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e2 43 Pinaud M, Lelausque JN, Chetanneau A, Fauchoux N, Ménégalli D, Souron R Effects of propofol on cerebral hemodynamics and metabolism in patients with brain trauma Anesthesiology 1990;73(3): 404-409 44 Li Q, Zhu M, Zhang Y, Dai S, Zhang J, Guo Q, Wang E Influential factors of cerebral oxygen saturation in pediatric cardiovascular surgery Zhong Nan Da Xue Xue Bao Yi Xue Ban 2018;43(3):287-292 45 Laaksonen L, Kallioinen M, Långsjö J, et al Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study Br J Anaesth 2018;121(1):281-290 46 Farag E, Kot M, Podolyak A, et al The relative effects of dexmedetomidine and propofol on cerebral blood flow velocity and regional brain oxygenation: A randomised noninferiority trial Eur J Anaesthesiol 2017;34(11):732-739 47 Drummond JC, Dao AV, Roth DM, et al Effect of dexmedetomidine on cerebral blood flow velocity, cerebral metabolic rate, and carbon dioxide response in normal humans Anesthesiology 2008;108(2): 225-232 48 Martin JC, Liley DT, Harvey AS, Kuhlmann L, Sleigh JW, Davidson AJ Alterations in the functional connectivity of frontal lobe networks preceding emergence delirium in children Anesthesiology 2014;121(4):740-752 49 Komatsu H, Taie S, Endo S, et al Electrical seizures during sevoflurane anesthesia in two pediatric patients with epilepsy Anesthesiology 1994;81(6):1535-1537 50 Anand KJ, Garg S, Rovnaghi CR, Narsinghani U, Bhutta AT, Hall RW Ketamine reduces the cell death following inflammatory pain in newborn rat brain Pediatr Res 2007;62(3):283-290 51 Brambrink AM, Evers AS, Avidan MS, et al Isoflurane-induced neuroapoptosis in the neonatal rhesus macaque brain Anesthesiology 2010;112(4):834-841 52 Briner A, Nikonenko I, De Roo M, Dayer A, Muller D, Vutskits L Developmental Stage-dependent persistent impact of propofol anesthesia on dendritic spines in the rat medial prefrontal cortex Anesthesiology 2011;115(2):282-293 53 Cattano D, Young C, Straiko MM, Olney JW Subanesthetic doses of propofol induce neuroapoptosis in the infant mouse brain Anesth Analg 2008;106(6):1712-1714 54 De Roo M, Klauser P, Briner A, et al Anesthetics rapidly promote synaptogenesis during a critical period of brain development PLoS One 2009;4(9):e7043 55 Fredriksson A, Pontén E, Gordh T, Eriksson P Neonatal exposure to a combination of N-methyl-D-aspartate and gamma-aminobutyric acid type A receptor anesthetic agents potentiates apoptotic neurodegeneration and persistent behavioral deficits Anesthesiology 2007;107(3):427-436 56 Hofacer RD, Deng M, Ward CG, et al Cell age-specific vulnerability of neurons to anesthetic toxicity Ann Neurol 2013;73(6):695-704 57 Jevtovic-Todorovic V, Hartman RE, Izumi Y, et al Early exposure to common anesthetic agents causes widespread neurodegeneration in the developing rat brain and persistent learning deficits J Neurosci 2003;23(3):876-882 58 Loepke AW, Istaphanous GK, McAuliffe JJ III, et al The effects of neonatal isoflurane exposure in mice on brain cell viability, adult behavior, learning, and memory Anesth Analg 2009;108(1):90-104 59 Loepke AW, Soriano SG An assessment of the effects of general anesthetics on developing brain structure and neurocognitive function Anesth Analg 2008;106(6):1681-1707 60 Paule MG, Li M, Allen RR, et al Ketamine anesthesia during the first week of life can cause long-lasting cognitive deficits in rhesus monkeys Neurotoxicol Teratol 2011;33(2):220-230 61 Sanders RD, Xu J, Shu Y, et al Dexmedetomidine attenuates isoflurane-induced neurocognitive impairment in neonatal rats Anesthesiology 2009;110(5):1077-1085 62 Slikker Jr W, Zou X, Hotchkiss CE, et al Ketamine-induced neuronal cell death in the perinatal rhesus monkey Toxicol Sci 2007; 98(1):145-158 63 Stratmann G, May LD, Sall JW, et al Effect of hypercarbia and isoflurane on brain cell death and neurocognitive dysfunction in 7-day-old rats Anesthesiology 2009;110(4):849-861 64 Uemura E, Levin ED, Bowman RE Effects of halothane on synaptogenesis and learning behavior in rats Exp Neurol 1985;89(3):520-529 65 Wang C, Slikker Jr W Strategies and experimental models for evaluating anesthetics: effects on the developing nervous system Anesth Analg 2008;106(6):1643-1658 66 Duan X, Li Y, Zhou C, Huang L, Dong Z Dexmedetomidine provides neuroprotection: impact on ketamine-induced neuroapoptosis in the developing rat brain Acta Anaesthesiol Scand 2014;58(9):1121-1126 67 Li J, Xiong M, Nadavaluru PR, et al Dexmedetomidine attenuates neurotoxicity induced by prenatal propofol exposure J Neurosurg Anesthesiol 2016;28(1):51-64 68 Zheng H, Dong Y, Xu Z, et al Sevoflurane anesthesia in pregnant mice induces neurotoxicity in fetal and offspring mice Anesthesiology 2013;118(3):516-526 69 Olutoye OA, Lazar DA, Akinkuotu AC, Adesina A, Olutoye OO Potential of the ovine brain as a model for anesthesia-induced neuroapoptosis Pediatr Surg Int 2015;31(9):865-869 70 Bo LJ, Yu PX, Zhang FZ, Dong ZM Dexmedetomidine mitigates sevoflurane-induced cell cycle arrest in hippocampus J Anesth 2018;32(5):717-724 71 van Hoorn CE, Hoeks SE, Essink H, Tibboel D, de Graaff JC A systematic review and narrative synthesis on the histological and neurobehavioral long-term effects of dexmedetomidine Paediatr Anaesth 2019;29(2):125-136 72 Wilder RT, Flick RP, Sprung J, et al Early exposure to anesthesia and learning disabilities in a population-based birth cohort Anesthesiology 2009;110(4):796-804 73 Sun LS, Li G, Miller TL, et al Association Between a Single General Anesthesia Exposure Before Age 36 Months and Neurocognitive Outcomes in Later Childhood JAMA 2016;315(21):2312-2320 74 McCann ME, de Graaff JC, Dorris L, et al Neurodevelopmental outcome at years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): An international, multicentre, randomised, controlled equivalence trial Lancet 2019;393:664-77 75 Warner DO, Zaccariello MJ, Katusic SK, et al Neuropsychological and Behavioral Outcomes after Exposure of Young Children to Procedures Requiring General Anesthesia: The Mayo Anesthesia Safety in Kids (MASK) Study Anesthesiology 2018;129:89-105 75a Glatz P, Sandin RH, Pedersen NL, Bonamy A, Eriksson LI, Granath F Association of Anesthesia and Surgery During Childhood With Long-term Academic Performance JAMA Pediatr 2017;171(1): e163470 75b O’Leary JD, Janus M, Duku E, et al A Population-based Study Evaluating the Association between Surgery in Early Life and Child Development at Primary School Entry Anesthesiology 2016;125: 272–279 76 Rackow H, Salanitre E, Green LT Frequency of cardiac arrest associated with anesthesia in infants and children Pediatrics 1961;28:697-704 77 Holzman RS, van der Velde ME, Kaus SJ, et al Sevoflurane depresses myocardial contractility less than halothane during induction of anesthesia in children Anesthesiology 1996;85(6): 1260-1267 78 Schieber RA, Namnoum A, Sugden A, Shiu GK, Orr RA, Cook DR Hemodynamic effects of isoflurane in the newborn piglet: comparison with halothane Anesth Analg 1986;65(6):633-638 79 Weiskopf RB, Moore MA, Eger EI II, et al Rapid increase in desflurane concentration is associated with greater transient cardiovascular stimulation than with rapid increase in isoflurane concentration in humans Anesthesiology 1994;80(5):1035-1045 80 Mkrtchyan N, Stern H Cardiac index during routine cardiovascular magnetic resonance in young children is reduced under general anesthesia Pediatr Cardiol 2016;37(2):426-427 81 Baumann P, Wiegert S, Greco F, Wellmann S, L’Abate P, Cannizzaro V Mechanical ventilation strategies alter cardiovascular biomarkers in an infant rat model Physiol Rep 2018;6(2):e13553 e3 82 Robinson S, Gregory GA Fentanyl-air-oxygen anesthesia for ligation of patent ductus arteriosus in preterm infants Anesth Analg 1981;60(5):331-334 83 Jooste EH, Muhly WT, Ibinson JW, et al Acute hemodynamic changes after rapid intravenous bolus dosing of dexmedetomidine in pediatric heart transplant patients undergoing routine cardiac catheterization Anesth Analg 2010;111(6):1490-1496 84 Cummings BM, Cowl AS, Yager PH, et al Cardiovascular effects of continuous dexmedetomidine infusion without a loading dose in the pediatric intensive care unit J Intensive Care Med 2015;30(8):512-517 85 Berkenbosch JW, Tobias JD Development of bradycardia during sedation with dexmedetomidine in an infant concurrently receiving digoxin Pediatr Crit Care Med 2003;4(2):203-205 86 Ingersoll-Weng E, Manecke Jr GR, Thistlethwaite PA Dexmedetomidine and cardiac arrest Anesthesiology 2004;100(3):738-739 87 Peden CJ, Cloote AH, Stratford N, Prys-Roberts C The effect of intravenous dexmedetomidine premedication on the dose requirement of propofol to induce loss of consciousness in patients receiving alfentanil Anaesthesia 2001;56(5):408-413 88 Bloor BC, Ward DS, Belleville JP, Maze M Effects of intravenous dexmedetomidine in humans II Hemodynamic changes Anesthesiology 1992;77(6):1134-1142 89 Mukhtar AM, Obayah EM, Hassona AM The use of dexmedetomidine in pediatric cardiac surgery Anesth Analg 2006;103(1):5256, table of contents 90 Chrysostomou C, Morell VO, Wearden P, Sanchez-de-Toledo J, Jooste EH, Beerman L Dexmedetomidine: therapeutic use for the termination of reentrant supraventricular tachycardia Congenit Heart Dis 2013;8(1):48-56 91 Chrysostomou C, Sanchez-de-Toledo J, Wearden P, et al Perioperative use of dexmedetomidine is associated with decreased incidence of ventricular and supraventricular tachyarrhythmias after congenital cardiac operations Ann Thorac Surg 2011;92(3):964972; discussion 972 92 Kam PC, Cardone D Propofol infusion syndrome Anaesthesia 2007;62(7):690-701 93 Burow BK, Johnson ME, Packer DL Metabolic acidosis associated with propofol in the absence of other causative factors Anesthesiology 2004;101(1):239-241 94 Cannon ML, Glazier SS, Bauman LA Metabolic acidosis, rhabdomyolysis, and cardiovascular collapse after prolonged propofol infusion J Neurosurg 2001;95(6):1053-1056 95 Kumar MA, Urrutia VC, Thomas CE, Abou-Khaled KJ, Schwartzman RJ The syndrome of irreversible acidosis after prolonged propofol infusion Neurocrit Care 2005;3(3):257-259 96 Fudickar A, Bein B Propofol infusion syndrome: update of clinical manifestation and pathophysiology Minerva Anestesiol 2009;75(5):339-344 97 Vasile B, Rasulo F, Candiani A, Latronico N The pathophysiology of propofol infusion syndrome: a simple name for a complex syndrome Intensive Care Med 2003;29(9):1417-1425 98 Cray SH, Robinson BH, Cox PN Lactic acidemia and bradyarrhythmia in a child sedated with propofol Crit Care Med 1998;26(12):2087-2092 99 Farag E, Deboer G, Cohen BH, Niezgoda J Metabolic acidosis due to propofol infusion Anesthesiology 2005;102(3):697-698; author reply 698-699 100 Wolf A, Weir P, Segar P, Stone J, Shield J Impaired fatty acid oxidation in propofol infusion syndrome Lancet 2001;357(9256):606-607 101 Barclay K, Williams AJ, Major E Propofol infusion in children BMJ 1992;305(6859):953; author reply 953-954 102 Culp KE, Augoustides JG, Ochroch AE, Milas BL Clinical management of cardiogenic shock associated with prolonged propofol infusion Anesth Analg 2004;99(1):221-226 103 von Ungern-Sternberg BS, Saudan S, Petak F, Hantos Z, Habre W Desflurane but not sevoflurane impairs airway and respiratory tissue mechanics in children with susceptible airways Anesthesiology 2008;108(2):216-224 104 Kim EH, Song IK, Lee JH, et al Desflurane versus sevoflurane in pediatric anesthesia with a laryngeal mask airway: A randomized controlled trial Medicine (Baltimore), 2017;96(35):e7977 105 Heard C, Harutunians M, Houck J, Joshi P, Johnson K, Lerman J Propofol anesthesia for children undergoing magnetic resonance imaging: a comparison with isoflurane, nitrous oxide, and a laryngeal mask airway Anesth Analg 2015;120(1):157-164 106 Mahmoud M, Radhakrishman R, Gunter J, et al Effect of increasing depth of dexmedetomidine anesthesia on upper airway morphology in children Paediatr Anaesth 2010;20(6):506-515 107 Scheiermann P, Herzog F, Siebenhofer A, Strametz R, Weberschock T Intravenous versus inhalational anesthesia for pediatric inpatient surgery: A systematic review and meta-analysis J Clin Anesth 2018;49:19-25 108 Rodriguez L, Morley-Fletcher A, Souza A, Rosengaus L, Nurko S Effect of anesthesia on gastroesophageal reflux in children: a study using BRAVO wireless pH study measurements Neurogastroenterol Motil 2015;27(11):1553-1558 109 Udassin R, Eimerl D, Schiffman J, Haskel Y Epidural anesthesia accelerates the recovery of postischemic bowel motility in the rat Anesthesiology 1994;80(4):832-836 110 Artru AA Renal effects of sevoflurane during conditions of possible increased risk J Clin Anesth 1998;10(7):531-538 111 Funk W, Moldaschl J, Fujita Y, Taeger K, Hobbhahn J Sevoflurane or halothane in inhalational anesthesia induction in childhood Anesthesia quality and fluoride level Anaesthesist 1996;45(1):22-30 112 Frink Jr EJ, Green Jr WB, Brown EA, et al Compound A concentrations during sevoflurane anesthesia in children Anesthesiology 1996;84(3):566-571 113 Bellos I, Iliopoulos DC, Perrea DN Pharmacological interventions for the prevention of acute kidney injury after pediatric cardiac surgery: a network meta-analysis Clin Exp Nephrol 2019;23(6): 782-791 114 Jo YY, Kim JY, Lee JY, Choi CH, Chang YJ, Kwak HJ The effect of intraoperative dexmedetomidine on acute kidney injury after pediatric congenital heart surgery: a prospective randomized trial Medicine (Baltimore) 2017;96(28):e7480 115 Hall JE, Uhrich TD, Barney JA, Arain SR, Ebert TJ Sedative, amnestic, and analgesic properties of small-dose dexmedetomidine infusions Anesth Analg 2000;90(3):699-705 e4 Abstract: The anesthetic management of postoperative surgical patients requires an understanding of not only the pharmacology of anesthetic agents but also an understanding of the physiologic perturbations that occur with surgery and anesthesia This chapter highlights anesthetic effects and the physiologic influence that anesthetics have on organ systems Key words: Anesthetic agents; inhalational, intravenous, and local anesthetics; neurotoxicity 129 Anesthesia Principles and Operating Room Anesthesia Regimens JOSEPH D TOBIAS • Intraoperative surgical anesthesia can be provided by several different techniques, including local anesthesia, monitored anesthesia care, regional anesthesia, and general anesthesia Local anesthesia (“local only”) involves the infiltration of a surgical site with a local anesthetic agent to render the site insensitive to pain This may be performed solely by the surgeon without the involvement of an anesthesia provider Monitored anesthesia care can be thought of as being equivalent to procedural sedation It involves monitoring a patient with standard monitors according to the American Society of Anesthesiologists (ASA; discussed later) while administering a sedative or analgesic agent intravenously to provide anxiolysis, sedation, and analgesia Monitored anesthesia care is frequently combined with either infiltration of the surgical site with a local anesthetic agent or a regional anesthetic technique The anesthetic agents used for monitored anesthesia care may include many of the same agents used for general anesthesia It generally includes a medication with amnestic or anxiolytic properties (midazolam, dexmedetomidine, or propofol) combined with a medication to provide analgesia, 1544 • The preoperative evaluation, which is performed prior to any anesthetic intervention, includes a history of present illness; past medical problems, including medication allergies; a past surgical and anesthetic history; a family history of anesthetic complications; a review of the patient’s current and possibly prior medical record, including the medication list; and a focused physical examination General anesthesia includes a combination of medications to provide amnesia, analgesia, muscle relaxation, and attenuation of the sympathetic nervous system’s response to surgical trauma The phases of general anesthesia include induction, maintenance, and emergence The standards for intraoperative anesthetic monitoring have been outlined by the American Society of Anesthesiologists and include an oxygen analyzer, noninvasive blood pressure cuff, continuous electrocardiogram, pulse oximeter, end-tidal carbon dioxide analyzer, precordial or esophageal stethoscope, temperature probe, and ventilator disconnect alarm • • • PEARLS Given the catastrophic effects of local anesthetic systemic toxicity (LAST), mechanisms to avoid it and prevent its occurrence are mandatory during the performance of regional anesthetic techniques in infants and children Epinephrine (5 mg/mL) is added to the local anesthetic solution during performance of a regional anesthetic technique to serve as a marker of inadvertent systemic injection Lipid emulsion should be readily available to treat LAST Following the successful completion of the surgical procedure, a plan is determined for the postoperative delivery of analgesia The plan should be a multimodality approach that may include intravenous opioids, agents to inhibit prostaglandin formation (acetaminophen or a nonsteroidal antiinflammatory agent), or a regional anesthetic technique For major surgical procedures, the most effective way to deliver opioids for postoperative analgesia is patient-controlled analgesia such as an opioid (fentanyl) or, occasionally, ketamine During the procedure, spontaneous ventilation with a native airway is maintained, eliminating the need for endotracheal intubation and controlled ventilation The depth of sedation may range from a state in which the patient is awake and relaxed with the ability to respond to verbal stimuli to a state of deep sedation in which a painful stimulus is required to elicit a response Regional anesthetic techniques may include peripheral nerve blockade or neuraxial anesthesia A peripheral nerve block involves the placement of a local anesthetic agent around a nerve or group of nerves (plexus) to render specific dermatomes insensitive to pain Examples of plexus blockade include cervical plexus blockade for superficial and deep neck surgery, brachial plexus blockade for upper extremity or shoulder procedures, and lumbar plexus blockade for hip or leg surgery.1–3 Intravenous regional anesthesia, the Bier block, is another example of a peripheral block that can be used to provide surgical anesthesia A Bier block involves the intravenous injection of a dilute local anesthetic into the vein of an extremity after that extremity has been exsanguinated by wrapping it with a CHAPTER 129 Anesthesia Principles and Operating Room Anesthesia Regimens bandage followed by occlusion with a tourniquet The technique has been successfully and safely employed by nonanesthesia providers to allow for fracture reductions and other orthopedic procedures in the emergency department setting.4,5 Although the latter technique is generally successful and easy to accomplish, it may not be feasible in younger children except when combined with deep sedation Given the use of an occlusive tourniquet, its duration is limited to 60 to 70 minutes due to tourniquet pain The major concern with the Bier block is that the amount of local anesthetic used approaches the toxic limit In the event of tourniquet failure, cardiovascular (CV) or central nervous system (CNS) consequences from the local anesthetic agent may occur Neuraxial anesthesia involves the injection of a local anesthetic agent into either the subarachnoid or epidural space This results in blockade of the spinal cord and its accompanying nerve roots to render an entire region of the body (lower abdomen, pelvis, perineum, or lower extremities) insensitive to pain Examples of neuraxial anesthesia include spinal, epidural, and caudal anesthesia.6,7 In infants and children, a regional anesthetic technique such as a peripheral nerve block or epidural anesthesia can be used instead of general anesthesia in patients with comorbid diseases or as a suitable alternative to general anesthesia.8 More frequently, the regional anesthetic technique is combined with a general anesthetic as part of a balanced anesthetic technique and continued into the postoperative period by use of a continuous infusion via a catheter to provide postoperative analgesia General anesthesia is the most frequently used intraoperative technique in the pediatric population It usually includes the administration of medications to provide the requisites of amnesia, analgesia, muscle relaxation, and attenuation of the sympathetic nervous system’s response to surgical trauma The phases of general anesthesia include induction, maintenance, and emergence The induction of anesthesia can be carried out with the administration of an intravenous anesthetic agent (thiopental, propofol, ketamine, or etomidate) or with an inhalational (volatile) anesthetic agent such as sevoflurane These agents may be combined with a neuromuscular blocking agent (NMBA) to facilitate endotracheal intubation or to provide surgical relaxation for specific procedures Advantages of an intravenous induction include the rapid onset of anesthesia and avoidance of issues associated with inhalation induction, including claustrophobia from anesthesia mask placement and the odor of the inhalational anesthetic agent In pediatric patients, the inhalation induction of anesthesia is frequently chosen to avoid the need for obtaining intravenous access in an awake child When inhalation induction is carried out without intravenous access, airway and CV issues may arise and mandate immediate treatment without intravenous access In such cases, if intravenous access cannot be rapidly obtained, it may be feasible to use the intramuscular (IM) route for a select number of medications (atropine, succinylcholine) However, more aggressive resuscitation, such as the administration of epinephrine for hemodynamic compromise, may require the use of intraosseous (IO) access.9 The majority of problems during inhalation induction (bradycardia or laryngospasm) can be easily reversed with appropriate airway techniques or the administration of IM medications Hemodynamic compromise, including cardiac arrest during inhalation induction, was far more common with the use of halothane given its negative inotropic and chronotropic properties.10 Given these and other concerns, halothane has been replaced by sevoflurane in clinical practice in most countries Even if intravenous access is present, the inhalational induction of anesthesia may be chosen, as it allows the maintenance of 1545 spontaneous ventilation even during deep planes of anesthesia (deep enough to allow for direct laryngoscopy and endotracheal intubation) Such a technique may be used if there is a question regarding the efficacy of bag-valve-mask ventilation, such as may occur in patients with a potentially compromised airway from infection, tumor, congenital or anatomic abnormalities.11 Following anesthetic induction, one progresses into the maintenance phase of general anesthesia This can be provided by the administration of intravenous agents, inhalational agents, or, often, a combination of the two An example of a balanced technique includes the combination of inhalational agents (a volatile anesthetic agent) or the continuous infusion of an intravenous anesthetic agent (propofol) and an opioid In most circumstances, the choice of maintenance anesthesia is based on the presence of comorbid features, the type of surgical procedure, and the preferences of the anesthesiologists Preoperative Evaluation Regardless of the type of procedure, patient’s status, and planned anesthetic technique, a preoperative evaluation is performed at some point prior to anesthetic care.12 This evaluation may be performed well in advance of the anticipated surgical procedure in a specialized clinic to allow for specific preoperative interventions, consultations, or preparation that may be required to allow for the safe completion of the anesthetic care and surgical procedure Alternatively, in low-risk patients without accompanying comorbid diseases, a preoperative survey can be performed and instructions given on the phone or via the Internet using a standardized survey This is followed by a review and physical examination by the anesthesia personnel on the day of surgery For patients who are already admitted to the hospital or those presenting for emergent or urgent surgical procedures, the preoperative evaluation may be performed the night before or just prior to the surgical procedure The preoperative evaluation includes a history of present illness; review of past medical problems and hospitalizations; medication allergies; past surgical and anesthetic history; family history of anesthetic complications; and a review of the patient’s current and possibly prior medical record, including the medication list For elective surgical procedures, the status of comorbid conditions should be optimized prior to the surgical procedure The latter may not be feasible for urgent or emergent cases The physical examination is directed primarily at the central nervous system, CV system, and respiratory system, including an examination of the airway The preoperative evaluation attempts to identify patients with a difficult airway, which may preclude successful endotracheal intubation using standard techniques of direct larygnoscopy.11 As a full description of the airway examination is beyond the scope of this chapter, the reader is referred to Bryant et al.11 for additional details An airway history should be obtained, seeking physical features as well as medical, surgical, and anesthetic factors that may indicate a difficult airway Examination of previous anesthesia records is helpful, although a patient’s airway may change with changes in weight, with aging, or with the development of comorbid conditions A physical examination of the airway is performed to detect physical characteristics associated with a difficult airway, such as a large tongue, small mouth, short neck (shortened thyromental distance), recessed mandible (micrognathia), limited extension or flexion of the neck, and limited mouth opening (Table 129.1) The patient is then asked to open the mouth so that the uvula and tonsillar pillars ... receiving digoxin Pediatr Crit Care Med 2003;4(2):203-205 86 Ingersoll-Weng E, Manecke Jr GR, Thistlethwaite PA Dexmedetomidine and cardiac arrest Anesthesiology 2004;100(3):738-739 87 Peden... but also an understanding of the physiologic perturbations that occur with surgery and anesthesia This chapter highlights anesthetic effects and the physiologic influence that anesthetics have on... infiltration of a surgical site with a local anesthetic agent to render the site insensitive to pain This may be performed solely by the surgeon without the involvement of an anesthesia provider Monitored