Lidocaine for Intubation ======================== þ IV vs. ET - IV will decrease ICP, ET will increase ICP - multiple studies show this þ Comment on Role of Lidocaine: - I think I know where this (often repeated) thought comes from. Just one study has looked at patients with elevated ICP's and ICP monitors in place prior to intubation. (Hamill, Anesthesiology 55: 578-581, 1981.) All of the patients had brain tumors, not acute injuries. And all of these patients have been on multiple medications to reduce ICP (steroids, diuretics, etc.) And none of the patients were given an RSI-type protocol. All were premedicated (morphine, valium, and atropine) then given an OR-type induction sequence with inhaled nitrous oxide. - Not much like acutely injured, non-premedicated patients receiving an RSI in the emergency department, are they? - Now for the good part. They gave IV lido and compared it to laryngotracheal lido. (There was no control group which didn't get any lido.) To give the laryngotracheal lido, they did laryngoscopy to visualize the cords and sqirted in some lido, then waited for a few seconds and intubated. So one group got laryngoscopy TWICE, and one group got it once. They found that if you do laryngoscopy twice, your ICP goes up more than if you just do it once. (Anyone surprised?) - So this is the study that supposedly "proves" that IV lidocaine prevents a rise in ICP during emergency RSI's in head injured patients... - I'm underwhelmed. - If anyone has better data than this, please post it! I've limited my review to human studies. Maybe there's some animal data out there that is applicable. (But please don't pull up any of the studies about suctioning in the ICU using Sux or Lido-and-Sux. It's a stretch to presume applicability with these studies, and they don't use the other component of RSI, which is sedation with a barbiturate. Barbiturates are potent ICP-reducing agents in themselves.) - Bill Bozeman >>show me the data that shows lidocaine-before-intubation does >>anybody any good. > >>we've stopped doing it around here, and in Seattle's EMS system. > >>Joseph M. Gifford, MD FACEP >>Seattle > >Depending on the intent of your question, the answer may be: > >(1) intravenous lidocaine clearly blunts the rise in ICP >associated with laryngoscopy and intubation in >patients with intracranial mass lesions >(Hamill JF et al. Lidocaine before endotracheal >intubation. Anesthesiology 1981;55:578-581). >Class I (RCCT) evidence on the evidence-based medicine scale. > >(2) thiopental before intubation is probably as >effective, and it is not apparent that the combination >of lidocaine and thiopental is better than either >alone. Class II evidence (uncontrolled series). > >(3) I'm not aware of any direct test of the hypothesis >that pre-intubation lidocaine prevents further cerebral >damage in patients with elevated ICP. But it seems >to me that it is cheap, probably without appreciable >risk (single dose, no infusion), and may be life- >or brain-saving in a few cases (I'll declare myself >an ICP expert and make this class III evidence). > >Tom Bleck (Thomas P. Bleck, M.D.) tbleck@virginia.edu my read of the evidence (cited below) is that: 1. topical lidocaine blunts the rise in BP, HR, & ICP with intubation 2. IV lidocaine may or may not have such an effect, conflicting data. small effect if any. 3. fentanyl/alfentanyl etc certainly superior to lidocaine in attenuating such rises 4. in the big picture, it is quite a stretch to suppose that a small attenuation of a small bump in BP & ICP with intubation (even if such small attenuation occurs) would be a factor in the outcome of such patients, and certainly no data exists to support such claims. 5. "it cant hurt" is a lousy argument (6. I agree with you that intubation with lorazepam alone was not a good idea) Joseph Gifford, MD Seattle 1. Zemenick RB No support for intravenous lidocaine airway reflex suppression during rapid sequence intubation [letter] Language: Eng Source: Ann Emerg Med 1995 Nov;26(5):660 2. Singh H; Vichitvejpaisal P; Gaines GY; White PF Comparative effects of lidocaine, esmolol, and nitroglycerin in modifying the hemodynamic response to laryngoscopy and intubation. Department of Anesthesiology and Pain Management, University of Texas, Southwestern Medical Center at Dallas 75235-9068, Language: Eng Source: J Clin Anesth 1995 Feb;7(1):5-8 Unique Identifier: 95290208 Abstract: STUDY OBJECTIVE: To compare the safety and efficacy of lidocaine, esmolol, and nitroglycerin in modifying the hemodynamic response to laryngoscopy and intubation. DESIGN: Randomized, placebo-controlled, double-blind study. SETTING: University-affiliated VA medical center. PATIENTS: 40 ASA physical status I and II patients undergoing electric surgery with general endotracheal anesthesia. INTERVENTIONS: Anesthesia was induced with thiopental sodium 5 mg/kg, and intubation was facilitated with vecuronium 0.15 mg/kg. Isoflurane (0.5% to 1%) and 50% nitrous oxide in oxygen were used for maintenance of anesthesia. In addition, patients received one of the following four study drugs intravenously (i.v.) prior to laryngoscopy: Group 1 (control) = saline 5 ml; Group 2 = lidocaine 1.5 mg/kg; Group 3 = esmolol 1.4 mg/kg; Group 4 = nitroglycerin 2 micrograms/kg. MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure (MAP) and heart rate (HR) were recorded every minute for 20 minutes following induction of anesthesia. Following laryngoscopy and intubation, MAP increased significantly in all four treatment groups (control 49% +/- 19%, lidocaine 55% +/- 26%, esmolol 25% +/- 11%, nitroglycerin 45% +/- 21%) compared with preinduction baseline values. In the esmolol-pretreated patients, the increase in HR was significantly lower (20% +/- 3%) compared with the nitroglycerin (37% +/- 8%), lidocaine (52% +/- 8%), and control (29% +/- 4%) groups. CONCLUSIONS: Lidocaine 1.5 mg/kg i.v. and nitroglycerin 2 micrograms/kg i.v. were ineffective in controlling the acute hemodynamic response following laryngoscopy and intubation. Esmolol 1.4 mg/kg i.v. was significantly more effective than either lidocaine or nitroglycerin in controlling the HR response to laryngoscopy and intubation (p < 0.05). Esmolol also was significantly more effective than lidocaine in minimizing the increase in MAP (25% vs. 55%). 3. Lev R; Rosen P Prophylactic lidocaine use preintubation: a review. Department of Emergency Medicine, University of California, San Diego 92103-8676. Language: Eng Source: J Emerg Med 1994 Jul-Aug;12(4):499-506 Unique Identifier: 95052454 Abstract: This article is a review of the use of prophylactic lidocaine as a preintubation medication. Intubation is associated with a cardiovascular response of elevated blood pressure and pulse, cough reflexes, occasional dysrhythmias, increased intracranial pressure, and increased intraocular pressure. In patients with atherosclerotic heart disease, potential intracranial lesions, and potential penetrating eye injuries, these responses to intubation are of greater risk. Various studies have reviewed the effect of lidocaine to blunt these responses. It is agreed that lidocaine blunts cough reflexes and dysrhythmias. Some studies note a response of lidocaine in blunting rises in pulse, blood pressure, intracranial and intraocular pressure. No studies document any harmful effects of prophylactic lidocaine given preintubation. A dose of prophylactic lidocaine of 1.5 mg/kg given intravenously 3 minutes before intubation is optimal. For suctioning of intubated patients, lidocaine can be given endotracheally in a 5-6 mg/kg dose diluted in 6 cc via simple administration at the entrance to the endotracheal tube. 4. Yukioka H; Hayashi M; Terai T; Fujimori M Intravenous lidocaine as a suppressant of coughing during tracheal intubation in elderly patients. Department of Anesthesiology and Intensive Care Medicine, Osaka City University Medical School, Japan. Language: Eng Source: Anesth Analg 1993 Aug;77(2):309-12 Unique Identifier: 93348952 Abstract: The effects of intravenously administered lidocaine on cough suppression in elderly patients over the age of 60 yr during tracheal intubation under general anesthesia were evaluated in two studies. In the first study, 100 patients received a placebo of either 0.5, 1.0, 1.5, or 2.0 mg/kg lidocaine intravenously 1 min before tracheal intubation. All visible coughs were classified as coughing. The incidence of coughing decreased as the dose of lidocaine increased. A dose of 1.5 mg/kg or more of intravenous lidocaine suppressed the cough reflex significantly (P < 0.01). In the second study, 108 patients received 2 mg/kg lidocaine intravenously or a placebo 1, 3, 5, 7, 10, or 15 min before intubation. The same criteria for determining whether a patient did or did not cough during tracheal intubation were used as in Study 1. The incidence of coughing decreased significantly (P < 0.01) when 2 mg/kg lidocaine was injected intravenously between 1 min and 3 min before attempting intubation. The cough reflex was almost entirely suppressed by plasma concentrations of lidocaine in excess of 4 micrograms/mL. The results suggest that intravenous administration of lidocaine is effective in suppressing the cough reflex during tracheal intubation in elderly patients under general anesthesia, but that relatively high plasma concentrations of lidocaine may be required for suppression of coughing. 5. Grange CS; Suresh D; Meikle R; Carter JA; Goldhill DR Intubation with propofol: evaluation of pre-treatment with alfentanil or lignocaine. Anaesthetics Unit, London Hospital Medical College, Whitechapel, United Kingdom. Language: Eng Source: Eur J Anaesthesiol 1993 Jan;10(1):9-12 Unique Identifier: 93162054 Abstract: The effect of lignocaine or alfentanil pre-treatment on conditions at orotracheal intubation following induction with propofol, but without the use of muscle relaxants, were compared in a prospective, controlled, double-blind study. Forty five healthy patients undergoing elective surgery were randomly allocated to receive either 0.9% saline (control), alfentanil 20 micrograms/kg-1, or lignocaine 1.5 mg kg-1 prior to induction with propofol 2.5 mg kg-1. Ease of intubation was scored on a four point scale from 'excellent' = 1 to 'not possible' = 4. Alfentanil pre-treatment allowed intubation in 93% of patients compared to 60% in each of the groups pre-treated with lignocaine or saline. Intubation scores of 1 or 2 were obtained in 14 out of 15 patients (93%) in the alfentanil group and this was significantly better than the lignocaine group (33%) or control group (20%). No difference was detected between the scores of the latter two groups.