Surgery Considerations for Patients with Autoimmune Diseases
In autoimmune conditions, the immune system mistakes body proteins as foreign antigens and begins attacking the body’s own tissues. This can occur in any body system or structure. In addition to the damage caused by the immune system attack, the overactivation of inflammatory responses contributes to the pathology of autoimmune conditions. A useful comparison is type 1 and type 2 diabetes mellitus. Type 1 diabetes is an autoimmune condition affecting the insulin-producing cells of the pancreas. Type 2 diabetes does not have an autoimmune mechanism and is instead related to insulin resistance of the cells (Hulst et al, 2019). Both lead to an inability to bring glucose into the cells and the buildup of sugar in the blood. Because they have the same outcome, the conditions are often assumed to be equivalent for surgical consideration; however, it has been found that people with type 1 diabetes are at higher risk for hyperglycemia and hypoglycemia after their procedure (Hulst et al, 2019). Patients with an autoimmune disease require special care when undergoing surgery.
Surgery considerations for autoimmune diseases are as varied as the conditions themselves. Antiphospholipid syndrome and multiple sclerosis are examples of conditions that require special considerations for surgery. In both cases, the effects of medication therapies for the autoimmune condition must be taken into account, as well as understanding how surgery could exacerbate underlying pathology.
Antiphospholipid syndrome (APS) is a disorder of blood clotting. In APS, the immune system creates antibodies that act against the body’s natural anticoagulant factors, causing the blood to be hypercoagulable (Kim et al, 2020). This leads to the abnormal formation of thrombi (blood clots) and can cause strokes, heart attacks and other tissue damage. Management of APS is focused on anticoagulation and can include anticoagulant drugs like warfarin and antiplatelet drugs like low-dose aspirin (Kim et al, 2020).
An autoimmune condition that impacts blood clotting has significant implications for surgery, and the risk of both perioperative bleeding and perioperative thrombosis must be managed. In some low bleeding risk surgeries, it is recommended that patients with APS continue taking aspirin since they are at high risk for thrombosis (Kim et al, 2020). For other surgeries, there is a recommendation to interrupt normal anticoagulation therapy with a withdrawal period of 5 to 7 days. It is suggested to instead use a high-dose bridging therapy, such as heparin (Kim et al, 2020). With the bridging therapy, there should be a 4-24 hour buffer period between the last dose of the anticoagulant and the start of the surgery, depending on the medication used. Bridging therapy should also be used after the surgery (Kim et al, 2020).
During surgery, coagulation monitoring and antithrombotic compression devices should be used. In emergency surgery, low-dose vitamin K or fresh frozen plasma can be given preoperatively in order to correct the effects of continuous anticoagulant therapy. Cardiac surgeries would also have their own additional considerations (Kim et al, 2020).
Despite precautions, surgery itself can be a triggering factor for catastrophic APS, causing microthrombi in organs. Care teams should be prepared for this risk and should provide immediate aggressive treatment with a combination therapy of glucocorticoid, heparin and IV antibodies if suspected (Kim et al, 2020).
Multiple sclerosis (MS) is an autoimmune condition affecting the central nervous system (CNS). In MS, the immune system attacks myelin, the fatty substance surrounding nerves that allows for fast signal conduction, causing pain and sensorimotor deficits. Medication to manage MS includes common pain medications, immunomodulatory medications such as interferons, and medication to regulate movement dysfunction, such as Baclofen (Makris et al, 2014).
Interference between medication therapy and anesthesia is an important consideration during surgery. For example, Baclofen can cause patients to be extremely sensitive to muscle relaxants, and may require a 2-week withdrawal period prior to surgery. However, research reported that 20% of MS patients see a resurgence of disease activity within 30 days if treatment is discontinued, so it is best if patients do not need to discontinue their therapies (Makris et al, 2014).
Prior to surgery, it is important for patients to undergo a respiratory assessment to help determine anesthesia risk, as some respiratory dysfunction is common. Patients can also be given a premedication such as midazolam to decrease stress, which is a trigger for MS symptoms (Makris et al, 2014).
Medications given during surgery can include neuromuscular blocking drugs (NMBDs). MS patients, however, can have unpredictable responses to NMBDs: changes in nerve receptors can increase resistance to the drugs or, conversely, loss of muscle mass can increase sensitivity. As a result, neuromuscular monitoring is necessary (Makris et al, 2014). Additionally, the NMBD succinylcholine should not be used for patients with MS due to the risk of hyperkalemia (high potassium levels) that can cause disease exacerbation and be life-threatening (Makris et al, 2014). Finally, there is some concern that demyelinated nerves will abnormally uptake local anesthetics, causing further damage, and caution is advised in using intravenous lidocaine. CNS blocks such as epidurals, however, have been shown not to cause disease complications (Makris et al, 2014).
References
Hulst AH, Polderman JAW, Kooij FO, et al. Comparison of perioperative glucose regulation in patients with type 1 vs type 2 diabetes mellitus: A retrospective cross-sectional study. Acta Anaesthesiol Scand. 2019;63(3):314-321. doi:10.1111/aas.13274
Kim JW, Kim TW, Ryu KH, Park SG, Jeong CY, Park DH. Anaesthetic considerations for patients with antiphospholipid syndrome undergoing non-cardiac surgery. J Int Med Res. 2020;48(1):300060519896889. doi:10.1177/0300060519896889
Makris A, Piperopoulos A, Karmaniolou I. Multiple sclerosis: basic knowledge and new insights in perioperative management. J Anesth. 2014;28(2):267-278. doi:10.1007/s00540-013-1697-2