Complications of Spinal Anesthesia | Neurologic & Cardiovascular Risks | Management Guidelines

1. بسم الله الرحمن الرحیم

2. COMPLICATIONS of SPINAL Ans. • By: • Dr.roushanfekr/anesthesiologist

3. COMPLICATIONS of neuraxial anesthesia: • 1--------NEUROLOGIC: • Paraplegia • CaudaEquina Syndrome • Epidural Hematoma • Nerve Injury • Post–Dural Puncture Headache • Transient Neurologic Symptoms • 2--------CARDIOVASCULAR: • Hypotension • Bradycardia • Cardiac Arrest • 3---------RESPIRATORY • 4-------INFECTION • 5-------BACKACHE • 6-------NAUSEA AND VOMITING • 7-------URINARY RETENTION • 8-------PRURITUS • 9-------SHIVERING

4. NEUROLOGIC: • The physiologic effects of neuraxial blocks may be misinterpreted as complications • Serious neurologic complications→ are rare • The true incidence of most neurologic injury→ is unknown

5. Paraplegia: • The frequency → 0.1 per 10,000 • the mechanism: • direct needle trauma to the spinal cord • the injection of a foreign substance into the CSF • Contamination by the descaling liquid used to cleanse the procedure • the chloroprocaine neurotoxicity • Adhesive arachnoiditis, caudaequina syndrome→ to be related to a combination of low pH and the antioxidant sodium bisulfite preservative • Profound hypotension or ischemia of the spinal cord • Anterior spinal artery syndrome→painless loss of motor and sensory function with sparing of proprioception→by the posterior column • The anterior cord→vulnerable to ischemic→ single and tenuous source of arterial blood supply (Adamkiewicz) • Ischemia caused →profound hypotension,mechanical obstruction, vasculopathy, or hemorrhage→irreversibleanterior cord damage

6. CaudaEquina Syndrome • The rate → 0.1 per 10,000 • The lumbosacral roots →vulnerable to direct exposure of large doses of LA: • a single injection of highly concentrated LA (5% lidocaine) • prolonged exposure to a LA through a continuous catheter • spinal catheters smaller than 24 G(↓ headache) : 1- to pooling of LA around the lumbosacralnerve roots 2- slow injectate flow through the fine-bore catheter: exposing them to high concentrations of LA

7. Epidural Hematoma: • the rates→ ˂ 0.06/10,000 after SA • after EA→ tenfold higher

8. Epidural Hematoma: • risk factors including : • Difficult or traumatic needle or catheter insertion • coagulopathy • elderly age • female gender • commonly features: Radicularback pain,prolongedblockade longer and bladder or bowel dysfunction • should prompt MRI on an urgent basis

9. Nerve Injury: • rate of radiculopathyorparesthesia orperipheral neuropathy→EA – CSE ˃SA • in adults for the purposes of perioperativeanesthesia or analgesia˃in the obstetric, pediatric, and chronic pain settings • difficult to determine because→ investigation, diagnosis, causation, outcomes are highly variable. • SA-EA (0.1 per 10,000) • CSEs (0.2 per 10,000), mostly in young, healthy patients.

10. Post–Dural Puncture Headache: • A relatively common complication • to result from puncture of the duramembrane: • neuraxial anesthesia • after myelography • diagnostic lumbar puncture • First, the loss of CSF through the dura →traction on pain-sensitive intracranial structures • Alternatively, the loss of CSF → compensatorypainful intracerebralvasodilationto offset the reduction in intracranial pressure

11. Post–Dural Puncture Headache: • The characteristic feature: a frontal or occipital headache that worsens with the upright or seated posture and is relieved by lying supine • Associated symptoms : nausea, vomiting, neck pain, dizziness, tinnitus, diplopia, hearing loss, cortical blindness, cranial nerve palsies, and even seizures. • In more than 90% of cases, the onset of characteristic symptoms →within 3days of the procedure, 66% start within the first 48h • Spontaneous resolution usually → within 7 days in the majority (72%) of cases, whereas 87% of cases resolve by 6 months

12. Post–Dural Puncture Headache: • Factors That Can Increase the Incidence of Headache After Spinal Puncture • • Age: Younger, more frequent • • Sex: Females > males • • Needle size: Larger > smaller • • Needle bevel: Less when the needle bevel is placed in the long axis of the neuraxis – noncutting needle ˂cutting • • Pregnancy: More when pregnant • • Dural punctures: More with multiple punctures • Factors That Do Not Increase the Incidence of Headache After Spinal Puncture • • Insertion and use of catheters for continuous spinal anesthesia • • Timing of ambulation

13. Post–Dural Puncture Headache: • Conservative management : • supine positioning • hydration • caffeine • and oral analgesics. • Sumatriptanhas also been used with varying effect but is not without side effects

14. Post–Dural Puncture Headache: • Epidural blood patch →definitive therapy • its safety and efficacy →well-documented • a single epidural blood patch→˃90% initial improvement rate • persistent resolution →61% to 75% of cases

15. Post–Dural Puncture Headache: • ideally performed 24 hours after dural puncture and after the development of classic symptoms • prophylactic epidural blood patching??? • the direction of spread was preferentially cephalad • A recent multinational, multicenter, randomized, blinded trial suggested that 20 mL of blood is a reasonable starting target volume→ blood will spread over a mean distance of nine spinal segments • A second patch may be performed 24 to 48 hours after the first in the case of ineffective or incomplete relief of symptoms

16. Transient Neurologic Symptoms(transient radicular irritation): • after intrathecal administration of every LA (Traditionally ,lidocaine) →SA • is usually characterized: • bilateral or unilateral pain in the buttocks →legs or, less commonly, isolated buttock or leg pain. • Symptoms occur within 24 hours of the resolution of SA • not associated with any neurologic deficits or laboratory abnormalities • mild to severe pain and typically resolves spontaneously in 1 week or less • highest after intrathecallidocaineand mepivacaineand is far less frequent withbupivacaine • The type of needle → reduced by a double-orifice needle→single-orifice→ ↑injecting anesthetic caudally in the thecalsac • not commonly →with epidural procedures(occurred with lidocaine) • commonly→ the lithotomy position • NSAID → the first line of treatment,butpain severe →even require opioids.

17. Hypotension: • in SA →hypotension (defined as SBP<90 mm Hg) • RISK FACTORS: • peak block height ≥T5 • age ≥ 40 years • basele SBP˂ 120 mm Hg • combined SA and GA • spinal puncture≥ L2-L3 interspace • the addition of phenylephrine to the LA • Hypotension (defined as a reduction MAP >30%) is associated with: chronic alcohol consumption,historyof hypertension, BMI, and the urgency of surgery. • TREATMENT: • prevention of hypotension caused by vasodilatation by a prophylactic (“preloading”) • infusion of colloid or crystalloid during the performance of the neuraxial block (“coloading”) • this is no longer recommended as a routine practice.

18. Bradycardia: • blockade of the thoracic sympathetic fibers (preganglioniccardiac accelerator fibers at T1-T5) • reflexive slowing of the HR as vasodilation→ reduces the venous return to the RA → stretch receptors • exaggerated bradycardia(40 to 50) : • baselineHR˂60 • age ˂37 years • male gender • nonemergency status • β-adrenergic blockade • prolonged case duration • Severe bradycardia (<40) →a baseline ˂60 and male gender

19. Cardiac Arrest: • The etiology→after SA is not understood • lack of vigilant monitoring and treatment • Hypoxemia • oversedation → severe bradycardia and asystole→suddenly ? during well-conducted SA • rare event • SA ˃epidural techniques • Most Recently → (0.04 per 10,000) during SA

20. RESPIRATORY: • Neuraxialopioids →respiratory depression→dose dependent • 3% after the administration of 0.8 mg of intrathecalmorphine • Rostral spread of opioids→to the respiratory centers in the brainstem • With lipophilicopioid→an early phenomenon (the first 30 minutes) • respiratory depression has never been described more than 2 hours after intrathecalfentanyl or sufentanil • With intrathecal morphine, there is a risk of late respiratory depression →24 hours after injection→ Respiratory monitoring • Patients with especially sensitive → • Older patients • sleep apnea • Coadministration of systemic sedatives • →neuraxialopioids should be reduced

21. INFECTION: • Bacterial meningitis and epidural abscess are rare, but potentially catastrophic • Sources of infection→ the equipment, the patient, or the practitioner • Staphylococcal infections(patient’s skin )are one of the most common → epidural • oral bacteri (Streptococcus viridans) are a common cause after SA→the clinician to wear a facemask • the presence of a concomitant systemic infection, diabetes, immunocompromisedstates and prolonged maintenance of an epidural (or spinal) catheter • ˂0.3 per 10,000 for SA→afterepidural techniques(Obstetric patients) ˃ SA˃ caudal block

22. INFECTION: • Guidelines: • (1) aseptic techniques during RA • (2)RA in the febrile or infected patient or the immunocompromised patient • (3) infectious risk of chronic pain treatments • (4) chlorhexidine in an alcohol base is the most effective antiseptic → neurotoxicity? • Aseptic meningitis secondary to chemical contamination and detergents→no longer present in modern preservative-free preparations

23. BACKACHE: • perhaps the most feared complication of neuraxial anesthesia • approximately 25% of all surgical patients • the incidence of which increases to 50% when surgery lasts 4 to 5 hours • neuraxialtechniques do not play a role in the development of back pain after delivery

24. NAUSEA AND VOMITING: • multiple mechanisms → • direct exposure of the chemoreceptive trigger zone (opioids), • hypotension associated with generalized vasodilation • gastrointestinal hyperperistalsis secondary to parasympathetic activity • Factors associated with developing nausea or vomiting: • the addition of phenylephrineor epinephrine to the LA • peak block height ≥T5 • baseline HR˂ 60 • use of procaine • history of motion sickness • the development of hypotension during spinal anesthesia • morphineadded to intrathecal or epidural →the most frequent risk of nausea or vomiting, whereas fentanyl and sufentanil carry the least frequent risk • (dose dependent)Using less than 0.1 mg morphine reduces the risk, without compromising the analgesic effect

25. URINARY RETENTION: • one third of patients after neuraxialanesthesia • blockade of the S2, S3,S4 → the detrusor muscle is weakened • Neuraxialopioids →suppressing detrusorcontractility and reducing the sensation of urge • Risk factor→ • male gender • Age • intrathecal morphine

26. PRURITUS: • the most common side effect related to the intrathecalopioids, with rates between 30% and 100% • Pruritus actually occurs more commonly after intrathecal than after IV opioid →not dependent on the type or dose • The mechanism→ unclear but is likely related to the central opioid receptor activation rather than histamine release • because naloxone, naltrexoneor the partial agonist nalbuphine can be used for treatment • Ondansetron and propofol are also useful therapies

27. SHIVERING: • The rate of shivering→55% • The intensity of shivering is likely related more to EA than spinal • profound motor block associated with SA compared with EA • can affect the thermosensitive basal sinuses • The addition of neuraxialopioids, specifically fentanyland meperidine, reduces of shivering • Recommended prevent strategies→ • prewarming (forced air warmer for at least 15minutes) • avoiding the administration of cold epidural and intravenous fluids