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see related editorial on page 1656
Low-Dose Propofol Sedation for Diagnostic Esophagogastroduodenoscopy: Results in 10,662 Adults Akira Horiuchi, MD1, Yoshiko Nakayama, MD2, Nao Hidaka, MD2, Yasuyuki Ichise, MD1, Masashi Kajiyama, MD1 and Naoki Tanaka, MD1
OBJECTIVE:
The use of propofol sedation during endoscopic procedures has increased in recent years. The aim of this study was to evaluate the safety and effectiveness of nurse-administered low-dose propofol sedation for diagnostic esophagogastroduodenoscopy (EGD).
METHODS:
We prospectively assessed the outcome and complications of low-dose bolus propofol for endoscopic sedation for diagnostic EGD. Propofol was administered by bolus injection, with a standard protocol of 40 mg for patients < 70 years old, 30 mg for patients 70–89 years old, and 20 mg for patients 90 years or older. When required for adequate sedation, additional doses were given, to a maximum of 120 mg. The primary outcome measure was respiratory depression, defined as oxygen desaturation (SpO2 < 90%) that continued for more than 20 s. Secondary measures included successful procedures, full recovery within 60 min of the procedure, and complications.
RESULTS:
All procedures were successful; 8,431 of 10,662 patients (79.1%) completed diagnostic EGD with a single bolus of propofol. Only 0.26% (28 patients) required transient supplemental oxygen supply; neither mask ventilation nor endotracheal intubation was required. Full recovery occurred in 99.9% of patients 60 min after the procedure. Men and younger patients required significantly higher doses of propofol than did the women and older patients (men vs. women, 46.5±19 vs. 42.7±15 mg, P = 0.0008; age 40–49 vs. age 50–59, 51.5±16 vs. 46.3±13 mg, P < 0.0001). Of the 400 patients, 368 (92%) wanted to drive home or to their offices, and all did so without incident. A total of 99% were willing to repeat the same procedure again.
CONCLUSIONS: Low-dose nurse-administered propofol sedation is safe and practical for diagnostic EGD. Am J Gastroenterol 2009; 104:1650–1655; doi:10.1038/ajg.2009.250; published online 9 May 2009
INTRODUCTION The success of diagnostic esophagogastroduodenoscopy (EGD) in the outpatient gastroenterological practice setting depends on patient acceptability. Recent issues with endoscopy include concerns about maintaining quality in the face of an increasing demand for services (1). Unsedated ultrathin EGD has been shown to be more cost effective and time efficient in comparison with sedated standard EGD (2–5). Although 5.2-mm-diameter videoscopes should result in enhanced patient acceptance of unsedated EGD (6), both transnasal and oral ultrathin EGDs have had limited use in routine outpatient practice (7).
Recently, the usefulness of low-dose propofol sedation for diagnostic EGD has been reported (8–10). Low-dose propofol sedation is associated with a low incidence of respiratory depression and is superior to benzodiazepines with regard to the rapidity of both induction of sedation and recovery (8–10). In addition, it has previously been shown that driving ability, based on the results of a driving simulator, was normal within 60 min (10). This article reviews our experience with diagnostic EGD on the basis of a protocol of nurse-administered age-adjusted dosing of bolus injections of a standard low-dose protocol of 40 mg for patients less than 70 years old, 30 mg for
1 Department of Gastroenterology, Showa Inan General Hospital, Komagane, Japan; 2Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan. Correspondence: Akira Horiuchi, MD, Department of Gastroenterology, Showa Inan General Hospital, 3230 Akaho, Komagane 399-4191, Japan. E-mail:
[email protected] Received 25 September 2008; accepted 3 February 2009
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patients 70–89 years of age, and 20 mg for patients 90 years or older, administered using an indwelling butterfly needle. This study was prospective and evaluated the outcome and complication of this method of propofol sedation for diagnostic EGD.
METHODS Propofol was administered for endoscopic sedation by nurses supervised by endoscopists. Both the nurses and the endoscopists had advanced cardiac life support certification. Training of nurses and endoscopists involves, in addition to such certification, advanced airway training, didactic training on propofol, observation of cases, and administration of propofol supervised by the anesthesiologist before beginning administration supervised only by the endoscopist. The training period typically lasts approximately 2 weeks. This study was conducted at the Showa Inan General Hospital and included only outpatients. Emergency procedures were excluded. Subjects were also excluded if they were less than 19 years old, pregnant, assigned to American Society of Anesthesiologists classes III and IV, overweight (body weight >100 kg), or allergic to the drug used or its components (soybeans or eggs). Standard monitoring at this unit included continuous assessment of peripheral oxygen saturation (SpO2) and heart rate. Clinical assessment of the patient, including measurement of respiratory effort by visual assessment and by palpation of the chest wall and abdominal excursion and/or palpation of exhaled breath, was performed routinely. When oxygen desaturation (SpO2 < 90%) lasted for more than 20 s, supplemental oxygen was given. The endoscopic team consisted of the nurse who administered the drugs and was responsible for the patient, the endoscopist, and a second nurse to assist both. This study was conducted in accordance with the Helsinki Declaration and was approved by the ethics committee at the hospital. Verbal and written informed consent was obtained from all subjects.
A decline in SpO2 to less than 90% that continued for more than 20 s was regarded as respiratory depression associated with the sedation. Vital signs were assessed frequently, but not on a periodic basis. In addition to monitoring of vital signs, the patient’s condition was assessed more globally by visual inspection. Monitoring and complications were recorded by a registered nurse. SpO2 was routinely captured by visual inspection of the monitor, and the value was recorded on the vital sign sheet. After the procedure, the patients were moved to the waiting room when they were able to stand by themselves, and they were discharged after they were fully awake. Full recovery, including consciousness and psychomotor function, was assessed using three criteria: (i) level of consciousness (fully awake and responding to questions from the recovery room nurse), (ii) ability to stand on one foot, and (iii) ability to walk in a straight line for 5 m without instability. These three criteria were assessed every 15 min starting 30 min after the procedure; full recovery was defined as meeting all three criteria. The nurses reconfirmed the absence of reemerging sedative effects and finally permitted the patients to leave the endoscopic unit. Outcome measures
The primary outcome measure was respiratory depression requiring supplemental oxygen. Respiratory depression was defined as an oxygen desaturation (SpO2 < 90%) that continued for more than 20 s. Secondary measures include successful procedure, full recovery within 60 min of the procedure, and the presence of any other complication. In addition, we provided questionnaires 1 day to 1 week after EGD to 400 patients enrolled in March and April 2007. The subjects were asked about their overall satisfaction with this procedure, whether they drove home or to the office afterward, and their willingness to undergo the procedure in the future.
Study design
Instruments
EGD was carried out in the lateral decubitus position. Patients received topical pharyngeal anesthesia with lidocaine. A butterfly needle for the bolus injection of propofol was placed on the subject’s forearm shortly before the start of EGD and removed after completion of the procedure. Propofol (Diprivan, AstraZeneca, Japan) was administered by bolus injection, with a standard protocol of 40 mg for patients < 70 years old, 30 mg for patients ages 70–89 years, and 20 mg for those 90 years or older. Adequate sedation was considered to have been achieved when the subject passed through the following sequence: eyes closing, one or two yawns, and cessation of body movements. The target level of sedation was moderate conscious sedation with the patient still being able to respond purposefully to verbal commands given. When the target level was not obtained or the subject was undersedated, additional injections of 20 mg of propofol were given. In no instance was more than 120 mg given.
The Olympus GIF-XP240, GIF-XQ260, or GIF-H260 videoscopes (Olympus, Tokyo, Japan) that were used have insertion diameters of 7.7, 9.0, and 9.5 mm, respectively. They all have an accessory channel diameter of 2.8 mm, a total length of 1,335 mm, and a working length of 1,030 mm.
© 2009 by the American College of Gastroenterology
Statistics
Data are presented as means and standard deviations. The χ2test, with Yates’ correction for continuity where appropriate, was used for comparison of categorical data. Fisher’s exact test was used when the numbers were small. For parametric data, Student’s t-test was used when two means were compared. Analysis of variance was used when three or more means were compared, and positive results were confirmed using Dunnett’s procedure. A value of P < 0.05 was regarded as significant. All statistical evaluation was carried out using SPSS software, version 12.0J (SPSS Japan, Tokyo, Japan). The American Journal of GASTROENTEROLOGY
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Table 1. Demographic and clinical data in 10,662 subjects who underwent diagnostic EGD using propofol sedation n (%) Gender: male
6,111 (57.3)
Mean age (range) (years)
56.9 (19–99)
Mean body weight (range) (kg)
53.7 (32–98)
Indication Screening
8,562 (80.3)
GI symptoms
1,822 (17.1)
Melena
149 (1.4)
Anemia
129 (1.2)
Propofol dose (mg) 20
52 (0.49)
30–40
8,379 (78.6)
50–60
916 (8.6)
70–80
1,070 (10)
100–120
245 (2.3)
Number of additional injections of propofol 0
8,431 (79.1)
1–2
1,986 (18.6)
≥3
245 (2.3)
Successful procedure
10,662 (100)
Mean procedure time (range) (min)
5.7 (3–8)
Oxygen administered
28 (0.26)
Mask ventilation required
0 (0)
Heart rate < 50 beats/min
1 (0.009)
Full recovery 60 min after the procedure
10,661 (99.9)
EGD, esophagogastroduodenoscopy; GI, gastrointestinal. Values are numbers (percentages) of patients except for mean age, body weight, and mean procedure time.
RESULTS Between January 2007 and June 2008, 10,662 patients successfully completeaad diagnostic EGD according to a standard protocol of low age-adjusted doses of propofol (Table 1). We cannot exclude the possibility that some patients may have become deeply sedated for a brief period of time. The subjects’ ages ranged from 19 to 99 years. The majority of indications for diagnostic EGD were gastric cancer screening (80.3%) or gastrointestinal symptoms (17.1%). A total of 8,431 patients (79.1%) completed diagnostic EGD after a single bolus injection of propofol. The mean procedure time was 5.7 min (range, 3–8 min). A biopsy was taken in 874 subjects (8.2%). Oxygen desaturation requiring supplemental oxygen (1–3 l/min) occurred in 0.26% (28 patients); mask ventilation or endotracheal intubation was not required in any case. In no case did a respiratory event or laryngospasm occur. Full The American Journal of GASTROENTEROLOGY
recovery within 60 min after the procedure was observed in 99.9% of patients (Table 1). The mean dose of propofol used was 44.9 ± 18 mg (Table 2). Male patients required significantly higher doses of propofol than did female patients (men vs. women, 46.5±19 vs. 42.7±15 mg, P = 0.0008). Subjects less than 50 years old required additional doses of propofol, which averaged 11.5 mg (men, 13.7 mg; women, 8.5 mg) for those ages 40–49 years, 14.6 mg (men, 17.6 mg; women, 10.9 mg) for those ages 30–39 years, and 23.8 mg (men, 30.3 mg; women, 20.4 mg) for those ages 19–29 years. Patients 80 years or older did not require additional doses of propofol. All patients 90 years or older completed diagnostic EGD with 20 mg, consistent with our previous report that the mean dose of propofol used in diagnostic EGD was 22 mg in 141 patients who were 90 years or older (9). The questionnaire was completed by 400 individuals (Table 3). Their mean age and mean body weight were 57.9 years and 59.6 kg, respectively. The majority rated their overall satisfaction for this procedure as excellent (76%) or good (18%). A total of 92% of these patients drove home or to their office after the EGD; no associated incidents were reported. Nearly all respondents (99%) said they were willing to repeat the procedure according to the same protocol, and 1% requested unsedated EGD.
DISCUSSION The advantages of propofol over benzodiazepines for endoscopic conscious sedation include an almost immediate onset of action and fast recovery. This study describes the outcomes and complications in nurse-administered, age-adjusted, lowdose propofol given to 10,662 patients undergoing diagnostic EGD. Previous reports have involved propofol doses ranging from 30 to 300 mg for endoscopic sedation (11–20). On the basis of our previous experience (9,10), the protocol adopted here focused on safety, with the initial dose of 30 or 40 mg of propofol designed to minimize hypoxemia during the procedure. Significant respiratory compromise (SpO2 < 90%) was rare compared with that in previous reports, and no patient required mechanical ventilation during the procedures via either endotracheal intubation or a mask (Table 1). All subjects in this study received topical pharyngeal anesthesia with lidocaine, and it is possible that the anesthesia contributed to the low dose of propofol required and to the low prevalence of respiratory depression. Topical pharyngeal anesthesia has previously been shown to be effective in patients undergoing EGD for the first time and in patients less than 40 years old (21). The requirement for supplemental oxygen was not associated with age or gender. It is not known whether the use of a thin endoscope (93% were examined using a GIF-XP240/XQ260) was related to the low incidence of hypoxia observed in this study. Only one patient (0.009%) experienced bradycardia (HR < 50 beats/min) (Table 1). One study with low-dose propofol reported rates of bradycardia of up to 10% (18); the difference VOLUME 104 | JULY 2009 www.amjgastro.com
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Age (years)
n (M/F)
Propofol dose (mg) a
P value
Total (range)
Male
Female
19–29
167 (64/103)
63.8±25 (40–120)
70.3 ± 27
60.4 ± 24
0.47
30–39
1,693 (939/754)
54.6±25 (40–120)
57.6 ± 18
50.9 ± 21
0.09
40–49
2,359 (1,393/966)
51.5±16 (40–120)
53.7 ± 18
48.5 ± 13
0.02
50–59
2,776 (1,588/1,188)
46.3±13 (40–120)
47.5 ± 15
44.7 ± 11
0.10
60–69
1,738 (1,038/700)
44.3±12 (40–120)
45.5 ± 13
42.6 ± 11
0.14
70–79
1,414 (833/581)
30.9±5 (30–70)
31.2 ± 6
30.3 ± 2
0.34
80–89
463 (234/229)
30 (30)
30
30
90–99
52 (22/30)
20 (20)
20
20
10,662 (6,111/4,551)
44.9±18
46.5 ± 19
42.7 ± 15
Total
0.0008
EGD, esophagogastroduodenoscopy. a There were significant differences in the total dose of propofol among each group except for the groups as follows: age 19–29 vs. age 30–39, P = 0.18; age 30–39 vs. age 40–49, P = 0.15; age 50–59 vs. age 60–69, P = 0.13; age 70–79 vs. 80–89, P = 0.28. Values are means ± s.d. except for number of patients and range of dose used of propofol. P value shows the difference between male and female genders.
Table 3. Demographic data and the results of questionnaires in 400 subjects who underwent diagnostic EGD using propofol sedation Gender: male
177 (59)
Mean age (range) (years)
57.9 (35–74)
Mean body weight (range) (kg)
59.6 (42–88)
Did you find propofol sedation for your EGD satisfactory? Excellent
302 (76%)
Good
70 (18%)
No
16 (4%)
N/A
12 (3%)
Did you drive home or to the office after your EGD? Yes
368 (92%)
No
32 (8%)
Did you experience any accidents shortly after your EGD? Yes No
0 (0%) 400 (100%)
Do you want to repeat the same procedure next time? Yes No
396 (99%) 4 (1%)
EGD, esophagogastroduodenoscopy; N/A, not available. Values are numbers (percentages) of subjects except for mean age and mean body weight.
may be linked to a difference in the sedation method, as the study with a higher rate used a combination of propofol, midazolam, and meperidine. © 2009 by the American College of Gastroenterology
Effective endoscopic sedation depends on the type of procedure and its duration. In most patients, an appropriate level of sedation can be achieved through the use of benzodiazepine combined with a narcotic. In contrast, propofol is administered by bolus titration with an initial dose of 30–50 mg followed by doses of 10–20 mg beginning 30–60 s later, with the appropriateness of additional bolus doses being determined by the level of sedation and respiratory effect. The mean procedure time for diagnostic EGD in this study was 5.7 min (range, 3–8 min). Additional injections of propofol were not required in 79.1% of patients. Importantly, because cardiopulmonary events may occur during an endoscopic procedure irrespective of whether sedation is used, the level of sedation was monitored by a registered nurse during the procedure. The sedation level was assessed using minimal, moderate, and deep sedation according to the American Society of Anesthesiology levels (8), but it was not recorded for each patient in this study. When moderate conscious sedation was not obtained or when subjects were undersedated, additional injections of 20 mg of propofol were given up to a maximum of 120 mg. The butterfly needle allowed maintenance of intravenous access during EGD; an alternative approach would be the use of an indwelling catheter. In contrast, when endoscopic procedures are predicted to last longer than 10 min, the use of benzodiazepine combined with a narcotic might be a better choice for achieving adequate sedation. In this study, American Society of Anesthesiologists physical status III and IV patients were excluded. For such patients, a minimum dose of benzodiazepine or propofol is often used along with continuous fluid infusion. Because the routine use of supplemental oxygen during EGD may mask respiratory depression (22), we chose not to administer supplemental oxygen routinely but only when needed. The American Journal of GASTROENTEROLOGY
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Table 2. The relationship between the age or gender of subject and the dose of propofol used in 10,662 subjects who underwent diagnostic EGD
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After unsedated EGD, patients can return to work and do not require a driver, potentially resulting in a decrease in the total costs associated with the procedure (2–4). However, some patients find unsedated EGD unacceptable, even with the use of these small-diameter instruments, as evidenced by the up to 40% refusal rate among patients who were asked to participate in comparative studies (4). Generally, patients would prefer to drive home after endoscopic procedures, irrespective of the use of sedation. The low dose of propofol used in this study was safe, and clinical recovery was rapid (Table 1). As shown in Tables 1 and 2, the average weight of patients in this study was 53.7 kg, and the dose used averaged 44.9 mg (0.84 mg/kg). Almost all subjects who so desired were able to drive home or to the office after full recovery. This differs markedly from the effects of midazolam, which impairs driving ability. Riphaus et al. (23) recommended that patients remain in a supervised environment for at least 3 h after propofol sedation and that patients refrain from driving and from unescorted use of public transportation for 24 h after sedation. However, these recommendations followed studies in which the propofol doses were 105 ± 60 mg, which is significantly more than the 44.9 ± 18 mg used in this study. Generally, patients are not permitted to drive themselves for 1 h after sedation. This is consistent with our previous study using a driving simulator, which showed that driving ability recovered to the basal level within 60 min of low-dose propofol sedation (10). In this study of subjects undergoing diagnostic EGD, the doses of propofol were based on a standard protocol resulting from our previous study (10). The actual choices were arbitrary and based on experience. Whether equally promising results would have been obtained with different doses, such as those based on age, gender, or weight, is not known exactly. Monitoring that includes continuous assessment of SpO2 and heart rate is standard in Japan, but blood pressure monitoring, which is routine in many Western countries, is not necessarily performed for EGD in Japan. It is generally standard practice to monitor blood pressure when administering propofol. We are therefore unable to comment on episodes of hypotension in our series. The patient-satisfaction survey and recovery analysis might have been improved if a formal psychometric analysis had been used. In conclusion, low-dose propofol sedation using temporary placement of a butterfly needle for diagnostic EGD was safe and practical in comparison with standard propofol sedation. CONFLICT OF INTEREST
Guarantor of the article: Akira Horiuchi, MD. Specific author contributions: Acquisition of data: Akira Horiuchi, Yoshiko Nakayama, Nao Hidaka, Yasuyuki Ichise, and Masashi Kajiyama. Analysis and interpretation of data: Akira Horiuchi. Drafting of the manuscript: Akira Horiuchi. Critical revision of the manuscript: Akira Horiuchi, Yoshiko Nakayama, and Naoki Tanaka. Financial support: None. Potential competing interests: None. The American Journal of GASTROENTEROLOGY
Study Highlights WHAT IS CURRENT KNOWLEDGE The use of propofol sedation during endoscopic procedures has increased in recent years. Previous reports have involved propofol doses ranging from 30 to 300 mg for endoscopic sedation. WHAT IS NEW HERE Low-dose, nurse-administered, age-adjusted dosing of propofol sedation is safe and practical for diagnostic EGD in adults, including those over 90 years of age. Low-dose propofol sedation may enable patients to drive themselves home or to their offices after the procedure.
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© 2009 by the American College of Gastroenterology
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