Case Title: High Spinal in the Obstetric Patient.
Patient Name—Patti Nidiffer.
Scenario Name—High Spinal in Obstetrics.
Simulation Developer(s)—Martin Eason, MD, Martin Olsen, MD.
Date(s) of Development—November 17, 2004.
Appropriate for the following learning groups: OB/GYN residents, anesthesia residents, medical students, anesthetist, labor, and delivery nursing personnel.
Target Learners—OB/GYN Residents.
High spinal is a rare but life-threatening complication most commonly associated with epidural analgesia. In epidural analgesia, a catheter is placed in the epidural space and a local anesthetic is injected into the epidural space via a needle or catheter. If the catheter is accidentally placed or migrates into an intrathecal location, or the needle is placed in the intrathecal space, the patient can receive an overdose of medication that can result in hypotension, bradycardia, and depending on the dose, diaphragmatic paralysis. Treatment includes hemodynamic and ventilatory support. Additionally, if support is not provided in a timely fashion, fetal compromise may ensue necessitating resuscitation after delivery. Involvement of the neonatal care team may be necessary. This scenario was originally designed to teach obstetric residents. Obstetrical residents may be the first responder for patients who are found to have high spinals and must be familiar with the immediate management of this complication. The scenario can be modified for anesthesiology personnel, nursing, or medical student learners.
At our institution, this scenario is part of a departmental integrated teaching program, where several scenarios are held on the same day. We schedule an entire morning and teach our obstetric residents via simulation methodology at that time. This scenario has been conducted for both OB/GYN residents and medical students.
Emergencies, such as this one, can be extremely dynamic. This scenario can be modified into a labor and delivery drill, which could include input from pediatric personnel for neonatal resuscitation as well as assessment of the performance of the unit’s secretary/clerk and other personnel as they assist in calls for help. The provision of anesthesia in labor is a multidisciplinary patient care activity in which anesthesia personnel provide pain relief for patients who are actively managed by obstetric personnel. In addition to obstetric care providers, labor and delivery nursing personnel perform vital monitoring functions and obstetric care. Moreover, in high-risk pregnancies or in emergency situations that may endanger fetal health, pediatric personnel may also be involved to ensure optimal care. It is also vital that administrative personnel (eg, unit clerks) recognize the need for rapid and effective communication of potential problems. Thus, the labor and delivery suite is a dynamic interdisciplinary environment that requires close coordination among team members. Anecdotal information leads us to believe that similar scenarios have been run by anesthesia academicians for their learners at other institutions.
The Accreditation Council for Graduate Medical Education developed core competences in 1999 as part of the outcome project. Core competences are as follows:
- Patient care
- Medical knowledge
- Practice-based learning and improvement
- Interpersonal and communication skills
- Systems-based practice
This simulation covers the following competences:
- Patient care
- Learners will identify a life-threatening complication
- Learners will initiate hemodynamic and ventilatory support
- If indicated, learners may initiate cardiopulmonary resuscitation in a pregnant patient
- Learners will understand the indications for emergent c-section and delivery
- Medical knowledge
- Learners will understand the pathophysiology of high-spinal anesthesia
- Learners will learn the pharmacology of vasopressors and their actions
- Learners will learn the physiologic effects of local anesthetics
- Learners will learn the physiologic effects of pregnancy and how they affect resuscitation
- Learners will increase their understanding of cardiopulmonary resuscitation in a pregnant patient
- Learners will assess fetal monitoring in a patient undergoing a life-threatening situation
- Interpersonal and communication skills
- Learners ability to successfully communicate with a critically ill patient will be assessed
- Learners ability to interact with a multidisciplinary group of health care providers will be assessed
- Depending on the scenario, learners will effectively communicate with family members
- System-based practice
- Learners will gain increased appreciation for mechanisms by which multiple providers within a delivery system interact in both positive and negative fashions to affect a patient’s outcome. In this scenario, a complication by anesthesia providers results in events, which are addressed by obstetric care providers.
- Learners will learn how to determine the best method to resolve a crisis within their logistical framework and how to use available resources (eg, who is available to help? How fast can the neonatal care team come? What operating room resources area available?)
- Learners will show empathy with family members in addressing a medical complication
- Learners will effectively interact with health care team members in a crisis situation
Guided Study Questions
- What is the mechanism of action by which epidural analgesia can progress to a high spinal?
- What are the symptoms of high spinal?
- What is the management of high spinal?
- How does resuscitation differ in a pregnant patient from a nonpregnant patient?
- What are the potential benefits to the patient’s resuscitation of a perimortem cesarean section?
1. Gabbe S, Niebyl JR, Simpson JL, et al. Obstetrics: Normal and Problem Pregnancies. 5th ed. Philadelphia: Churchill Livingstone Elsevier; 2007:399–404.
2. Gautier P. Obstetric regional anesthesia. In: Hadzic A. Textbook of Regional Anesthesia. OH: McGraw-Hill; 2007:710–711.
3. McCutchen T, Gerancher JC. Epidural anesthesia: unintended intrathecal injection. In: Atlee J. Complications in Anesthesia. Amsterdam: Elsevier; 2007:244.
4. Atta E, Gardner M. Cardiopulmonary Resuscitation in Pregnancy. Obstet Gynecol Clin North Am 2007;34:585–597, xiii.
5. American Heart Association. Cardiac arrest associated with pregnancy. Circulation 2005;112:150–153.
6. Kar GS, Jenkins JG. High spinal anesthesia: 2 cases encountered in a survey of 81,322 cases. Int J Obstet Anesth 2001;10:189–191.
7. Smith HM, Jacob AK, Segura LG, Dilger JA, Torsher LC. Simulation education in anesthesia training: a case report of successful resuscitation of bupivacaine-induced cardiac arrest linked to recent simulation training. Anesth Analg 2008;106:1581–1584.
Noninvasive blood pressure cuff
METI HPS or Laerdal mannequin
Endotracheal intubation tube
Video of fetal monitoring (videos are available at: www.ob-efm.com)
Simulated prenatal flow sheet
Simulated admission history and physical
Setup and preparation: 15 minutes
Simulation: 15 minutes
Debriefing: 20–30 minutes
BACKGROUND AND BRIEFING INFORMATION (FOR FACILATOR/CO-COORDINATOR EYES ONLY)
High spinal is an uncommon but potential life-threatening complication to both mother and fetus that may accompany labor epidural analgesia. During the procedure, local anesthetic is injected into the epidural space via a needle or catheter. The local anesthetic works by blocking nerve transmission along the nerve roots. Rarely, either from a misplaced needle or catheter, or catheter migration, the local anesthetic is injected into the subarachnoid, or intrathecal, space. The epidural dose is approximately 10 times the intrathecal dose, and therefore, injection of an epidural dose causes significant blockade of nerve transmission. Additionally, the higher dose will have result in a more cephalad spread of the anesthetic. The effects include hypotension from blockade of sympathetic fibers, rapid onset of sensory and motor block, bradycardia from blockade of the cardioacceleratory fibers, and eventually apnea from either blockade of cervical nerve roots causing diaphragmatic paralysis or from hypotension affecting the medullary respiratory center. These effects are particularly precarious in a parturient because of the already deleterious effects of the gravid uterus on cardiac preload. This complication should therefore be diagnosed rapidly and treated.
The patient will typically present with symptoms of lightheadedness, nausea, and complaints of numb or heavy legs. The signs include hypotension, initially tachycardia, followed by bradycardia and respiratory arrest. Assessment should include rapid evaluation of blood pressure and level of blockade. Once a high spinal is suspected, rapid resuscitation should be instituted. The management steps include administration of pressors, rapid fluid administration, lateral uterine displacement, elevation of the legs, discontinuance of the local anesthetic infusion, and ventilatory support. Aspiration precautions, such as cricoid pressure, should also be taken.
If the situation deteriorates to cardiac arrest, cardiopulmonary resuscitation in a parturient is particularly ineffective and steps such as placing the patient on a board may slightly improve resuscitative measures. Serious consideration should be given to timely emergent operative delivery for saving the fetus and to improve maternal resuscitation. Fetal survival is dependent on the time from cardiac arrest to the time of delivery; the maximal time being 5 minutes. Therefore, hysterotomy should begin no later than 4 minutes after the onset of cardiac arrest. Delivery empties the uterus and relieves aortocaval compression. Moreover, delivery allows access to the infant, so newborn resuscitation can begin.
When the learners are called into the room, the patient is able to speak in full sentences. She points out that she is nauseated, and she is frightened. If Phenergan is administered her hypotension worsens. If asked, she says that her legs feel “funny.” She will then complain that it is difficult to catch her breath. During this time her blood pressure gradually decreases from baseline to 70/40, and her heart rate will initially increase then will begin to decrease. If the blood pressure is not corrected then it will continue to decrease to 55/30. If the pressure is allowed to drop below 70 she becomes confused as the history is being obtained and the history may not be completed as the patient becomes unresponsive when the pressure drops below 70. The oxygen saturation level will no longer be readable when the pressure drops below 70. She becomes apneic shortly afterward from the hypotension and progression of the anesthetic block. As apnea begins, the saturation levels will begin to decrease coincident with the apnea. Once the blood pressure falls below 80, the fetal heart rate will initially increase to the 160 momentarily then drop below 100 and worsen if maternal hypotension is not corrected.
When the learners note the patient’s symptoms, they should consider hypotension and assess blood pressure. Once they note that she is hypotensive, they should check her block level to assess for an intrathecal injection of anesthetic. Once this is ascertained, they institute resuscitative measures and call for help. These include left uterine displacement, elevation of the patient’s legs, and administration of pressor agents, fluid administration, and oxygen. Once she is noted to be unresponsive and apneic, respiratory support in the form of bag/valve ventilation should be instituted using cricoid pressure. This should be quickly followed with intubation. If an infusion of anesthetic is present, it should be discontinued.
If hemodynamic support is not given, she will deteriorate to ventricular tachycardia and fibrillation. If ventilation does not occur (even despite hemodynamic support), she will continue to desaturate and after 3 minutes (or sooner if hemodynamic support is not given) will undergo a cardiac arrest from ventricular dysrhythmia.
The fetal heart rate will decrease as above and over time will decrease to severe bradycardia until maternal hypotension and hypoxemia are resolved.
Patient is a 32-year-old G1, P0 female in active labor at approximately 39 weeks gestation. She has had an unremarkable prenatal course. She requests epidural analgesia.
Shortly after placement of the epidural, the anesthesiologist is called away. The patient will demonstrate significant complaints of shortness of breath and fear. She will also complain of her legs “feeling weird.”
At our institution, this scenario is run with the residents completely blinded to the educational plan. Diagnosis and management of the simulated patient is part of their learning objectives. In this scenario, the differential diagnosis could include: anxiety, panic attacks, drug overdose, pulmonary embolus, high spinal, and pulmonary edema.
PATIENT DATA BACKGROUND (FOR LEARNER)
History of Present Illness
Patti Nidiffer is a 32-year-old G1, P0 patient, who presented in active labor at 39 weeks and 2 days gestation. Her prenatal course has been essentially unremarkable. She had one urinary tract infection during her pregnancy. She is Rh negative and received Rhogan at 26 weeks gestation. She is 220 pounds.
This scenario begins at approximately at 7:05 am. The patient received her epidural at approximately 6:55 am just before shift change at 7:00 am. The anesthesiologist was quickly called away for a code blue on another floor shortly after epidural placement. The anesthesiologist did not assess the patient after the loading dose and began the infusion shortly after placement of the epidural. The residents are called in to see the patient, because she is complaining of nausea. The nurse requests an antiemetic. The nurse is not yet familiar with the patient’s case because she has not received a sign-out report. All she knows is that the patient just received her epidural. If requested, the anesthetist or anesthesiologist will be involved in a code on another floor and will be temporarily unavailable.
Medical and Surgical History
Review of her chart will show appendicitis at age 12. No other surgeries. No other hospitalizations.
The patient is a smoker. She drank alcohol until she found out she was pregnant. She denies drug abuse. She lives with her boyfriend and is employed in a fast food restaurant.
There is no family history of anesthetic reactions.
Review of Systems
History of sinus headaches. Central nervous system otherwise negative.
No history of mitral valve prolapse. Cardiovascular otherwise negative.
Pulmonary: had an upper respiratory infection 10 days ago.
Renal: urinary tract infection during pregnancy.
Gastrointestinal: negative for liver disease.
Endocrine is negative for diabetes and thyroid.
Prenatal vitamins only
General: pregnant patient attached to fetal monitor. (The voice of the mannequin sounds distressed).
Weight: 220 lbs.
Height: 5’ 3”.
Vital signs: heart rate initially 100 beats per minute, blood pressure initially 105/60 (has been running in the 120/70), and respiratory rate initially 15 breaths per minute, oxygen saturation initially 98%; fetal heart tones are in the 130.
Airway: appropriate mouth opening. Good dentition, no protruding incisors. Mallampati class II. Hyomental distance is 3 fingerbreadths. No tongue enlargement. Cervical range of motion is intact.
Lungs: clear to auscultation bilaterally, no wheezes.
Heart: regular in rate, no murmur, no gallop, no rub.
Abdomen: gravid uterus.
Extremities: 2+ edema, fetal pulse present.
Neurologic examination: when initially evaluated, cannot feel pinprick until T4 dermatome; grip strength is 3/5.
Admission hemoglobin: 11.5
White count: 10
Chest x-ray—if ordered: patient will deteriorate before chest x-ray is taken
- Labor and delivery nurse
- Voice of the mannequin
- Optional: distraught and worried family member who must be dealt with as the patient’s condition deteriorates
- Patient care
- Learner will understand the signs and symptoms of high spinal.
- Methods to assess high spinal.
- Management of local anesthesia induces hypotension is reviewed. These include hemodynamic and ventilator support. The former includes bedside maneuvers, pharmacologic intervention, and fluids. The latter includes effective bag-valve ventilation, cricoid pressure, and endotracheal intubation.
- Cardiopulmonary resuscitation in a parturient is discussed. Issues can include the proper location for chest compression (higher on the sternum), lateral uterine displacement, removal of uterine and fetal monitors prior to defibrillation, the lack of effect on fetus health of defibrillation, and the need for smaller endotracheal tubes in parturients due to possible airway edema. The need for rapid emergent operative delivery to save infant and mother if no improvement is seen within a few minutes.
- Medical knowledge
- The pathophysiology of high spinal
- The pharmacology of local anesthetics and their effects on the cardiovascular and pulmonary systems.
- The pharmacology of resuscitative drugs.
- The physiologic changes in pregnancy that affect resuscitative efforts
- Hemodynamic changes: aortocaval compression
- Pulmonary changes: higher oxygen consumption, smaller FRC
- Airway changes: increased airway edema may make intubation more difficult
- Gastroesophageal sphincter tone is decreased increasing the risk of aspiration
- Bedside maneuvers and how their physiologic effects on circulation
- How operative delivery affects maternal circulation and affects resuscitation
- Interpersonal and communication skills
- Effectiveness of communication between learners and team members. Were the instructions clear? Did the learners address the team members specifically? Was there “closing of the loop?”
- Optional: assessment could be offered concerning the learners’ interaction with the upset family member. How effective were the issues communicated to the family members? Did the learners answer all their questions and address their concerns?
- Systems-based practice
- This scenario occurs at a time of shift change. Times of shift change can be associated with increased breakdown in services due to distractions of change in responsibilities. Importance of sign out should be discussed.
- In this scenario, the anesthetist or anesthesiologist is unavailable having been called away to a code on another floor. The learner should consider other options (eg, ER physicians, respiratory therapist).
- Concept of triaging and the challenges of taking care of more than one sick patient can be discussed.
- Concept of awareness of all actions performed by other physicians on one’s own patient could be discussed.
- Consideration of process to obtain assistance (eg, what is the procedure to get neonatology team?).
- Process for activating operating room team; how long does it take to activate team?
- Location of resuscitative equipment in learners’ institution.
- Does the learner know of the availability of pastoral services at his/her institution for family members?
- How does the learner interact with other team members in a crisis situation? Does he/she treat others with respect? Does he/she interact with them in a professional manner?
- How does the learner interact with a distraught family member? Does he/she show appropriate empathy?