End-stage kidney disease (ESKD) requiring dialysis is a growing global problem. Dialysis patients often require surgery and invasive procedures for ESKD-related problems, including vascular access surgery, parathyroidectomy, and kidney transplantation, as well as elective or emergency surgery for other problems.
Pre-anesthetic management
Pre-anesthetic medications
Prevention of aspiration Diabetes-related gastroparesis may increase the risk of lung aspiration during induction of general anesthesia.
Anxiolytics Do not give intravenous mida** immediately before surgery to relieve anxiety, and titrate at a small dose (usually 05mg)。In patients with ESKD, the binding rate of mida** to protein is reduced, so the plasma free mida** concentration increases;In addition, the elimination of Mida** and its main metabolite, 1-hydroxymida**, was also slowed.
Opioids If intravenous opioid analgesia is required immediately before surgery, titrate at a small dose (eg, fentanyl, 25 g once).
Emergency surgical considerations
Nephrology consultation should be sought if dialysis is required as soon as possible prior to emergency surgery to correct severe hyperkalaemia, metabolic acidosis, or intravascular hypervolume.
Management of hyperkalemia— Nephrologic consultation may be required in the presence of hyperkalemia to assess the need for preoperative dialysis, but there are no guidelines for the maximum safe value of potassium before anesthesia induction. In addition, ECG abnormalities do not progress sequentially with potassium elevation, and the absence of ECG changes does not rule out hyperkalemia-induced cardiac arrest. However, if the serum potassium is 55MEQ L or with significant ECG changes, we will not use succinylcholine.
Management of hyperkalaemia for emergency surgery depends on the patient's usual and current serum potassium values, as well as the urgency of the procedure (i.e., whether it is safe to postpone surgery for dialysis). Other factors include the extent to which potassium release is expected to result from intraoperative tissue damage, the amount of blood loss and fluid transfer is projected, and the presence of acid-base disturbances (eg, metabolic acidosis) that may affect the rate of intraoperative potassium rise. If the serum potassium is 5 before or during emergency surgery5meq/l：
We generally continue the surgery, with special attention to intraoperative continuous ECG monitoring and immediate intraoperative potassium measurement. Succinylcholine should not be used because it may further elevate serum potassium and induce rapid ECG changes, leading to life-threatening arrhythmias. It is best for surgeons, anesthesiologists, and nephrologists to discuss the risks associated with continuing surgery versus dialysis followed by surgery, especially if ECG features of hyperkalaemia are seen. 1-2 hours of hemodialysis is generally sufficient to reduce the total body potassium concentration and blood potassium concentration to a safer range.
When dialysis is not possible, doctors perform surgery for life-threatening surgical conditions (eg, severe bleeding), regardless of potassium levels and ECG changes. If serum potassium is 65meq l, the anesthesiologist must temporarily control hyperkalemia with medication. Specific conditions for this hyperkalemia emergency** include:
Intravenous calcium (eg, calcium chloride 500 to 1000 mg) directly antagonizes the effect of hyperkalemia on cell membranes. Monitor ionized calcium so that hypocalcemia does not exacerbate potassium cardiotoxicity.
Intravenous insulin (usually combined with intravenous glucose) drives extracellular potassium ions into the cell.
If severe acute metabolic acidosis (i.e., pH < 71-7.2), Bicarbonate can be given 1-2 mEq kg to increase the pH value and drive extracellular potassium ions into the cell. If after 30 minutes, the pH is still 71. This dose can be repeated.
Continuous renal replacement** or haemodialysis (eg, during cardiopulmonary bypass during cardiac surgery) can be performed in the operating room if equipment and personnel are available, but are generally not necessary.
Management of intravascular volume overload— If the patient is hypervolemous, the surgeon, anesthesiologist, and nephrologist should discuss the risks associated with moderate or severe preoperative volume overload and dialysis followed by surgery, if time permits. Intraoperative fluid or blood transfusions can exacerbate preoperative intravascular volume overload and pulmonary edema, and postoperative dialysis and noninvasive positive pressure or controlled mechanical ventilation may need to be scheduled as soon as possible. High doses of loop diuretics may be effective in dialysis patients who still have some residual kidney function and urine output.
Intraoperative anesthesia management
Local anesthesia— Dialysis patients are often selected for local anesthesia with monitored anesthesia care (MAC) if surgical needs are sufficient. Sedatives, anxiolytics, or analgesics may be titrated intravenously in small doses as appropriate during MAC. Choose drugs with fast onset and short duration of action in order to quickly titrate to onset of action and promote rapid patient recovery. It is important to note that these drugs have dose-dependent respiratory depression and hypotensive effects. In addition, the volume of distribution, protein binding, and excretion of these drugs in patients with ESKD are altered, so drug metabolism may be slowed. We opt for propofol infusions and minimize opioids and benzodiazepines.
Regional anesthesia— Dialysis patients typically choose this modality if regional anesthetic techniques, such as peripheral nerve blocks or neuraxial anesthesia (spinal anesthesia or epidural), are sufficient for surgical requirements. Special considerations for patients with ESKD include the slow onset of the local anesthetic chosen due to low serum bicarbonate concentrationsDue to reduced protein binding, local anesthetics may have a shorter duration of action.
As with the combination of local anesthesia and MAC, regional anesthesia has the advantage of avoiding the risk of general anaesthesia and eliminating the need to administer multiple intravenous *** intravenous sedation, anxiolytics, or analgesics, titrated in small doses, if necessaryHowever, opioids should be used sparingly and benzodiazepines should not be used.
General anesthesia
Anesthesia induction. Sedative-hypnotic anesthetic-inducing and adjunctive drugs ESKD does not significantly alter the pharmacokinetics and pharmacodynamics of the sedative-hypnotic inducing drug propofol, which we usually use:Carefully titrate the drug in small doses (eg, 1 to 2 mg kg) to induce general anesthesia。High-dose boluses of propofol may cause severe hypotension (due to dilated veins and arteries) and decreased myocardial contractility.
When intubation is not required for rapid sequential intubationNMBA SelectionIf RSII is not required, non-depolarizing NMBAs are usually chosenAtracurium, cis-atracurium, or rocuroniumFacilitation laryngoscopy. The elimination of atracurium or cis-atracurium does not depend on renal function. However, the slow onset of action in both cases (3 to 4 minutes for atracurium and 5 to 7 minutes for cis-atracurium) is not well suited for RSII. As mentioned above, rocuronium bromide is a suitable alternative, especially for patients who require RSII.
Remifentanil intubation techniqueThe remifentanil intubation technique can facilitate laryngoscopy in patients who do not require RSII, thus avoiding the use of NMBA. This is done by giving propofol 1 to 2 mg kg, followed by a larger dose of the ultra-short-acting opioidFor fentanyl (eg, 2 to 3 g kg), it only takes about 2 minutes to get good intubation conditions。We give ephedrine 10 mg in combination with more than propofol and remifentanil to minimize severe bradycardia and hypotension caused by the combination of the latter two high doses, particularly in patients with ESKD.
Awakening from anesthesia— The following drugs can antagonize the effects of NMBA
Neostigmine There was no difference in pharmacokinetics between patients with ESKD and patients with normal renal function, neostigmine, a single dose of the anticholinesterase drug routinely used at the end of surgery.
Sugammadex Sugammadex is a chelating agent that encapsulates rocuronium or vecuronium bromide to rapidly antagonize neuromuscular blockade.
Intraoperative precautions
Fluid management— Intravenous fluid management in dialysis patients is difficult. Hypervolemia may lead to pulmonary edema, while hypovolemia may cause hemodynamic instability.
Liquid options include:
CrystalloidWe generally opt for balanced electrolyte solutions, but if the patient has hyperkalemia, normal saline. However, supplementation with large amounts of normal saline may result in hyperchloremic metabolic acidosis compared with equilibrium electrolyte solutions. It is important to note that hyperkalaemia may occur in patients with ESKD who are completely fasted (NPO) and intravenous fluids are not dextrose. However, if the patient has hyperglycemia or hypokalaemia, glucose-containing solutions should not be used, and glucose-containing solutions should be monitored if they are given.
Colloidal fluids-In rare cases where patients with ESKD need to be expanded rapidly and substantially, and there is no indication or condition for packed red blood cell transfusion, doctors in the United States use 5% albumin. In other countries, there are other colloidal fluids available, such as succinyl gelatin.
BloodBlood transfusions should be avoided as much as possible during the perioperative period. However, if HB < 7 g DL, especially if bleeding persists during surgery, red blood cell transfusions are usually needed. Potassium should be measured regularly during transfusions, as hyperkalaemia may occur in patients with anuria.
Blood sugar control— Maintain blood glucose < 180 mg dl (<10 mmol L) throughout the perioperative period, regardless of diabetes mellitus. Patients may develop hyperglycemia or hypoglycemia, especially those on dialysis for type 1 diabetes. Even in the absence of diabetes, glucose intolerance is characteristic of uremia.
Zhang Ziyin, The First Affiliated Hospital of Guangzhou University of Chinese Medicine.
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