Event 3: Post-Operative

Postoperative Day 0

Mrs. Smith arrives in the Post Anesthesia Care Unit (PACU).

Patient admitted to PACU – orders as follows:

  • Patient-controlled analgesia is prescribed
    • hydromorphone 0.2 mg demand dose with a lock-out interval of q (every) 10 minutes
    • adjunct analgesia includes 
      • acetaminophen 1000 mg IV q 6 hours for 48 hours (Maximum total daily dose of acetaminophen by any route)1
      • ketorolac 30 mg IV q 6 hours for 48 hours (serum creatinine  normal 0.64 – 1.27 mg/dl)
  • Vital signs q1 hour x4, q2 hours x2, q4 hours


  1. OFIRMEV® (acetaminophen) injection prescribing information. Cadence Pharmaceuticals, Inc.

Mrs. Smith’s Postoperative Orders

  • Assess respiratory rate and level of consciousness using Richmond  Agitation and Sedation Scale (RASS) every 2 hours 
  • Chest tube to water seal record output every 30 minutes x 2, every hour x2, then every 4 hours
  • Strict NPO (nothing by mouth)
  • Nasogastric tube – DO NOT Manipulate – place to low continuous wall suction, forward flush with 10 ml every 6 hours
  • Jejunostomy tube – connect to gravity drainage 
  • C-PAP – inspiratory positive airway pressure (IPAP) 10 cm H2O expiratory positive airway pressure (EPAP) 5 cm H2O during sleep – O2 concentration 40%
  • Continuous end tidal CO2 (EtCO2) monitoring

Test Your Knowledge

Question 1

True or false: When assessing a patient’s pain, the clinician should  believe the patient’s pain rating, and treat pain aggressively to reduce the pain rating.

Correct. Yes, clinicians should believe patients’ reports of pain, but should treat the patient not the pain rating. Pain therapy should be balanced with an assessment the pain tolerability and patient safety.

Question 2

True or false: There are serious risks of harm associated with opioid pain therapy that is not carefully planned.


Question 3

True or false: Opioid dosing should be titrated to patient-reported pain intensity.


Question 4

True or false: Patients are at highest risk for serious opioid-induced events during the first 24 hours following surgery.


Question 5

The best way to monitor for opioid-induced respiratory depression is respiratory rate.


Surgical Team Unit Meeting

The team discusses the use of gabapentin in this case.

Postoperative Day 1

Mrs. Smith’s pain is not well controlled.

  • Mrs. Smith continues to report experiencing 8 out of 10 pain using the numeric rating scale (NRS) despite IV PCA,  IV acetaminophen and ketorolac 
    • Respiratory rate ranges from 16 to 22 per minute with no signs of respiratory depression
    • Sedation level using the RASS is in the range of +1 restless to 0 alert and calm. During the night she was assessed as -1 drowsy
    • Pulse-oximetry readings for O2 saturation (SpO2)  are all within normal limits (95% to 98%)  with supplemental oxygen therapy @ 2L per nasal cannula 
    • End tidal CO2 readings remain within the normal range established for the patient (35 to 45)
  • After care coordination rounds the following orders were placed:
    • hydromorphone PCA (0.2 mg/ml) intravenous (IV)
      • Basal rate: 0 mg, PCA Dose: 0.2 mg, Lockout Interval: 10 minutes
      • Nurse administered supplemental bolus of 0.2 to 0.4 mgs hydromorphone IV q 4 to 6 hours as needed for periods of severe pain  
      • Continue respiratory rate, sedation level, and pulse oximetry and end tidal CO2 monitoring   
    • gabapentin 300 mg every 8 hours via jejunostomy tube
      • Monitor renal function
    • continue scheduled acetaminophen 1000 mg IV every 6 hours
    • continue ketorolac 30 mg IV q6h as needed for pain
      • Monitor serum creatinine

Postoperative Day 2

Mrs. Smith’s pain plan is modified.

  • Mrs. Smith continues to progress post operatively. Her vital signs remain stable, she reports improvement with pain management (pain 5 out of 10 NRS scale). Continues to use C-PAP at night with  EtCO2 in normal range ( 35- 45 mmHg)
  • After Care Coordination rounds, today’s orders as follows:
    • begin tube feeding via jejunostomy tube, titrate to goal rate
    • discontinue IV acetaminophen 1000 mg every 6 hours
    • discontinue IV ketorolac 30 mg every 6 hours
    • continue hydromorphone PCA
      • Basal rate: 0 mg, PCA Dose: 0.2mg, Lockout Interval: 10 minutes
      • Nurse administered supplemental bolus of 0.2 to 0.4 mgs hydromorphone IV q 4 to 6 hours as needed for periods of severe pain  
    • continue gabapentin to 300 mg every 8 hours via jejunostomy tube
    • acetaminophen 650 mg via jejunostomy tube every 6 hours
    • ibuprofen 600 mg via jejunostomy tube every 6 hours as needed for  pain

Post-Op Day 4

Surgical Team Unit Meeting

Mrs. Smith's surgical team meets to discuss her pain and analgesia needs on post-op day 4.

Analgesic Gaps

  • Gaps in analgesia should be avoided!  
    • Frequent monitoring of pain severity and PCA device maintenance
    • Educate patients to appropriately access their PCA demand dosing to prevent worsening of pain with activity (e.g., coughing and deep breathing, repositioning in bed, getting out of bed, or ambulating) 
  • Most IMPORTANT, determine appropriate equi-analgesic conversions when transitioning from IV PCA to the oral or an alternate route 
  • Emerging novel PCA technologies will hopefully help to reduce analgesic gaps


Chen PP, et al. Anesthesia & Analgesia. 2001;92:224-227.

Transitioning From IV to Oral Opioids

  • FIRST:  Know who you are treating
    • Opioid tolerant or naïve?
    • Healthy or sick? 
      • pre-existing or current health issues
      • renal or hepatic impairment that may effect the metabolic pathways of selected opioid analgesics
    • Young or old?
    • Low or high risk for aberrant drug-related behavior?
    • Sleep disturbance or OSA?
    • Morbid obesity?
  • SECOND:  Know what you are treating
    • Acute or chronic pain?
    • Do you understand the cause(s) of pain or not?
      • Nociceptive or neuropathic?
      • Depression?
      • Sleep disorder?
  • THIRD:  Think about if the patient is a good candidate for long-acting opioids
    • For Mrs. Smith, she is:
      • Not opioid tolerant
      • Does not have a known source for chronic pain
      • Is recovering from surgery, and likely to continue to have improving pain over time
      • Has a relatively low opioid requirement
      • Therefore, long-acting opioids are not indicated
  • FOURTH:  Select your drugs carefully
    • For Mrs. Smith:
      • Since she is not able to take medications by mouth, an opioid that is available in oral solution should be selected. Most opioids are all available as oral solutions. 
  • FIFTH:  Convert current IV opioid to an equianalgesic PO dose
    • consult a pharmacists to assist equianalgesic conversion tables may differ and serve only as a guide
    • if a switch in opioid is considered, for patients who are tolerant and have been maintained on one opioid for an extended time (weeks to months) it is IMPORTANT to decrease the dose of the new opioid by at least 30% (when switching from one opioid to another) due to incomplete cross-tolerance
  • FINALLY:  Make plans for monitoring the patient’s response to the oral opioid.
  • For Mrs. Smith: An individualized plan of care
    • Administer the first dose of oxycodone oral solution via the jejunostomy tube before discontinuing the IV PCA demand dose only
    • Evaluate the effectiveness of the dose in relieving pain
    • Discontinue the IV PCA after determining that the dose is effective


de Leon-Casasola OA. American Journal of Medicine. 2013;126(3 Suppl 1):S3-11.

Mrs. Smith: Transitioning from IV PCA to Oral Opioids

  • Step 1: Calculate the past 24 hour total opioid requirement:
    • Mrs. Smith used 30 demand dose (0.2 mg) in the past 24 hours
      • 0.2 X 30 = 6 mg of hydromorphone delivered by the patient in 24 hours
    • Mrs. Smith’s primary nurse administered 2 supplemental doses of IV hydromorphone 0.4 mg for each dose
      • 0.4 X 2 = 0.8 mg of hydromorphone administered by the nurse in 24 hours  
    • Total dose of hydromorphone IV in the past 24 hours = 6.8 mg
  • Step 2: Convert the IV hydromorphone dose to IV morphine
    • 1.5 mg of IV hydromorphone is = 10 mg of IV morphine
    • 6.8 mg of IV hydromorphone is =  45.3 mg of IV morphine
  • Step 3: Convert IV morphine equivalent to an oral morphine equivalent (10 mgs IV morphine = 30 mgs of oral morphine)     
    • 45.3 mg of IV morphine X 3 = 136 mg of oral morphine
  • Step 4: Convert the oral morphine equivalent to an equivalent dose of oral oxycodone
    • 30 mg of oral morphine = 20 mg of oral oxycodone
    • 136 mg of oral morphine = 90 mg of oral oxycodone in 24 hours
  • Step 5: Determine how to distribute the equianalgesic dose over 24 hours or if the dose should be decreased or increased based on the patient’s pain

Since Mrs. Smith was expected to have less pain following the removal of her chest tube, 10 mg of oxycodone oral solution every 3 to 4 hours was prescribed via her jejunostomy tube.

Conversion Chart for Selected Opioids

Conversion for Selected Opioids
Opioid IV (mgs) PO (mgs)
Morphine 10 30
Hydromorphone 1.5 7.5
Fentanyl 0.1 Transmucosal only
Oxycodone NA 20
Levorphanol (Levo=Dromoran) 2 acute 4 acute
Oxymorphone 1 10

Codeine, hydrocodone and fentanyl patch not listed. Buprenorphine had nor oral dose given and 0.3 listed for IV. I left this is red since it was a change. All the rest were the same.

Conversions Used with permission: American Pain Society. Principles of analgesic use in the treatment of acute pain and cancer pain. 6th ed. (pp. 19–21). Chicago, IL: American Pain Society, 2008.

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