90‐year‐old man presents after a ground‐level fall. He is found to have bruising on all extremities and a scalp laceration that requires suture repair for hemostasis. His daughter accompanies him to the emergency department and reports that he took dabigatran for his chronic atrial fibrillation 4 hours prior to the admission. Imaging reveals a moderate subdural hematoma. What is the best option for reversing effects of dabigatran?No reversal is required if the INR is < 2Administer idarucizumabAdminister plateletsAdminister fresh frozen plasmaAdminister cryoprecipitateOral anticoagulants alternative to warfarin for reducing the risk of thromboembolic events in patients with chronic atrial fibrillation include rivaroxaban, apixaban, and dabigatran. Rivaroxaban and apixaban are factor Xa inhibitors. Dabigatran is a direct thrombin inhibitor. A major advantage of these medications is that they do not require routine INR monitoring. In clinical trials, bleeding events on these medications were comparable to, or lower than warfarin for similar indications. The major drawbacks of these agents are (1) their anticoagulation effect is not reliably measured by common laboratory tests, and (2) effects can be difficult to reverse. In 2016, the FDA approved idarucizumab as a specific reversal agent for dabigatran. Fresh frozen plasma (FFP) can be used to resuscitate patients on these medications who suffer low‐ to moderate‐risk bleeding events. However, FFP is not a specific reversal agent. It takes time to infuse and cannot rapidly reverse coagulopathy. Administration of FFP can also lead to volume overload and transfusion reactions. For all of these reasons, FFP is not an ideal therapy. This patient has a life‐threatening intracranial hemorrhage that requires rapid reversal of dabigatran. Idarucizumab is a monoclonal antibody fragment developed to rapidly, durably, and safely reverse the anticoagulant effect of dabigatran in emergency situations. PCC can also be considered to reverse dabigatran if idarucizumab is unavailable.Answer: BPollack, C.V., Reilly, P.A., Van Ryn, J., et al. (2017) Idarucizumab for Dabigatran reversal – full cohort analysis. N Engl J Med , 377 (5), 431–441.Faraoni, D., Levy, J.H., Albaladejo, P., et al. (2015) Updates in the perioperative and emergency management of non‐vitamin K antagonist oral anticoagulants. Crit Care , 19, 1–6.
12 Analgesia and Anesthesia
Toni Manougian, MD, MBA1 and Bardiya Zangbar, MD2
1 Department of Critical Care Anesthesiology, New York Medical College, Westchester Medical Center, Valhalla, NY, USA
2 Division of Trauma and Acute Care Surgery, New York Medical College, Westchester Medical Center, Valhalla, NY, USA
1 Which of the following effects of epidural analgesia is correct:For patients without serious lung pathology, mid thoracic epidural analgesia has no effect on lung function.Decreased gastric secretions, peristalsis, and enhanced gastric motility results from sympathetic splanchnic blockade at the T5‐L1 level.Renal blood flow is increased and an indwelling urinary catheter is always necessary when using continuous epidural analgesia.Neuraxial analgesia (NA) has no effect on the surgical stress response. NA does not affect oxygen consumption, vasopressin, catecholamine, cortisol, or glucose levels.Thoracic epidural catheters above T4 level are safe and unlikely to cause cardiovascular effects.All of the choices are false regarding thoracic epidural catheters except choice A. Pulmonary function is unaffected by thoracic epidural analgesia in patients with normal function. However, severe pulmonary disease is a relative contraindication for brachial plexus blocks. Brachial plexus blocks such as an interscalene block affect ipsilateral hemi‐diaphragmatic excursion and reduce functional residual capacity and pulmonary function as much as 40%. Interestingly, the recurrent laryngeal nerve may also be blocked and can cause complete airway obstruction in a patient with existing vocal cord palsy. A blockade at the T5‐L1 level will increase gastric secretions, peristalsis, and enhanced gastric motility due to increased parasympathetic activity and sympathetic splanchnic blockade making choice B incorrect answer. Renal blood flow is auto‐regulated and unaffected by epidural analgesia. When thoracic epidural catheters are used, indwelling urinary catheters are not always required. Lumbar epidural analgesia however, can cause urinary retention, especially when blocking S2 to S4 spinal segments. Therefore, lumbar epidural catheters are more likely to affect bladder function than thoracic epidurals (choice C). One of the major benefits when choosing neuraxial analgesia (NA) is to blunt the sympathetic stress response. NA reduces oxygen consumption and decreases levels of vasopressin, catecholamines, cortisol, and glucose (choice D). Choice E is incorrect, because blocks at the T1‐4 level result in sympathetic blockade and profound cardiovascular effects. Blocks at T1‐T4 result in hypotension from both bradycardia and decreased cardiac contractility.Answer: AMian A, Chaudhry I, Huang R, Rizk E, Tubbs RS, Loukas M. Brachial plexus anesthesia: A review of the relevant anatomy, complications, and anatomical variations. Clin Anat. 2014; 27(2):210–21.Basse L, Werner M, Kehlet H. Is urinary drainage necessary during continuous epidural analgesia after colonic resection? Reg Anesth Pain Med. 2000; 25(5):498–501.
2 A 45‐year‐old man is admitted to the ICU with pneumonia, fever, agitation, and confusion. He acutely becomes increasingly agitated and is treated with haloperidol. His vital signs are respiratory rate of 18/min, oxygen saturation 94%, heart rate 92/min, blood pressure 154/78 mmHg, and temperature 38.9 °C. He is sweating, drooling with painful contractions of the neck, and is salivating. Which of the following medications is the treatment of choice? Benztropine (Cogentin)Lorazepam (Ativan)Metoclopramide (Reglan)Dantrolene (Ryanodex)Quetiapine (Seroquel)The patient is exhibiting signs of a dystonic reaction and his symptoms are best treated with benztropine. Dystonic reactions are an unwanted effect after administration of neuroleptic medications. Dystonic reactions can occur immediately, or be delayed hours to days. Classic features of dystonic reaction to medications such as haloperidol are cholinergic symptoms such as increased salivation and spasmodic or sustained involuntary contractions of muscles in the face, neck, trunk, pelvis, extremities, or larynx. Dystonic reactions, while not usually life threatening, are distressing for patients and families. Benztropine, an anticholinergic agent, is used for symptomatic improvement (choice A). While some symptoms can be improved with benzodiazepines, this class of medication may worsen his confusion, blunt his respiratory drive, and contribute to ICU delirium, so choice B is not the best answer. Metoclopramide (Reglan) exerts an antiemetic effect by antagonist activity at central D2 receptors in the chemoreceptor trigger zone and may potentiate the dyskinesia symptoms, so choice C is incorrect. Dantrolene (Ryanodex) is used in reversal of malignant hyperthermia and has no primary role in treatment of dystonic reactions (choice D). While haloperidol (Haldol) is associated with neuroleptic malignant syndrome, the side effects manifested is mental status change in the form of agitated delirium with confusion or catatonic signs and mutism. Other symptoms include muscular rigidity which can be demonstrated by moving the extremities and is characterized by “lead pipe rigidity” or stable resistance through all ranges of movement. Hypothermia is common and extremely high temperatures greater than 40 °C is common. Autonomic dysfunction in the form of tachycardia with hypertension and tachypnea along with dysrhythmias may occur. In the scenarios of induced neuroleptic malignant syndrome, dantrolene can be an antidote. Quetiapine (Seroquel) is a second‐generation antipsychotic and known to be rare in causing extrapyramidal side effects and has no role in treatment of dystonic side effects (choice E).Answer: ADigby G, Jalini S, Taylor S. Medication‐induced acute dystonic reaction: the challenge of diagnosing movement disorders in the intensive care unit. BMJ Case Resp. 2015; 2015:bcr2014207215Goff DC, Arana GW, Greenblatt DJ, Dupont R, Ornsteen M, Harmatz JS, Shader RI. The effect of benztropine on haloperidol‐induced dystonia, clinical efficacy and pharmacokinetics: a prospective, double‐blind trial. J Clin Psychopharmacol 1991; 11(2):106–12.
3 A 75‐year‐old woman underwent a cholecystectomy for a gangrenous gallbladder. Postoperatively, the patient appears calm and you would like to extubate the patient in the next 24 hours. Which of the following represents the best stepwise approach to pain and sedation?Short‐acting narcotic infusion with fentanyl and propofol.Standing IV acetaminophen (Ofirmev), low‐dose ketamine (Ketalar) infusion, and PRN hydromorphone (Dilaudid) IV push.Short‐acting narcotic infusion with fentanyl, plus dexmedetomidine (Precedex) drip plus gabapentin (Neurontin) PO.Short‐acting remifentanil and propofol infusions.Propofol
