|Year : 2015 | Volume
| Issue : 3 | Page : 151-157
Propofol versus traditional sedative methods for colonoscopy in a low-resource setting
Olusegun Isaac Alatise1, Afolabi M Owojuyigbe2, Momohsani A Yakubu2, Augustine E Agbakwuru1, Aramide F Faponle2
1 From the Department of Surgery, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
2 From the Department of Anaesthesia, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
|Date of Web Publication||30-Nov-2015|
Olusegun Isaac Alatise
From the Department of Surgery, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State
Source of Support: None, Conflict of Interest: None
Aims and Objectives: We set out to determine the safety and efficacy of the use of three sedative regimens, namely propofol alone, propofol with benzodiazepine and/or opioids and benzodiazepine with opioids in Nigerian patients undergoing diagnostic colonoscopy at a Nigerian tertiary hospital.
Patients and Methods: A total of 120 patients undergoing outpatient colonoscopy were assigned prospectively to one of the three treatment regimens. Patients in Group A (n = 40) received propofol alone (PRO), Group B (n = 40) received propofol with midazolam and/or fentanyl and Group C (n = 40) received opioids and midazolam (fentanyl and midazolam – conscious sedation). Study outcome measures include the level of sedation, length of the procedure, sedation/recovery time, patient satisfaction and adverse
Results: Patients receiving PRO alone received higher doses of PRO compared with PRO and additives (P = 0.043). The overall procedure and sedation duration were similar in both PRO containing groups but statistically significantly shorter than the conscious sedation group (P < 0.0001, P < 0.006). The recovery time was statistically shorter in the PRO additives group compared to the other two groups (P < 0.0001). While the drop in blood pressure was similar in all the groups (P = 0.227), the occurrence of hypoxaemia was higher in the PRO containing groups (P < 0.0001). Overall physicians and patients pain assessment scores were statistically different in the three groups (both P < 0.0001).
Conclusion: Our data suggest that PRO sedation is safe when used for outpatient diagnostic colonoscopy in low-resource settings with better patients and physician satisfaction. The synergistic sedative effect of midazolam and/or opioids combined with PRO help reducing the dose of PRO used with better recovery.
Keywords: Colonoscopy, conscious sedation, midazolam, Nigeria, opioids, propofol
|How to cite this article:|
Alatise OI, Owojuyigbe AM, Yakubu MA, Agbakwuru AE, Faponle AF. Propofol versus traditional sedative methods for colonoscopy in a low-resource setting. Niger Postgrad Med J 2015;22:151-7
|How to cite this URL:|
Alatise OI, Owojuyigbe AM, Yakubu MA, Agbakwuru AE, Faponle AF. Propofol versus traditional sedative methods for colonoscopy in a low-resource setting. Niger Postgrad Med J [serial online] 2015 [cited 2021 May 6];22:151-7. Available from: https://www.npmj.org/text.asp?2015/22/3/151/170736
| Introduction|| |
Colonoscopy is the procedure of choice for the diagnosis and treatment of colorectal conditions. It plays a central role in the screening and follow-up of colorectal cancer patients., However, colonoscopy is regarded as invasive and is generally assumed to be an uncomfortable and often painful procedure. Therefore, it has become a standard practice to achieve a satisfactory level of relaxation and cooperation during the procedure using intravenous (IV) premedication in most developed countries.,,
Sedation is intended primarily to reduce patient's anxiety and discomfort, consequently improving their tolerability and satisfaction for the procedure. It also minimises patient's risk of physical injury during an examination and provides the endoscopist with an ideal environment for a thorough examination that culminates in higher completion and detection rates and removal of advanced adenomas., However, sedation may delay patient recovery and discharge, add to the overall cost of an endoscopic procedure and increase the risk of cardiopulmonary complications., In spite of these considerations, the use of sedation during endoscopy continues to increase worldwide.
The use of sedation for routine endoscopic procedures, including colonoscopy, varies widely across cultures. This variation in sedation practice is greater than any other culturally based variation in the technical performance of endoscopy. These differences may reflect many different factors, which include the personal differences and training of the endoscopists, the availability of anaesthetic services, the need to train colleagues in endoscopic techniques, the cost and availability of monitoring equipment, differences in the availability and use of common drugs and particularly, the expectations of the patient.
Until recently, traditional sedatives made up of the combination of a benzodiazepine with an opioid were routine for colonoscopy in developed countries. The combination of these agents is used to achieve conscious sedation. They are either given as bolus or careful titration using small, incremental doses and allowing sufficient time between doses to assess effect. However, the use of propofol (PRO) based sedation has gained increasing popularity.,,, PRO is a short-acting hypnotic agent believed by gastroenterologists to have superior pharmacokinetic properties compared to opioid/benzodiazepine combination.,,,, Its benefits over traditional sedative agents are believed to include faster recovery, improved sedative effect, better patient and physician satisfaction and greater efficiency within the endoscopy unit. It has also being validated to be safe when used in gastroenterologist-directed administration setting.,,
A previous study has also shown that PRO lacks analgesic properties; hence, using PRO as a single agent is ineffective for endoscopy when titrated to moderate levels of sedation. Also, when endoscopic procedures are attempted on patients who are moderately sedated using PRO alone, they typically demonstrate withdrawal responses during colonoscopy. These effects are blocked by co-administration of even small doses of opioids and/or benzodiazepines. Similarly, administration of PRO in combination with low doses of opioids and/or benzodiazepines can be titrated to moderate levels of sedation with high success rates for completing endoscopic procedures and with maintenance of high levels of patient satisfaction. Targeting PRO to moderate levels of sedation by giving it in combination with low doses of opioids and/or benzodiazepines could improve the safety profile of PRO by reducing the frequency of deep sedation and general anaesthesia.
Currently, no standard guideline exists for sedation for colonoscopy in Nigeria. A study by Nwokediuko and Obienu  showed that sedation using benzodiazepines was almost routine for upper gastrointestinal endoscopy by Nigerian gastroenterologists. No study has been done to assess the practice in lower gastrointestinal endoscopy. Setting practice based on patients satisfaction and acceptability is of utmost importance. In this study, we report the results of the use of three sedative regimens, namely PRO alone, PRO with benzodiazepine and/or opioids and benzodiazepine with opioids in Nigerian patients undergoing diagnostic colonoscopy at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Osun State, Nigeria to assess safety and efficacy of the sedative regimens.
| Patients and Methods|| |
Study design and setting
This was a single centre, prospective, comparative study involving consecutives patients who underwent colonoscopy at the endoscopy unit of OAUTHC, Ile-Ife, Osun State, Nigeria from January 2013 to June 2014. The endoscopy unit runs from Monday to Friday during the week and on emergency basis during the weekend. The unit offers open access endoscopy services being mostly accessed by patients from Osun, Ondo, Ekiti and some parts of Kwara, Kogi, Oyo and Edo States with an estimated population of about 10 million according to 2006 National population census. The people of Ife/Ijesa zone of Osun State where the institution is located are predominantly Yorubas, who along with other Nigerian tribes, also reside permanently in this area. Peasant farming is the major occupation of the people. A sizeable number are engaged in commercial and small-scale industrial enterprises, whereas majority of those educated are civil servants.
The inclusion criteria included a total of 120 adults aged above 18 years who were American Society of Anesthesiologists (ASA) class 1 (healthy subjects), 2 (mild systemic disease) or 3 (moderate to severe systemic disease) and who had ability to give informed consent for elective outpatient endoscopy. Exclusion criteria included inability or unwillingness to provide informed consent, emergency procedures, pregnancy, history of addiction to opiates and/or sedatives, psychiatric disorder, the need of oxygen supplementation because of pre-existing disease, allergy to study medications and ASA classes 4–5. Patients who had incomplete procedure due to any reason were also excluded from the study. Ethical clearance (ERC/2013/02/17) was obtained before the commencement of this study from the OAUTHC Ethics and Research Committee.
A focused medical history, physical examination and pre-procedural questionnaire describing patient demographics were completed for all the patients.
Procedure and patients' assignment
Patients were initially planned to be assigned to four groups which include Group A – PRO alone, Group B – propofol with midazolam, Group C – propofol with fentanyl and Group D – fentanyl and midazolam. The first patient was assigned to a group by balloting. The subsequent patients go to the next groups. After the initial 50 patients, Groups B and C were merged into one group (propofol with midazolam and/or fentanyl [PROADD]) based on the similar pattern of response observed after first review of the study. Pethidine or pentazocine was used to replace fentanyl when the stock of fentanyl was exhausted and could not be replaced early. All colonoscopies were performed by one gastroenterologist (AOI). All the procedures were performed using Olympus CF 140 L and PCF-140 colonoscopes. Polyethylene glycol was utilised for bowel preparation for most of the patients except where contraindicated when water enema was administered. An anaesthesiologist (YMSA) administered most of the sedative agents and carried out the anaesthetic protocol. Sedation endpoints were procedural sedation characterised by drowsiness, facial relaxation, slurred speech and tolerance to insertion of the colonoscope. The study was not blinded to both the endoscopist and the anaesthesiologist, because the view of the sedatives was clear. All the patients were placed on IV line with continuous running normal saline. The initial dose of midazolam used in all the groups was standard, and this was 2.5 mg and was increased gradually as required to a dose of 0.1 mg/kg up to a maximum dose of 5 mg while the initial dose PRO was 0.5 mg/kg body weight. The initial dose of the fentanyl, pethidine and pentazocine given was 1 µg/kg, 50 mg and 15 mg, respectively. This was increased gradually as needed. Those patients in Group D that experienced significant discomfort during the procedure making it difficult to achieve complete colonoscopy were given PRO in addition.
Assessment of safety
All patients were continuously monitored using multi-parameter monitor for pulse rate, oxygen saturation (pulse oximetry) and mean arterial blood pressure (serial blood pressure measurements every 5 min). All patients were given supplemental oxygen intranasally (2 L/min) if the oxygen saturation dropped below 90% at any time during the sedation period. Other manoeuvres such as chin lift and jaw thrust were deployed as necessary. Facilities to establish a secure airway were available during the procedure. The drop in saturation below 90% was noted for each of the patients irrespective of the treatment group. A change in mean arterial blood pressure of above 10 mm Hg from baseline was considered significant. Episodes of alteration in heart rate, 20% below the baseline or 20% above the baseline, were considered significant.
Assessment of regimens efficacy
Sedative efficacy was assessed on patients immediately after the procedure by the attending anaesthetist while at recovery room using modified visual analogue scale (MVAS). MVAS grade not acceptable pain as 0; poor pain control which necessitated conversion to general anaesthesia as 1, fair pain control which is described as pain and discomfort as 2; good pain control which is described as little discomfort and complaints as 3; and excellent pain control which is described as no complaint as 4. The patients were also asked whether they would agree to another colonoscopy if their doctor thought it was medically necessary. Immediately after the procedure, the endoscopist's evaluation of the sedation efficacy was obtained (1 = poor, 2 = fair, 3 = good and 4 = excellent). Duration of sedation was taken as time from injection of sedative to when the patient recovered from the sedative. Duration of the procedure was the time from intubation of the scope till complete withdrawal. Duration of recovery was taken as the difference between duration of sedation and duration of the procedure. All these durations were kept by the attending anaesthetist. Recovery from the sedation was assessed using clear headedness, orientation in time, person and place and ability to work unsupported.
All data obtained were entered into a personal computer and analysis was performed using Statistical Package for Social Sciences (SPSS, version 21.0; Chicago, IL, USA) program. Kruskal–Wallis, Mantel–Haenszel and c2 tests were used to perform overall tests for the presence of any significant differences among the three groups for continuous, ordered categorical and unordered categorical variables, respectively. When the overall tests were significant, pair-wise tests between groups were performed using Wilcoxon rank-sum tests for continuous variables, Mantel–Haenszel tests for ordered categorical variables and c2 tests for unordered categorical variables. Post-hoc multiple comparison of on e-way ANOVA was also used to assess the level of significance among the three groups. The criterionfor statistical significance was P < 0.05. The two primary outcomes measured in the present study were the higher level of patient comfort and the shorter recovery times in the three groups of patients.
| Results|| |
A total of 120 consenting patients who had colonoscopy were recruited into the study. [Table 1] shows demographics and procedure indications among three groups. There were no significant differences among the groups for age (P = 0.845), gender (P = 0.504), ASA score (P = 0.244) or procedure indication (P = 0.246).
The median dose of PRO used in PRO alone group was 230 mg (range: 100–400 mg) while median dose of PRO used in PRO and additive group was 120 mg (70–250 mg). The difference in the dose of PRO in the two groups was statistically different (P = 0.043). The median dose of midazolam used in conscious sedation group was 5 mg (2.5–5 mg) while the median dose of midazolam in the PRO and additive was 2.5 mg. The median dose of fentanyl and pentazocine used in conscious sedation was 100 µg and 30 mg, respectively.
Duration of sedation in patients receiving PRO alone was marginally shorter when compared to those receiving PRO and additives, but this was not statistically significant (P = 0.656); however, this was statistically different when compared with those receiving conscious sedation (P < 0.0001) [Table 2]. Overall, there was statistically significant difference in total procedural time among the three arms. The duration of the procedure was shorter for the PRO alone and PRO with additives groups when compared to conscious sedation group (P = 0.002; P = 0.032 respectively). [Figure 1] shows the mean plot of the duration of recovery in the three groups. The recovery time was statistically shorter for PRO and additives group when compared with the other two groups (P < 0.0001).
Vital sign changes and complications
The cecum was intubated and the procedure completed in all 120 patients. No patient in the study required assisted ventilation or treatment of hypotension or bradycardia. Slightly more than a quarter of the patients in PRO alone group had a drop in the systolic blood pressure and diastolic blood pressure recorded [Table 3]. The changes in blood pressure observed in the three groups were not statistically significant. The PRO containing group had statistically significant drop in Oxygen saturation when compared to conscious sedation (P = 0.0001). While none of the patients in the PRO containing groups had nausea or vomiting during or after the procedure, 10 (25.0%) patients in the conscious sedation group had significant nausea and vomiting.
Evidence of intra-procedural pain
[Table 3] shows the pain score by the patients from the patient's perspective and physician's perspective. There were statistically significant differences in the three groups. PRO containing groups had least experience of pain. Another interesting finding in PRO containing groups was that five patients gave a history of sweet dreams while under sedation.
The cost implication of introducing PRO into colonoscopy in our hospital was estimated as five thousand naira ($30) while the cost of conscious sedation was two thousand naira ($15). As shown in [Table 3] when all the patients were asked if they would be willing to pay more for PRO sedation, 70% of the patients in conscious sedation group would be willing to pay more for sedation.
| Discussion|| |
The present study compared and evaluated the safety and efficacy of PRO alone, midazolam and/or opioids in combination with PRO versus midazolam in combination with opioids for conscious sedation in the performance of outpatient colonoscopy in low-income setting. It was found that the two primary outcome measures in the present study that were the higher level of patient comfort and the shorter recovery times were best observed in the group of patients sedated with PROADD. The findings corroborated previous studies that demonstrated that PRO in combination with other sedatives is a reasonable option to obtain an adequate depth of sedation, improved patient tolerance and avoid high dose-related side effects of PRO such as prolonged recovery time.,,, PRO has limited analgesic effect, and so higher doses are often required when it is used as a single agent for gastrointestinal endoscopy, resulting in higher sedation levels.,, Despite the possible plausible justification for combination therapy, some other studies had demonstrated no benefits compared with the use of PRO alone.,, However, recent meta-analysis suggested that PRO in combination with other sedatives can significantly reduce the total dose of PRO compared with PRO alone sedation for gastrointestinal endoscopy.
In the index study, we found that the overall procedure time was significantly lower with PRO containing regimen. The possible reason for this may be due to the fact that it was possible to push through loops when patients were under adequate depth of sedation with PRO. Performing this manoeuvre when conscious sedation is used may be difficult because of pain perceived by the patient. Utilising this technique may be more relevant to black African patients undergoing colonoscopy because of the documented longer sigmoid colon that is prone to looping.,,, Similarly, PRO containing sedative has also been shown to reduce the frequent need for repositioning during colonoscopy and the use of abdominal pressure. Since these techniques are important tools of an experienced colonoscopist, it may be wise to suggest that PRO containing sedative may not be the optimal approach during training in colonoscopy.
Despite the effectiveness of PRO sedation, it is known to have significant cardiopulmonary depressive effects such as hypoxia, hypotension, arrhythmias and respiratory depression, which may require cardiopulmonary support. It had also been suggested that combination therapy may have synergistic inhibitory effects worsening the cardiopulmonary depression associated with PRO. In this current study, however, no statistically significant worsening cardiopulmonary depression was observed in the two PRO containing regimens. Similarly, the hypotension observed in the three groups was comparable. The reason why the comparable hypotension was observed in the three groups was not obvious. Further study will be needed to substantiate the findings in a large, possibly multicentre study. However, the hypoxaemia observed in the PRO containing groups was significantly higher. This study also emphasises the fact that irrespective of sedatives used, close monitoring of patients is very vital. The tendency is high to be slack with patients monitoring when conscious sedation is being used, especially in low-resource settings. A good number of patients on conscious sedation also had hypotension and hypoxaemia. The previous study showed that patients' age was found to be an independent risk factor for a significant drop in O2 saturation. Though the current study was not powered to evaluate the effect of age on hypoxaemia and hypotension, we advise regular supply of oxygen intranasally and close monitoring of blood pressure during colonoscopy irrespective of sedatives regimen used.
Another interesting finding of this study was the lack of any significant relation between the use of sedation and colonic perforation, as this is often put forward against deep sedation during colonoscopy. It is believed that pain experienced by patients can give an idea of the possibility of looping and stretching of the mesentery. While this may be true, a previous study showed that possibility of colonic perforation may even be higher in unsedated patients compared with sedated patients. We believe the critical factor that warns of the risk of perforation is palpation of fixed colonic resistance with the hand holding the colonoscopic shaft. The endoscopist should not push against fixed resistance regardless of the level of sedation. Hence, the technical ability of the endoscopist performing colonoscopy is vital to prevent colonoscopy-related complications. The comfort of the patients should not be traded for lack of technical ability of the endoscopist. Emphasis should be placed on the quality of training and certification of the colonoscopist before practice is established in low-income settings. Unfortunately, most low-income settings lack standard training guidelines. It is also very difficult to adapt some of the training guidelines used in high-income countries because of lack of volume that is a resultant of lack of screening guidelines and out of pocket payment for procedures. As endoscopy practice and training improve in low-income settings, sedation should be an important target for any continuous improvement programme not only to make the examination more acceptable to patients but also above all to optimise its diagnostic potential.
Another argument against introduction of deep sedation to colonoscopy is the cost of getting anaesthetists to administer the agents. We found that PRO sedation is twice the cost of conscious sedation in our hospital. When patients were asked if they will be willing to pay double for sedation to have colonoscopy, surprisingly most of the patients were willing to pay more for colonoscopy to have a pain-free procedure. Obviously what is important to our patients is to have stress-free procedure. Most of them that could afford the procedure would also be able to afford the cost of sedation for colonoscopy. Sedatives not only reduce high level of anxiety associated with colonoscopy but also ensure amnesia that encourage repeat procedure if necessary.
In high-income countries, endoscopic nurses are now being trained to administer deep sedation with PRO under the supervision of a gastroenterologist., This has been found to be safe in well-selected patients. The introduction of this practice to low-income settings can help to reduce cost of PRO sedation during colonoscopy. This task shifting phenomenon may also help to improve efficiency in endoscopy practice in low-resource settings where there are inadequate anaesthetists to serve routine surgical practice in the country.
Though this study had an inherent weakness as it was not scheduled in a blinded fashion to the colonoscopist, it was difficult to remain confidently blinded for technical reasons (different colour of the sedative medicines and infusion schedule procedures, which could easily unblind the endoscopists). In addition, we excluded patients with incomplete colonoscopies to avoid unpredictable variability in the duration of the procedure. We did not evaluate for amnesia after the procedure as it represents a poor indicator of efficacy of conscious sedation. Similarly, this was a single centre study with small sample size. We believe the results of this should be confirmed in larger multi-centred studies.
| Conclusion|| |
Our data suggest that PRO sedative is safe and can be administered to patients during colonoscopy in low-resource settings. We also found that the synergistic sedation with a low dose of midazolam and or opioids combined with PRO was superior to a standard combination of midazolam and the opioid for colonoscopies as far as patient comfort and recovery times were concerned. The combination therapy also had a PRO sparing effect that can help to reduce the possible side-effects of PRO. The safety profile of synergistic sedation was comparable with that of conscious sedations.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]