childbirth pain medication

  • midwives care has large impact on how women deal w pain

pain physiology:

  • where tissue trauma happens from heat/ pressure/ stretching/ hypoxia, imflamitory endogenous chemicals released and exite nerves creating electrical impulse along sensory nerve fibre.

  • affected nerve (first order neuron) then carries electric impulse towards spinal cord and CNS

  • 2 types of afferent nerve fibres

  • (electric implse travel faster along thick A-delta fibre and slower along thinner C-fibres)

  • thalamus interprets impulse as pain

  • intensity if pain depends on frequency of nerve impulse.

labour pain transmission pathway:

  • pain impulse in labour travel along thoracic/ lumbar/ sarcal nerve pathway

  • 1st stage- from upper and lower uterine segments and cervix (slow pain)

  • transitional stage- from cervix/ vagina/ bladder/ rectum (slow pain)

  • 2nd stage- from pelvic floor/ perenium/ vulva (fast pain)

slow pain- visceral pain

1st stage- origin of slow pain:

  • hypoxia/ distortion/ stretching of uterine muscles/ dialation of cervix

  • pressure on tissue and organs around uterus and lombo-sacral regions

  • pressure on bladder/ urethra/ rectum

  • increase in intensity can cause fear which can cause production of cortosoil (stress hormone)

  • cortisol can have negitive impact on oxytocin and so can slow labour

  • cortisol can reduce production of endogenous endorphins and encephalins and so brain percieve higher level of pain.

fast pain- somatic pain:

  • late 1st stage and 2nd stage pain

  • sharp and well organised pain

  • felt in exact area of stimulus/ trauma

  • body response- wothdraw immediately from pain and ahrmful stimulus to avoid further damage.

non pharmacological pain handling:

  • deep breathing

  • relaxation

  • meditation

  • heat

  • massage

refered pain:

  • dermatome- region of body where deep visceral neurons and superficial somatic neurons enter spinal cord at same time and share info to spinal cord.

  • slow pain from intercostal tissue or organs is felt as throbbing.

pain at beginning of second stage of labour:

  • due to babies pressure on birth canal and near structures

  • originates from visceral and somatic pain

  • pain intense/ sharp and local

epidural analgesia:

  • injection of local anastetic and opioid combination

  • given in lower back

  • can cause numbing in lower body

advantages:

  • reduce stress in mothers

  • positive birthing experience

  • bonding and feeding

disadvantages:

  • reductio of mobility

  • relaxes pelvic floor- can be increased labour

  • risk of instrumental delivery