Complications in Spinal Anesthesia

Abstract

The justification of this chapter is based on knowing the neurological complications that can be triggered during or after spinal anesthesia since it is one of the most performed procedures in anesthesiology, the main objective is to make a chapter with the most described complications in spinal anesthesia. What are the complications of spinal anesthesia? What complications have been described during the procedure or during its postoperative recovery? The spinal anesthesia technique is a necessary procedure to perform a surgical intervention whose objective is to temporarily block the brain’s ability to recognize painful stimuli. Knowing possible complications that can occur during spinal anesthesia or in the postoperative period allows for early diagnosis and treatment. Complications in anesthesia can be clinically manifested by headache, gluteal pain that radiates to the lower limbs, neuropathy, severe paresthesia, among others, and can generate reversible and irreversible disabling lesions depending on their mechanism of injury.

1. Introduction

The theme addressed is of great importance for the field of anesthesiology; spinal anesthesia is an invasive technique necessary for regional blockages and is one of the most carried out in surgical interventions, so that recognizing the pathophysiology of neurological damage, diagnosing and treating the complications that may occur the question that starts this chapter What are the neurological complications of spinal anesthesia?

Spinal anesthesia is a technique widely used for its efficacy and safety, and it is also known as spinal, subarachnoid, intradural, or intrathecal anesthesia. It is characterized by the administration of an anesthetic in the subarachnoid space that is located between the pia mater and arachnoid meninges in order to generate a sequential block in the nerve fibers. The neurological complications of spinal anesthesia are of great importance in anesthesiology because some can be serious and be due to multiple previous patients, pharmacological, and genetic factors that can intervene in the complications, as it is a technique widely used in surgery and anesthesiology. When it is necessary to perform a surgical intervention whose objective is to interrupt the connection between the peripheral nervous system and the brain, spinal anesthesia is used to block painful stimuli. This technique and its complications recognize them and immediately treat the complications that occur during or after the anesthetic act [1].

Nerve injury related to the block is a disabling complication of spinal anesthesia, usually seen during the surgical procedure, postoperatively, and some patients may require an intensive care unit. This technique is a procedure used for interventions on the lower extremities, hip, perineum, lower abdomen, and lumbar spine [2].

2. Pathophysiology of neurological complications

Physiopathologically, there are multiple complications of neurological origin that can arise after spinal anesthesia. To do this, we must know the three mechanisms by which a peripheral nerve can suffer an injury [3].

• Mechanical or traumatic injury

• Vascular or ischemic injury

• Chemical or neurotoxic injury

The mechanical injury of the nerve can be due to contact between the needle and the nerve [4], causing direct trauma to the nerve, rupture of the perineurium, loss of the protective environment within the fascicle with myelin, and consequent axonal degeneration. The location of the needle tip during anesthetic injection plays a crucial role in the severity of nerve injury; needlestick injuries during puncture can cause nerve injury by several mechanisms [5].

Damage to the nerve vasculature during blocks can cause local or diffuse ischemia from direct injury or acute occlusion of the arteries or from hemorrhage within a nerve sheath [6].

Local anesthetics and adjuncts reduce neural blood flow depending on the agent and their concentration, for example, epinephrine reduces neural blood flow to a greater extent than local anesthetics alone and has the potential to cause local vasoconstriction [7].

Chemical nerve injury results from tissue toxicity of injected solutions (e.g., local anesthetics, alcohol, or phenol) or their additives. The toxic solution can be injected directly into the nerve or into adjacent tissues, causing an acute inflammatory reaction or chronic fibrosis involving the nerve [8].

The neurotoxicity of local anesthetics has been done in in vitro models, particularly with intrathecal application. There is evidence that almost all local anesthetics can have myotoxic, neurotoxic, and cytotoxic effects in various tissues under certain conditions; however, local anesthetics vary in their neurotoxic potential [9].

In mechanisms of neurological damage, the main determinant of the prognosis is the residual integrity of the axons, and the severity of the lesion is classified according to the degree of axonal interruption in neuropraxia, axonotmesis, and neurotmesis [10].

Among the factors that influence neurological injury are surgical factors [11].

2.1 Surgical positioning

Neurological complications occur as a result of patient positioning for surgical procedures (Figures 1 and 2), and these include traction, transection, compression, contusion, ischemia, and stretch [12]. Nerve roots are more susceptible to traction and compression because they lack epineural and perineural tissue; however, the dorsal and ventral roots of the spinal nerves are protected from lateral traction by the wedge of a cone of dura mater that surrounds the spinal-root nerve complex at the intervertebral foramen [13].

Figure 1.

Description: Lithotomy position. Source: Dr. María Fernanda Calderón León.

Figure 2.

Description: Transvaginal hysterectomy surgical procedure plus anterior and posterior colpoperioneoraphy, a procedure that lasts about 2 to 4 hours, keeping the patient in the same position. Source: Dr. María Fernanda Calderón León.

A history of preoperative neurologic deficit places a patient at increased risk of neuronal injury and can result from several mechanisms: entrapment, metabolic, ischemic, toxic, and demyelinating. Patients with preexisting pathology of the spinal canal have a higher incidence of neurological complications after neuraxial blockade than patients without such pathology. Lumbar disc injuries increase the risk of neurological complications of spinal anesthesia [14, 15].

3. Types of neurological complications of spinal anesthesia

• Postspinal puncture headache is the most common complication of spinal anesthesia and may be accompanied by chest pain, neck pain, and depression. Management includes early recognition, admission for analgesic management, and neuroimaging studies to rule out other pathologies [16, 17].

• Pneumocephalus is characterized by postsurgical neurological signs such as headache, neck stiffness, altered level of consciousness, or respiratory depression in the most severe cases [18].

• Cauda equina syndrome as a complication may occur and is characterized by bilateral weakness and pain in the lower extremities after the anesthetic act. This may indicate transient or persistent neurological damage due to involvement of the cauda equina of the spinal cord, and it may be asymmetric with a unilateral deficit and present after neuraxial anesthesia, which may complicate the postoperative period and require additional studies such as electromyography, tomography, or magnetic resonance imaging and multidisciplinary management [19, 20, 21].

• Hypotension during the intraoperative phase of spinal anesthesia may complicate preexisting coronary artery disease, worsen prior mental decline, or precipitate stroke [22].

• A reversible pathology is the transient neurological syndrome that is clinically manifested by gluteal pain that radiates to the lower limbs, neuropathy, and severe paresthesia is transient with recovery after neurorehabilitation, patients recover functionality [23].

• Spinal hematomas account for 8% of neuraxial anesthesia complications. Subdural hematoma, epidural hematoma, may require surgical management, after which symptoms can resolve [24].

• Cerebral venous thrombosis and cerebral ischemia comprise two catastrophic complications; cases of this complication following spinal anesthesia have been described and generate high mortality [25].

• toxic or infectious encephalomyelitis after spinal anesthesia can cause symptoms characterized by neurological deterioration, facial paralysis, cranial nerve III paralysis, paraplegia, and cerebral edema in diagnostic studies such as brain tomography [26].

• The cases of myelitis, myelinolysis (Figure 3), are infrequent; they are observed in the immediate postoperative period with a new deficit or lack of neurological recovery measured by the anesthetic recovery scales, the spinal cord damage is only observed in the magnetic resonance (MRI) of the spinal cord or altered MRI of the brain in cases of myelinolysis [27].

Figure 3.

Source: Javier Aquiles, Hidalgo Acosta. Description: Myelinolysis.

Description: The (Table 1) represents complications of spinal anesthesia that can be mild or severe, the diagnosis, treatment, and the recommendations of the authors for the management of complications of spinal anesthesia.

Author	Complication	Management	Recommendation	Diagnosis
Vallejo M, et al	Postdural puncture headache	Nonopioid analgesics, opioids, supine position, Follow-up the first 24–48 h	Spinal needles of “pencil tip” design that do not cut	CT, MRI
Ahmad M, et al.	Pneumocephalus	Analgesia, 40–100% oxygen, supine position	Pneumocephalus requires immediate surgical intervention	CT
Merino W, et al.	Cauda equina syndrome	Pregabalin, tramadol, dexamethasone, methylprednisolone	Early detection and treatment of complications after neuraxial anesthesia	Lumbar MRI
Lacassie H, et al.	Epidural infection, Postmeningeal puncture Meningitis	Antibiotic therapy for Staphylococci sp., Staphylococcus aureus, Viridans Streptococcus, Pseudomonas aeruginosa, Alpha-hemolytic Streptococci	Use sterile cap, mask, and gloves, and perform skin asepsis with chlorhexidine prior	Lumbar puncture and study of cerebrospinal fluid
Freire F, et al	Cauda equina Syndrome	Corticosteroids,; gastric mucosa protectors and rehabilitation, carbamazepine, and; amitriptyline	Perform a thorough history and complete evaluation to rule out external causes	Axial tomography; computerized lumbosacral spine; Column nuclear magnetic Resonance; lumbosacral, motor sensory conduction velocity in lower limbs
Hewson D, et al.	Peripheral nerve injury	Objectives: correct the underlying pathology; alleviate the symptoms; support, reassure and inform the patient	Nerve localization methods, the timing of blocks, needle techniques and design, injection pressure control, and choice of local and adjunctive anesthetic	Further investigation of possible causes of nerve injury should be conducted by a neurologist and neurophysiologist
Epstein N	Intracranial hypotension, subdural hematomas, and double vision/cranial nerve palsy	Clinical – surgical	Detect potential neurological risks/complications/adverse events	MRI of the brain, spine, CT of the brain and spine
Russell R, et al.	Cerebral vein thrombosis and death	Headache treatment	Adequate follow-up after discharge	CT and MRI of the brain
Arce D, et al.	Toxic encephalomyelitis	Intravenous betamethasone at a rate of 24 mg on the first day, with progressive reduction. The patient was maintained with 8 mg intravenous for 2 months, associated with physiotherapy sessions	Neurorehabilitation, admission to the intensive care unit	Brain CT

Table 1.

Complications of spinal anesthesia, diagnosis, management, and recommendation.

Source: Javier Aquiles, Hidalgo Acosta.

4. Conclusions

This review maintains the intended significance as it provides practical knowledge of the possible complications that may arise during the performance of this invasive spine technique.

Neurological complications in anesthesia can be mild, such as headache, transient a paradigm neurological syndrome is clinically manifested by gluteal pain that radiates to the lower limbs, neuropathy, and severe paresthesia, among others; serious complications can be fatal. It is important to be aware of complications.

The pain reported by the patient when advancing the needle or injecting the medication may indicate the placement of the needle at the intraneural level, so the injection must be stopped.

Patients with preexisting pathology of the spinal canal have a higher incidence of neurological complications after neuraxial blockade than patients without such pathology.

Complications can be due to multiple factors, all of which can be responsible for neurological complications. Blockade-related nerve injury remains one of the most common disabling complications.

Acknowledgments

A special thank you to my mother, teacher Mrs. Juana Narcisa Acosta Alcívar, an example to follow in education in Ecuador, Abigucho, Claris, Lucciana.

This is done with full funding from the authors.

Conflict of interest

The authors declare no conflict of interest.

Notes/thanks/other declarations

Thanks.

Appendices and nomenclature

CT	computed tomography
MRI	Magnetic nuclear resonance