Endoscopy 2006; 38(7): 677-683
DOI: 10.1055/s-2006-925244
Original Article
© Georg Thieme Verlag KG Stuttgart · New York

Quality of psychomotor recovery after propofol sedation for routine endoscopy: a randomized and controlled study

A.  Riphaus1 , T.  Gstettenbauer1 , M.  B.  Frenz1 , T.  Wehrmann1
  • 1Dept. of Internal Medicine I (Gastroenterology and Interventional Endoscopy), Siloah Hospital, Hanover (Teaching Hospital of Hanover Medical School), Hanover, Germany
Further Information

T. Wehrmann, M. D., Ph. D.

Dept. of Internal Medicine I · Klinikum Hannover-Siloah

Roesebeckstraße 15 · 30449 Hannover · Germany

Fax: +49-511-9272669

Email: twehrmann@hotmail.com

Publication History

Submitted 8 September 2005

Accepted after revision 22 January 2006

Publication Date:
29 June 2006 (online)

Table of Contents

Background and study aims: Propofol sedation is increasingly being used for endoscopy in the outpatient setting. In view of the agent’s short period of action, current recommendations that patients should avoid driving or using public transport unescorted for 24 h may be too strict. Psychomotor recovery and driving skills before and after sedation were therefore assessed.
Patients and methods: A total of 100 patients undergoing routine upper or lower gastrointestinal endoscopy were randomly sedated either with propofol alone or with midazolam plus pethidine. The recovery time and quality of recovery were assessed. Psychomotor recovery was evaluated using the number connection test (NCT) and a driving simulator test 1 h before and 2 h after the endoscopic procedure.
Results: Ninety-six patients completed the 2-hour post-sedation procedure. Vital signs were recorded, and no clinically relevant complications occurred. The mean recovery time and quality of recovery were significantly better after propofol sedation (14 ± 9 min vs. 25 ± 8 min and 8.7 ± 1.3 vs. 6.3 ± 1.1 points) (P < 0.01). Psychomotor and driving skills after propofol sedation were similar to the baseline results, while in the midazolam/pethidine group, patients showed significantly more lane deviations (1.1 ± 0.9 vs. 1.6 ± 0.9), time over the speed limit (0.3 ± 0.83 vs. 0.6 ± 0.88), missed stoplights more often (0.05 ± 0.31 vs. 0.11 ± 0.35), and had slower reaction times for unexpected events (1.11 ± 0.46 s vs. 1.39 ± 0.44 s) (P < 0.01). The time needed to complete the NCT after sedation did not differ between the two groups (32.1 ± 12.0 s vs. 33.4 ± 12.6 s for propofol; 31.5 ± 11.2 s vs. 34.6 ± 12.8 s for midazolam/pethidine).
Conclusions: Current recommendations that patients should refrain from driving and unescorted use of public transport for 24 h after sedation may need to be reconsidered in patients who receive propofol sedation.

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Introduction

Propofol is widely used as a short-acting sedative for routine endoscopy in the outpatient setting. It provides a faster recovery time and an earlier return to normal daily activity, with minimal post-sedative cognitive impairment. Despite the increasing usage of short-acting sedatives, the recommendations that patients should refrain from driving and using public transport unescorted for a 24-h period remain unchanged [1] [2]. There is a lack of evidence to support such advice, and it may not reflect the more rapid recovery that is achieved after the administration of shorter-acting agents. While a recent study by Sinclair et al. [3] has shown that general anesthesia with desflurane and propofol does not have a significant influence on post-anesthetic driving skills in comparison with a non-sedated control group, it is not yet clear how the driving performance is affected after sedation with propofol alone in comparison with midazolam (plus an opioid) for routine endoscopy.

Willey et al. [4] have recently shown that commonly used discharge criteria such as the Aldrete score, which mainly focus on cardiovascular and respiratory stability, do not reflect psychomotor function. This remained significantly impaired in patients who had undergone sedation with midazolam (plus an opioid) for upper gastrointestinal endoscopy, despite the fact that they were deemed ready to leave the endoscopy unit according to the discharge score.

Using a driving simulator to evaluate patients’ driving skills, as an additional measure to psychometric tests for assessing psychomotor recovery after sedation, might therefore more accurately reflect patients’ ability to drive and use public transport.

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Patients and methods

A total of 100 consecutive patients undergoing routine gastroscopy and colonoscopy were eligible for the study. Inclusion criteria included age over 18 and a valid driver’s license. Exclusion criteria included regular use of benzodiazepines or opioids, any clinical evidence of hepatic encephalopathy, and an American Society of Anesthesiologists (ASA) physical status of class IV or V.

The patients were randomly assigned, using a computer-generated list, to receive propofol alone or midazolam/pethidine for sedation. The examiners of psychomotor and driving skill tests (A.R., T.G.) were blinded to the randomization group and were not involved in the endoscopic procedures. All of the patients provided written informed consent to undergo the endoscopic procedures and to participate in the number counting test (NCT) and driving simulation, and formal approval was obtained from the institutional review board. The patients’ demographic and clinical data are shown in Table [1].

Table 1 Demographic and clinical data for 96 patients who underwent upper or lower gastrointestinal endoscopy under sedation with propofol or with midazolam/pethidine in randomized fashion (control group)
Midazolam/pethidine Propofol
n % n %
N 47 49 49 51
Females (n) 23 49 22 45
Mean age (y) * 51 ± 10 52 ± 12
Mean BMI (kg/m2) * 27 ± 7 28 ± 6
Narcotic use (n) 0 0
Benzodiazepine use (n) 2 4 2 4
Alcohol abuse ** (n) 2 4 1 2
ASA class I 16 34 15 31
ASA class II 14 30 18 37
ASA class III 17 36 16 33
Gastroscopy 18 38 19 39
Colonoscopy 29 62 30 61
* Means plus or minus standard deviation. ** As defined by a reported daily alcohol consumption of > 60 g/d for at least 1 year. None of the differences between the two groups are statistically significant. ASA: American Society of Anesthesiologists; BMI: body mass index.

After randomization, four patients had to be excluded from the analysis. There was a lack of communication with one patient due to language problems, and two further patients left the hospital ahead of schedule without repeating the driving simulation. One patient with (endoscopically managed) post-polypectomy bleeding was excluded from the post-endoscopic evaluation due to continuous monitoring after the procedure.

Driving skills were tested using the Foerst F10P interactive driving simulator (Dr.-Ing. Reiner Foerst Ltd., Gummersbach, Germany; provided by the safety standards authority TÜV Nord, Hamburg, Germany), which was temporarily located in the hospital. The patient sits in front of the monitor and uses a steering wheel, accelerator, and brakes to control the vehicle. The road scene display changes in accordance with the patient’s actions. Sound feedback relating to speed and collision is also provided. The scenario includes rural and urban road sections. The patients encounter vehicles that have to be passed and vehicles that pull out onto the road suddenly and have to be avoided. The urban section includes intersections with traffic signals, with pedestrians crossing. In the rural section, a roe deer suddenly crosses the road, and the reaction time needed to stop the vehicle or the time to collision with the deer is recorded automatically. At the end of each run, the test results were documented on the basis of measures of lane position, speed, number of collisions, missed stoplights, reaction time required for the crossing deer, and time needed for the defined distance of 2.6 km (1.62 miles) for the rural and the urban section. Speed limits were set according to German traffic regulations - 50 km/h (31 mph) for urban traffic and 100 km/h (62 mph) for rural roads. All of the patients attended a 10-min training session before the baseline driving simulator run was performed.

Baseline cognitive psychomotor performance was assessed using a number connection test (NCT). The NCT was also used to rule out subclinical hepatic encephalopathy, which might have an impact on the driving simulation, especially after midazolam administration [5] [6]. The NCT, commonly used to diagnose and assess the progression of subclinical hepatic encephalopathy, is a marker of impaired cerebral function in otherwise clinically inconspicuous patients. The test is easy to perform and has been used to predict psychomotor function after various anesthetic procedures [7].

Part A of the NCT involves an A4-sized page with variously arranged numbers ranging from 1 to 25. These have to be connected in ascending order as fast as possible. The time needed to connect the 25 digits was assessed as a measurement of cognitive processing time and psychomotor skill [8]. Age-related normal values with the NCT-A have been obtained in 681 individuals without liver disease [9]. In accordance with these, values of less than 40 s were considered normal in the present study.

After evaluation of the baseline data, the patients were prepared for endoscopy. A temporary intravenous line was inserted on the back of a hand, and standard monitoring (i. e., pulse oximetry, automated noninvasive blood-pressure measurement, and electrocardiography) was applied. All of the patients received continuous oxygen supplementation at 2 l/min via a nasal cannula.

Sedation was administered by an independent physician (board-certified for intensive care and resuscitation), who was not involved in the endoscopic procedure. In the propofol group, sedation was induced by an intravenous bolus of 40 mg propofol (Propofol 1 %, Fresenius-Kabi, Bad Homburg, Germany) (< 70 kg body weight) or 60 mg (≥ 70 kg b. w.), respectively, and repeated doses of 20 mg were administered if necessary. In the midazolam group, sedation was induced by an intravenous bolus injection of 2.5 mg midazolam (Midazolam-Ratiopharm, Merckle Ltd., Blaubeuren, Germany). In addition, a single bolus of 25 mg (for upper gastrointestinal endoscopy) or 50 mg pethidine (if the patient was undergoing colonoscopy; Dolantin, Aventis, Frankfurt am Main, Germany) was administered. Repeated doses of intravenous midazolam were allowed to ensure adequate sedation (with a maximum dosage of 7.5 mg midazolam).

The patient’s cooperation during endoscopy was rated by the endoscopist on a visual analogue scale (VAS) ranging from 0 to 10 points (0, poor cooperation; 10, excellent cooperation). For technical reasons, the endoscopist was not blinded to the sedation regimen used.

The time until the patient was fully alert was documented. Thirty minutes after completion of the procedure, the post-anesthesia recovery score (PARS), adopted from Kankaria et al. [10], was obtained by registered staff nurses in the endoscopy unit. The nurses had not been involved in the endoscopic procedures, but on the other hand were not blinded to the sedation used. For PARS, patients are assigned scores of 0, 1, or 2 for each of the following categories: 1, activity (inability to move the limbs, ability to move two or four limbs with or without instruction); 2, respiration (evidence of apnea, labored breathing, or a normal breathing pattern); 3, circulation (blood pressure in comparison with baseline before sedation: ± 50 %, ± 20 - 50 %, ± 20 %); 4, consciousness (hypnotic, arousal, or fully awake); and 5, skin color (cyanotic, pink, or normal). Complete recovery is indicated by the maximum PARS of 10 points.

Two hours after completion of the endoscopic procedure, all of the patients underwent reevaluation of the NCT with a different number allocation and then used the driving simulator.

Statistical analysis. All data are given as means plus or minus standard deviation. For statistical comparison, the Mann-Whitney U-test, the Wilcoxon rank-sum test, and Fisher’s exact test were used when appropriate. A value of P < 0.05 was regarded as significant. After correction of the data for multiple testing in the same individuals (using the Bonferroni correction), P < 0.01 was judged as significant. Data analysis was carried out on a personal computer using a statistical software package (Instat, GraphPad Software, Inc., San Diego, California, USA).

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Results

In all, 96 patients (51 men, 45 women; mean age 52 ± 12 years) completed the 2-hour post-sedation procedure (Table [1]). The main indications for upper gastrointestinal endoscopy were suspected reflux disease (n = 26) or unclear epigastric pain (n = 11). Colonoscopy was carried out for screening purposes (n = 42), for surveillance after polyp removal or surgery for colonic carcinoma (n = 5), and due to a positive fecal occult blood test (n = 12). The two groups were well matched for demographic as well as for procedural characteristics, and there were also no significant differences between the groups with regard to special characteristics that might have had an impact on cognitive and psychomotor function (Table [1]). All of the examinations were undertaken for diagnostic purposes. However, polypectomy had to be performed in 16 patients in the propofol group and 14 patients in the midazolam/pethidine group.

The mean dosages of the sedative drugs administered are shown in Table [2].

The mean duration of the endoscopic procedures was 12 ± 4.8 min (range 3 - 34 min) (Table [2]). Vital signs were recorded, and no clinically relevant complications due to either the endoscopic procedure or the sedation were observed (Table [2]). Five patients developed oxygen desaturation (SpO2 < 90 %) during the procedure (three patients in the propofol group and two patients in the midazolam group). Hypoxemia resolved in all of the patients after they were instructed to take a deep breath and after the supplemental oxygen flow rate was increased to 4 - 6 l/min (Table [2]). Mask ventilation was not necessary in any cases. No other complications were documented.

There were no significant differences between the two study groups with regard to patients’ cooperation as rated by the endoscopist (Table [2]).

The mean time until the patients were fully alert after the procedure was significantly shorter in the propofol group than after sedation with midazolam/pethidine (Table [2]).

The quality of recovery was better after propofol sedation than after administration of midazolam plus pethidine, as documented by a significantly higher PARS in the propofol group than in the group receiving midazolam/pethidine for sedation (P < 0.01; Table [2]).

Table 2 Procedural characteristics and results of recovery in 96 patients undergoing upper or lower gastrointestinal endoscopy who were randomly assigned to receive sedation with either midazolam/pethidine or with propofol
Midazolam/pethidine
(n = 47)
Propofol
(n = 49)
Procedure duration
Overall (min)
Gastroscopy (min)
Colonoscopy (min)

11 ± 5.2 (3 - 32)
7 ± 2 (3 - 10)
14 ± 4.6 (10 - 32)

12 ± 4.6 (4 - 34)
8 ± 2 (4 - 12)
14 ± 4.6 (3 - 34)
Midazolam dose (mg) 4.5 ± 2.4 (2.5 - 7.5) -
Pethidine dose (mg) 40.4 ± 12.3 * (25 - 50) -
Propofol dose (mg) - 105 ± 60 (40 - 200)
Spo2 < 90 % 2 3
Systolic blood pressure < 90 mm Hg 2 3
Heart rate < 50/min 3 3
Patient cooperation (rated by endoscopist, VAS) 8 ± 1 (5 - 10) 9 ± 0.6 (7 - 10)
Recovery time (min) 25 ± 8 (9 - 50) 14 ± 9 ** (23 - 36)
PARS (points) 6.3 ± 1.1 (5 - 8) 8.7 ± 1.3 ** (6 - 10)
All parametric data are given as means plus or minus standard deviation and range (in brackets).
PARS: Post-Anesthesia Recovery Score; VAS: visual analogue scale.
* It should be noted that 29 patients received an additional intravenous bolus of 50 mg pethidine and that 18 patients received an additional bolus of 25 mg of pethidine.
** P < 0.01 between the two groups. None of the other differences were significant.

The time needed for the NCT before sedation was almost the same in both sedation groups. Two hours after sedation the patients in the propofol group were able to accomplish the test in nearly the same time as needed before the procedure, while the patients in the midazolam/pethidine group showed a trend toward a longer time for completing the test, although the difference was not significant (Tables [3], [4]).

Table 3 Parameters of psychomotor recovery in 47 patients undergoing upper or lower gastrointestinal endoscopy before and 2 hours after sedation with midazolam plus a single bolus of pethidine
Before sedation After sedation P
Time to complete the 25-digit NCT (s) 28 (28.3 to 34.8) 29 (29.7 to 37.1) 0.02
Collisions on the two road sections (n) 1.0 (0.66 to 1.21) 1.0 (0.84 to 1.33) 0.12
Lane deviations on the two road sections (n) 1.0 (0.82 to 1.30) 1.0 (1.28 to 1.83) 0.00004
Reaction time to deer crossing (s) 0.9 (0.99 to 1.24) 1.5 (1.26 to 1.52) 0.00007
Missed stoplights (n) 0.0 (- 0.03 to 0.16) 0.0 (0.00 to 0.22) 0.99
Events over speed limit during the two road sections (n) 0.0 (0.02 to 0.45) 0.0 (0.34 to 0.85) 0.0017
All data are given as medians with 95 % confidence intervals.
NCT: number connection test.
Tab. 4 Parameters for psychomotor recovery in 49 patients undergoing upper or lower gastrointestinal endoscopy before and 2 h after sedation with propofol alone.
Before sedation After sedation P
Time to complete the 25-digit NCT (s) 28 (28.6 to 35.6) 29 (29.8 to 37.5) 0.05
Collisions on the two road sections (n) 1.0 (0.55 to 1.12) 1.0 (0.61 to 1.22) 0.55
Lane deviations on the two road sections (n) 1.0 (0.92 to 1.44) 1.0 (0.87 to 1.37) 0.60
Reaction time to deer crossing (s) 0.9 (1.02 to 1.25) 0.8 (0.98 to 1.24) 0.08
Missed stoplights (n) 0.0 (0.00 to 0.13) 0.0 (- 0.03 to 0.15) 1.0
Events over speed limit during the two road sections (n) 0.0 (0.01 to 0.40) 0.0 (0.11 to 0.59) 0.16
All data are given as medians with 95 % confidence intervals.
NCT: number connection test.

During the driving simulation, the total times required to pass the urban road section (before sedation with midazolam/meperidine 4.1 ± 1.3 min; after sedation 4.5 ± 1.5 min; before propofol sedation 4.3 ± 1.3 min, after propofol sedation 4.4 ± 1.5 min.) and to pass the rural road section (before sedation with midazolam/meperidine 3.5 ± 0.9 min, after sedation 3.5 ± 1.1 min; before propofol sedation 3.5 ± 1.0 min, after propofol sedation 3.5 ± 1.1 min) were almost equal in both groups.

Driving skills 2 h after propofol sedation were almost unaffected in comparison with the baseline results with regard to the time needed for the rural and urban road section, the numbers of collisions and of significant lane deviations, as well as with regard to the frequency of missed stoplights and time needed to react to the deer (Table [4]). In contrast, the patients in the midazolam/pethidine group required slightly more time to complete the rural and urban road section (difference not significant), had a significantly larger number of lane deviations, and reacted more slowly to the crossing deer, while the number of collisions did not increase in comparison with the baseline results (Table [3]). The frequency of events when patients were speeding was also significantly higher 2 h after midazolam/pethidine sedation, but not after propofol administration (Tables [3], [4]).

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Discussion

This study shows that in patients undergoing sedation with propofol for endoscopic procedures, performance in the driving simulator 2 h after sedation is similar to that before the endoscopy procedure. This contrasts with the findings in the group of patients receiving midazolam/pethidine for their endoscopic procedures, in whom simulator performance was significantly poorer 2 h after the endoscopy.

Sedation and analgesia are routinely used to improve patient tolerance for gastrointestinal endoscopy. Recovery from sedation can vary significantly. Although alertness can be recovered quickly and the patient may be fit for discharge, the risk of impaired neuromotor function has influenced recommendations regarding participation in traffic. Most international recommendations on the recovery of patients from sedated endoscopy ban the patient from active participation in traffic for 24 h [11] [12]. This includes not only driving a car but also cycling, operating machinery, or even using the public transport system unaccompanied. The evidence base for these recommendations is poor, and most of the recommendations were proposed at a time when exclusively benzodiazepines were used for sedation during endoscopic procedures.

Two different aspects of post-endoscopic recovery have been investigated: firstly, the criteria for discharge (mainly influenced by the patient’s vital signs) after sedated endoscopy or day-case surgery; and secondly, other psychomotor aspects of recovery after these procedures.

Most patients can be discharged from outpatient surgery units within 2 h of sedation using the Post-Anesthetic Discharge Scoring System for evaluation [13]. This time interval appears to be equivalent to the criteria used for discharge after endoscopy (e. g., Aldrete’s discharge score, the Post-Anesthesia Recovery Score [10] [14]). However, these scoring systems mainly focus on the stability of the vital signs and do not specifically address the cognitive and psychomotor functions that are essential for the patient to leave the endoscopy unit in a safe condition and return to normal activities.

One of the first studies to highlight this problem was published in the 1970s by Korttila [15] and showed that psychomotor testing provided a more sensitive index of patients’ recovery than clinical assessment. In a more recent study, Willey et al. [4] demonstrated that psychomotor function remained significantly impaired when patients reached an Aldrete discharge score of 10, which indicates complete recovery from sedation.

In patients receiving midazolam plus an opioid (e. g., meperidine/pethidine), which is the commonly used sedation regimen for colonoscopy, complex reaction time, fine motor control, and perception were found to be impaired for at least 30 min after the procedure. The study data demonstrated that residual affects of midazolam affect various aspects of psychomotor function for at least 1 h after injection [16].

Midazolam appears to be the main reason for the prolonged psychomotor impairment after sedation. A study by Thapar et al. [17] suggested that midazolam was the key drug in producing prolonged psychomotor and subjective impairment in comparison with fentanyl and propofol.

The practical aspect of impaired psychomotor function is of particular importance, as there is a well-established body of data that highlights an increased risk of accidental injury and death associated with the use of benzodiazepines and narcotic drugs at therapeutic levels on an outpatient basis [18] [19] [20] [21] [22]. An additional point of interest, particularly in developed countries in which there are increasing numbers of single households, is the fact that a significant number of patients are unable to obtain an escort, despite the clear advice to refrain from driving and use of public transport [23]. This may lead to avoidable accidents, and it may not be a sustainable practice to admit such patients to hospital purely on the grounds of their inability to get home without an escort. The use of sedative compounds that have a shorter duration of action and a faster recovery time is therefore an issue of substantial interest.

Due to its short time of action and short half-life, propofol leads to a much faster recovery after sedation, as has been borne out in a large number of studies [24] [25] [26] [27] [28] [29]. However, only a small number of studies have addressed the aspect of psychomotor recovery after propofol administration. In a randomized trial, Sinclair et al. [3] compared psychomotor recovery and driving skills after general anesthesia with intravenous propofol plus fentanyl and inhalational N2O/O2, alcohol, or no drugs. There were no significant differences in postanesthetic driving skills at 2, 3, or 4 h between the patients and the control individuals. Nor were any significant differences found between the three groups with regard to a pen-and-paper test of psychomotor performance. However, the performance of patients with a legal blood alcohol concentration of 0.08 % differed significantly from the other groups. The study suggested that driving skills return to normal within 2 h after general anesthesia with the above-mentioned short-acting drugs.

A further interesting aspect with regard to the effect of the blood alcohol concentration and blood propofol concentration on psychomotor and driving skills was recently highlighted by Grant et al. [30]. In this study, the impairment in decision-making and secondary reaction times with a blood propofol concentration of 0.2 µg/ml was no greater than that observed with a blood alcohol concentration of 20 mg/100 ml - equivalent to the Swedish drink-driving limit, which is set much lower than the United Kingdom drink-driving limit, for example, with a blood alcohol concentration of 80 mg/100 ml.

The results of the present study support current evidence in showing for the first time that driving skills after propofol sedation for endoscopy are similar to the results assessed before the procedure. The pronounced impairment of driving capabilities observed in the midazolam/pethidine group can be considered particularly significant, since it has been shown that a marked improvement in such skills may occur due to a learning effect if a driving simulation is repeated [31].

One might argue that the use of different doses of pethidine in the present trial (25 mg for upper and 50 mg for lower gastrointestinal endoscopy) could be a confounding variable. However, since this dose regimen represents the current local standard, it was found preferable for the study to reflect the ”real-world situation“ in the control arm rather than using a more pharmacodynamically balanced study design. When the effects of midazolam plus 25 mg of pethidine (n = 18) were compared with midazolam plus 50 mg of pethidine (n = 29) in relation to the driving simulation parameters, no apparent differences were detected (all differences with P > 0.5).

The NCT results in this study did not differ before and after sedation in either group. This was in contrast with the driving skills observed. In the setting used in this study, it was decided to use the NCT, as it is simple to perform and highly sensitive as a measurement of latent impaired cognitive function and psychomotor competence, without needing a special computerized setting. The driving simulator was then used to reflect a more complex real-life situation.

The findings showing no change in the NCT are similar to those reported by Vasudevan et al. [6], who showed that the NCT was not affected in 38 patients used as a control group 2 h after therapeutic upper gastrointestinal endoscopy under sedation with midazolam. In contrast, the time required to complete the NCT was significantly prolonged after midazolam sedation in the 61 cirrhotic patients. The NCT results of the present study can therefore be taken as indirect evidence of the relatively good underlying health of the participating patients and in particular of an absence of confounding liver disease.

It is important to stress that the data are only valid for relatively healthy individuals without severe comorbidity who underwent standard endoscopic procedures. The effect of propofol on patients with higher comorbidity and the effect of higher dosages of propofol (e. g., for longer-lasting interventional endoscopic procedures) remain unclear and should be subject to further research.

This study did not have a control group of individuals not undergoing any sedation, nor was there a control group not undergoing endoscopy. The latter point would have controlled for the effects of anticipating endoscopy. However, as both patient groups did undergo endoscopy in the study, it was decided not to use such a control. Similarly, a group of patients undergoing endoscopy without sedation was also not included, as this would have further subdivided the patients into those with upper or lower gastrointestinal endoscopies. In our experience, it is difficult to persuade patients to undergo in-patient unsedated colonoscopy.

One might argue that the reversal of midazolam (e. g., by the use of flumazenil) might have a similar effect to the use of propofol. Indeed, the results of a double-blind comparison of midazolam antagonized by flumazenil and propofol for day-case anesthesia showed that flumazenil tended to improve test results for psychomotor recovery (flicker fusion frequency and Trieger test) after midazolam [32]. Early recovery after propofol anesthesia was associated with better psychomotor test results and less impairment of mental state, as judged by sedation and amnesia scoring. However, it is important to remember that the half-life of flumazenil is much shorter than that of midazolam and its metabolites. The danger of this approach is the relative ”safety“ of the patient having good respiratory function and psychomotor skills immediately after the use of flumazenil, but with a risk of further delayed respiratory depression and cognitive and psychomotor impairment. The routine use of flumazenil is therefore not recommended, and patients who require its use after midazolam sedation should be monitored for longer periods.

The ability to drive appears to be much less impaired after propofol sedation than with blood alcohol levels that are considered legal for driving in many countries [30]. On the basis of the available information, it would seem appropriate to vary the recommendations regarding driving after sedation depending on the regimen used. In particular, the data from the present trial would support a much shorter ban on unescorted use of the public transport system and probably also a shorter ban on driving after propofol sedation. However, large-scale dedicated studies would help determine when patients can safely leave the endoscopy unit to resume driving in the post-sedation period, so that the current recommendations that patients should refrain from driving for 24 h after sedation with propofol can be reconsidered.

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Acknowledgment

The driving simulator used in this trial was provided by a grant from Fresenius-Kabi Deutschland Ltd., Bad Homburg, Germany.

Competing interests: None declared

In brief

Current guidelines on driving after undergoing a sedated endoscopy recommend refraining from driving for 24 hours. Our data show that patients undergoing propofol mono-sedation have driving simulation results similar to their baseline performance and no psychomotor impairment. This could lead to a differentiated recommendation on driving restriction after endoscopy.

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  • 15 Korttila K. Recovery after intravenous sedation: a comparison of clinical and paper and pencil tests used in assessing late effects of diazepam.  Anaesthesia. 1976;  31 724-731
  • 16 Nuotto E J, Korttila K T, Lichtor J L. et al . Sedation and recovery of psychomotor function after intravenous administration of various doses of midazolam and diazepam.  Anesth Analg. 1992;  74 265-271
  • 17 Thapar P, Zacny J P, Choi M. et al . Objective and subjective impairment from often-used sedative/analgesic combinations in ambulatory surgery, using alcohol as a benchmark.  Anesth Analg. 1995;  80 1092-1098
  • 18 Sobel K G, McCart G M. Drug use and accidental falls in an intermediate care facility.  Drug Intell Clin Pharm. 1983;  17 539-542
  • 19 Neutel C I. Risk of traffic accident injury after a prescription for a benzodiazepine.  Ann Epidemiol. 1995;  5 239-244
  • 20 Johansson K, Bryding G, Dahl M L. et al . Traffic dangerous drugs are often found in fatally injured older male drivers.  J Am Geriatr Soc. 1997;  45 1029-1031
  • 21 Bastos M L, Galante L. Toxicological findings in victims of traumatic deaths.  J Forensic Sci. 1976;  21 176-186
  • 22 Vermeeren A. Residual effects of hypnotics: epidemiology and clinical implications.  CNS Drugs. 2004;  18 297-328
  • 23 Ogg T W. An assessment of postoperative outpatient cases.  Br Med J. 1972;  4 573-576
  • 24 Patterson K W, Casey P B, Murray J P. et al . Propofol sedation for outpatient upper gastrointestinal endoscopy: comparison with midazolam.  Br J Anaesth. 1991;  67 108-111
  • 25 Carlsson U, Grattidge P. Sedation for upper gastrointestinal endoscopy: a comparative study of propofol and midazolam.  Endoscopy. 1995;  27 240-243
  • 26 Sipe B W, Rex D K, Latinovich D. et al . Propofol versus midazolam/meperidine for outpatient colonoscopy: administration by nurses supervised by endoscopists.  Gastrointest Endosc. 2002;  55 815-825
  • 27 Wehrmann T, Kokabpick S, Lembcke B. et al . Efficacy and safety of intravenous propofol sedation during routine ERCP: a prospective, controlled study.  Gastrointest Endosc. 1999;  49 677-683
  • 28 Seifert H, Schmitt T H, Gultekin T. et al . Sedation with propofol plus midazolam versus propofol alone for interventional endoscopic procedures: a prospective, randomized study.  Aliment Pharmacol Ther. 2000;  14 1207-1214
  • 29 Riphaus A, Stergiou N, Wehrmann T. Sedation with propofol for routine ERCP in high-risk octogenarians: a randomized, controlled study.  Am J Gastroenterol. 2005;  100 1957-1963
  • 30 Grant S A, Murdoch J, Millar K. Blood propofol concentration and psychomotor effects on driving skills.  Br J Anaesth. 2000;  85 396-400
  • 31 Martin J P, Sexton B F, Saunders B P. et al . Inhaled patient-administered nitrous oxide/oxygen mixture does not impair driving ability when used as analgesia during screening flexible sigmoidoscopy.  Gastrointest Endosc. 2000;  51 701-703
  • 32 Norton A C, Dundas C R. Induction agents for day-case anaesthesia: a double-blind comparison of propofol and midazolam antagonised by flumazenil.  Anaesthesia. 1990;  45 198-203

T. Wehrmann, M. D., Ph. D.

Dept. of Internal Medicine I · Klinikum Hannover-Siloah

Roesebeckstraße 15 · 30449 Hannover · Germany

Fax: +49-511-9272669

Email: twehrmann@hotmail.com

#

References

  • 1 Korttila K. Recovery from outpatient anaesthesia: factors affecting outcome.  Anaesthesia. 1995;  50 (Suppl) 22-28
  • 2 Korttila K. Recovery period and discharge. In: White PF (ed) Outpatient anesthesia. New York; Churchill Livingstone 1990: 369-371
  • 3 Sinclair D R, Chung F, Smiley A. General anesthesia does not impair simulator driving skills in volunteers in the immediate recovery period: a pilot study.  Can J Anaesth. 2003;  50 238-245
  • 4 Willey J, Vargo J J, Connor J T. et al . Quantitative assessment of psychomotor recovery after sedation and analgesia for outpatient EGD.  Gastrointest Endosc. 2002;  56 810-816
  • 5 Assy N, Rosser B G, Grahame G R. et al . Risk of sedation for upper GI endoscopy exacerbating subclinical hepatic encephalopathy in patients with cirrhosis.  Gastrointest Endosc. 1999;  49 690-694
  • 6 Vasudevan A E, Goh K L, Bulgiba A M. Impairment of psychomotor responses after conscious sedation in cirrhotic patients undergoing therapeutic upper GI endoscopy.  Am J Gastroenterol. 2002;  97 1717-1721
  • 7 Schwender D, Muller A, Madler M. et al . Recovery of psychomotor and cognitive functions following anesthesia: propofol/alfentanil and thiopental/isoflurane/ alfentanil.  Anaesthesist. 1993;  42 583-591
  • 8 Oswald W D, Roth E. Der Zahlenverbindungs-Test (ZVT). Handanweisung. Göttingen; Hogrefe 1978
  • 9 Reitan R M. Validity of the trail making test as an indication of organic brain damage.  Percept Mot Skills. 1958;  8 271-276
  • 10 Kankaria A, Lewis J H, Ginsberg G. et al . Flumazenil reversal of psychomotor impairment due to midazolam or diazepam for conscious sedation for upper endoscopy.  Gastrointest Endosc. 1996;  44 416-421
  • 11 British Society of Gastroenterology .Clinical practice guidelines: safety and sedation during endoscopic procedures. London; British Society of Gastroenterology 2003 http://http://www.bsg.org.uk/clinical_prac/guidelines/sedation.htm
  • 12 Hofmann C, Jung M. Empfehlungen der DGVS für die Durchführung endoskopischer Untersuchungen. Stuttgart; Sauerbruch und Scheuerlen 2002
  • 13 Chung F. Recovery pattern and home-readiness after ambulatory surgery.  Anesth Analg. 1995;  80 896-902
  • 14 Aldrete J A. Modifications to the postanesthesia score for use in ambulatory surgery.  J Perianesth Nurs. 1998;  13 148-155
  • 15 Korttila K. Recovery after intravenous sedation: a comparison of clinical and paper and pencil tests used in assessing late effects of diazepam.  Anaesthesia. 1976;  31 724-731
  • 16 Nuotto E J, Korttila K T, Lichtor J L. et al . Sedation and recovery of psychomotor function after intravenous administration of various doses of midazolam and diazepam.  Anesth Analg. 1992;  74 265-271
  • 17 Thapar P, Zacny J P, Choi M. et al . Objective and subjective impairment from often-used sedative/analgesic combinations in ambulatory surgery, using alcohol as a benchmark.  Anesth Analg. 1995;  80 1092-1098
  • 18 Sobel K G, McCart G M. Drug use and accidental falls in an intermediate care facility.  Drug Intell Clin Pharm. 1983;  17 539-542
  • 19 Neutel C I. Risk of traffic accident injury after a prescription for a benzodiazepine.  Ann Epidemiol. 1995;  5 239-244
  • 20 Johansson K, Bryding G, Dahl M L. et al . Traffic dangerous drugs are often found in fatally injured older male drivers.  J Am Geriatr Soc. 1997;  45 1029-1031
  • 21 Bastos M L, Galante L. Toxicological findings in victims of traumatic deaths.  J Forensic Sci. 1976;  21 176-186
  • 22 Vermeeren A. Residual effects of hypnotics: epidemiology and clinical implications.  CNS Drugs. 2004;  18 297-328
  • 23 Ogg T W. An assessment of postoperative outpatient cases.  Br Med J. 1972;  4 573-576
  • 24 Patterson K W, Casey P B, Murray J P. et al . Propofol sedation for outpatient upper gastrointestinal endoscopy: comparison with midazolam.  Br J Anaesth. 1991;  67 108-111
  • 25 Carlsson U, Grattidge P. Sedation for upper gastrointestinal endoscopy: a comparative study of propofol and midazolam.  Endoscopy. 1995;  27 240-243
  • 26 Sipe B W, Rex D K, Latinovich D. et al . Propofol versus midazolam/meperidine for outpatient colonoscopy: administration by nurses supervised by endoscopists.  Gastrointest Endosc. 2002;  55 815-825
  • 27 Wehrmann T, Kokabpick S, Lembcke B. et al . Efficacy and safety of intravenous propofol sedation during routine ERCP: a prospective, controlled study.  Gastrointest Endosc. 1999;  49 677-683
  • 28 Seifert H, Schmitt T H, Gultekin T. et al . Sedation with propofol plus midazolam versus propofol alone for interventional endoscopic procedures: a prospective, randomized study.  Aliment Pharmacol Ther. 2000;  14 1207-1214
  • 29 Riphaus A, Stergiou N, Wehrmann T. Sedation with propofol for routine ERCP in high-risk octogenarians: a randomized, controlled study.  Am J Gastroenterol. 2005;  100 1957-1963
  • 30 Grant S A, Murdoch J, Millar K. Blood propofol concentration and psychomotor effects on driving skills.  Br J Anaesth. 2000;  85 396-400
  • 31 Martin J P, Sexton B F, Saunders B P. et al . Inhaled patient-administered nitrous oxide/oxygen mixture does not impair driving ability when used as analgesia during screening flexible sigmoidoscopy.  Gastrointest Endosc. 2000;  51 701-703
  • 32 Norton A C, Dundas C R. Induction agents for day-case anaesthesia: a double-blind comparison of propofol and midazolam antagonised by flumazenil.  Anaesthesia. 1990;  45 198-203

T. Wehrmann, M. D., Ph. D.

Dept. of Internal Medicine I · Klinikum Hannover-Siloah

Roesebeckstraße 15 · 30449 Hannover · Germany

Fax: +49-511-9272669

Email: twehrmann@hotmail.com