Neuraxial Anesthesia Lecture Notes PDF

Neuraxial Anesthesia Dr. Inas Shatnawi Anesthesia specialist Review Type of surgery Why neuraxial; mandatory or elective? Prepare for GA, needle sizes, medications History taking: medical, surgical, drugs, allergy, … Vital signs Explain the procedure...

Neuraxial Anesthesia Dr. Inas Shatnawi Anesthesia specialist Review Type of surgery Why neuraxial; mandatory or elective? Prepare for GA, needle sizes, medications History taking: medical, surgical, drugs, allergy, … Vital signs Explain the procedure Position, mark the space Sterile gloves, surgical set, sterilize the field Proceed with injection Reposition Observe vitals, keep an eye on the patient Complications of Neuraxial Blocks Inadequate Anesthesia or Analgesia Neuraxial blocks are associated with a small failure rate that is usually inversely proportional to the clinician’s experience. Failure may still occur, even when CSF is obtained during spinal anesthesia. Factors may responsible: Movement of the needle during injection Incomplete entry of the needle opening into the subarachnoid space Loss of potency of the local anesthetic solution. Complications of Neuraxial Blocks High Neural Blockade Exaggerated spread of neural blockade can occur with either spinal or epidural: Administration of an excessive dose. Failure to reduce standard doses in selected patients (eg, the elderly, pregnant, obese, or very short). Unusual sensitivity or spread of local anesthetic may be responsible. Signs and symptoms: Dyspnea Numbness or weakness in the upper extremities. Nausea often precedes hypotension. Once it is recognized, patients should be reassured, oxygen supple mentation may be required, and bradycardia and hypotension should be treated. Complications of Neuraxial Blocks High Neural Blockade “High spinal”: block extends to cranial nerves; AKA “total spinal.” Unconsciousness, apnea, and hypotension resulting from high levels of spinal anesthesia Treatment involves: maintain an adequate airway and ventilation and supporting the circulation (ABC) Supplemental oxygen  assisted ventilation  intubation, and mechanical ventilation if necessary. Hypotension can be treated with rapid administration of intravenous fluids, a head-down position, and intravenous vasopressors. Bradycardia can be treated early with atropine Complications of Neuraxial Blocks Intravascular Injection Accidental intravascular injection of the local anesthetic for epidural and caudal anesthesia can produce very high serum levels. Extremely high levels of local anesthetics affect the central nervous system (seizure and unconsciousness) and the cardiovascular system (hypotension, arrhythmias, and depressed contractility) Treatment is resuscitative (ABC), and lipid emulsion should be employed. Complications of Neuraxial Blocks Urinary Retention Local anesthetic block of S2–S4 root fibers decreases urinary bladder tone and inhibits the voiding reflex. Epidural opioids can also interfere with normal voiding. These effects are most pronounced in male patients. Urinary bladder catheterization should be used for all but the shortest acting blocks. Complications of Neuraxial Blocks Backache As a needle passes through skin, subcutaneous tis sues, muscle, and ligaments it causes varying degrees of tissue trauma. Bruising and a localized inflammatory response ± reflex muscle spasm  postoperative backache. ≈ Remember that up to 25% to 30% of patients receiving general anesthesia also complain of back ache postoperatively, and a significant percentage of the general population has chronic back pain. Postoperative backache is usually mild and self-limited. Other treatment options: paracetamol, NSAIDs, and warm or cold compressor. Complications of Neuraxial Blocks Post-dural Puncture Headache PDPH characteristics : Bilateral, frontal or retroorbital, or occipital and extends into the neck Throbbing or constant Associated with photophobia and nausea Associated with body position; aggravated by sitting or standing and decreased by lying down flat. The onset of headache is usually 12–72 hour following the procedure. Complications of Neuraxial Blocks Post-dural Puncture Headache The incidence of PDPH is related to: needle size (The larger the needle, the greater the likelihood) needle type (Cutting-point needles are associated with a higher incidence of PDPH than pencil-point needles of the same gauge) patient population: young age, female, and pregnancy. Conservative treatment: supine position, analgesics, IV or oral fluid, and caffeine. An epidural blood patch is an effective treatment for PDPH. It involves injecting 15–20 mL of autologous blood into the epidural space at, or one interspace below, the level of the dural puncture. Complications of Neuraxial Blocks Neurological Injury Either nerve roots or spinal cord may be injured. Spinal cord injury may be avoided if the neuraxial blockade is performed below the termination of the conus (L1 in adults and L3 in children). Postoperative peripheral neuropathies can be due to direct physical trauma to nerve roots. Although most resolve spontaneously, some are permanent Complications of Neuraxial Blocks Spinal or Epidural Hematoma Trauma to epidural veins often causes minor bleeding in the spinal canal  usually has no consequences. A clinically significant spinal hematoma can occur in the presence of abnormal coagulation or a bleeding disorder. Hematoma’s mass effect  compress neural tissue and cause direct pressure injury and ischemia Symptoms: sharp back and leg pain with + motor weakness ± sphincter dysfunction. Surgical decompression within 8–12 hr  good neurological recovery. Complications of Neuraxial Blocks Meningitis and Arachnoiditis A result of contamination of the equipment or injected solutions, or organisms tracked in from the skin. Clinically, it is marked by pain and other neurological symptoms. Strict sterile technique should be employed, and face masks should be worn by all individuals in the room where neuraxial blocks are to be placed. Complications of Neuraxial Blocks Epidural Abscess Spinal epidural abscess (EA) is a rare but potentially devastating complication of neuraxial anesthesia. Signs and Symptoms: Back pain Nerve root or radicular pain Motor and/or sensory deficits Sphincter dysfunction. Fever 26-year-old medically-free male patient is undergoing knee arthroscopy. What anesthetic options are available for this patient? Which one do you prefer? General anesthesia Neuraxial anesthesia 55-old-year smoker female patient has severe hip pain and is advised to have hip replacement. She’s hypertensive and diabetic. She takes her medication regularly and takes occasional aspirin 100mg Preop vitals: BP= 150/85.. HR= 85.. O2sat= 96% CVS exam is unremarkable. EF= 50% What is your choice of anesthesia? And which one do you prefer? GA Spinal Combined spinal+epidural 22-year-old female patient has a planned CS. She’s healthy and fasting and would like to have a spinal anesthesia. What are your considerations? Coagulopathy (meds or physiological) Hydration status (IV fluid bolus) After induction of anesthesia, her blood pressure dropped to 80/45. what is your best management? IV fluid Left side tilting Ephedrine 60-year-old male patient with a history of cervical disc herniation. He complains of neck pain, limitation of neck movement and bilateral hand parasthesia. He’s supposed to have a corrective surgery for the cervical spine. But it’s two months far from now. What else can you do to help the patient for pain and symptoms relief? Analgesic drugs Physiotherapy Cervical epidural injection Thank You !