Learning objectives
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List potential complications of neuraxial anesthesia.
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Recognize and manage common anesthesia complications.
The most common modes of anesthesia used in obstetrics are neuraxial and general anesthesia. Examples of neuraxial anesthesia include epidural anesthesia and spinal anesthesia. This chapter begins with potential complications of neuraxial anesthesia. Fig. 6.1 demonstrates the important anatomy for these neuraxial anesthesia techniques. At the end of this chapter, we also discuss the complications of general anesthesia.
Intravascular Infusion of Local Anesthetic
Pathophysiology
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Results from cannulation of blood vessels by the epidural catheter
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Usually prevented by giving a small “test dose” of lidocaine and epinephrine to test for intravascular placement or unrecognized placement in the spinal space before full dose is given
Symptoms
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“Ringing” or “buzzing” in the ears
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“Funny” or “metallic” taste in the mouth
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Tingling sensation around the lips
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Muscular twitching
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Loss of consciousness
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Cardiac arrest
Management
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Supportive care
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Stop epidural infusion
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Reassure patient that symptoms will resolve
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If appropriate and possible, replace the epidural catheter
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If the patient has bupivacaine-induced cardiac arrest, give Intralipid 20% bolus (1.5 mg/kg), followed by continuous intravenous infusion of 0.25 mg/kg for 60 minutes
High/Total Level of Spinal Anesthesia
Risk Factors
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Unrecognized placement of the epidural catheter in the subarachnoid space
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Performance of a spinal following an inadequate epidural where an infusion was previously running via a catheter
Symptoms
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Dizziness
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Shortness of breath
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Weakness in hands
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Sudden agitation (may be due to hypoxia or relative hypotension)
Management
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Supportive care
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Patients may need their breathing assisted with a bag-valve mask
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Stop infusion of local anesthetic
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Assess the level of the block to either a difference in temperature (using alcohol or ice) or a difference in sharp touch, remembering these dermatomes ( Fig. 6.2 ):
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T4 = nipple line
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T6 = xiphoid process
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T10 = umbilicus
Fig. 6.2
Sensory assessment of dermatomes is used to determine level of neuraxial anesthesia.
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Use level of block to monitor symptom progression/resolution
Hypotension
Pathophysiology
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Local anesthetic blockade of autonomic fibers results in vasodilation
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Vasodilation results in decreased cardiac preload and consequent hypotension
Management
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Manually displace the uterus or tilt the patient to one side (usually left lateral) to increase blood return to the heart ( Fig. 6.3 )
