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Psychomotor recovery in very old patients after total intravenous or balanced anaesthesia for cataract surgery

2001; Elsevier BV; Volume: 86; Issue: 2 Linguagem: Inglês

10.1093/bja/86.2.203

1471-6771

Jens C. Kubitz, J. Epple, A. Bach, J. Motsch, E. Martin, H. Schmidt,

Cardiac, Anesthesia and Surgical Outcomes

We compared psychomotor recovery after total intravenous anaesthesia (TIVA) with remifentanil/propofol and balanced anaesthesia (BAL) with etomidate/fentanyl/isoflurane in 40 patients, ASA I–III, aged ≥80 yr undergoing elective cataract surgery. Recovery times were recorded and psychomotor recovery was assessed according to simple reaction time, critical flicker fusion frequency (CFF) and short-term memory 30 min, 2 h and 1 day after surgery. Physical characteristics of patients in the two groups (19 in the TIVA group and 21 in the BAL group) were comparable. The TIVA group recovered significantly more quickly. Both groups showed a poorer psychomotor performance 30 min after surgery than at baseline assessment, but simple reaction time and short-term memory were close to baseline values 2 h after surgery. Only performance in the CFF test remained below baseline at this point. No deficits in psychomotor performance were noted on the first day after surgery. We conclude that there is only a minor deficit in psychomotor function in elderly patients 2 h after cataract surgery under general anaesthesia and that psychomotor function recovers completely by 24 h after surgery. We compared psychomotor recovery after total intravenous anaesthesia (TIVA) with remifentanil/propofol and balanced anaesthesia (BAL) with etomidate/fentanyl/isoflurane in 40 patients, ASA I–III, aged ≥80 yr undergoing elective cataract surgery. Recovery times were recorded and psychomotor recovery was assessed according to simple reaction time, critical flicker fusion frequency (CFF) and short-term memory 30 min, 2 h and 1 day after surgery. Physical characteristics of patients in the two groups (19 in the TIVA group and 21 in the BAL group) were comparable. The TIVA group recovered significantly more quickly. Both groups showed a poorer psychomotor performance 30 min after surgery than at baseline assessment, but simple reaction time and short-term memory were close to baseline values 2 h after surgery. Only performance in the CFF test remained below baseline at this point. No deficits in psychomotor performance were noted on the first day after surgery. We conclude that there is only a minor deficit in psychomotor function in elderly patients 2 h after cataract surgery under general anaesthesia and that psychomotor function recovers completely by 24 h after surgery. Life expectancy has increased considerably over the last few decades and, accordingly, so has the proportion of elderly patients requiring surgery and anaesthesia. Simultaneously, an increasing number of surgical procedures is performed on an outpatient basis. In order to avoid delays in the postanaesthesia care unit (PACU) and in the time to discharge after outpatient anaesthesia, fast and predictable recovery of cognitive function is of major importance. It is particularly a matter of concern in aged patients, as the morphological and physiological changes in the brain related to ageing have to be taken into consideration. It is known that in elderly patients the required dose of certain anaesthetics is lower.1Christensen JH Andreasen F Jansen JA Thiopentone sensitivity in young and elderly women.Br J Anaesth. 1983; 55: 33-39Crossref PubMed Scopus (21) Google Scholar 2Jakobs JR Revers JG Marry J White WD Bai SA Smith LR Aging increases pharmacodynamic sensitivity to the hypnotic effects of midazolam.Anesth Analg. 1995; 80: 143-148PubMed Google Scholar However, little is known about how recovery of cognitive function is affected by anaesthesia in elderly patients. We investigated the effect of total intravenous anaesthesia (TIVA) with remifentanil and propofol and BAL with fentanyl and isoflurane on psychomotor recovery in patients aged ≥80 yr. Here we present a subgroup analysis of a clinical trial with pharmacoeconomic endpoints in which 124 patients (aged ≥65 yr) were enrolled. The results of this study have been accepted for publication elsewhere.3Epple J, Kubitz J, Schmidt H, Motsch J, Böttiger BW, Martin E, Bach A. Comparative analysis of costs of total intravenous anaesthesia with propofol and remifentanil versus balanced anaesthesia with isoflurane and fentanyl. Eur J Anaesth, in pressGoogle Scholar Following institutional review board approval, 40 patients aged ≥80 yr, ASA physical status I–III, undergoing elective cataract surgery under general anaesthesia were included in this single-blind study. All patients gave written informed consent. Prospective patients with a history of an allergic reaction to one of the drugs used in this study were ineligible for participation. A computer-generated randomization schedule was used to assign patients randomly to receive either TIVA with remifentanil and propofol or BAL with fentanyl and isoflurane. In order to avoid any effects of premedication on the postoperative psychomotor test results, none of the patients received sedative drugs as premedication. A peripheral intravenous cannula was placed for drug and fluid administration and standard monitoring'comprising pulse oximetry, automated arterial pressure cuff measurements and electrocardiogram'was applied. Subjects were monitored for systolic and diastolic arterial pressure, heart rate and haemoglobin oxygen saturation throughout surgery and the recovery period. Before induction of anaesthesia, all patients were preoxygenated for 2 min. In the TIVA group, anaesthesia was induced with propofol 1.5 mg kg−1 and remifentanil 1 μg kg−1 over a 3 min period. In the BAL group, subjects received etomidate 0.1–0.3 mg kg−1 and fentanyl 1.5 μg kg−1 for induction of anaesthesia. Approximately 3 min after starting anaesthesia, mivacurium 0.15 mg kg−1 was administered in both groups to achieve muscle relaxation. After tracheal intubation, all patients were ventilated mechanically to normocapnia with oxygen-enriched air (FiO2=0.4) and a constant fresh gas flow of 3 litres min−1. Anaesthesia was maintained by a continuous infusion of propofol 0.05–0.1 mg kg−1 min−1 and remifentanil 0.15–0.3 μg kg−1 min−1 in the TIVA group and with isoflurane 0.8–2.5 MAC and a bolus of fentanyl 0.1 mg at the beginning of surgery in the BAL group. Infusion rates and MAC were adjusted, if necessary, to achieve an adequate depth of anaesthesia and to provide haemodynamic stability. Hypotension and bradycardia were treated with sympathomimetic and anticholinergic drugs, respectively, following institutional guidelines. At the end of surgery, anaesthesia was stopped and the patients' lungs were ventilated manually with 100% oxygen. After adequate respiration had been resumed and the patients were able to open their eyes on command, the trachea was extubated and patients were transferred to the PACU, where monitoring of vital signs was continued. The duration of surgery and anaesthesia was recorded. Recovery was assessed by recording the time to respond to verbal commands (open eyes) and extubation. The Aldrete score4Aldrete JA Kroulik D A postanesthetic recovery score.Anesth Analg. 1970; 49: 924-933Crossref PubMed Scopus (935) Google Scholar was recorded upon arrival in the PACU and every 15 min thereafter until the patients achieved a score of ≥9. The score includes five tasks that assess muscle activity, respiratory efficiency, changes in systolic arterial pressure from the preanaesthetic level, consciousness and skin colour. The maximum score is 10. Psychomotor and cognitive function tests used during the study included: simple visual reaction time, simple auditory reaction time, critical flicker fusion frequency (CFF) and short-term memory. These tests have been used in a similar way in previous studies and are considered suitable for detecting even minor impairment of psychomotor function.5Hindmarch I Psychomotor function and psychoactive drugs.Br J Clin Pharmacol. 1980; 10: 189-209Crossref PubMed Scopus (455) Google Scholar 6Cashman JN Power SJ An evaluation of tests of psychomotor function in assessing recovery following a brief anesthetic.Acta Anaesthesiol Scand. 1980; 33: 693-697Crossref Scopus (14) Google Scholar They are easy to use and are not time consuming, which is an important factor in psychomotor testing in the early postoperative period. To evaluate the simple visual reaction time, the patient was instructed to press a button when a red light of about 3 cm diameter, placed approximately 80 cm from the eyes, was illuminated. In the test of simple auditory reaction time, the red light was replaced by an auditory stimulus, which could easily be heard by the patient, as verified before the start of the test. Each test was performed three times per session; mean results (expressed in seconds) were recorded. In this test, the patient was shown a flickering red light, which was of the same diameter and placed at the same distance as the one used for the simple visual reaction time. Its flicker frequency was slowly increased and the patient was instructed to report as soon as the light appeared to be continuous. The test was performed three times per session; the mean results, expressed in hertz, were recorded. In the short-term memory test, patients were asked to memorize five words, which were read to them twice and which they had to repeat once in order to exclude communication problems. After 2 min, in which patients had to fill in a concentration test in order to distract them from constantly repeating the given words, they were asked to recall those five words and the number of correctly recalled words was recorded. Different words were used in each session (Table 1).Table 1Words used in the short-term memory test (translated from German)TimeWords used in testPreoperativelyflower, street, plate, day, bed30 minapple, book, cup, moon, spoon120 mingrass, knife, picture, cake, light1 dayearth, chair, time, glass, glasses Open table in a new tab In addition to these tests, a visual analogue scale (VAS) was used to evaluate the intensity of sedation. According to this scale, a score of 0 represented no sedation/totally awake and a score of 100 represented the deepest sedation imaginable. At each time point, patients were asked to move the pointer on the VAS to the place where they considered their sedation to be most accurately represented. The numerical equivalent was noted by the observer. Patients feeling too drowsy to perform this test were not given a value. On the evening before anaesthesia, the patients were familiarized with this series of tests and the VAS and baseline values were obtained. The tests and the VAS were repeated 30 min, 120 min and 1 day after the end of surgery, and were always carried out by the same observer. In addition to the assessment of each psychomotor test, we wanted to evaluate test compliance, defined as the ability and willingness to perform the complete series of tests at the given time points. Patients were always asked to perform the tests but the decision to do so was ultimately their own. Patient characteristics were compared using the χ2 test and Student's t-test. Recovery times, atropine requirements, VAS results and between-group differences in the psychomotor recovery tests were analysed with two-way analysis of variance (ANOVA). Psychomotor recovery test results were further analysed with Student's paired t-test for comparison between preoperative and postoperative values. Fisher's exact probability test was used for comparison of test compliance. For all statistical tests, a two-sided P-value of <0.05 was considered statistically significant. Statistical analysis was performed using SPSS version 6.0.1. Data are expressed as mean (sd) unless stated otherwise. For simple reaction time and CFF tests, postoperative results are presented as mean changes (sd), i.e. the difference between the mean baseline value and the mean postoperative value at the given time point. Forty ASA class II–III patients were enrolled in this study. The two study groups were similar with respect to physical characteristics and duration of surgery (Table 2). However, immediate recovery, as assessed by times to awakening and to meeting the Aldrete recovery criteria4Aldrete JA Kroulik D A postanesthetic recovery score.Anesth Analg. 1970; 49: 924-933Crossref PubMed Scopus (935) Google Scholar (score ≥9), differed between the two groups, with significantly shorter times being observed in the TIVA group (Table 2). One subject in the TIVA group had a myocardial infarction on the day after surgery and was excluded from the analysis at this time point. The patient was transferred to the cardiac intensive care unit, where coronary arteriography showed three-vessel disease.Table 2Physical characteristics and recovery times (mean (SD)). ns, not statistically significantly differentTIVA (n=19)BAL (n=21)P valueAge (yr)84.5 (80–89)83.2 (80–88)nsGender (male/female)12/716/5nsASA physical status I/II/III (n)0/13/60/9/12nsDuration of surgery (min)27.6 (12.0)28.6 (12.1)nsTime (min) toExtubation7.0 (3.0)13.8 (5.8)<0.01Eye opening7.0 (2.9)15.9 (5.7)<0.01Aldrete score ≥911.5 (8.1)39.8 (26.3)<0.01 Open table in a new tab In the TIVA group, atropine was administered for treatment of bradycardia in 18 of the 19 patients, whereas only 12 of the 21 patients in the BAL group received atropine. The mean dose of atropine differed significantly (P=0.003) between the two groups (0.55 mg in the TIVA group and 0.25 mg in the BAL group). There was a significant difference between groups with respect to the ability to complete the testing session 30 min after surgery. Eighteen of the 19 patients in the TIVA group completed the whole series of tests at that time, whereas only 11 of 21 patients in the BAL group did so. However, 120 min after surgery and on the day after surgery, test compliance between the groups was comparable (Table 3). Common reasons for omitting psychomotor testing were feeling sleepy or drowsy, nausea, vomiting or simply 'not being in the mood to do the test series for unknown reasons'. The latter was the main reason why more patients in the TIVA group did not perform the psychomotor tests 120 min and 1 day after surgery, although they were considered capable of doing so by the observer.Table 3Test compliance (number of patients who participated in psychomotor testing at the given time points); *significant difference between the TIVA and BAL groups (P<0.01)TIVA (n=19)BAL (n=21)Preoperatively192130 min1811*120 min16181 day1620 Open table in a new tab The results of the VAS are presented in Figure 1. In the TIVA group, 18 of 19 patients completed the VAS 30 min after the end of surgery, whereas only 14 of 21 in the BAL group did so. Patients in the TIVA group had significantly lower sedation scores than patients in the BAL group at this time point. In both groups, patients felt significantly more tired at the time points 30 min and 120 min postoperatively compared to the preoperative value, but on the first postoperative day sedation scores did not differ from baseline values. The results of the simple reaction time tests, the CFF and short-term memory test are shown in Table 4. Thirty minutes after the end of anaesthesia, both visual and auditory reaction times were significantly longer than baseline in both groups, but there were no differences from baseline 2 h and 1 day after the end of anaesthesia. A significant between-group difference was observed in the mean change in auditory reaction time 30 min after surgery (P=0.04). At this time point, auditory reaction time was significantly shorter in the TIVA group. However, there were no between-group differences in mean change in reaction time at any of the other time points.Table 4Results of psychomotor tests. For each test, data are expressed as mean changes (SD); n=number of patients. *Significantly different from pre-operative value (P<0.05); #significantly different from pre-operative value (P 60 yr is close to preoperative values 2 h after general anaesthesia with propofol or etomidate–vecuronium–isoflurane for day-case cataract surgery. However, early or short-term postoperative cognitive function was found to be impaired after major surgery in elderly patients.14Dijkstra JB Houx PJ Jolles J Cognition after major surgery in the elderly: test performance and complaints.Br J Anaesth. 1999; 82: 867-874Crossref PubMed Scopus (100) Google Scholar 15O'Keffe ST Chonchubhair AN Postoperative delirium in the elderly.Br J Anaesth. 1994; 73: 673-687Crossref PubMed Scopus (180) Google Scholar In a study by Keita and colleagues,16Keita H Gilles P Giraud O et al.Aging prolongs recovery of psychomotor functions at emergence from propofol-alfentanil anaesthesia.Can J Anaesth. 1998; 45: 1211-1214Crossref PubMed Scopus (8) Google Scholar cognitive function in elderly patients undergoing elective orthopaedic surgery under propofol–alfentanil anaesthesia did not return to preoperative values within the first 2 h after surgery whereas younger patients showed the same test performance as they did before surgery at that time. In a multicentre study in which 1218 patients scheduled for major non-cardiac surgery were enrolled, Moller and colleagues17Moller JT Cluitmans P Rasmussen LS et al.Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD1 investigators. International Study of Post-Operative Cognitive Dysfunction.Lancet. 1998; 351: 857-861Abstract Full Text Full Text PDF PubMed Scopus (1819) Google Scholar demonstrated postoperative cognitive dysfunction in 25.8% of patients 1 week after surgery and in 9.9% of patients 3 months after surgery. Williams-Russo and colleagues18Williams-Russo P Urquhart BL Sharrock NE Charlson ME Cognitive effects after epidural vs. general anesthesia in older adults. A randomized trial.J Am Med Assoc. 1995; 274: 44-50Crossref PubMed Scopus (365) Google Scholar found no differences in neuropsychological test performance between general and regional anaesthesia 1 week and 6 months after orthopaedic surgery, but that 5% of patients had impaired cognitive function 6 months after surgery. It is likely, therefore, that the reason why patients in the present study did not show impaired postoperative psychomotor function 1 day after surgery is related to the minimally invasive character and short duration of cataract surgery, which has been found to be related to early postoperative cognitive dysfunction.17Moller JT Cluitmans P Rasmussen LS et al.Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD1 investigators. International Study of Post-Operative Cognitive Dysfunction.Lancet. 1998; 351: 857-861Abstract Full Text Full Text PDF PubMed Scopus (1819) Google Scholar Within the confines of the psychomotor test battery used in this study, we conclude that there is only a minor postoperative deficit in psychomotor function in elderly patients 2 h after the end of general anaesthesia with remifentanil and propofol or fentanyl and isoflurane given for cataract surgery, and that there is no psychomotor dysfunction 1 day after the end of anaesthesia. Our results suggest that psychomotor function recovers more quickly after TIVA with remifentanil and propofol than after BAL with fentanyl and isoflurane. This study was supported by a grant from Glaxo Wellcome GmbH & Co., Hamburg, Germany.