Complications of regional anaesthesia in obs
- 1. COMPLICATIONS OF REGIONAL TECHNIQUES IN OBSTETRICS Dr.Sreejith.H
- 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. 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. 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. COMPLICATIONS OF NEURAXIAL ANAESTHESIA Adverse or exagerrated physiological responses Complications Related To Needle/ Catheter Placement Drug Toxicity
- 6. ADVERSE OR EXAGERRATED PHYSIOLOGICAL RESPONSES Urinary retention High block Total spinal anesthesia Cardiac arrest Anterior spinal artery syndrome Horner's syndrome
- 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. Misplacement No effect/inadequate anesthesia Subdural block Inadvertent subarachnoid block1 Inadvertent intravascular injection Catheter shearing/retention Inflammation Arachnoiditis Infection Meningitis Epidural abscess
- 9. DRUG TOXICITY Systemic local anaesthetic toxicity Transient Neurological Symptoms Cauda Equina Syndrome
- 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. 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. 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. 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. 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. 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. 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. 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. DIFFERENTIAL DIAGNOSIS Eclampsia , migraine, tension headache , pneumocephalus Infections including sinusitis& meningitis Cortical vein thrombosis & saggital sinus thrombosis Hypertensive encephalopathy Subdural haematoma
- 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. 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. 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. Symptoms Hypotension Dyspnoea Inability to speak & loss of consciousness Numbness or weakness of hand Nasal mucosa become engorged
- 24. 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
- 26. INADEQUATE ANALGESIA Failure rate of epidural analgesia ranges from 1.5% to 5 % depending on the skill of the anaesthetist
- 28. 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
- 29. 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
- 30. 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
- 31. 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
- 32. 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
- 33. 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
- 34. URINARY RETENTION Role of epidural analgesia in urinary retention is unclear Obstetric factors Long labor Edema Instrumental delivery Perineal trauma Haematoma pain
- 35. 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
- 36. 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