Labour Analgesia PDF

LA B O UR AN A L G E SI A Dr. Alaa Yousif Mahmood  DEFINITION OF PAIN An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage,. The Physiology of Pain in Labor  1st stage of lab...

LA B O UR AN A L G E SI A Dr. Alaa Yousif Mahmood  DEFINITION OF PAIN An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage,. The Physiology of Pain in Labor  1st stage of labor – mostly visceral ◦ Dilation of the cervix and distention of the lower uterine segment ◦ Dull, aching and poorly localized ◦ Slow conducting, visceral C fibers, enter spinal cord at T10 to L1  2nd stage of labor – mostly somatic ◦ Distention of the pelvic floor, vagina and perineum ◦ Sharp, severe and well localized ◦ Rapidly conducting A-delta fibers, enter spinal cord at S2 to S4 Does Labor Pain Need Analgesia?  Analgesia for Labor and Delivery Always controversial! “Birth is a natural process” Women should suffer!! Concerns for mother’s safety Concerns for baby Concerns for effects on labor The Ideal Labor Analgesic Good pain relief No autonomic block (no hypotension) No adverse maternal or neonatal effects No motor block No effect on labor and delivery: No increase in C/S rate No increase in forceps/vacuum delivery Patient can ambulate Economical: cost and personnel  Labor Analgesia Non-Pharmacological Pharmacological Non-Pharmacological Psycho prophylaxis – birth partner.mother Relaxation and breathing excises. TENS Acupuncture Relaxation in warm water hypnosis Intradermal water inj.  Nonpharmacologic strategies Psycho prophylaxis – birth partner.mother Nonpharmacologic strategies Hydrotherapy Nonpharmacologic strategies Aromatherapy in Childbirth  Nonpharmacologic strategies Transcutaneous electrical nerve (TENS) stimulation  Two paired of electrodes attached to women back T10-L1.  Low- intensity electrical stimulation is given continuously or applied by women herself as a contraction begin.  Block afferent fibers and preventing pain to travel from uterus to spinal cord synapses , and facilitate release of endorphinCan be effective as epidural anesthesia  Carries no risk to the mother and fetus  1. Nonpharmacologic strategies.Acupuncture  Based on concept that illness result from an  imbalance of energy , to correct the imbalance  needles are inserted into the skin at specific body points , activation of these point lead to release of endorphins.  Helpful in first stage of labor 1. Nonpharmacologic strategies.Application of Heat and Cold Heat Application : Effective in relief back pain and raises the pain threshold. To increase blood flow and relieves muscle ischemia. increases relaxation Cold application: Applied to the back, chest, and face to increase comfort slowing transmission of pain. 1. Pharmacological Narcotic analgesic (opioid analgesic) strategies  Act by decrease sensation of pain.  Used for their analgesic effect , all drugs in this category cause CNS depression , respiratory depression. Narcotic analgesic includes: pethidine (meperidin) , fentanyl remifentanil, morphine, tramadol pethidine is the most commonly used analgesic in labor because it has additional sedative and antispasmodic actions , these make it effective not only for reliving pain but also for relaxing cervix and providing feeling of euphoria and well-being Narcotic antagonist : naloxon (Narcan)  pharmacological strategies Advantages and disadvantages of narcotic (opioid ) administration Advantages an increased ability for a woman to cope with labor The medications may be nurse-administered It has no amnesic effect but create a felling of well-being or euphoria Disadvantages Frequent occurrence of uncomfortable side effects, such as nausea and vomiting, pruritus, drowsiness, and Pain is not eliminated completely nausea and vomiting (they should always been given with an anti-emetic). delayed gastric emptying (increasing the risks if general anaesthesia is subsequently required). short-term respiratory depression of the baby. possible interference with breastfeeding piates tend to be given as intramuscular injections, however, an alternative is a subcutaneous or intravenous infusion by a patient-controlled analgesic. Inhalational analgesia Nitrous oxide (NO) in the form of Entonox (an equal mixture of NO and oxygen) advantage It has a quick onset, a short duration of effect, and is more effective than pethidine. disadvantage may cause light-headedness and nausea. hyperventilation may result in hypocapnoea, dizziness and ultimately tetany and fetal hypoxia. not suitable for prolonged use from early labour because It is most suitable later on in labour or while awaiting epidural analgesia. Regional Anesthesia/Analgesia Epidural analgesia Spinal analgesia Combined Spinal Epidural (CSE) analgesia Paracervical block Lumbar sympathetic block Pudendal block Perineal infiltration Epidural Analgesia  The main indication is for effective pain relief There are other maternal and fetal conditions for which epidural analgesia would be advantageous in labour. These are: prolonged labour. maternal hypertensive disorders. multiple gestation. certain maternal medical conditions. a high risk of operative intervention. Not suitable for early labour(restrict mobility) or late labour(immenant labour) Contraindication Patient refusal or inability to cooperate Increased intracranial pressure secondary to a mass lesion Skin or soft tissue infection at the site of needle placement Frank coagulopathy Recent pharmacologic anticoagulation* Uncorrected maternal hypovolemia (e.g., hemorrhage) Inadequate training in or experience with the technique Inadequate resources (e.g., staff, equipment) for monitoring and resuscitation Technique Discusion Intravenous Hydration A balanced electrolyte solution (e.g., lactated Ringer’s solution) without dextrose is the most commonly used intravenous fluid for bolus administration. Patient Positioning Sitting or lateral?? There is little evidence that patient position influences the extent of neuroblockade during initiation of epidural analgesia/anaesthesia.  Technique the woman’s back is cleansed and local anaesthetic is used to infiltrate the skin. The position an extreme left lateral, or sat up but leaning over Flexion at the upper spine and at the hips helps to open up the spaces between the vertebral bodies of the lumbar spine. A. The epidural catheter is normally inserted at the L2–L3, L3–L4 or L4–L5 interspace and should come to lie in the epidural space, which contains blood vessels, nerve roots and fat The catheter is aspirated to check for position and, if no blood or cerebrospinal fluid is obtained, a ‘test dose’ is given to confirm the catheter position. This test dose is a small volume of dilute local anaesthetic that would not be expected to have any clinical effect. the catheter is correctly sited  FOLLOW UP After the loading dose is given, the mother should be kept in the right or left lateral position, blood pressure should be measured every 5 minutes for 15 minutes. Hypotention du to vasodilatation caused by blocking of the sympathetic tone to peripheral blood vessels. This hypotension i may cause a fetal bradycardia. It should be treated with intravenous fluids and, if necessary, vasoconstrictors such as ephedrine. The mother should never lie supine, as aorto-caval compression can reduce maternal cardiac output and so compromise placental perfusion. Hourly assessment of the level of the sensory block  Choice of Drugs The epidural solution is usually a mixture of low-concentration local anaesthetic (e.g. 0.0625–0.1 per cent bupivacaine) with an opioid such as fentanyl. Combining the opioid with the local anaesthetic reduces the amount of local anaesthetic required and this reduces the motor blockade and peripheral autonomic effects of the epidural (e.g. hypotension). Pain and analgesic requirements vary depending on several factors, including parity, stage of labor, presence of ruptured membranes, oxytocin augmentation, and whether the opioid is administered in combination with a local anesthetic. Local anesthetics were administered to block both the visceral and the somatic pain of labor Intrathecal opioids effectively relieve the visceral pain of the early first stage of labor,.  Spinal anaesthesia A spinal block is considered more effective than that obtained by an epidural, and is of faster onset. A small volume of local anaesthetic is injected into subarachnoid space. This may be used as the anaesthetic for Caesarean sections, trial of instrumental deliveries (in theatre), manual removal of retained placentae and the repair of difficult perineal and vaginal tears. Spinals are not used for routine analgesia in labour Complications of regional analgesia 1-Accidental dural puncture during the search for the epidural space should occur in no more than 1 per cent of cases. 2-Accidental total spinal anaesthesia (injection of epidural doses of local anaesthetic into the subarachnoid space) causes severe hypotension, respiratory failure, unconsciousness and death. 3-Spinal haematomata and neurological complications are rare, and are usually associated with other factors such as bleeding disorders. 4-Drug toxicity can occur with accidental placement of a catheter within a blood vessel. This is normally noticed by aspiration prior to injection. Complications of regional analgesia 5-Bladder dysfunction can occur if the bladder is allowed to overfill because the woman is unaware of the need to micturate, particularly after the birth while the spinal or epidural is wearing off 7-Backache during and after pregnancy is not uncommon 8-Hypotesthesia, but can still occur with an epidural although more commonly with a spinal. 9-Short-term respiratory depression of the baby is possible because all modern epidural solutions contain opioids which reach the maternal circulation and may cross the placenta. Side Effects of Neuraxial Analgesia 1. Hypotension 2. Pruritis 3. Nausea and vomiting 4. Fever 5. Shivering 6. Urinary retension 7. Recrudescence of HSV 8. Delayed Gastric emptying  Conclusion “The delivery of the infant into the arms of a conscious and pain-free mother is one of the most exciting and rewarding moments in medicine.” Moir DD. Extradural analgesia for caesarean section. Br J Anaesth