Anesthesia & Co-existing Diseases in the Parturient

1. Anesthesia & Co-existing Diseases in the Parturient Joseph E Pellegrini, CRNA, PhD

2. Co-existing Disease • Estimated that approximately 10-15% of all parturients have some co-existing disease • Most benign • Discussion for all diseases beyond scope of this discussion • Autoimmune Diseases • Effects 1-2 % of all pregnancies • Systemic Lupus Erythematosus • Systemic Sclerosis (Scleroderma) • Myasthenia Gravis • Diabetes Mellitus • Obesity • Neurological and Neuromuscular Disease • Multiple Sclerosis

3. Systemic Lupus Erythematosus • Multisystem inflammatory disease of unknown etiology that is characterized by the production of autoantibodies against cell membrane antigens • Most common in women in childbearing years • Overall see more prevalence in African Americans, Asians & Native Americans than Caucasians • Occurs in 1:1200 deliveries

4. Systemic Lupus Erythematosus

5. Systemic Lupus Erythematosus • Anesthetic Management • Coordinated effort between OB, Rheumatology & Anesthesia • Evaluate for organ involvement • Periocarditis • Typically asymptomatic • Evaluate EKG for prolongation of PR interval or non-specific T wave changes • Evaluate exercise tolerance • Valvular Disorders • More prone to Valvular thickening (51%), Vegetations (43%), Regurgitation (25%) and Stenosis (4%) • Prophylactic antibiotics only required if patient at high risk for endocarditis (previous infective carditis, unrepaired cyanotic heart disease, implanted prosthetic devices, cardiac transplantation with cardiac valvulopathy). Not recommended for women with common valvular lesions undergoing GU procedures (which includes vaginal delivery) • Neuropathies • Central & Peripheral neuropathaties noted in approximately 25% of all SLE patients • Vocal Cord palsy – evaluate all SLE prior to implementation of GA/CLE etc • Note any area of sensory deficit prior to implementation of any neuraxial anesthesia/analgesia • Early implementation of Regional Anesthesia recommended

6. Systemic Sclerosis (Scleroderma) • Scleroderma is a chronic progressive disease characterized by deposition of fibrous connective tissue in the skin and other tissues • 240 million Americans have Scleroderma • No proven treatment exists for the arrest of scleroderma • Therapy geared towards improving existing symptoms and preventing end organ damage • Five times more prevalent in women than men • Occurs between the ages of 30-50 • Death is usually 15-20 years after diagnosis from renal failure & malignant hypertension • Becoming more of a problem with recent trend towards first time pregnancies at 30+ years of age • Effect on Pregnancy • Typically symptoms unchanged with pregnancy • Approximately 20% will have worsening of symptoms with significant esophageal reflux, cardiac arrhythmias, arthritis, renal crisis • ACE inhibitors are treatment of choice for scleroderma associated renal crisis • However ACE inhibitors are typically not administered during pregnancy secondary to high incidence of teratogenicity however they should be given at the first indication of maternal hypertension • Evaluate parturient for evidence of renal, pulmonary & cardiac dysfunction • Work in collaboration with specialists • Some obstetricians recommend termination of pregnancy in advanced disease • Prone to pulmonary HTN, cardiac dysfunction, obstructive uropathy (from enlarged uterus) • No increased frequency of miscarriage • Preterm labor occurs in 25% of pregnancies (as compared to a 5% national average)

7. Systemic Sclerosis (Scleroderma) • Anesthetic Management • Requires a multi-disciplinary approach • Evaluation of patient should be done prior to labor and delivery • History & Physical directed toward detection of underlying systemic dysfunction • Lab tests • CBC, Coagulation profile, Full Chemistry Panel with creatinine clearance, ABG, Urinalysis with protein • Evaluate for presence of Reynaud’s phenomenon prior to ABG • EKG & PFT’s • Should be performed in all patients • Echocardiography useful to evaluate ventricular dysfunction, pericardial and pleural effusions and pulmonary HTN • Very thorough examination of upper airway • Can have severe limitation of oral opening • Evaluate maximal oral opening, ability to sublux the mandible, visualization of oropharyngeal structures, degree of atlanto-occipital joint extension and presence of nasal or oral telangiectasias • Prepare for possibility of awake intubation (equipment for fiberoptic and emergency cricothyrotomy should be available in labor and delivery suite)

8. Systemic Sclerosis (Scleroderma) • Anesthetic Implications • Epidural anesthesia can be used • Can see severe prolongation of motor and sensory blockade • Initiate analgesia/anesthesia using small incremental doses • Incremental doses preferable over continuous infusion for laboring analgesia • Decision to use epidural or GETA dependent on urgency for cesarean section • Spinal anesthesia has been used but difficulty treatment of hypotension • Epidural anesthesia preferable over Spinal anesthesia • General Anesthesia most frequently used in severe cases • Awake versus RSI?? • CVP cannulation may be required in patients with diffuse cutaneous involvement • Extensive skin involvement may lead to inaccurate non-invasive blood pressure readings • Arterial blood pressure measurements preferable in severe cases • Radial artery catheterization contraindicated in patients with Reynaud’s phenomenon • Brachial artery catherization can be used

9. Myasthenia Gravis • Rare Autoimmune Disorder • Progressive muscle weakness • Destruction of ACTH receptors • Typically treated with anticholinergic agents such as neostigmine or edrophonium • Women 3 times more likely to develop • Typically manifests before age 40 • Pregnancy can exacerbate symptoms(cholinergic crisis) • Usually requires adjustment of neostigmine doses

10. Myasthenia Gravis (Contraindicated Drugs)

11. Myasthenia Gravis • Anesthetic Management • Careful History and Physical Exam • Best if done before she presents for L&D • Document all medications dose & frequency • Look for possible interactions between drugs • Most commonly on neostigmine • Maintain on normal regimen • IV dose is given in ratio of 30:1 to oral dose • Monitor fetal HR closely • Observe for s/s of “cholinergic crisis”

12. Myasthenia Gravis • Cholinergic Crisis • Profound muscle weakness • Respiratory failure • Loss of bowel and bladder function • Disorientation • Diplopia

13. Myasthenia Gravis • Anesthetic Management • Regional Anesthesia preferable to General Anesthesia • If GETA is required keep to absolute minimum • 1/2 MAC usually adequate • Highly sensitive to both depolarizing and non-depolarizing neuromuscular blocking agents • Intubation doses are typically 1/2 to 1/3 normal • More receptive to effects of opioids and local anesthetic agents

14. The Diabetic Parturient Diabetes Mellitus prevalence 6.8-8.2% in the general population Most common medical problem of pregnancy Incidence 1:700 to 1:1000 gestations Hyperplasia of -cells of maternal islets of Langerhans Pregnancy produces higher levels of insulin Altered insulin requirements throughout pregnancy Two types Type 1 – Decrease in insulin secretion Primarily an autoimmune disorder Type 2- Resistance to insulin in target tissues Accounts for 90-95% of the cases of DM in U.S. Gestational Diabetes Refers to DM that is first diagnosed in pregnancy Present in 4% of all pregnancies in U.S. Insulin requirements Diet Control

15. Gestational Diabetes Associated with: Advanced maternal age Obesity Family history of DM History of stillbirth, neonatal death, or fetal malformation or macrosomia Presents when patients cannot mount a sufficient compensatory insulin response during pregnancy More prevalent in 2nd and 3rd trimesters After delivery most parturients return to normal glucose tolerance Recurrence rate with subsequent pregnancies 52-68%

16. Prevalence Rates

17. Whites Classification

18. Major Complications • Acute Complications • Diabetic Ketoacidosis • Hyperglycemic nonketotic state • Primarily occurs in Type II diabetes • Hypoglycemia • Chronic Complications • Macrovascular • Coronary • Cerebrovascular • Peripheral Vascular • Microvascular • Retinopathy • Nephropathy • Neuropathy • Autonomic • Somatic

19. The Diabetic Parturient • Pregnancy associated with a progressive peripheral resistance to insulin in 2nd & 3rd trimester • Diabetes associated with higher incidence of gestational HTN, polyhydramnios and cesarean delivery • Initiation of early glycemic control is the best way to prevent fetal structural abnormalities • Determination of hemoglobin A1C concentrations help determine adequacy of glycemic control • Normal range is 4-6% • Increased risk of microvascular and macrovascular disease begins at 6.5%

20. Stiff Joint Syndrome 30-40% in Type 1 Diabetics Occurs in patients with long-standing type 1 diabetes and is associated with nonfamilial short stature, joint contractures and tight skin Direct laryngoscopy can be difficult in 30% of all parturients with DM C-spine rigidity (atlanto-occipital joint) Ensure plan for emergency airway in place Planned general anesthesia Awake intubation? Fiberoptic intubation Preanesthestic management Controversial Some recommend pre-anesthetic flexion-extension cervical spine x-rays No evidence to indicate that having pre-anesthetic cervical spine series makes a difference

21. Anesthetic Management Maternal insulin requirements increase progressively during the 2nd and 3rd trimester & decrease at the onset of labor and continue to decrease following delivery Preanesthestic Evaluation Absorption of SQ insulin is unpredictable IV insulin therapy more flexible Obtain Preoperative or pre-anesthesia intervention serum glucose levels Controversy regarding use of insulin infusion during labor and delivery Tighter controls recommended if patient is going to cesarean section Evaluate End Organ Damage Diabetic Autonomic Neuropathy HTN Orthostatic Hypotension Painless MI Decreased HR variability Decreased response to medications Atropine and propanolol Resting tachycardia Neurogenic atonic bladder Hemoglobin A1C Measure of overall serum glucose Gastroporesis with delayed emptying Sodium Citrate Consider metoclopramide and H2 antagonist premed

22. Management in Operating Room Intraoperative Ensure good intravenous line in place Evaluate preoperative serum glucose levels with IV start Begin D5W 1-1.5 ml/kg/hr as an IV piggy back into crystalloid solution Administer insulin Either One-half of total daily dose as intermediate form (NPH) plus an intraoperative “sliding scale Continuous infusion of regular insulin Start infusion based on serum glucose using formula: Units/hr = Plasma glucose/150+ (desired range of 150 etc) i.e. plasma glucose of 220/150 = 1.4 units/hr (usually delivered in 250 units regular insulin/250 ml 09% NaCl solution Monitor Blood Glucose Maintain serum glucose > 100 mg/dl Avoid hypoglycemia and hyperglycemia Infection Important cause of morbidity in pregnant women No data regarding incidence of CNS infection after administration of neuraxial anesthesia Obviously ensure strict aseptic technique during administration Poor wound healing noted in diabetic parturients **Can see protamine sulfate anaphylaxis in patients taking NPH or protamine zinc insulin

23. Clearance of Local Anesthetic One study showed delayed clearance and higher serum levels following epidural lidocaine administration in diabetic groups Study used 20 ml Possible toxicity if large volumes used Caudal anesthesia etc Moises EC et al. Eur J Clin Pharmacol. Pharmacokinetics of lidocaine and its metabolite in peridural anesthesia administered to pregnant women with gestational diabetes mellitus. 2008 Dec;64(12):1189-96

24. Diabetes Mellitus

25. Obesity • Obesity is a public health issue in most developed countries • Obese parturients at risk for medical & obstetrical (and anesthesia) complications during pregnancy • Difficulty with intubation • All know difficulties with intubation and GETA • Problems with placement of neuraxial anesthesia • Significant differences in anesthetic requirements during labor & delivery and at cesarean section

26. Obesity • Study to determine the minimum local anesthetic concentration (MLAC) of bupivacaine in women at term gestation • MLAC for obese women (> 30kg/m2) was 41% lower than non-obese women • Despite lower anesthetic concentrations administered to obese women they achieved higher sensory blockade with no differences in pain scores • Greater distribution of epidural local anesthestic within epidural space in obese women • Don’t standardize epidural dose Panni MK, Columb MO. Obese parturients have lower epidural local anesthetic requirements for analgesia in labour. Br J Anaesth 2006; 96: 106-10.

27. Multiple Sclerosis • Major cause of neurological disability in young adults • incidence of 0.3-0.8% of population • Presents over a period of several years as two general patterns: • Exacerbating remitting- attacks appear abruptly & resolve over several months • Chronic progressive • Manifest as neurological defects that present as pyramidal, cerebellar or brainstem symptoms

28. Multiple Sclerosis • Etiology is unclear • ? Link to previous exposure to viral agent that may trigger autoimmune response • Loss of myelin in CNS • Most common Symptoms • Motor weakness, impaired vision, ataxia, bladder & bowel dysfunction and emotional lability • No curative treatment • Treat symptomatically & by immunosuppression • Often tx is marked by relapses & regression of Sx

29. Multiple Sclerosis • Interaction with pregnancy • No effect on progression of MS • Slight increased risk for relapse during pregnancy • Stress, exhaustion, infection and hyperpyrexia may contribute to relapse (most often in the postpartum period) • Pregnancy does not have an overall negative effect on the long-term outcome of MS

30. Multiple Sclerosis • Anesthetic Management • Careful assessment of neurological and respiratory compromise (if any) • Note any areas of motor weakness, visual disturbances or bowel and bladder disorders • Auscultate all lung fields • Assess any anomalous finding with AP & Lateral Chest X-ray and pulmonary function test before analgesic intervention initiated

31. Multiple Sclerosis • Concerns w/ neuraxial anesthesia • exposures of de-mylinated areas of spinal cord to potential neurotoxic effects • concerns over relapse of symptoms • Recommended • Do not exceed concentrations > 0.25% bupivacaine in CLE infusions • Epidural anesthesia better tolerated than SAB • SAB has been successfully employed • CSF concentrations 4 fold higher with SAB than CLE • CSE technique well tolerated with IT opioids

32. Multiple Sclerosis • General Anesthesia • Not contraindicated • Succinylcholine should be avoided with severe musculoskeletal involvement • Remain cognizant of pulmonary complications and maintenance of normal body temperature

33. Multiple Sclerosis

34. Questions??Pellegrini@son.umaryland.edu