Pain Relief in Labor

Learning Objectives Understand when and how to use various pain relief strategies Understand importance of pain relief strategies in aiding the progression of labor and promoting maternal well being Understand pharmacological and non pharmacological ways to manage pain

“Almost all women experience pain during labor but the response of individual women to labor pain is widely different” – from WHO website

Definitions Pain Unpleasant sensory and emotional experience associated with actual or potential tissue damage It is important to determine how a woman is coping and what her desires and fears are during labor. Relieving suffering and pain are themselves worthy goals to strive for Not all women in labor need medications. It is important to assess how she is doing and coping.

Adverse consequences to labor pain Produces physiological changes in addition to emotional distress Hyperventilation Maternal alkalosis that impairs O2 transfer to fetus Utero / Placental vasoconstriction Affect placental perfusion Psychological effects Maternal anxiety and pain increase the dysfunction of labor 1.Shifting the oxygen hemoglobin disociation curve to the Left increasing oxygen’s affinity to maternal Hb 2.Also causes ureto/placental vasocontriction

Adequate pain relief in labor Decreases maternal anxiety Shortens labor Decreases the need for intervention Makes labor a more positive experience

Support Maternal anxiety and pain increase the dysfunction of labor Physiologic discomforts add to labor pain and therefore should be addressed Anxiety and fear should be reduced by providing information and support

Support Companions Shortens labor Decreases the need for pain medications Decreases interventions including operative vaginal delivery and C-section

Types of Non-pharmacological Pain Management Decrease painful stimuli Stimulate peripheral receptors Increase descending inhibitory pathways on pain receptors

Decrease Painful Stimuli Maternal movement and position change to enhance comfort Counter pressure on a woman’s sacrum

Stimulate Peripheral Sensory Pathways Massage Water immersion Aromatherapy Superficial heat or cold packs Accupuncture or accupressure

Increase pain inhibitory pathways Distraction and focusing techniques Audio relaxation

Systemic Pharmacological methods Nitric Oxide Inhaled Self administered for the duration of contraction Good for transition phase (late active phase) or short procedures Quick on quick off with low side effect profile

Systemic Pharmacologic Methods Narcotics ( ie. Morphine) Given IM / IV Can be given early in labor Side effects: respiratory depression in baby if given close to delivery (This is easily reversed with Naloxone) variations in fetal heart rate

Local pharmacological techniques Pudendal block Peripheral nerve block Low systemic effects Use Lignocaine (use 30 ml of 0.5% for block and then can still use 10ml into perineum for repair) Useful in second stage labour, especially prior to any vaginal instrumentation for delivery Anaesthetize early enough to provide sufficient time for effect You are trying to anaesthetize the pudendal nerve as it passes through the lesser sciatic notch 2 approaches: through vagina or perineum

Local pharmacological techniques Pudendal block: Vaginal Approach Use Lt index finger to palpate woman’s left ischial spine through vagina Advance needle towards the left ischial spine by placing the needle tip just beyond your fingertip to guide it to proper position Be careful not to get needle-stick injury Advance needle through vaginal mucosa until it pierces sacrospinous ligament Always aspirate before injecting to be sure you are not in a vessel…. If you aspirate blood, DO NOT INJECT because IV lignocaine can cause death Inject approx 15 ml on each side

Local pharmacological techniques Pudendal block: Perineal Approach Place two fingers in vagina to guide needle through perineal tissue to tip of woman’s ischial spine Inject approximately 15 ml on either side of 0.5% lignocaine

Local pharmacological techniques Perineal infiltration Perineal skin infiltration Infiltration of local anesthetic (lignocaine) Useful in instrumental vaginal delivery, episiotomy and in repair of a perineal laceration

Regional anesthesia Epidural Little systemic effects on baby Can provide pain relief throughout entire labor and delivery Associated with longer 1st and 2nd stages of labor, oxytocin augmentation, malpositions and instrumental vaginal delivery Do not stop epidural in 2nd stage and allow for longer 2nd stage before intervening.