Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing orthopedic surgeries

Le titrage de l’isoflurane à l’aide du BIS peut hâter la récupération des patients âgés en chirurgie orthopédique



This study was designed to investigate the effect of bispectral index (BIS) monitoring on the recovery profiles, level of postoperative cognitive dysfunction, and anesthetic drug requirements of elderly patients undergoing elective orthopedic surgery with general anesthesia.


Sixty-eight patients over the age of 60 were randomized into one of two groups. In the standard practice (SP) group, the anesthesiologists were blinded to the BIS value, and isoflurane was titrated according to standard clinical practice. In the BIS group, isoflurane was titrated to maintain a BIS value between 50–60.


The total isoflurane usage was 30% lower in the BIS group compared to the SP group (5.6 ± 3 vs 7.7 ± 3 mL, P < 0.05). The time to orientation was faster in the BIS group compared to the SP group (9.5 ± 3vs 13.1 ± 4 min,P < 0.001). There were no differences in the postoperative psychometric tests between the two groups.


There was no difference in the level of postoperative cognitive dysfunction between the two groups. However, titration of isoflurane using the BIS index decreased utilization of isoflurane and contributed to faster emergence of elderly patients undergoing elective knee or hip replacement surgery.



Rechercher l’effet du monitorage par l’index bispectral (BIS) sur les profils de récupération, le niveau de déficit cognitif postopératoire et les besoins d’anesthésiques chez des patients âgés qui subissent une intervention orthopédique non urgente avec anesthésie générale.


Soixante-huit patients de plus de 60 ans ont été répartis au hasard en deux groupes. Pour ceux du groupe de pratique courante (PC), la valeur du BIS n’était pas connue des anesthésiologistes et l’isoflurane a été titré selon les normes de la pratique clinique. Pour les patients du groupe BIS, l’isoflurane a été titré de façon à maintenir un BIS entre 50 et 60.


L’utilisation totale d’isoflurane a été plus basse de 30 % dans le groupe BIS, comparé au groupe PC (5,6 ± 3 vs 7,7 ± 3 mL, P < 0,05). Le retour à la conscience a été plus rapide dans le groupe BIS, comparé au groupe PC (9,5 ± 3 vs 13,1 ±4 min, P < 0,001). Les tests psychométriques postopératoires n’ont présenté aucune différence intergroupe.


Le niveau de déficit cognitif postopératoire n’était pas différent d’un groupe à l’autre. Cependant, le titrage de l’isoflurane à l’aide de l’index BIS a permis de réduire l’utilisation d’isoflurane et a favorisé une récupération plus rapide chez des patients âgés qui subissent la mise en place d’une prothèse totale de hanche.


  1. 1

    Nielson WR, Gelb AW, Casey JE, Penny FJ, Merchant RN, Manninen PH. Long-term cognitive and social sequelae of general versus regional anesthesia during arthroplasty in the elderly. Anesthesiology 1990; 73: 1103–9.

  2. 2

    Dodds C, Allison J. Postoperative cognitive deficit in the elderly surgical patient. Br J Anaesth 1998; 81: 449–62.

  3. 3

    Gustafson Y, Brannstrom B, Berggren D, et al. A geriatric-anesthesiologic program to reduce acute confusional states in elderly patients treated for femoral neck fractures. J Am Geriatr Soc 1991; 39: 655–62.

  4. 4

    Williams-Russo P, Urquhart BL, Sharrock NE, Charlson ME. Post-operative delirium: predictors and prognosis in elderly orthopedic patients. J Am Geriatr Soc 1992; 40: 759–67.

  5. 5

    Rogers MP, Liang MH, Daltroy LH, et al. Delirium after elective orthopedic surgery: risk factors and natural history. Int J Psychiatry Med 1989; 19: 109–21.

  6. 6

    O’Keeffe ST, Chonchubhair AN. Postoperative delirium in the elderly. Br J Anaesth 1994, 73: 673–87.

  7. 7

    Johansen JW, Sebel PS. Development and clinical application of electroencephalographic bispectrum monitoring. Anesthesiology 2000; 93: 1336–44.

  8. 8

    Gan TJ, Glass PS, Windsor A, et al. Bispectral index monitoring allows faster emergence and improved recovery from propofol, alfentanil, and nitrous oxide anesthesia. Anesthesiology 1997; 87: 808–15.

  9. 9

    Song D, Joshi GP, White PF. Titration of volatile anesthetics using bispectral index facilitates recovery after ambulatory anesthesia. Anesthesiology 1997; 87: 842–8.

  10. 10

    Folstein MF, Folstein SE, McHugh PR. “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12: 189–98.

  11. 11

    Parikh SS, Chung F. Postoperative delirium in the elderly. Anesth Analg 1995; 80: 1223–32.

  12. 12

    Chung FF, Chung A, Meier RH, Lautenschlaeger E, Seyone C. Comparison of perioperative mental function after general anaesthesia and spinal anaesthesia with intravenous sedation. Can J Anaesth 1989; 36: 382–7.

  13. 13

    Letourneau JE, Denis R. The reliability and validity of the Trieger tests as a measure of recovery from general anesthesia in a day-care surgery unit. Anesth Prog 1983; 5: 152–5.

  14. 14

    Dion P. The cost of anesthetic vapours (Letter). Can J Anaesth 1992; 39: 633–4.

  15. 15

    Aldrete JA, Kroulik D. A postanesthetic recovery score. Anesth Analg 1970; 49: 924–34.

  16. 16

    Pousada L, Leipzig RM. Rapid bedside assessment of postoperative confusion in older patients. Geriatrics 1990; 45: 59–66.

  17. 17

    Doenicke AW, Roizen MF, Hoernecke R, Harbauer K, Schubert S, Zaba Z. TIVA with etomidate or propofol in day-case surgery: is the bispectral index a useful parameter to lower the maintenance dose? Anesth Analg 1999, 88: S53(abstract).

  18. 18

    Stevens WC, Dolan WM, Gibbons RT, et al. Minimum alveolar concentrations (MAC) of isoflurane with and without nitrous oxide in patients of various ages. Anesthesiology 1975; 42: 197–200.

  19. 19

    Katoh T, Suguro Y, Ikeda T, Kazama T, Ikeda K. Influence of age on awakening concentrations of sevoflurane and isoflurane. Anesth Analg 1993; 76: 348–52.

  20. 20

    Gold MI, Abello D, Herrington C. Minimum alveolar concentration of desflurane in patients older than 65 yr. Anesthesiology 1993; 79: 710–4.

  21. 21

    Katoh T, Bito H, Sato S. Influence of age on hypnotic requirement, bispectral index, and 95% spectral edge frequency associated with sedation induced by sevoflurane. Anesthesiology 2000; 92: 55–61.

  22. 22

    Kazama T, Ikeda K, Morita K, et al. Comparison of the effect-site ks of propofol for blood pressure and EEG bispectral index in elderly and younger patients. Anesthesiology 1999; 90: 1517–27.

  23. 23

    Moller JT, Cluitmans P, Rasmussen LS, et al. Longterm postoperative cognitive dysfunction in the elderly: ISPOCD1 study. Lancet 1998; 351: 857–61.

  24. 24

    Dijkstra JB, Houx PJ, Jolles J. Cognition after major surgery in the elderly: test performance and complaints. Br J Anaesth 1999; 82: 867–74.

  25. 25

    Ranta SO-V, Laurila R, Saario J, Ali-Melkkilä T, Hynynen M. Awareness with recall during general anesthesia: incidence and risk factors. Anesth Analg 1998; 86: 1084–9.

Download references

Author information

Correspondence to Jean Wong.

Additional information

Supported in part by a grant from Aspect Medical, Newton, MA, USA.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wong, J., Song, D., Blanshard, H. et al. Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing orthopedic surgeries. Can J Anesth 49, 13–18 (2002).

Download citation


  • Sevoflurane
  • Desflurane
  • Minimum Alveolar Concentration
  • Bispectral Index
  • Postoperative Delirium