a healthy individual can and generally has a lower risk of mortality for any given serum potassium level as compared with the general population [15]. In contrast to other electrolyte abnormalities, the patient with hyperkalemia may not voice any specific complaints. The ECG is often used as a screening test for electrolyte disturbance, but it has overall poor sensitivity and specificity (Figures 22.1 and 22.2). ECG tracing changes that may be seen in hyperkalemia are listed in Table 22.1. While it is an easy and noninvasive test, the EMS clinician must not exclusively rely on an ECG for patient evaluation [13]. Specific management of hyperkalemia will be addressed later in the chapter.
Figure 22.1 ECG of a patient with hyperkalemia. Note wide complex tachycardia and development of sine wave.
Figure 22.2 ECG of patient with hyperkalemia with junctional bradycardia.
Magnesium
Like potassium, the kidney functions to excrete magnesium from the body. A kidney that is impaired by acute or chronic disease may lose its ability to conserve magnesium, while ESRD implies loss of ability to excrete magnesium. Thus, hypomagnesemia can occur in kidney disease and hypermagnesemia in ESRD. A patient with a magnesium disturbance may have an arrhythmia or ECG abnormality, often related to QT interval changes. Classically, patients with low magnesium have increased reflexes and weakness with a prolonged Qtc interval. Hypermagnesemia is associated with hyporeflexia, mental status changes, and respiratory depression progressing to cardiac arrest. ECG findings may mimic hyperkalemia with peaked T‐waves, QRS widening, and possibly complete heart block [4,16].
Table 22.1 ECG changes in hyperkalemia
| Peaked T‐waves | Slow atrial fibrillation |
| PR prolongation | Sine wave |
| Wide unusual QRS complexes | Asystole |
| Conduction blocks | Ventricular fibrillation |
| Bradycardia | Wide complex pulseless electrical activity |
Pericarditis
Inflammation of the pericardium with or without effusion is a known complication for dialysis patients. Uremic pericarditis is defined as development of pericarditis before or within 8 weeks of initiating dialysis, while dialysis‐associated pericarditis is thought to occur after the 8‐week mark of dialysis treatment. More classic etiologies such as infectious, postmyocardial infarction, and constrictive are also possible [17].
A patient with both uremic and dialysis‐associated pericarditis may present similarly with fever, chest pain that can be positional in nature, and a friction rub heard on cardiac exam. Classic ECG findings may not be present, as the inflammatory cells associated with noninfectious ESRD pericarditis do not involve the epicardium. The ultimate treatment for ESRD pericarditis is dialysis [4, 17].
Cardiac tamponade is a realistic possibility, and it should be considered in the hypotensive, dyspneic ESRD patient with distant heart sounds, elevated jugular venous pressure, pulsus paradoxus, or electrical alternans on ECG [17]. Focused point of care ultrasound may be used to aid in this diagnosis in the prehospital setting.
Cardiovascular disease
Cardiovascular disease is prevalent in the ESRD and CKD population. Accounting for 39% of deaths among dialysis patients, death from cardiovascular disease is more common in CKD patients than their progression to ESRD. While kidney disease and heart disease have similar causal factors, unique properties of the renal patient’s physiology also impose higher cardiac risk. Such factors as inflammation, oxidative stress, uremia, and metabolic abnormalities contribute to higher coronary artery disease incidence and mortality. Diagnosis of cardiac disease can be more difficult in this patient population. Typical ECG findings of ischemia may be subtle due to baseline ECGs with underlying left ventricular hypertrophy and acute changes related to electrolyte disorders or fluid overload. When present, though, classic ST‐segment changes indicative of acute coronary syndrome are the same in the ESRD patient as the nondialysis patient [18,19].
Stroke is also more common in renal disease patients than the general population. The risk is increased in patients with more advanced CKD, and even higher rates of stroke exist in the first year after dialysis begins. Both hemodialysis and peritoneal dialysis carry elevated stroke risks, although incidence may be slightly lower for the latter [20].
Hematologic
Patients with kidney disease are often anemic. Their red blood cell counts tend to be low, with hemoglobin usually less than 10 g/dL upon starting dialysis [1]. The cause is multifactorial and includes renal undersecretion of erythropoietin, a hormone responsible for red blood cell production [4].
Uremic bleeding is also thought to be multifactorial, though primarily due to platelet dysfunction. The resulting prolonged bleeding time can cause complications in the trauma setting and with routine access of fistulas and grafts during hemodialysis, prompting activation of the EMS system for potentially life‐threatening hemorrhage [21]. When presented with a bleeding dialysis patient, the EMS clinician may need to be more aggressive than usual with regard to direct pressure, hemostatic agents, and tourniquet application.
Infection
Renal patients, especially those with ESRD, have an increased risk for infection, with greater associated morbidity and mortality. Uremia is associated with dysfunction in both innate and adaptive immune systems
