Beta Blockers for ENT Surgery

Transcription

1 Beta Blockers for ENT Surgery Dr. Giuliano Michelagnoli U.O. Anestesia e Rianimazione Nuovo Ospedale di Prato

2 Perioperative Beta-Blockade 1. Reduction of perioperative cardiovascular risk 2. Multimodal analgesia 3. Adrenergic response control 4. Controlled Hypotension

3 Perioperative Beta-Blockade 1. Reduction of perioperative cardiovascular risk 2. Multimodal analgesia 3. Adrenergic response control 4. Controlled Hypotension

4 Lancet 2008; 372:

5 Bouri S, et al. Heart 2013;0:1 9

6 Reduction in mortality, in cardiovascular events,, expecially in patients with 2 ore more risk factors JAMA, April 24, 2013 Vol 309, No. 16

7 BetaBlockers to prevent perioperative death in non cardiac surgery: more questions than answers Timing of beta-blockade starting Titration to heart rate vs Blood pressure Dose Type of drug (cardioselectivity) Beta Blockade seem to reduce the incidence of perioperative myocardial ischemia Beta blockers started early before surgery and not titrated could be associated with an increased incidence of stroke More research is needed

8 Beta-Blockers in multimodal analgesia Multimodal analgesia is an approach to preventing postoperative pain that involves administering a combination of opioid and nonopioid analgesics that act at different sites within the central and peripheral nervous systems in an effort to improve pain control while eliminating opioid-related side-effects, reduce surgical stress, Current Opinion in Anesthesiology 2010, 23:

9 Beta Blockers for multimodal analgesia in Fast Track Surgery Journal of Clinical Anesthesia (2013) 25, Anesth Analg 2007;105: Journal of International Medical Research : 1861

10 Control of Adrenergic response to stimulation Cochrane Database of Systematic Reviews 2013 Jul 3;7:CD004087

11 Results 72 RCTs included in the metanalysis investigating: Mortality and Major Morbidity (primary outcome): only 2 trials Arrhythmias, Myocardial ischemia, both of them (secondary outome) respectively: 40, 11, 20 RCTs 32 types of drug belonging to different classes Arrhythmias was observed in 2932 cases Myocardial Ischemia in 1616 cases

12 Beta Blockers in preventing the incidence of arrhythmias in response to tracheal intubation Beta Blockers (14 studies) Combined Beta Blockers to Alfa Blockers (4 studies) Treatment Group (Cases/total) Control Group (Cases/total) 18/371 (4,8%) 31/218 (14,2%) 1/74 (1,3%) 3/29 (10,3%) Comparison 9,4% OR 0,23 CI95% P=0,0001 9% OR 0,13 CI 95% P=0,07 Drugs studied were: Esmolol (10 cases) at different dosages: 25,50,100,200 mg iv before induction; or 3 mcg/kg, 2 mcg/kg, 1,4 mg/kg, 500 mcg/kg plus continuous infusion Labetalol (4 cases in association) Metoprolol (2 cases) Pindolol (1 case) Practolol (1 case) Beta Blockers alone prevent the occurrence of Arrhythmias in response to tracheal intubation

13 Beta Blockers in preventing the incidence of Myocardial Ischemia in response to tracheal intubation Beta Blockers (10 studies) Treatment Group (Cases/no AMI)) Control Group (cases/no AMI) 5/269 (1,8%) 8/190 (4,2%) Comparison 2,4% OR 0,61 CI95% P=0,41 6 of the 10 studies were on high risk patients and 4 were not blinded No Subgroup analysis has been done because the totality of the studies included were conducted with esmolol Beta Blockers alone do not prevent the occurrence of Myocardial Ischemia in response to tracheal intubation

14 Controlled Hypotension Reduction of the systolic blood pressure to 80 90mm Hg, a reduction of mean arterial pressure (MAP) to 50 65mm Hg or a 30% reduction of baseline MAP Reduces bleeding Reduces the need for blood transfusions Provides a satisfactory bloodless surgical field

15 Surgical Bleeding and Hypotension Bleeding: the volume of blood that appears in the operative field in a given time ɸ = ΔP/R Bleeding depends on local tissue pressure and on peripheral vascular resistance The difficulty in controlling the bleeding flow by hypotension is because the target pressure, measured at the level of the large vessels, is different from the pressure at the level of tissue circulation in the operated zone

16 Reduction of intraoperative bleeding: physiologic bases P and R in the surgical field are local variables that depend on: Systemic P and R, measured at the level of large arteries Regulation of the arteriolar tone by the sympatetic nervous system Autoregulation of microcirculation

17 Ideal Hypotensive Agent Easy administration Short onset time Quick reversal after discontinuation Rapid elimination without toxic metabolites Predictable and dose-dependent effect

18 Drugs used to induce controlled hypotension Drugs 2007; 67 (7):

19 Controlled Hypotension Dexmedetomidina for ENT Surgery Canadian Journal of Anaesthesia 1995 / 42: 5 / pp consenting ASA I and II patients undergoing FESS were randomly assigned to receive either SNP (Group I) or esmolol (Group II) as the primary hypotensive agent. Optimal surgical conditions for FESS were provided with minimal esmolol-induced hypotension (MABP > 65 mmhg). While Sodium Nitroprusside-induced hypotension did not provide good quality surgical field until severe levels of hypotension were present (MABP mmhg).

20 Controlled Hypotension for ENT Surgery Saudi J Anaesth Apr-Jun; 7(2): consenting ASA I and II patients undergoing FESS were Randomly assigned to receive either DEX or ESM, with a MAP Target of mmhg Both dexmedetomidine or esmolol reached the target pressure and are effective in providing ideal surgical field during FESS. Emergence time and time to reach an Aldrete score > 9 were significantly lower in ESM group Compared with esmolol Sedation score was lower in ESM group Time to first analgesic drug was significantly longer in DEX group dexmedetomidine offers the advantage of inherent analgesic, sedative and anesthetic sparing effect)