5.1d Pharmacological Pain Management Flashcards
Pharmacologic Pain Management
- Implemented before pain gets severe to prevent catecholamines from prolonging labor
Sedatives
- Relieve anxiety and induce sleep
- Can augment analgesics and reduce nausea from opiates
Barbiturates (Seconal)
- Crosses placenta and has long half-life
- Can cause respiratory/vasomotor depression (patient and fetus)
- Can cause neonate CNS depression
- Avoided if birth is anticipated within 12-24 hours
Phenothiazines (Phenergan)
- Does not relieve pain
- Adjunct medication with opiates to enhance analgesic effects
- Decreases anxiety, Increase sedation, Reduce n/v
Metoclopramide (Reglan) - Antiemetic can potentiate effects of analgesics. May be better choice than Phenergan
Benzodiazepines (Valium, Ativan)
- Enhances pain relief and reduces n/v with opiates
- Causes maternal amnesia
- Disrupts thermoregulation of newborns
Flumazenil (Romazicon) - Antidote for Benzo sedation/respiratory depression.
Analgesia
- Pain relief without loss of consciousness
Anesthesia
- Analgesia, amnesia, relaxation and reflex activity
First Stage of Labor Medications
- Opioid agonist analgesics
- Opioid agonist-antagonist analgesics
- Epidural block
- Spinal epidural
- Nitrous oxide
Second Stage of Labor Medications
- Nerve block analgesia/anesthesia
- Local infiltration anesthesia
- Pudendal block
- Spinal block
- Epidural block
- CSE analgesia
- Nitrous Oxide
Vaginal Birth Medications
- Local infiltration anesthesia
- Pudendal block
- Epidural block
- Spinal block
- CSE analgesia
- Nitrous Oxide
C-Section Medication
- Spinal block
- Epidural block
- General anesthesia
Opioids (Systemic Analgesia)
- IV/IM/PCA (Patient Controlled Analgesia)
- Effective in early labor but limited in late labor
SIDE EFFECTS
- Respiratory depression
- Sedation
- N/V, Dizziness, Altered Mental Status, Euphoria
- Decreased gastric motility, delayed gastric emptying, urinary retention
- Aspiration
- Maternal and Fetal Bradycardia/Hypotension/Hypoxemia
CROSSES PLACENTA EASILY AND CAN CAUSE RESPIRATORY DEPRESSION IN FETUS AFTER BIRTH
Opioid Agonist Analgesics
- Meperidine, Fentanyl, Remifentanil
- Meperidine and normeperidine can cross placenta and cause neonatal sedation and neurobehavioral changes. CANNOT BE REVERSED WITH NALAXONE
- No Amnesic Effect
- Enhances ability to rest in between contractions
- Do not administer until labor has been established EXCEPT to enhance rest during prolonged early labor
Opioid Agonist-Antagonist Analgesic
- Nalbuphine (Limited analgesic contribution)
- Produces withdrawal symptoms in women with opioid dependence
- Provides adequate analgesic with less n/v or respiratory depression
- Sedation may be greater
Opioid Antagonist
- Naloxone (Narcan)
- Reverses respiratory depression
Nerve Block Analgesia/Anesthesia
- Produces sensory/motor block over a specific region of the body
- Variety of local anesthesia used to produce regional analgesia/anesthesia (some analgesia/complete analgesia)
- Interruption of conduction of nerve impulses
Local Perineal Infiltration Anesthesia
- Lidocaine/Chloroprocaine injection
- Epinephrine usually added to localize and intensify effects and prevent bleeding
- Used for episiotomy or repairing lacerations.
Pudendal Nerve Block
- Local anesthetic used to relieve lower vagina, vulva, and perineal pain
SECOND STAGE - If episiotomy, forceps, or vacuum are to be used
THIRD STAGE - If episiotomy or lacerations are preformed
- Does not affect hemodynamic or respiratory function
- Does not affect vital signs
- Patients lose the bearing down reflex
Spinal Anesthesia/General Anesthesia
General - Only used when spinal is contraindicated or emergency (completely asleep)
Spinal - Preferred method and safer.
Spinal Anesthesia Risks
- Bleeds
- Infection (Greatly reduced with use of disinfectant)
- Spinach Headache
- Nerve damage (very rare)
- Nausea (from blood pressure changes)
- Shivering (from extra adrenaline)
- SOB
- Chest Pain/Shoulder Pain
Spinal Anesthesia
- Used for cesarean birth and numbs from the nipple (T6) to the feet
- Used for vaginal birth and numbs from hips (T10) to feet
- Patient sits or side lying with back curved to widen intervertebral space
- Higher levels of anesthesia for cesarean births require patient be supine with head and shoulders elevated. Placing wedge under patients hips prevents supine hypotension
- Effects will occur within 5-10 min (can possibly take 20+ min)
- Lasts about 1-3 hours
- For vaginal birth needle is inserted between contractions
Nursing Interventions Spinal Anesthesia
- Prior to injection Vitals should be assessed every 20-30 min. Fluid balance is assessed. Bolus IV is also administered 15-30 min before induction.
- After injection BP/Pulse/RR/FHR must be assessed every 5-10 min
- Hypotension (below 100 or 20% of baseline) or fetal distress is cause for emergency care
RISKS - CSF leakage from puncture site can cause Post Dural Puncture Headache (PDPH)
TREATMENT - Epidural blood patch is the best way to treat PDPH
- Oral analgesics and Methylxanthines (caffeine) can also be used
Hypotension and Decreased Placental Perfusion
- 20% decrease in pre-block baseline or less than 100 systolic pressure
- Fetal bradycardia
- Absent/minimal FHR variability
Nursing Interventions for Hypotension/Decreased Placental Perfusion
- Lateral position or pillow under hip to displace uterus
- IV infusion at specific rate
- Non-rebreather mask 10-12 L/min
- Elevate legs
- Notify OB and Anesthesiologist
- Administer vasopressor (if other treatment fails)
- Monitor BP and FHR every 5 minutes
- Combination of local anesthetics and opioids reduces motor function loss and enhances patients ability to push effectively.
Neuraxial Anesthetic Symptoms (Needs to be Assessed)
- Hypotension, lightheadedness, dizziness, fever, pruritis
- Loss of consciousness, convulsions, slurred speech, bizarre behavior
- Limited movement, numbness of tongue/mouth, metallic taste,
- Urinary retention
- Local anesthetic toxicity
- Tinnitus
- Longer Second Stage of Labor
- Increase Oxytocin Use
- Increased likelihood of forceps or vacuum assisted birth
Spinal Epidural Risks
- Bleeding
- Headache (most common)
- Back discomfort (rare)
- Infection (low due to sterile procedure)
- Paralysis (rare)
Spinal Epidural
- Most effective pharmacologic pain relief for labor
- Local anesthetic, Opioid analgesic, or both injected into epidural space
- Injected between 4th and 5th lumbar vertebrae
- Combination of Local and Opioid reduces anesthetic requirement and provides greater degree of motor function.
- Done in modified SIMS position
Spinal Epidural Process
- After catheter is inserted, a test dose is used to verify positioning of catheter.
- Likelihood of misplacement is greater in obese patients
- After catheter is initiated, preferred position is side lying to prevent supine hypotension
Spinal Epidural Considerations
- O2 should be available incase of hypotension
- Ephedrine/Phenylephrine can be used to vasoconstrict for hypotension
- FHR and contractions must be monitored carefully due to patient being less aware of their contractions
- Continuous Infusion Epidural (CIE) is most common
- CIE with opioids reduces motor block allowing more patient mobility
- PCEA (Patient Controlled Epidural Analgesia) can also be used
Spinal Block Advantages/Disadvantages
Advantages
- Ease
- Absence of Fetal Hypoxia
- Maintenance of maternal blood pressure
- Conscious
- Good muscular relaxation
- Blood loss is not excessive
Disadvantages
- Hypotension
- Impaired breathing, Cardiopulmonary resuscitation may be needed
- Increased likelihood of episiotomy/forceps/vacuum
- Bladder/Uterine Atony (Lowered Tone) and PDPH risk is higher
Epidural Advantages/Disadvantages
Advantages
- Most effective pain relief
- Good relaxation
- Airway reflexes remain intact
- Only partial motor paralysis
- Fetal complications are rare but can occur with rapid absorption of medication or maternal hypotension
Disadvantages
- Patient mobility and control over labor is limited
- Orthostatic Hypotension/Dizziness/Sedation/Weakness of Legs
- CNS Effects if medication is administered into blood vessel by accident
- Respiratory arrest can occur if high dose is injected into subarachnoid space
- Higher rate of fever
- Urinary Retention/Pruritis
- Increased use of oxytocin/forceps/vacuum
Combined Spinal and Epidural
- Blocks pain without compromising motor function
- Opioid is mixed with local anesthetic
- Patient maintains better motor function
Epidural and Intrathecal (Spinal) Opioids
- Fentanyl, Sufentanil, Preservative-Free Morphine
- Used for post-operative pain
- Eliminates need for local anesthetic and only uses opioids
- Does not cause maternal hypotension or affects VS
Epidural Morphine After C-Section
- Early Ambulation
- Facilitated bladder emptying
- Enhanced peristalsis
- Helps prevent clot formation in lower extremities
SIDE EFFECTS
- N/V
- Pruritis
- Urinary Retention
- Delayed Respiratory Depression
Contraindications of Spinal/Epidural Analgesia
- Risk of hemorrhage which can cause hypovolemia and hypotension (dangerous)
- If patient is receiving anticoagulants (heparin within last 12 hours)
- Infection at needle insertion site
- Intracranial pressure caused by mass/lesion
- Allergy, Refusal, Cardiac Conditions
Nitrous Oxide
- Patient controlled analgesia/anesthesia
- Diminishes pain and anxiety
BENEFITS - Low cost
- Less invasive
- Less intensive monitoring
- Does not limit mobility
- Does not affect uterine cavity
- Rapid onset
- Quick clearance (through exhalation)
- Self administered
SIDE EFFECTS - N/V, dizziness, drowsiness
General Anesthesia
- Rarely used for vaginal birth
- Necessary if epidural/spinal block is contraindicated
RISKS - Difficult to intubate patient
- Aspiration of gastric contents
PROCESS - Patient is pre-medicated with antacids to neutralize acidic contents
- Sometimes they are also given H2-Receptor Blockers to decrease gastric acid contents
- Prevent supine hypotension with wedge under the hips
- Patient is pre-oxygenated with non-rebreather mask for 2-3 min
Informed Consent
- Advantages/Disadvantages must be explained
- Patient must agree
- Consent must be given freely
Neuraxial Anesthesia Nursing Interventions
PRIOR TO BLOCK - Assess VS, hydration, labor progress, FHR and pattern - IV Bolus of fluid if ordered - Obtain lab results - Assess pain levels - Assist patient to void DURING BLOCK - Assist patient maintaining proper position - Guide patient through experiences - Assist with Documentation of VS, Time, Amount of Medication Given - Oxygen suction readily available - Monitor for Local Anesthetic Toxicity WHILE BLOCK IN EFFECT - Continue monitoring VS and FHR - Continue assessing pain levels - Monitor for bladder distension (bed pan, catheter, position change) - Promote safety (bed rails up, call light, monitor anesthetic effects) AFTER BLOCK IS WEARING OFF - Bed rails up - Call light in reach
Epidural Benefits
- Better pain relief and continuous pain relief throughout labor
- Will not become groggy but allows for rest and sleep
Epidural Drawbacks
- Must remain in bed and limits position change
- Needs foley catheter
- Lengthened labor due to lack of urge to bear down
- May affect newborn breastfeeding behaviors
- Hypotension from uteroplacental insufficiency and FHR deceleration
- PDPH
- Fever which may trigger neonatal sepsis
IV Pain medication Benefits
- Easy and Rapid Onset
- Limited duration (patient can walk once medication wears off)
- Allows rest
IV Pain Medication Drawbacks
- Grogginess/Sleepiness/Disorientation
- Decrease variability of FHR
- Neonatal Respiratory Depression if given close to birth
- May negatively impact newborn breastfeeding behavior
Nursing Interventions for IV Pain Medication
- Encourage patient to void prior
- Siderails should be up on bed
- Explain she will be sleepy and to encourage rest
- Maintain quiet atmosphere
- Position in left lateral
Metoclopramide (Reglan)
- Reduces Anxiety
- Potentiates Analgesics
- Relieves Nausea
Hydrochloride (Nubain)
- Unlikely to cause respiratory depression
Naloxone
- If used, assess patients pain level because it may abruptly return
Continuous Epidural Block Interventions
- Assist into modified SIMS to administer the block
- Alternate position side to side every hour
- Assist patient in urinating every 2 hours to prevent bladder distension
- Assess BP frequently due to hypotension risk
Opioid Abstinence Syndrome Manifestations
- Anorexia
Spinal Block BP Drop
- Change position from supine to lateral