Anesthesia & Co-existing Diseases in the Parturient

Joseph E Pellegrini, CRNA, PhD

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

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

Systemic Lupus Erythematosus

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

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)

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)

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

Systemic Sclerosis (Scleroderma)

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

Myasthenia Gravis (Contraindicated Drugs)

Antibiotics Gentamycin Kanamycin Steptomycin Plymyxin Colistin Tetracycline Lincomycin

Tocolytics

Magnesium Sulfate

Cardiac Meds

Quinidine Propanolol

Beta Mimetics

Ritrodrine Terbutaline

Others

Quinine Penicillamine Lithium Salts

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”

Myasthenia Gravis

Myasthenia Gravis

Cholinergic Crisis Profound muscle weakness Respiratory failure Loss of bowel and bladder function Disorientation Diplopia

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

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

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%

Prevalence Rates

Modified White Classification of Diabetes Mellitus During Pregnancy

Class Age of onset (yrs) Duration of diabetes (yrs)

Vascular Disease

Insulin Required

Gestational Diabetes

A1

A2

Any

Any

Any

Any

-

-

-

+

Pregestational Diabetes

B

C

D*

F

R

T

H

>20 <10 - +

10-19 (or) 10-19 - +

<10 (or) >20 + +

Any Any + +

Any Any + +

Any Any + +

Any Any + +

*Vascular Disease in D is hypertension or benign retinopathy

F, Nephropathy; R, proliferative retinopathy; T, status-post renal transplant; H, ischemic heart disease

Whites Classification

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

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%

The Diabetic Parturient

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

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

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

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

Diabetes Mellitus

Fetal Glucose Utilization

0

50

100

150

200

Dia

beti

c M

ate

rnal

Insu

lin

Req

(%

)

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

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 foranalgesia in labour. Br J Anaesth 2006; 96: 106-10.

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

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

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

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

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

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

Multiple Sclerosis

Overview of Anesthetic Management for the pregnant MS patient 1. Most methods of analgesia will be beneficial because they will reduce stress2. Obtain careful history & note any neuromuscular anomalies and areas of weakness.3. Epidural analgesia (with local anesthetics) is particularly appealing because it is helpful in

relieving abdominal & pelvic spasticity that can interfere with spontaneous delivery.4. Research indicates that bupivacaine concentrations for continuous epidural infusions that exceed a

0.25% concentration can lead to exacerbation of neurological symptoms (when used for laboringanalgesia).

1. It is suggested that the lowest concentration of local anesthetic and volume that canachieve effective analgesia should be used.

a. Typically use concentrations of 0.0625% - 0.125% bupivacaine or 0.08% -0.125% ropivacaine with 1-2 ug/ml of fentanyl

b. Intrathecal opioids have not been investigated fully but anecdotal analysisshows that fentanyl, morphine and sufentanil have been successfully usedwithout causing exacerbation of symptoms

5. The use of intrathecal local anesthetics is controversial because of the potential highconcentrations of subarachnoid local anesthetic levels (research has shown that drugconcentrations of local anesthetics are 3-4 times higher in the CSF following subarachnoidadministration of a local anesthetic when compared to epidurally administered local anesthetics).

6. Epidural anesthesia is the preferred method for cesarean section.7. General anesthesia does not exacerbate the course of MS but succinylcholine should be avoided in

patients having severe musculoskeletal involvement. Particular attention must be directed towardsthe prevention of pulmonary complications and the maintenance of normal body temperature.

Questions??

Pellegrini@son.umaryland.edu