1. Management of Pain in Labor andDeliveryProfessor Hassan Nasrat

2. Pathway of Labor PainFirst stage: The pain the pain is mainly viscera the signal entersthe spinal cord after traversing the T10, T11, T12, and L1.Second stage: The pain is a combination of visceral pain fromuterine contractions and cervical stretching in addition to thesomatic pain produced by stretching of the vagina, pelvicligaments and pressure on pelvic floor.The pain is transmitted via three sacral nerves (S2, S3, and S4),which comprise the pudendal nerve.At this stage patients experience rectal pressure and an urge to"bear down" as the presenting part descends into the pelvicoutlet. 3. Approach to management of labor painUsing alternative medicine approach: It dealsmainly with emotional components of pain.Using the conventional medicine approach: dealsmainly with physical components of pain. 4. Conventional approach to the management oflabor painSystemic approach: With pharmacologicagents either parenteral or inhalation.Regional (neuraxial) techniques: Refers tolocal anesthetics placed around the nerves of thecentral nervous system. 5. Systemic approach to management of pain inlabor:Opioids (e.g. morphine, fentanyl, meperidine).Mixed opioid agonists-antagonists (e.g. pentazocine).Non-opioid agents are promethazine, Pentobarbital, andDiazepam. The antihistamines e.g. promethazine are oftenadministered in combination with an opioid to potentiateanalgesia and decrease side effects, such as nausea andvomiting.Inhalation agents: Entonox which contain oxygen andnitrous oxide in equal mix of 50% each. 6. Regional approach or techniques (neuraxialanalgesia):Epidurals.Spinals.Combined spinal-epidurals (CSE).Local injection as pudendal and paracervical nerve block,which are usually performed for specific indications. Those twomethods have the advantages that it is performed by theobstetrical provider.Lumber sympathetic block: 7. Pudendal BlockIndications: To alleviate pain induced by minor surgicalprocedures (e.g. episiotomy) or intervention involving theperineum such as applying low forceps and sometimes-ventousdelivery.The target: The sensory and motor fibers of the pudendalnerve (sacral nerve roots 2,3, and 4) .Complications: Are rare and include:Hematoma formation from breaking of a blood vessel.Infection at the site of injection.Ischial region paresthesias or sacral neuropathy may beexperienced on the first few days after delivery.Systemic toxicity from inadvertent intravascular. 8. Regional Techniques(Epidural, Spinal)Advantages of epidural and spinal anesthesia:1. Provide effective pain relief (for 90-95% of women).2. Provide pain relief for operative procedures such as forceps,episiotomy repair, or even cesarean section.3. Mothers can remain cooperative.4. Systemic side effects of narcotics are reduced since it is given viathe epidural route rather than I.V.5. Lower the blood pressure: is useful and effective in themanagement of hypertensive women e.g. with pre-eclampsia. 9. Epidural Vs. Spinal intrathecal routesThe dose of thedrugs usedThe onset of actionThe spinal is rapid inaction since the drugsare depositeddirectly into thecerebrospinal fluidWith spinal a (CSF)lower dose ofdrug is used 10. Table 13-3: Drugs used in regional spinal and epidural analgesia and its mechanismof action 11. Techniques of administering epidural anesthesia 12. Maintenance of epidural analgesia:Once the catheter in place maintenance ofanalgesia is by:Intermittent bolus injections, or continuousepidural infusion using a special infusionpump.PCA Patient-controlled epidural analgesia.In the later case the patient herself is taughtto administer a dose of analgesic drugdepends on her perception of pain. 13. Contraindications to spinal and epiduralanesthesiaAbsolutePatient refusal.Coagulopathy.Patient on therapeutic anticoagulation.Skin infection at injection site.Raised intracranial pressure.Hypovolaemia.RelativeUncooperative patientsPre-existing neurological disorders:Fixed cardiac output states. E.g. aortic stenosis, hypertrophic obstructivecardiomyopathy (HOCM), mitral stenosis and complete heart block.Anatomical abnormalities of vertebral column.Patients on prophylactic low dose heparin. 14. Complications of spinal and epiduralanesthesia (Immediate)Hypotension: Common side effect due to blockage of sympatheticnerves with subsequent dilation of the vascular beds of the lower halfof the body and decrease of the venous return. Prevented by loadingthe patient circulation by intravenous infusion of an isotonic electrolytesolutionFailed block: 15. Complications of spinal and epiduralanesthesia (Delayed)Post dural puncture headache (post-spinal headache):Results from unintentional dural puncture leading to leakageof CSF. Treatment by autologous epidural blood patch (i.e.,sterile injection of 15 to 20 mL of the patient's fresh bloodinto the epidural space, preferably at the site of the duralpuncture).Backache: .Urinary retention:Infection:Maternal temperature elevation: 16. Rare but life threatening Complications ofspinal and epidural anesthesia )Systemic toxicity: The most common etiology is accidentalinjection of local anesthetic into a blood vessel.High spinal: Refers to more cephalad progression of the level ofanesthesia than planned. Consequences can be very serious Itmay include:Massive sympathectomy that results in hypotension.Block of the cardiac accelerator fibers.Dyspnea and respiratory depression and nausea.Complete diaphragmatic paralysis if the C3 to C5 roots.Aspiration of gastric contents.Spinal epidural hematoma: more likely in patients with disordersof coagulation and in those receiving anticoagulants 17. Effect of neuraxial analgesia on theprogress and outcome of labor:Neuraxial analgesia tends to slow labor and beenassociated with increased rates of instrumentaland cesarean delivery. In such cases as long asthe fetal condition stable is stable the standardtime limit for the stages of labor should not beapplied. 18. Thanks