Chapter 24 – Sedation and Analgesia




Chapter 24 Sedation and Analgesia


Sandra J. Cunningham , Katherine J. Chou , and Robert M. Kennedy



Overview


The recognition, assessment, and management of pain in children can be challenging, given the wide range of developmental stages, the difficulty in differentiating pain from anxiety, and the concern that relieving pain may obscure the diagnosis. Therefore, provision of analgesia to younger patients is often suboptimal. In fact, making the child more comfortable can facilitate the physical examination and required diagnostic testing. This includes patients with abdominal pain, headache, and trauma victims.


The goals of sedation are to provide optimal patient comfort during a procedure while maintaining patient safety. Adhere to strict protocols when administering procedural sedation in order to minimize adverse effects. Persons involved in the sedation process must be experienced in resuscitation in the case of an untoward event. Most importantly, ensure that the provider(s) administering the sedation and monitoring the status of the child are not the same person as the individual who is performing the procedure.


Several factors can affect the success of sedation, such as the patient’s psychological development, pain threshold, and the pre-procedural anxiety level. Parental presence decreases both child and parent anxiety and does not negatively impact the procedure success rate. Adult behaviors that help to decrease pain or distress are distraction, direct commands to use a coping strategy, praise, and allowing the child to make some choices rather than giving overall control of the procedure to the child. Conversely, some adult behaviors may increase pain or distress and these are not always intuitive, e.g., reassurance and apology. Criticism of the child’s behavior must be avoided.



Procedural Sedation and Analgesia


Procedural sedation and analgesia (PSA) employs sedatives or dissociative agents, which are administered at dosages and rates that allow the patient to maintain airway control, protective reflexes, and cardiorespiratory function. Be prepared, however, to intervene to support airway and ventilation, if necessary.


Acceptable candidates for PSA in the ED are patients who are American Society of Anesthesiology (ASA) Physical Status Classification Classes I or II (see Table 24.1). Perform the assessments and reassessments for PSA pre-sedation, intra-sedation, and post-sedation.




Table 24.1 American Society of Anesthesiologists (ASA) Physical Status Classification System




























ASA Class Patient description
I Healthy, no underlying organic disease
II Mild or moderate systemic disease that does not interfere with daily routines (e.g., well-controlled asthma, essential hypertension)
III Organic disease with definite functional impairment (e.g., severe steroid-dependent asthma, insulin-dependent diabetes, uncorrected congenital heart disease)
IV Severe disease that is life-threatening (e.g., head trauma with increased intracranial pressure)
V Moribund patient, not expected to survive
E (suffix) Physical status classification appended with an “E” connotes a procedure undertaken as an emergency (e.g., an otherwise healthy patient presenting for fracture reduction is classified as ASA physical status 1E)


Pre-Sedation


When choosing a medication, take into account the physical and mental status of the patient, including age, vital signs, current medical condition, past medical and sedation history, other medications given at home or in the ED, allergies, last oral intake of fluids or solids, and psychological state. Also consider the procedure being performed, including expected level of pain and likely duration.


The recent intake of solids or liquids is not an absolute contraindication for PSA. Determine the risks and benefits of immediately performing versus delaying the procedure. Data on aspiration risk have been extrapolated from anesthesia literature where the airway is being manipulated (e.g., endotracheal intubation). By definition, with appropriate PSA, the patient will maintain airway control and protective reflexes. See Table 24.2 for the American Academy of Pediatrics and the ASA preferred pre-procedural fasting guidelines.




Table 24.2 Pre-procedural fasting AAP/ASA guidelines
























Age Solids (includes milk) Clears
<6 months 4–6 hours 2 hours
≥6–36 months 6 hours 2 hours
≥36 months 6–8 hours 2 hours

Anticipate both common and uncommon complications. These include vomiting or aspiration, allergic reactions, paradoxical reactions, anaphylaxis, abnormal movements or seizures, airway compromise, respiratory depression and hypoxia, apnea, and cardiorespiratory arrest. Complications generally result from errors in medication dosing, inadequate monitoring, inadequate skill level of the provider, use of multiple agents (≥3), premature discharge of the patient, higher levels of ASA categorization, or young age. Patients are at the greatest risk of complications about five minutes after administration of PSA and after the procedure is completed, when the stimulus has been removed.



PSA Equipment


When administering medications with the potential for compromise of ventilation or circulation, continuously monitor the patient with a cardiorespiratory monitor, pulse oximeter, and end-tidal carbon dioxide monitor (ETCO2). Equipment that must be immediately available at the patient’s bedside include bag-mask apparatus with a proper-sized mask, suction with a large-diameter suction catheter, an oxygen source, and the correct size nonrebreather face mask (Table 24.3).




Table 24.3 PSA equipment
























Blood pressure cuffs and sphygmomanometer Bag-valve-mask apparatus
Cardiac monitor Endotracheal tubes and stylets
Epinephrine (allergic reactions) Large-bore suction device
Oral/nasal airways Laryngoscope
Oxygen source Pulse oximeter and ETCO2
Resuscitation medications (atropine, epinephrine) Specific antidotes

Other resuscitation equipment, such as laryngoscopes, endotracheal tubes, and resuscitation medications must be rapidly available, if needed.



Consent


Once the PSA medication has been chosen, explain to the parents the nature of the procedure and the expected effect of the drug, including possible side effects. Hospitals differ on whether a separate informed consent for PSA is required, although there is no evidence that a separate consent form enhances patient or parental satisfaction, and it is not required by the Joint Commission on Accreditation.



Intra-Sedation


During PSA, continually monitor airway, breathing, and circulation status, with written documentation at specified intervals (5–15 minutes). The provider performing the procedure cannot also monitor the patient.



Post-Sedation


Continue to monitor airway, breathing, and circulation status until the patient is awake and no longer at risk for cardiorespiratory compromise. Before discharge from the ED, the patient must return to a baseline level of alertness and motor ability. Give the parent appropriate discharge instructions, including a contact number for the ED.



Medication Administration


Medications can be given by a variety of routes, including intranasal (IN), inhalational, intramuscular (IM), intravenous (IV), oral (PO), and rectal (PR). The intravenous (IV) route provides the most reliable and predictable sedation. Many drugs can be titrated to accommodate the level of sedation needed and the length of the procedure. Rapid IV administration can lead to hypotension and cardiorespiratory compromise. Always infuse medications at an IV port close to the catheter hub to ensure that the drug reaches the vascular system immediately. When medications are given more distally in the IV tubing while fluids are running, there is a potential for a rapid bolus of the drug.


The intramuscular route can provide deep sedation without the need for an IV, but drugs cannot be titrated and this route lacks the precise control of the IV route. Oral, intranasal, inhalational, and rectal routes are generally appropriate for less painful procedures, procedures in which a local anesthetic will also be used, or as sedation for diagnostic procedures, such as a CT scan. The inhalation route (nitrous oxide) is appropriate for cooperative children of three years and older who are able to follow directions.


Before administration of the medication, use relaxation techniques such as guided imagery or hypnosis, and attempt to create a calm atmosphere (e.g., dim lighting, noise elimination). Insert an intravenous line, if needed, and place the child on a cardiorespiratory monitor, which includes continuous pulse oximetry. Pulse oximetry provides an early warning of desaturation, since visible cyanosis does not occur until 5 g/dL of hemoglobin are desaturated (generally at an oxygen saturation <70%). Although an oxygen source must be immediately available, the routine administration of oxygen during PSA will limit the provider’s ability to detect hypoventilation when the pulse oximeter displays a decreasing oxygen saturation. Capnography measures ETCO2, which is the highest value of carbon dioxide at the end of expiration of each breath and will detect early hypoventilation before oxygen desaturation. It is recommended for routine monitoring and specifically when using etomidate, ketamine, or propofol.



PSA Medications (See Table 24.4)




Table 24.4 PSA medications



































































































































































































































Drug Route Dose Onset Duration Max Dose Side Effects Comments
Etomidate IV 0.15-0.2 mg/kg <1 min <12 min 20 mg Pain at injection site, vomiting


  • ↓O2 sat, ↓BP



  • Respiratory depression (with opioids)



  • Myoclonus (not assoc. with EEG changes)



  • Adrenal insufficiency (multiple doses)

Slow IV push over 1 minute
May require a second dose
Propofol IV 1.5 mg/kg <1 min <15 min 30 mg Pain at injection site


  • Apnea, ↓BP



  • Lactic acidosis (continuous infusion)

Slow IVP over 1 min


  • Additional dose: 0.5 mg/kg

Ketamine IM


  • IV



  • IN

3–4 mg/kg


  • 1.5 mg/kg



  • 1 mg/kg in 0.5 mL



  • 0.25 mL/nostril

4–5 min


  • 1–2 min

20–30 min


  • 10–15min

150 mg


  • 75 mg

Vomiting, laryngospasm, ↓O2 sat


  • Emergence reaction



  • Post-procedure ataxia



  • ↑ Oral and airway secretions



  • ↑ Sympathomimetic activity



  • ↑ Intraocular pressure

Slow IVP over 1 min


  • Additional doses: 0.5 mg/kg

Propofol plus IV 0.5–1 mg/kg/
ketamine 0.5–1 mg/kg
Dexmedetomidine IV 2 mcg/kg over 10 min ↑BP, nausea, vomiting Can have slow onset and recovery
Infuse 1 mcg/kg/h
Nitrous oxide (see text)
Morphine IM


  • IV



  • SC

0.1–0.2 mg/kg 1–2 min 1–3 h 15 mg Respiratory depression (especially when used with other agents)


  • ↓ BP in if hypovolemic



  • Nausea, vomiting



  • Histamine release

Slow IVP over 1 min
Fentanyl IV


  • Infuse

1–5 mcg/kg


  • 0.5 mcg/kg/min

1–2 min 30 min 100 mcg


  • 25 mcg/min

Respiratory depression and hypoxia (can occur (with appropriate dose and IV rate)


  • Chest wall rigidity with rapid bolus



  • ↓ Pulse, ↓BP



  • Nausea, vomiting

Use in combination with midazolam


  • Facial pruritus early sign of sedation



  • Chest wall rigidity may require larger naloxone dose

Fentanyl (100 mcg/2 mL) IN 1.5 mcg/kg


  • Min 20 mcg

1–2 min max 60 mcg
Midazolam


  • (5 mg/mL)

IV/IM


  • PO



  • PR



  • IN

0.1 mg/kg


  • 0.5–1 mg/kg



  • 0.5 mg/kg



  • 0.25–0.4 mg/kg

5–10 min


  • 5–10 min

30–60 min


  • 30–60 min

IV/IM: 5 mg


  • PO: 20 mg



  • IV: 5 mg

↓ Complications used as a single agent


  • ↓ Respirations in combination with opioids

Administer before other agents


  • Antidote: flumazenil (see below)

Methohexital PR 25 mg/kg <10 min 60–90 min 1 g Minimal adverse effects at low doses Effects are dose-dependent and range from mild sedation to coma
↓O2 sat, hiccups, cough, ↑salivation No analgesic effects
Pentobarbital PO


  • PR

2–6 mg/kg


  • 2 mg/kg



  • Min 30 mg

Up to 45 min 2–4 h PO: 150 mg


  • PR: 60 mg

Prolonged period to arousal


  • Agitation

Most success in children <8 yrs


  • Limited use due to onset and duration

Ketorolac IM/IV 0.5 mg/kg 0.5–1 h 6 h 30 mg Nausea, gastritis, drowsiness 5 day course maximum
Interstitial nephritis Do not use in renal or hepatic failure
Use for sickle cell pain and renal colic
Oxycodone PO 0.05–0.15 mg/kg 0.5–1 h 6 h 5 mg Nausea, vomiting, constipation, gastritis Useful in sickle cell pain crisis
Codeine/acetaminophen PO 0.5–1.0 mg/kg as codeine 0.5–1 h 4–6 h 30 mg Nausea, vomiting, constipation Useful in sickle cell pain crisis
Abdominal pain Various formulations available or dose codeine and acetaminophen separately
Acetaminophen PO 15 mg/kg 0.5–1 h 4 h 650 mg No anti-inflammatory effect
PR
Ibuprofen PO 10 mg/kg 6 hrs 800 mg Gastritis, inhibits platelet aggregation Has anti-inflammatory effects
↓ GI distress with food or milk
Do not use with renal insufficiency
Antidotes
Naloxone (for opioids) IV


  • IM



  • SC



  • ETT

0.1 mg/kg <1 min 60 min 2.0 mg first dose Seizure risk if opioid dependent including newborns of drug-addicted mother Have at bedside when using fentanyl


  • Smaller doses (0.01 mg/kg/dose) may reverse respiratory depression but maintain analgesia



  • Narcotic effects may outlast naloxone

Flumazenil IV 0.02 mg/kg 1–3 min 1 mg Crying, agitation Administer via 0.2 mg increments over 15 sec


  • Repeat dose in 60 sec, to 1 mg max



  • Useful for iatrogenic/known overdose



  • Not for reversal of known side effects



  • Benzodiazepine may outlast flumazenil



Opioids


Opioids are potent analgesics that elevate the pain threshold causing analgesia, euphoria, and respiratory depression. An advantage of opioids is that they are reversible with the pure antagonist, naloxone (Table 24.4). The serum half-life of naloxone is approximately 60 minutes, so be aware that the effects of the opioid may outlast the naloxone. For patients who require a prolonged course of naloxone, infuse a drip that delivers, per hour, two-thirds of the dose that was required to achieve the desired response initially.



Morphine


Morphine is the principal alkaloid of opium. It has minimal hemodynamic effects in the euvolemic patient when used in appropriate doses. Use morphine for procedures such as burn debridement and hydrotherapy, and abscess incision and drainage, and to control pain in patients with burns or sickle cell vaso-occlusive crisis.



Fentanyl


Fentanyl is a synthetic opioid that is 24–100 times more potent than morphine. Use fentanyl for painful procedures of short duration such as fracture reduction or incision and drainage of an abscess or pilonidal cyst.


Fentanyl combined with midazolam (see Benzodiazepines below) provides potent analgesia for short, painful procedures. Administer the midazolam first, followed by fentanyl. Generally, with this combination, the total dose of fentanyl can be decreased by about 50%.



Benzodiazepines


Benzodiazepines possess sedative-hypnotic, anxiolytic, and antegrade amnestic effects. When used as a single agent, they have a low risk of complications, although they are often combined with other drugs, such as opioids, for painful procedures. Untoward effects of benzodiazepines are reversible with the antagonist flumazenil (Table 24.4), which is appropriate for iatrogenic or known overdose of benzodiazepines. Do not use flumazenil routinely to reverse the known effects of benzodiazepines. Monitor the patient for resedation since the half-life of the benzodiazepine may outlast that of flumazenil.



Midazolam

Indications for use include anxiety-provoking or non-painful procedures such as CT scan or gynecologic examination, or procedures in which a local anesthetic will be used, e.g., laceration repair. Use midazolam in combination with an opioid to augment sedation for painful procedures.



Etomidate


Etomidate is a non-barbiturate sedative-hypnotic that has been used for several decades as an induction agent in the operating room. Initially in EDs it was used as a pre-intubation induction agent but has subsequently gained favor as a PSA medication. It has no analgesic properties, so patients undergoing a painful procedure will need additional medication, such as lidocaine or an opioid. Etomidate produces amnesia for the event in the majority of patients. Use etomidate for procedures of very short duration such as a CT scan of the head, reduction of a dislocation, foreign body removal, abscess incision and drainage, and lumbar puncture.



Propofol


Propofol is a potent sedative-hypnotic agent that has no analgesic or amnestic effects. Because of its potency, it can be used alone for painful procedures of short duration, such as fracture reduction and incision and drainage of an abscess or pilonidal cyst. It is contraindicated in patients with soy and egg allergies.



Nitrous Oxide


Nitrous oxide is a sedative-hypnotic that has no anesthetic qualities but causes a detached feeling in the patient. It is a two-tank system capable of delivering a mixture of up to 70% nitrous oxide and 30% oxygen. Attach a scavenger device from the nitrous oxide tank to wall suction to eliminate the potential for leakage of nitrous oxide into the atmosphere. Prepare an additional suction device in case the patient vomits, which is an indication for discontinuing the nitrous oxide. Administer 100% oxygen for 1–3 minutes before starting nitrous oxide, then initiate nitrous oxide at low levels (30–40%) for 2–3 minutes. Subsequently, increase nitrous oxide to 50–60% (steady state) and keep at this level for 2–3 minutes or throughout the procedure, if the desired level of comfort is met. During the most painful part of the procedure, 70% nitrous oxide can be used, with a return to the steady state percentage when complete. Dial down nitrous oxide in the same slow manner that it was raised. When nitrous oxide is discontinued, administer 100% oxygen for 3–5 minutes.


As a safety measure, the nitrous oxide delivery stops if the oxygen becomes diminished. Discontinue the nitrous oxide if there is no effect after 2–3 minutes; 10% of the population does not respond. Nitrous oxide is contraindicated in patients with head trauma or impaired mental status, abdominal distention or obstruction, pneumothorax, respiratory depression, and pregnancy.



Ketamine


Ketamine is a phencyclidine derivative that provides potent sedation and analgesia and dissociates the central nervous system (CNS) from outside stimuli such as pain, sight, and sound. Use ketamine for painful procedures of short or moderate duration such as fracture reduction, incision and drainage, or wound repair. It is not necessary to administer midazolam or an antisialagogue with ketamine.


Since there is no spectrum of dissociation (it is either present or absent), additional increments of the drug will not increase the level of dissociation. Titrate the drug to achieve the dissociated state over the length of the procedure.


Absolute contraindications of ketamine include age under three months and psychosis. Relative contraindications include procedures that stimulate the posterior pharynx (endoscopy), active respiratory disease, cardiovascular disease, history of airway problems (tracheal stenosis), CNS masses or hydrocephalus (ketamine is safe to use in head trauma), glaucoma or acute globe injury, hyperthyroidism, porphyria, or when there is a history of a previous adverse reaction. Perform meticulous oral suctioning if using for intraoral procedures to avoid pooling of secretions.



Propofol With Low-Dose Ketamine

This combination provides potent sedation with a good safety profile. Theoretically, propofol-related hypotension and respiratory depression are reduced by the increased norepinephrine induced by ketamine and the ketamine-related emesis is reduced by the antiemetic and anxiolytic properties of propofol.



Dexmedetomidine


Dexmedetomidine is a CNS α2-agonist that provides profound sedation with few cardiovascular and respiratory effects. Reported side effects include xerostomia, bradycardia, rash, orthostatic hypotension, and rebound hypertension. If necessary, the antidote atipamezole will reverse the sedative and cardiovascular effects.



Barbiturates


Barbiturates are sedative-hypnotics that can provide mild to deep sedation, depending on the dose. They have no analgesic qualities. Give barbiturates for anxiety-provoking procedures such as CT scan or procedures in which a local anesthetic will be used (e.g., laceration repair).



Methohexital

Methohexital is an ultra-short-acting barbiturate that is given rectally, avoiding the need for an IV catheter.

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Sep 22, 2020 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 24 – Sedation and Analgesia
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