CC
A 68-year-old (age is a risk factor) African American (highest risk factor) female with a history of end-stage renal disease (ESRD) presents with her third episode of acute pericoronitis in 18 months.
HPI
The patient has an impacted lower third molar that causes intermittent pain and has given rise to moderate right-sided facial swelling, fever, malaise, and anorexia.
PMHX/PDHX/medications/allergies/SH/FH
The patient’s medical history is notable for poorly controlled diabetes mellitus, hypertension, hypercholesterolemia (all risk factors), ESRD on hemodialysis on a Monday–Wednesday–Friday schedule, secondary hyperparathyroidism (renal osteodystrophy), and anemia. Her dental history is significant for multiple extractions over the past 20 years. Medications include insulin, felodipine (a calcium channel blocker), metoprolol (a beta-blocker), and losartan (an angiotensin receptor blocker).
Imaging
A panoramic radiograph reveals a mesioangular impacted right mandibular third molar with a pericoronal radiolucency. Renal osteodystrophy (secondary hyperparathyroidism) is evident as seen by a generalized “ground-glass” pattern of the bone, loss of lamina dura, and a maxillary unilocular radiolucency (osteitis fibrosa cystica). This is a result of decreased renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (active vitamin D). A decrease in active vitamin D results in reduced gastrointestinal adsorption of calcium with a corresponding increase in parathyroid hormone to augment serum calcium levels by increasing bone resorption.
Labs
Laboratory tests are ordered based on the severity and acuity of symptoms related to ESRD in conjunction with the patient’s nephrologist and internist. Baseline complete blood count, metabolic panels, liver function tests, and coagulation studies are usually obtained.
The following laboratory study results were obtained for this patient:
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Complete blood count: white blood cells (WBCs), 14,000/μL; hemoglobin, 9.2 g/dL; hematocrit, 29.2%; platelets, 265,000/μL
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Chemistry: sodium, 145 mEq/L; potassium, 5.6 mEq/L; bicarbonate, 22 mEq/L; blood urea nitrogen (BUN), 68 mg/dL; creatinine, 6.9 mg/dL; glucose, 167 mg/dL; calcium, 7 mg/dL; phosphate, 5.2 mg/dL
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Coagulation studies: prothrombin time, 11 seconds; partial thromboplastin time, 33 seconds; international normalized ratio, 1.0
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Liver function tests: aspartate aminotransferase, 42 U/L; alanine aminotransferase, 33 U/L; γ-glutamyl transpeptidase, 43 U/L; alkaline phosphate, 34 U/L
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Urinalysis: 3+ proteinuria; no red blood cells, WBCs, or casts
The laboratory findings are characteristic of ESRD. The hemoglobin and hematocrit are decreased secondary to the decreased production of erythropoietin by the kidneys. The elevated BUN and creatinine levels reflect severely reduced glomerular filtration rate (GFR), which is also responsible for the elevated serum potassium. Proteinuria is a result of increased glomerular permeability. The decreased calcium level should be corrected to the serum albumin level (or by checking an ionized calcium level); if confirmed, it could be a result of decreased gastrointestinal absorption of calcium secondary to decreased renal production of active vitamin D. She has a 28-pack-year smoking history (risk factor).
Examination
General. The patient is a mildly obese female in mild distress secondary to pain.
Vital signs. Her blood pressure is 162/98 mm Hg, heart rate is 104 bpm, respirations are 18 breaths per minute, and temperature is 38.8°C.
Neurologic. She is alert and oriented to place, time, and person.
Maxillofacial. There is fluctuant, tender, and erythematous right-sided facial swelling extending from the angle of the mandible to the right submandibular space. The floor of the mouth and the oropharyngeal airway are normal. The right mandibular third molar (tooth #32) is noted to be impacted with swelling of the surrounding operculum. Right submandibular lymphadenopathy is noted.
Pulmonary. The chest is clear to auscultation bilaterally.
Cardiovascular. She has a regular rate and rhythm with no murmurs, rubs, or gallops.
Extremities. There is no swelling, edema, or muscle weakness. She has left upper arm arteriovenous fistula, which is patent with a good thrill.
Assessment
End-stage renal disease complicating management of an odontogenic abscess.
Treatment
The management of a patient with ESRD is often complicated. Of particular concern are fluid status and electrolyte balance. Ideally, correction of metabolic and fluid abnormalities should be made in conjunction with a nephrologist before any surgical interventions. This may be preferably accomplished by performing a dialysis session (to achieve euvolemia and normal electrolytes) or occasionally by judicious hydration (in case of hypovolemia). Knowing the patient’s current weight and comparing it with her “dry weight” from the dialysis clinic (the ideal body weight in absence of edema, dyspnea, or poorly controlled hypertension) is very helpful to decide about volume status management. Careful electrolyte management (for hypo- or hyperkalemia) can be reached by either performing dialysis or using exchange resins to lower potassium if dialysis is not immediately available. Dialysis is typically performed either by hemodialysis (most commonly used modality in the United States and directly applicable to this case) or peritoneal dialysis (less common in the United States but widely used in other countries). The optimal control of blood pressure can be challenging in patients with ESRD, ranging from persistent hypertension, intradialytic hypotension, labile hypertension, or persistent hypotension. Ultrafiltration (removal of fluid during dialysis) and antihypertensive medications are routinely used for hypertension, and midodrine is often used in patients with hypotension.
Many medications, particularly antibiotics, need to be appropriately dosed or avoided based on the level of kidney function and dialyzability of the drug. All patients with ESRD who are able to take oral nutrition should have a renal diet low in sodium and potassium but increased protein (as opposed to pre-ESRD patients, who need to be on moderate protein restriction). Patients receiving dialysis are best scheduled for surgery the day after dialysis (to optimize fluid and electrolyte balance and to avoid the consequences of possible intradialytic hypotension on the days of dialysis). The patient’s usual dialysis can be resumed the day after surgery. In case of postoperative hyperkalemia or fluid overload, dialysis may be needed urgently after surgery. The use of exchange resins (polystyrene sulfonate) can lower the serum potassium level rapidly. However, and because their onset of action is slow, the newly approved potassium-lowering agents such as patiromer (Veltassa) and sodium zirconium cyclosilicate (Lokelma) are not indicated in acute severe hyperkalemia and are only useful for management of chronic mild to moderate hyperkalemia in patients with ESRD. Patients undergoing hemodialysis often are on low to moderate (considered isocoagulant) doses (500–5000 IU) of heparin during dialysis to prevent filter clotting. If there is a particular concern about increased peri- and postoperative risks of bleeding, waiting a minimum of 6 hours after cessation of heparin or avoiding heparin for that preoperative session is a reasonable management strategy. Patients with successful renal transplants may be considered to have adequate renal function but commonly receive immunosuppressive drugs, including corticosteroids, placing them at increased risk for infections and adrenal insufficiency (requiring stress doses of hydrocortisone) in the perioperative period.
The initial management of this febrile and anorexic patient included fluid resuscitation. In patients with ESRD who are septic and hypovolemic, normal saline should be administered by stepwise boluses of 500 cc at a time (to avoid volume overload). Fluid resuscitation caused dilutional reduction of the serum creatinine to 6.1 mg/dL. The patient’s elevated temperature was treated with acetaminophen after blood cultures were drawn. As much as possible, nonsteroidal antiinflammatory drugs (NSAIDs) should be avoided even in patients with ESRD who are nonoliguric. This is helpful in preserving their residual urine output that has a mortality benefit in this population.
Although the degree of hyperkalemia was only mild and the cardiac tolerance of mild hyperkalemia is typically much better in ESRD patients, an electrocardiogram was performed to evaluate for loss of P waves, widened QRS complex, and peaked T waves (none of which were present). Kayexalate was given orally to lower the serum potassium level. The patient was started on intravenous (IV) clindamycin. No dosing adjustment was needed because the clearance of this drug is largely hepatic. Preoperative pain control was achieved primarily with a scheduled hydrocodone–acetaminophen combination with morphine for breakthrough pain. Hydrocodone and morphine are metabolized hepatically via conjugation, but their metabolites are renally excreted. The half-lives therefore tend to increase in those with ESRD, and a reduction in frequency of administration (every 8 hours) was needed to avoid toxicity and excessive sedation.
Hyperglycemia was initially treated with sliding-scale insulin. On the second day after admission, incision and drainage of the right submandibular abscess and removal of the right mandibular third molar were performed under a general anesthetic. The postoperative course was uneventful. The patient was placed on an ESRD renal diet as soon as she was able to eat, and at that time, her usual insulin regimen was begun.
Complications
This patient had already reached ESRD and was already on chronic dialysis. In case of advanced chronic kidney disease (CKD) before initiation of dialysis, the development of uremic symptoms (often when the GFR is <10 or 15 mL/min) is associated with a variety of symptoms. These symptoms are listed in Table 100.1 .
