the presence of flumazenil (choice A). Naltrexone (Vivitrol) is a competitive antagonist to mu receptors. Flumazenil (Anexate) is structurally similar to midazolam and is a nonspecific competitive antagonist of the benzodiazepine receptor (GABAA) in the central nervous system (CNS) (choice B). Flumazenil has a limited role in the management of benzodiazepine overdose, purportedly to avoid the need for procedure (i.e., intubation), and is contraindicated in the presence of a known seizure disorder or benzodiazepine dependence. It can reverse the effect of benzodiazepines in the CNS and precipitate seizures making choice C incorrect. Flumazenil rapidly undergoes hepatic metabolism to inactive metabolites and its half‐life is not long, about 40–80 minutes, thus the duration of effect of a long‐acting benzodiazepine or a large benzodiazepine dose can exceed that of flumazenil making choices D and E incorrect. However, in the right scenario, flumazenil as a reversal and rescue medication can be lifesaving. The recommended initial dose in adults is 0.2 mg IV given by slow push over 1–2 minutes. Doses can be repeated 0.2 mg, but one must watch for a maximum dose of 2 mg.Answer: BKreshak AA, Cantrell FL, Clark RF, Tomaszewski CA. A poison center's ten‐year experience with flumazenil administration to acutely poisoned adults. J Emerg Med. 2012; 43(4):677–82.Weinbroum AA, Flaishon R, Sorkine P, Szold O, Rudick V. A risk‐benefit assessment of flumazenil in the management of benzodiazepine overdose. Drug Saf 1997; 17(3):181–96.Shalansky SJ, Naumann TL, Englander FA. Effect of flumazenil on benzodiazepine‐induced respiratory depression. Clin Pharm 1993; 12(7):483–7.Seger DL. Flumazenil‐‐treatment or toxin. J Toxicol Clin Toxicol 2004; 42(2):209–16.Murray L Little M Pascu O Hoggett KA. Toxicology Handbook. 3rd Edition. eBook ISBN: 9780729584951.19 A 40‐year‐old man with a history of depression is admitted to the ICU after laparotomy and lysis of adhesions. He was using a fentanyl PCA but developed autonomic dysfunction, confusion, and muscular rigidity. The PCA was stopped because it was suspected that he was exhibiting serotonin syndrome . When stable, you will need to rethink the pain management plan. What is the best course of action?Stop fentanyl PCA and order tramadol (Ultram)Continue fentanyl PCA and add methadone (Dolophine)Stop fentanyl PCA and order meperidine (Demerol)Stop the fentanyl PCA and order a morphine PCAStop the fentanyl PCA and order oxycodoneSome opioids including fentanyl, methadone, and demerol act as serotonergic agents that contribute to the development of serotonin syndrome. Medications in this class of opioids are the synthetic and semisynthetic opioids. Serotonin syndrome results from over‐dosage or coadministration of narcotics with serotonin reuptake inhibitor antidepressants (SSRIs). Synthetic piperidine opioids are pro‐serotonergic in their own right and can act as serotonin reuptake inhibitors. This class of narcotics includes fentanyl, methadone, oxycodone, meperidine (Demerol), and tramadol (choices B, C, and E). Morphine is not in this class and does not inhibit serotonin reuptake (choice D) and is the correct answer. Clinical manifestations of serotonin syndrome results from increased postsynaptic stimulation of 5‐hydroxytryptamine, 2A and 1A serotonin receptors in the central and peripheral nervous system. Since this patient has a history of depression and is receiving a synthetic opioid, serotonin syndrome is suspected.Answer: Dvan Ewijk CE, Jacobs GE, Girbes ARJ. Unsuspected serotonin toxicity in the ICU. Ann Intensive Care. 2016; 6(1):85.Pathan H, Williams J. Basic opioid pharmacology: an update. Br J Pain. 2012; 6(1):11–16.Pedavally S, Fugate JE, Rabinstein AA. Serotonin syndrome in the intensive care unit: clinical presentations and precipitating medications. Neurocrit Care. 2014; 21(1):108–13.
20 A 130 kg, 70‐year‐old man fell 2 weeks ago during a hiking trip and sustained a femur fracture and cervical spine injury. He has a history of heavy snoring and has a BMI of 38. His course was complicated by acute kidney injury but his GFR is now 35 and recovering. He is cooperative and comfortable on a PCA with hydromorphone (Dilaudid) 0.2 mg every 10 minutes. You prefer to do an awake bronchoscopy without intubation to evaluate his recent fever and infiltrate seen on the chest x‐ray. Which of the following techniques is the best option for this procedure?Give a hydromorphone (Dilaudid) bolus and start a propofol infusion while maintaining spontaneous respirations.Topicalization is contraindicated; prepare to intubate for bronchoscopy using rocuronium and propofol.Topicalization of the recurrent and superior laryngeal nerves to anesthetize the tongue, epiglottis, vocal cords, and trachea.Topicalization of the hypoglossal nerve to anesthetize the base of the tongue and arytenoids and aryepiglottic folds.Bilateral superficial cervical plexus block.Different techniques are used to sedate and anesthetize the airway for an awake bronchoscopy using a variety of medications such as benzodiazepines, short‐acting opioids (fentanyl, remifentanil), propofol, ketamine, or dexmedetomidine. In cooperative patients at risk for airway obstruction or difficult intubation, topicalization may be a good choice and should be considered. This can be achieved by anesthetizing the airway with regional techniques with or without sedation or in combination with inhaled anesthetic agents such as viscous lidocaine.Sensation to the oropharynx, and larynx and trachea must be blocked to perform an awake fiberoptic bronchoscopy or intubation. There are several ways to achieve the necessary analgesia, but the sensory nerves should be anesthetized. The superior laryngeal nerve supplies sensory innervation to the base of the tongue, epiglottis and aryepiglottic folds, and arytenoids. It also supplies motor innervation to the external branch of the cricothyroid muscle. The recurrent laryngeal nerve supplies sensory innervation to the vocal cords and trachea (choice C).The combination of narcotic bolus (Dilaudid) and propofol infusion is likely to result in apnea that would require intubation. Since this patient could have a difficult intubation (presence of cervical spine injury and a BMI of 38), this is not the best plan (choice A). Topicalization is not contraindicated in this patient and should be considered before intubation (choice A). The hypoglossal nerve is purely motor and does not need to be blocked (choice D). A superficial cervical plexus block provides anesthesia to the skin of the anterolateral neck and auricular areas and skin inferior to the clavicle. This block can be used in thyroid or clavicular surgery but would not anesthetize the airway or facilitate an awake bronchoscopy (choice E).Answer: CElmaddawy AEA, Mazy AE. Ultrasound‐guided bilateral superficial cervical plexus block for thyroid surgery: The effect of dexmedetomidine addition to bupivacaine‐epinephrine. Saudi J Anaesth. 2018; 12(3):412–8.Simmons ST, Schleich AR. Airway regional anesthesia for awake fiberoptic intubation. Reg Anesth Pain Med. 2002; 27(2):180–92.
21 An 89‐year‐old man fell off a ladder and fractured ribs 3, 4, 5, and 6 on the left side. He is a smoker and has a history of chronic obstructive pulmonary disease (COPD). His pain score is 9/10 and he is taking shallow breaths. He takes antiplatelet medications for atrial fibrillation but cannot remember his last dose. His SpO 2 reads 92% on a 30% face mask. His vital signs are stable. What intervention do you want to recommend to control his pain?Lidocaine patchOxycodoneHydromorphone (Dilaudid) PCAErector spinae block (ESP) plus hydromorphone (Dilaudid) PCA and gabapentinIntercostal nerve block (ICNB)Given his age and pre‐existing COPD, this patient is at risk for pulmonary complications of thoracic trauma. He is in significant pain and appears to be splinting with hypoventilation. The side effects of narcotics such as increased risk for ICU delirium, constipation, and nausea also make these agents a less attractive option when used alone (choices B and C). Erector spinae (ESP) blocks work through a combination of different mechanisms, particularly anesthetic spread to the thoracic paravertebral space. There is evidence to suggest that ESP block results in decreased postoperative pain and opioid requirement for a wide array of thoracic and abdominal procedures including in the management of rib fractures. Intercostal nerve blocks (ICNB) for multiple rib fractures require multiple injections of local anesthetics increasing the risk of toxicity. Choice E, ICNB alone is not the best choice as multimodal approach is recommended to control pain in patients with blunt thoracic trauma. Moreover, being on antiplatelet therapy increases the risk of bleeding for intercostal nerve block (choice E). Choice A, lidocaine patch would not provide sufficient pain relief and continued splinting with shallow breathing may contribute to atelectasis. The patch may cause some numbness to the skin but because of its superficial site of action, it does not decrease fracture pain. Erector spinae blocks in combination with narcotics and gabapentin would establish a multimodal pain control regimen and is conditionally recommended by latest EAST guidelines (choice D) (Figure 12.2).Figure 12.2 Erector spinae plane block. ES: erector spinae; LD: latissimus dorsi; IL: iliocostalis lumborum; Lo:
