Spinal anesthesia without hypotension a myth or reality?

Transcription

1 Spinal anesthesia without hypotension a myth or reality? Peter Poredoš, MD, PhD, DESA peter.poredos@kclj.si University Medical Centre Ljubljana, Slovenia Department for Anesthesiology and Intensive Care

2 Conflicts No conflict of interest

3 Content History Physiology - mechanisms Hemodynamic status in different patient categories Prevention and treatment of hypotension

4 History James Leonard Corning 1885 first published descriptions of neuraxial blockade technique (epidural/spinal) August Bier 1898 first surgery under spinal anesthesia Edo Šlajmer 1901 first spinal anesthesia in Slovenia (surgeon!!!)

5 History Zgodovina hemodinamike

6 Background Hypotension still the most frequent complication of SA - incidence of >60% with higher spinal block Matsota P, et al. J Anesth 2015; 29(3): Higher incidence of hypotension: elderly higher spinal block higher local anaesthetic dose patient position higher sympathetic activity (arterial hypertension) obesity pregnancy. Maayan-Metzger A, et al. Am J Obstet Gynecol 2010; 202(1): 56. Somboonviboon W, et al. J Med Assoc Thai 2008; 91(2):

7 Mechanism Spinal block Th10 Preganglionic sympathetic block SVR and venodilation inflow of venous blood into the heart SV and HR SV & HR SVR=80x (MAP-RAP)/MVS CO blood pressure

8 No.of patients Young healthy patients our study Th12 Th11 Th10 Th9 Th8 Th7 Th6 Th5 Th4 Th3 Spinal block sensory level Group L Group H p < 0,001 compared to Group H No.of blocked dermatomes above S5 (H vs L) Time to max sensory block (min) (H vs L) 18.5 vs. 13.3, p< vs. 10.9, p=0.026 Poredoš P, Signa Vitae 2016

9 % change in CI Young healthy patients CI * 40 * * Baseline * p < 0.05 according to baseline p < according to baseline * Time after spinal block (min) Poredoš P, Signa Vitae 2016

10 SAP (mmhg) SVRI (dyne+s/cm 5 *m 2 ) Young healthy patients hypotension * * * * * * * * * * Time after spinal block (min) Time after spinal block (min) * p < 0.05 according to baseline p < according to baseline Poredoš P, Signa Vitae 2016

11 SVI (ml/m 2 /beat) HR (beat/min) Young healthy patients compensation * * * * * * * * * Time after spinal block (min) Time after spinal block (min) * p < 0.05 according to baseline p < according to baseline Poredoš P, Signa Vitae 2016

12 CI (L/min/m 2 ) Young healthy patients correlations R² = 0, R 2 =0.987, R=0.993, p<0.001 SVI: β=0.849, p<0.001 HR: β=0.573, p< SVI (ml/m 2 ) Sensory block height: R 2 =0.006, R=0.077, p=0.622 Poredoš P, Signa Vitae 2016

13 Young healthy patients complications Hypotension Bradycardia Phenylephrine requirement Atropine requirement Nausea Group H (n=20) 7 (35%) 3 7 (35%) 3 5 (25%) Group L (n=20) 2 (10%) 0 2 (10%) 0 1 (5%) p-value Poredoš P, Signa Vitae 2016

14 Elderly Incidence of hypotension 27-80% Critchley LA, et al. Br J Anaesth 1994; 73: resting sympathetic nervous activity and baroreceptor reflex activity with advancing age Decrease in CO 10-20%, SVR 20%, MAP 30% Meyhoff CS, et al. Eur J Anaesthesiol 2007; 24(9):

15 Elderly SVRI main mechanism Nakasuji M. Journal of clinical anesthesia 2012; 24: Sensory block height after aplication of hyperbaric local anesthetic 3-4 spinal segments higher than in younger Veering BT, et al. Anesthesiology 1991; 74:

16 Hypertensive patients Increased neurogenic activity baseline SVR values Singla D KS, et al. J Anaesth Clin Pharmacol 2006; 22: Stone JG, et al. Br J Anaesth 1988; 61:

17 Parturients Incidence of hypotension % Birnbach DJ, Soens MA. Minerva Anestesiol 2008; 74: Main mechanism: dependence on SY vascular tone Contributing factors: LA sensitivity, aortocaval compression, susceptibility to effects of SY block ( sensitivity to endogenous vasoconstrictors) Aim: preserve hemodynamic stability, including uterine blood flow

18 Obese Higher spinal because of CSF volume, longer duration Cause: dilated venous plexus compresses cerebrospinal space CSF, also epidural fat

19 Obese 15mg hyperbaric bupivacaine Obese vs.non-obese no difference in complications rate Max block Th8 in lean vs. Th6 in fat Lithotomy position: increases spinal block height autotransfusion ml, but minimal increase in venous return

20 Obese McCulloch WJ, et al. Br J Anaesth 1986; 58(6):

21 Solution: fluids? Colloids preload or coload prevented a decrease in CO, but not hypotension Riesmeier A, et al. Anesth Analg 2009; 108(2): Colloids more effective than crystalloids (RR 0.68 ( )) Cyna AM, et al. Cochrane Database Syst Rev 2006; (4): CD

22 Cyna AM, et al. Cochrane Database Syst Rev 2006; (4): CD

23 Solution: patient position? Trendellenburg Zorko N, et al. Anesth Analg 2009; 108:

24 Solution: vasoconstrictors? Dyer RA, et al. Anesthesiology 2009; 111:

25 Solution: vasoconstrictors? no significant differences in hypotension between ephedrine and phenylephrine, both effective Cyna AM, et al. Cochrane Database Syst Rev 2006; (4): CD Cyna AM, et al. Cochrane Database Syst Rev 2006; (4): CD

26 Solution: vasoconstrictors? no significant differences in hypotension between ephedrine and phenylephrine, both effective Cyna AM, et al. Cochrane Database Syst Rev 2006; (4): CD Ephedrine crosses placenta umbilical ph (treatment) Lee A, et al. Can J Anaesth 2002; 49: High doses of ephedrine tachycardia and hypertension Phenylephrine no effect on oxygen supply for the fetus Dopamine, glycopyrrolate Thiele RH, et al. Anesth Analg 2011; 113:

27 Solution: vasoconstrictors? Despite aggressive infusion of vasoconstrictors 25% of patients still episodes of hypotension Ngan Kee WD, et al. Anesth Analg 2004; 98: Combination of ephedrine and phenylephrine has no advantage compared with phenylephrine alone ( eph & phe): hypotension nausea and womiting hemodynamic control ph & BE Ngan Kee WD, et al. Anesth Analg 2008; 107:

28 Solution: LA dose? Lower dose (<7.5mg of bupivacaine) hypotension, severity of hypotension, pharmacological treatment Lower dose combined with fentanyl Fan SZ, et al. Anesth Analg 1994; 78: Langesaeter E, et al. Anesthesiology 2008; 109: Ben-David B, et al. Reg Anesth Pain Med 2000; 25: Van de Velde M, et al. Anesth Analg 2006; 103:

29 Solution: Spinal block height?

30 Solution: leg compression Bjørnestad E, et al. Eur J Anaesthesiol 2009; 26(10):

31 Solution: combination? Crystalloids + phenylephrine infusion only 1.9% of hypotension Ngan Kee WD, et al. Anesthesiology 2005; 103(4):

32 Unilateral spinal block Hypotension 22.4% vs. 5%, p<0.01 Max change in SBP according to baseline: -28% vs. -8%, p<0.001 Casati A, et al. Reg Anesth Pain Med 1999; 24(3): No hypotension in high risk patients (>60 y, ASA III-IV) with unilateral spinal anesthesia Chohan U, et al. J Pak Med Assoc 2002; 52(2): fold reduction in the incidence of clinically relevant hypotension Casati A, et al. Minerva Anestesiol 2001; 67(12):

33 Prediction of hypotension Baseline HR variability Skin conductance Baseline mean arterial pressure Baseline systemic vascular resistance Baseline heart rate values Low weight gain in pregnancy and a greater increase in arterial pressure on moving from the supine to the lateral position

34 Conclusions Hypotension still the most common complication of spinal anesthesia Main mechanism for hypotension in spinal anesthesia is peripheral vasodilation with a consequent decrease in afterload Hypotension prevention and treatment should be individual no single method completely prevents hypotension