Complications of regional anaesthesia in obs


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Complications of regional anaesthesia in obs

  2. 2.  Regional anaesthesia is a safe and widely utilised method of analgesia for labour.  The majority of caesarean sections are managed using spinal (intrathecal), epidural or combined spinal / epidural (CSE) techniques.  Although serious complications are uncommon with regional anaesthesia, they must be considered and should be discussed with the patient.
  3. 3.  Over 100 years ago August Bier performed the first recorded spinal anaesthetic  complications from the use of regional anaesthesia have been described over this same period of time  Bier also being the first to describe a ‘spinal’ or ‘post dural-puncture headache’
  4. 4.  In 1950’s decline in use of neuraxial technique due its complications  over the last thirty years the increased use of regional anaesthesia for caesarean section due to its increased safety  General anaesthesia is now used in less than 5% of caesarean sections  There are still a number of important complications that are associated with regional anaesthesia and analgesia
  5. 5. COMPLICATIONS OF NEURAXIAL ANAESTHESIA  Adverse or exagerrated physiological responses  Complications Related To Needle/ Catheter Placement  Drug Toxicity
  6. 6. ADVERSE OR EXAGERRATED PHYSIOLOGICAL RESPONSES  Urinary retention  High block  Total spinal anesthesia  Cardiac arrest  Anterior spinal artery syndrome  Horner's syndrome
  7. 7. COMPLICATIONS RELATED TO NEEDLE/CATHETER PLACEMENT Trauma  Backache  Dural puncture/leak  Postdural puncture headache  Diplopia  Tinnitus Neural injury  Nerve root damage  Spinal cord damage  Cauda equina syndrome Bleeding  Intraspinal/epidural hematoma
  8. 8. Misplacement  No effect/inadequate anesthesia  Subdural block  Inadvertent subarachnoid block1  Inadvertent intravascular injection Catheter shearing/retention Inflammation  Arachnoiditis Infection  Meningitis  Epidural abscess
  9. 9. DRUG TOXICITY  Systemic local anaesthetic toxicity  Transient Neurological Symptoms  Cauda Equina Syndrome
  10. 10. HYPOTENSION  Defined as a 20-30% decrease in systolic BP or systolic BP less than 100 mm Hg  Occurs due to sympathetic blockade leading to vasodilatation  Aorto-caval compression  Incidence & severity depends on Height of block Position of parturient Whether prophylatic measurements taken to avoid such hypotension
  11. 11.  Measures to decrease risk of Hypotension Intravenous administration of fluids Avoidance of aorto caval compression Vigilant monitoring of BP at frequent intervals  Uterine blood flow is directly dependant on maternal blood pressure  FHR evaluation is helpful
  12. 12. Treatment  Administration of iv crystalloids  Placement of mother in full lateral position  Administration of supplimental oxygen  Incremental dose of ephedrine(5-10 mg) Why phenylepherine?
  13. 13. BRADYCARDIA  Most commonly after spinal anaesthesia  May progress to Complete heart block or asystole  Caused by blockade of preganglionic cardiac accelerator fibers (T1-T4)  Decrease in venous return leading to decrease action of right atrial stretch receptors  Usually responds to iv atropine
  14. 14. ACCIDENTAL DURAL PUNCTURE  Common & problematic complication of epidural placement  Incidence upto 3%  Can lead PDPH upto 70% cases  May be detected at the time of insertion of epidural needle or after placement of the catheter  Management is to remove the needle & reposition the catheter at a different interspace  Placement of a catheter in the subarachnoid space to become a continuous spinal technique
  15. 15. SPINAL HEADCHE CAN BE REDUCED BY  Injection of CSF from the epidural syringe back into the subarachnoid space through needle  Insertion of an epidural catheter into subarachnoid space  Injection of preservative free NS through intrathecal catheter beforeits removal  Adminstration of continuous intrathecal labor analgesia  Leaving the intrathecal catheter insitu for a total of 12 to 20 hrs
  16. 16. POST DURAL PUNCTURE HEADACHE(PDPH)  Incidence :0.5-2% for spinal 1-7.6% for epidural  PDPH has typical feature of postural headche that is worsened by standing / staining &relieved by lying down  Aetiology Due to CSF leaking through dural puncture site, leading to intracranial hypotension. This causes settling of brain & strecthing of intracranial nerves, meninges,blood vessels
  17. 17. DIAGNOSIS  Severe , disabling fronto-occipital headache with radiation to the neck & shoulders  Presents 12 hrs or more after dural puncture  Worsens on sitting & standing ,relieved by lying down & abdominal compression  May be associated photophobia, vertigo, nausea & vomiting, diplopia, hearing loss, tinnitus. Convulsions & visual field efects
  18. 18. DIFFERENTIAL DIAGNOSIS  Eclampsia , migraine, tension headache , pneumocephalus  Infections including sinusitis& meningitis  Cortical vein thrombosis & saggital sinus thrombosis  Hypertensive encephalopathy  Subdural haematoma
  19. 19. MANAGEMENT OF PDPH Conservative  Bedrest  Encourage oral fluids & or intravenous hydration  Caffeine – either iv (eg: 500 mg caffeine in 1 litre saline) or orally  Regular analgesia  Reassurance
  20. 20. Interventional - Epidural patch  First described more than 40 yrs ago  Most effective treatment of PDPH  Injecting 20 ml of patient’s own blood into epidural space near puncture site  Form a clot obstructing dural tear  Causes increase in CSF pressure & cerebral vasoconstriction  Success rate only 61 %
  21. 21. TOTAL SPINAL BLOCK  After excessive cephalic spread of local anaesthetic  Can occur during single shot spinal anasthesia  Inadvertent intrathecal spread of epidural medication after unintentional dural puncture or catheter migration  Subdural spread of local anaesthetic can also cause a high block characterised by high sensory level sacral sparing incomplete / absent motor block
  22. 22. Symptoms  Hypotension  Dyspnoea  Inability to speak & loss of consciousness  Numbness or weakness of hand  Nasal mucosa become engorged
  23. 23. INTRAVASCULAR INJECTION OF LOCAL ANAESTHETIC CNS symptoms : restlessness,diziness,tinnitus,perioral parasthesia, difficulty in speaking, seizures, loss of conciousness CARDIOVASCULAR EFFECTS  May progress from increased blood pressure to bradycardia,  Depressed ventricular function & ventricular tachycardia and fibrillation MATERNAL CONVULSION were the single most common untoward event
  24. 24. INADEQUATE ANALGESIA  Failure rate of epidural analgesia ranges from 1.5% to 5 % depending on the skill of the anaesthetist
  25. 25. NEUROLOGIC COMPLICATIONS  Direct trauma to spinal cord is very rare  Nerve root trauma  Cauda equina syndrome / adhesive arachnoiditis are due to chemical toxicity  Thrombosis of anterior spinal artery may lead to motor weakness or paralysis & loss of pain & temparature sensation
  26. 26. CENTRAL NERVOUS SYSTEM INFECTIONS  Infection may be exogenous in origin caused by contamination of equipment or pharmacologicalic agents or by colonisation of catheter  Endogenous spread may occur from a site of infection elsewhere in the body Epidural abscess  1 in 10000 cases  Fever , backpain, localized infection at the level of epidural site 2 to 3 days after procedure Meningitis  may be associated with bacteraemia
  27. 27. SPINAL & EPIDURAL HAEMATOMA Incidence  1 in 150000 for epidural  1 in 220000 for spinal Risk Factors  Low platelet count  INR level above 1.4  Use of anticoagulants & thromboprophylaxis with LMWH Recent guidelines is to defer regional technique 10- 12 hrs in a parturient who has received preoperative LMWH OR 24 hrs for those receiving higher dose of LMWH
  28. 28. BACKACHE  Low backache is common after delivery  3-45 % women receiving epidural  40% for spontaneous vaginal delivery  25% for instrumantal delivery Factors which may predispose for increase incidence in epidural  Use of larger needle  Supraspinous ligament haematoma  Difficult identification of epidural space  Prolonged assumption of a unnatural position during labor or delivery  Sacroilaiac strain
  29. 29. TRANSIENT NEUROLOGICAL SYMPTOMS  First described in 1993  Also known as transient radicular irritation  Characterized by backpain radiating to the legs without sensory or motor deficits  Occuring after resolution of spinal block & resolving spontaneously within several days  Most commonly seen with HYPERBARIC LIDOCAINE(11.9%)  Also reported with tetracaine(1.6%),bupivacaine(1.3%),mepivacaine , prilocaine,procaine,ropivaciane
  30. 30.  Incidence is highest among outpatients(early ambulation) after surgery in the lithotomy position & lowest among inpatients in positions other than lithotomy  Pathogenesis is believed to represent concentration dependant neurotoxicity of local anaesthetics
  31. 31. URINARY RETENTION  Role of epidural analgesia in urinary retention is unclear Obstetric factors  Long labor  Edema  Instrumental delivery  Perineal trauma  Haematoma  pain
  32. 32. NAUSEA & VOMITING  Is usually associated with hypotension due to spinal blockade  Responds to treating of hypotension  May be also due surgical stimuli such as traction of peritoneum  Associated with use of opioids
  33. 33. EFFECTS ON 2ND STAGE OF LABOR & CAESAREAN SECTION Mainly two controversies  Whether it prolongs 2nd stage of labor?  Whether it increases the need of operative delivery? Strong local anasethetic solution with high motor blockade compromises parturient’s ability to actively push