Patient maintained sedation for colonoscopy using a target controlled infusion of propofol

Safety and efficacy of target-controlled infusion versus intermittent bolus administration of propofol for sedation in colonoscopy: a randomized controlled trial

BACKGROUND

Our objective was to compare the safety and efficacy of Target-Controlled Infusion (TCI) versus intermittent bolus of propofol for colonoscopy sedation.

METHODS

We conducted a randomized (1:1), single-blind, parallel-group superiority trial with fifty ASA I or II patients, both sexes, aged 18 to 65 years, Body Mass Index ≤ 30 kg.m-2, undergoing colonoscopy, allocated to receive propofol by TCI (effect-site, 2 μg.mL-1 plus 0.5 μg.mL-1 until unconsciousness and as necessary for agitation) or intermittent bolus (1 mg.kg-1 plus 0.5 mg.kg-1 every 5 minutes or as above). The primary safety outcome was the need for airway maneuvers and the primary efficacy outcome was the need for interventions to adjust the level of sedation. Secondary outcomes included incidence of agitation, propofol dose, and time to recovery.

RESULTS

The median (IQR) number of airway maneuvers and interventions needed to adjust sedation was 0 (0‒0) vs. 0 (0‒0) (p = 0.239) and 1 (0‒1) vs. 3 (1‒4) (p < 0.001) in the TCI and control groups, respectively. Agitation was more common in the intermittent bolus group ‒ 2 (0‒2) vs. 1 (0‒1), p < 0.001. The mean ± SD time to recovery was 4.9 ± 1.4 minutes in the TCI group vs. 2.3 ± 1.6 minutes in the control group (p < 0.001). The total propofol dose was higher in the TCI group (234 ± 46 µg.kg-1.min-1 vs. 195 ± 44 µg.kg-1.min-1 (p = 0.040)).

CONCLUSIONS

During colonoscopy, TCI is as safe as intermittent bolus of propofol while reducing the incidence of agitation and the need for dose adjustments. However, intermittent bolus administration was associated with lower total propofol dose and earlier recovery.

Patient-maintained propofol sedation for adult patients undergoing surgical or medical procedures: a scoping review of current evidence and technology

Patient-maintained propofol sedation (PMPS) is the delivery of procedural propofol sedation by target-controlled infusion with the patient exerting an element of control over their target-site propofol concentration. This scoping review aims to establish the extent and nature of current knowledge regarding PMPS from both a clinical and technological perspective, thereby identifying knowledge gaps to guide future research. We searched MEDLINE, EMBASE, and OpenGrey databases, identifying 17 clinical studies for analysis. PMPS is described in the context of healthy volunteers and in orthopaedic, general surgical, dental, and endoscopic clinical settings. All studies used modifications to existing commercially-available infusion devices to achieve prototype systems capable of PMPS. The current literature precludes rigorous generalisable conclusions regarding the safety or comparative clinical effectiveness of PMPS, however cautious acknowledgement of efficacy in specific clinical settings is appropriate. Based on the existing literature, together with new standardised outcome reporting recommendations for sedation research and frameworks designed to assess novel health technologies research, we have made recommendations for future pharmacological, clinical, behavioural, and health economic research on PMPS. We conclude that high-quality experimental clinical trials with relevant comparator groups assessing the impact of PMPS on standardised patient-orientated outcome measures are urgently required.

A Prototype Patient-Maintained Propofol Sedation System Using Target Controlled Infusion for Primary Lower-Limb Arthroplasty

Each year, many operations in the UK are performed with the patient awake, without the use of general anaesthesia. These include joint replacement procedures, and in order to reduce patient anxiety, the supervising anaesthetist delivers the sedative propofol intravenously using a target-controlled infusion (TCI) device. However, it is clinically challenging to judge the required effect-site concentration of sedative for an individual patient, resulting in patient care issues related to over or under-sedation. To improve the process, patient-maintained propofol sedation (PMPS), where the patient can request an increase in concentration through a hand-held button, has been considered as an alternative. However, due to the proprietary nature of modern TCI pumps, the majority of PMPS research has been conducted using prototypes in research studies. In this work, a PMPS system is presented that effectively converts a standard infusion pump into a TCI device using a laptop with TCI software. Functionally, the system delivers sedation analogous to a modern TCI pump, with the differences in propofol consumption and dosage within the tolerance of clinically approved devices. Therefore, the Medicines and Healthcare products Regulatory Agency (MHRA) has approved the system as a safe alternative to anaesthetist-controlled TCI procedures. It represents a step forward in the consideration of PMPS as a sedation method as viable alternative, allowing further assessment in clinical trials.

Anaesthetist-controlled versus patient-maintained effect-site targeted propofol sedation during elective primary lower-limb arthroplasty performed under spinal anaesthesia (ACCEPTS): study protocol for a parallel-group randomised comparison trial

BACKGROUND

The clinical efficacy of effect-site targeted patient-maintained propofol sedation (PMPS) compared to anaesthetist-controlled propofol sedation (ACPS) for patients undergoing awake joint replacement surgery is currently unknown. There is no commercially available medical device capable of delivering PMPS so we have designed and built such a device. We plan a clinical trial to compare PMPS to ACPS and to collect data relating to the safety of our prototype device in delivering sedation.

METHODS

The trial is an open-label, randomised, controlled superiority trial recruiting adults who are undergoing elective primary lower-limb arthroplasty with sedation by propofol infusion by effect-site targeting into two equal-sized parallel arms: PMPS and ACPS. The primary research objective is to compare the body-weight-normalised rate of propofol consumption when sedation for surgery on adults undergoing elective primary lower-limb arthroplasty under spinal anaesthesia is patient-maintained versus when it is anaesthetist-controlled. The study primary null hypothesis is that there is no difference in the rate of propofol consumption when sedation is patient-maintained versus anaesthetist-controlled.

DISCUSSION

This is the first trial to test the superiority of effect-site-targeted patient-maintained propofol sedation versus anaesthetist-controlled propofol sedation in terms of total propofol consumption during the sedation period. The results of this trial will help inform clinicians and device manufacturers of the clinical efficacy and safety of patient-maintained propofol sedation applied to a common operative setting.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Registry, ISRCTN29129799 . Prospectively registered on 12 June 2018.

The feasibility of office-based propofol sedation for dental care in patients with intellectual disability by sedation practitioners

BACKGROUND

The quality of oral health care for intellectually disabled patients is a significant challenge due to behavioral issues. Intravenous propofol sedation may be useful to relieve the anxiety and fear, and make dental procedures more acceptable. The aim of this study was to evaluate the safety and effectiveness of propofol sedation, by trained nonmedical sedation practitioners, during dental treatments in an office-based setting.

METHODS

Intellectually disabled patients (124) were subjected to restorative dental procedures and moderately sedated using intravenous propofol. Vital signs, cooperation of the patient, and sedation depth were continuously assessed.

RESULTS

Propofol sedation was effective for dental treatment. All procedures resulted in a sufficient level of sedation without moderate or severe complications.

CONCLUSION

Propofol sedation can be safely and effectively performed in an office-based setting by sedation practitioners, who have experience in propofol sedation and are trained in the care of patients with disabilities.

Unsedation colonoscopy can be not that painful: Evaluation of the effect of "Lamaze method of colonoscopy"

AIM

To evaluate the pain relieving effect of intervention with "Lamaze method of colonoscopy" in the process of colonoscopy.

METHODS

Five hundred and eighty-five patients underwent colonoscopy were randomly divided into three groups, Lamaze group, anesthetic group and control group. Two hundred and twenty-four patients of Lamaze group, the "Lamaze method of colonoscopy" were practiced in the process of colonoscopy. The Lamaze method of colonoscopy is modified from the Lamaze method of childbirth, which helped patients to relieve pain through effective breathing control. One hundred and seventy-eight patients in anesthetic group accepted sedation colonoscopy. For 183 patients in control group, colonoscopy was performed without any intervention. The satisfactory of colon cleaning, intestinal lesions, intubation time, success ratio, pain grading and complications were recorded. All data were statistically analyzed.

RESULTS

There were no significant differences at base line of the three groups (P > 0.05). Anesthetic group shows advantage in intubation time than the other two groups (P < 0.05). Lamaze group shows no advantage in intubation time than that in control group (P > 0.05). The anesthetic group showed an apparent advantage in relieving pain (P < 0.01). Therefore, the "Lamaze method of colonoscopy" performed in colonoscopy could relieve pain effectively comparing with control group (P < 0.05). The patients in anesthetic group had the highest incidence of complications (P < 0.05).

CONCLUSION

The performance of the "Lamaze method of colonoscopy" in the process of colonoscopy could relieve patients' pain, minimize the incidence of complications, and is worthy promotion in clinical practice.

A prospective, randomized controlled trial of conscious sedation using propofol combined with inhaled nitrous oxide for dental treatment

PURPOSE

Adverse reactions during propofol sedation include a decrease in arterial blood pressure, propofol-induced pain on injection, and airway complications. The purpose of this study was to investigate whether combined use of intravenous propofol and inhaled nitrous oxide could decrease the hypotensive and other adverse effects of propofol.

PATIENTS AND METHODS

We designed and implemented a prospective, randomized controlled trial. Patients undergoing dental procedures requiring intravenous sedation were randomly allocated to 2 groups: group P comprised those receiving sedation with propofol alone, and group N+P comprised those receiving sedation with 40% nitrous oxide inhalation and propofol. During the dental procedures, the sedation level was maintained at an Observer's Assessment of Alertness/Sedation scale score of 4 by adjusting propofol's target plasma concentration. Nitrous oxide inhalation was the predictor variable, whereas the hemodynamic changes, amount and concentration of propofol, and adverse events were the outcome variables.

RESULTS

Eighty-eight patients were successfully analyzed without any complications. The total amount of propofol was significantly less in group N+P (249.8 ± 121.7 mg) than in group P (310.3 ± 122.4 mg) (P = .022), and the mean concentration of propofol was significantly less in group N+P (1.81 ± 0.34 μg/mL) than in group P (2.05 ± 0.44 μg/mL) (P = .006). The mean blood pressure reduction in group N+P (11.0 ± 8.0 mm Hg) was significantly smaller than that in group P (15.8 ± 10.2 mm Hg) (P = .034). Pain associated with the propofol injection and memory of the procedure were less in group N+P (P = .011 and P = .048, respectively). Nitrous oxide did not affect respiratory conditions or recovery characteristics.

CONCLUSIONS

The results of this study suggest that nitrous oxide inhalation combined with propofol sedation attenuates the hypotensive effect and pain associated with propofol injections, along with potentiating the amnesic effect.

Target-controlled infusion of propofol versus intermittent bolus of a sedative cocktail regimen in deep sedation for gastrointestinal endoscopy: comparison of cardiovascular and respiratory parameters

OBJECTIVE

To investigate whether target-controlled infusion (TCI) with propofol, a method that has theoretically better control of drug concentration, produces less cardiovascular and respiratory suppression than an intermittent bolus of a sedative cocktail regimen in deep sedation for gastrointestinal endoscopy.

METHODS

In total 100 participants who had undergone esophagoduodenoscopy (EGD) and 120 who had undergone colonoscopy were prospectively and randomly enrolled to receive TCI with propofol or intermittent bolus of cocktail regimen containing midazolam, alfentanil and propofol until they were unresponsive to verbal commands. The target concentration was adjusted and the bolus of the cocktail regimen was added based on their responses. The nadir values of heart rate, blood pressure and oxygen saturation during and after the procedure were recorded.

RESULTS

The nadir systolic blood pressure during the endoscopy in the cocktail regimen group was significantly lower than that in the TCI with propofol group. In the cocktail regimen group, the incidence of hypotension during colonoscopy and that of bradycardia during EGD were higher than those in the TCI with propofol group. No participants in the TCI with propofol group experienced hypoxia during endoscopy. In the cocktail regimen group, six participants who had undergone EGD and six who had undergone colonoscopy showed transient hypoxic episodes during or after endoscopy.

CONCLUSION

TCI with propofol produced less cardiovascular and respiratory suppression than intermittent bolus of a sedative cocktail regimen in deep sedation for gastrointestinal endoscopy.

Reaction time-monitored patient-maintained propofol sedation: a pilot study in oral surgery patients

Previous volunteer studies of an effect-site controlled patient-maintained sedation system using propofol have demonstrated a risk of oversedation. We have incorporated a reaction time monitor into the handset to add an individualised patient-feedback mechanism. This pilot study assessed if the reaction time-feedback modification would prove safe and effective in 20 healthy patients receiving sedation while undergoing oral surgery. All patients successfully sedated themselves without reaching any unsafe endpoints. All 20 maintained verbal contact throughout. The mean (SD) lowest peripheral blood oxygen saturation was 98.0 (2.1)% breathing room air. No patient required supplementary oxygen. The mean (SD) maximum effect-site propofol concentration reached was 1.6 (0.5) μg.ml(-1). The present system was found to be safe and effective, allowing oral surgery treatment under conscious sedation, but preventing oversedation.

Patient-maintained propofol sedation using reaction time monitoring: a volunteer safety study

Previous volunteer studies of an effect-site controlled, patient-maintained sedation system using propofol have demonstrated a risk of over-sedation. We have incorporated a reaction-time monitor into the handset of the patient-maintained sedation system to add an individualised patient-feedback mechanism. This study assessed if such reaction-time feedback modification would reduce the risk of over-sedation in 20 healthy volunteers deliberately attempting to over-administer themselves propofol. All the volunteers successfully sedated themselves without reaching any unsafe endpoints. All volunteers maintained verbal contact throughout, in accordance with the definition of conscious sedation. The mean (SD) lowest S(p) O(2) was 97 (1.7) % when breathing room air and no volunteer required supplementary oxygen. The mean (SD) maximum effect-site propofol concentration reached was 1.7 (0.4) μg.ml(-1) . The present system was found to be safer than its predecessors, allowing conscious sedation, but preventing over-sedation.

[Sedation and analgesia during gastrointestinal endoscopy]

Sedative and analgesic premedication is frequently used during gastrointestinal endoscopy. Sedation improves patient's compliance, helping the examinations and their safe completion, but it lengthens the procedures, increases the costs, and complications can occur. Sedative drugs are applied during upper and lower gastrointestinal endoscopy, and also at ERCP. The review summarizes the different forms of sedation, drugs, future techniques and possibilities of improvements. Moreover, sedation practice in Hungary is also described.

Randomized controlled trial of patient-controlled sedation for colonoscopy: Entonox vs modified patient-maintained target-controlled propofol

AIM

Propofol sedation is often associated with deep sedation and decreased manoeuvrability. Patient-maintained sedation has been used in such patients with minimal side-effects. We aimed to compare novel modified patient-maintained target-controlled infusion (TCI) of propofol with patient-controlled Entonox inhalation for colonoscopy in terms of analgesic efficacy (primary outcome), depth of sedation, manoeuvrability and patient and endoscopist satisfaction (secondary outcomes).

METHOD

One hundred patients undergoing elective colonoscopy were randomized to receive either TCI propofol or Entonox. Patients in the propofol group were administered propofol initially to achieve a target concentration of 1.2 μg/ml and then allowed to self-administer a bolus of propofol (200 μg/kg/ml) using a patient-controlled analgesia pump with a handset. Entonox group patients inhaled the gas through a mouthpiece until caecum was reached and then as required. Sedation was initially given by an anaesthetist to achieve a score of 4 (Modified Observer's Assessment of Alertness and Sedation Scale), and colonoscopy was then started. Patients completed an anxiety score (Hospital Anxiety and Depression questionnaire), a baseline letter cancellation test and a pain score on a 100-mm visual analogue scale before and after the procedure. All patients completed a satisfaction survey at discharge and 24 h postprocedure.

RESULTS

The median dose of propofol was 174 mg, and the median number of propofol boluses was four. There was no difference between the two groups in terms of pain recorded (95% confidence interval of the difference -0.809, 5.02) and patient/endoscopist satisfaction. There was no difference between the two groups in either depth of sedation or manoeuvrability.

CONCLUSION

Both Entonox and the modified TCI propofol provide equally effective sedation and pain relief, simultaneously allowing patients to be easily manoeuvred during the procedures.

Procedural sedation and obesity: waters left uncharted

BACKGROUND

Moderate sedation during endoscopy may pose increased risks among obese patients.

OBJECTIVE

To review the literature that considers aspects of sedation within the obese population and to identify gaps in our knowledge.

DESIGN

Literature-based review.

RESULTS

There may be increased risks among obese patients undergoing moderate sedation. In particular, the presence of obstructive sleep apnea may identify a subset of patients at higher risk for complications.

LIMITATIONS

English language literature only.

CONCLUSIONS

Although obesity may be associated with increased risks of procedural sedation, future studies should better clarify such risks to better inform clinical decision making.

Recent advances in patient-controlled sedation

PURPOSE OF REVIEW

Advances in minimally invasive procedures have resulted in an increased demand for procedural sedation. Patient-controlled sedation (PCS) has been in clinical use for almost 20 years, but has not been reviewed in over 10 years.

RECENT FINDINGS

Advances in microprocessor technology, increased demand for procedural sedation in a cost-conscious environment, and the availability of readily titratable pharmacologic agents together stimulated the development of alternative sedation practices. Continued research into the neurobiology of pain perception and the placebo effect has also played a role. PCS and patient-maintained sedation, primarily with propofol, have emerged as intriguing clinical alternatives to traditional sedation based in part on extensions of traditional PCA models.

SUMMARY

PCS has been applied to a wide variety of procedures, but systems that can be applied 'off-the-shelf' are not easy to tune. New approaches to PCS may address these limitations. Better understanding of the psychology of sedation may lead to better patient acceptance of PCS.

Future directions in endoscopic sedation

The role of sedation in endoscopic procedures has increased and so has the demand for advances in its administration. The pursuit of new agents or administration techniques and their study specific to endoscopic nonsurgical procedures is necessary to improve patient comfort and safety.The science of moderate and deep sedation specific to endoscopy is fledgling but approaching new horizons.

The role of the endoscopy nurse or assistant in endoscopic sedation

Properly trained nursing personnel and allied staff are essential to the safe and effective practice of endoscopic sedation. Such individuals should possess a thorough understanding of the pharmacology of sedation agents, as well as the ability to monitor patients under sedation, recognize potential complications, and initiate appropriate and timely interventions. The endoscopy nurse or assistant must also understand their institutional policies and procedures pertaining to procedural sedation.

[Target-controlled infusion (TCI) - a concept with a future?: state-of-the-art, treatment recommendations and a look into the future]

Over the last 10 years the technique of target-controlled infusion (TCI) has substantially influenced the development and practice of intravenous anaesthesia. It opened the possibility of many new and exciting applications of perioperative anaesthetic care. More recent and current developments, such as open TCI (target-controlled infusion) and the availability of generic anaesthetic agents combined with modern infusion pumps, means that TCI can become a standard procedure in anaesthesia and is no longer just a research tool for specialists and enthusiasts. This review explains the fundamentals and applications of intravenous drug delivery by TCI and gives practice guidelines to successfully implement the technique into clinical practice. The aim is to provide a comprehensive reference based on clinically proven evidence.

Closed claims review of anesthesia for procedures outside the operating room

PURPOSE OF REVIEW

The demand for anesthesia services is increasing due to more complex procedures being performed outside the operating room. We reviewed the literature and closed malpractice claims in the American Society of Anesthesiologists' Closed Claims database to assess liability and injury associated with anesthesia for procedures outside the operating room (nonoperating-room anesthesia, n = 24) compared with intra-operative surgical anesthesia (operating room, n = 1927) claims.

RECENT FINDINGS

A higher proportion of patients in nonoperating-room anesthesia claims underwent monitored anesthesia care (58 vs. 6%, P < 0.001) and were at the extremes of age (50 vs. 19%, P = 0.003) than in operating room claims. Half of the nonoperating-room anesthesia claims occurred in the gastrointestinal suite. Inadequate oxygenation/ventilation was the most common specific damaging event in nonoperating-room anesthesia claims (33 vs. 2% in operating room claims, P < 0.001). The proportion of death was increased in nonoperating-room anesthesia claims (54 vs. 24%, P = 0.003). Nonoperating-room anesthesia claims were more often judged as having substandard care (P = 0.003) and being preventable by better monitoring (P = 0.007).

SUMMARY

Nonoperating-room anesthesia claims had a higher severity of injury and more substandard care than operating room claims. Inadequate oxygenation/ventilation was the most common mechanism of injury. Maintenance of minimum monitoring standards and airway management training is required for staff involved in patient sedation.

Anaesthesia and sedation for gastrointestinal endoscopy

PURPOSE OF REVIEW

Wide variations exist around the world in the practice of sedation for endoscopy, in terms of the depth of sedation, drug choices, delivery methods and the practitioners involved. These variations are driven by historical, cultural and economic factors. Professional bodies have promulgated guidelines in an attempt to unify and raise standards for sedation and monitoring. Nevertheless, preventable morbidity associated with sedation still occurs. A review of the recent literature is therefore justified.

RECENT FINDINGS

The main themes in this literature are the advent of the widespread use of propofol by non-anaesthesiologists, and particularly non-medical staff; novel methods for administering propofol; the acceptability of endoscopy without sedation; and emerging technologies that obviate the need for endoscopy.

SUMMARY

There is still much scope to research and refine sedation techniques for endoscopy. We believe that the involvement of anaesthesiologists in this research is vital.

Effect-site targeted patient-controlled sedation with propofol: comparison with anaesthetist administration for colonoscopy

Patient-controlled sedation (PCS) allows patients to match their sedation requirement to perceived discomfort. The significant delay in onset of sedation may be overcome with effect-site steered target controlled infusion, but previously only trials in volunteers have been carried out. We therefore conducted a randomised, double-blind controlled trial comparing effect-site steered propofol PCS with anaesthetist-administered propofol sedation in 40 patients presenting for colonoscopy. The initial effect-site target in the PCS group was 0.8 microg.ml(-1), increment was 0.1 microg.ml(-1) and lockout was 3 min. Patient and endoscopist satisfaction and operating conditions were similar between the two groups. PCS patients were sedated more slowly (13 [7.1] vs. 3 [1.1] min; p < 0.0001) and less deeply (minimum BIS value: 71 [16] vs. 58 [15]; p = 0.13) than anaesthetist-administered propofol sedation patients. More of the latter patients were hypotensive, but all patients had similar recollection of events during the procedure and similar quality of recovery.

Effect-site controlled patient maintained propofol sedation: a volunteer safety study

Effect-site concentration is a mathematical term related to the clinical effect of a drug. We have designed a patient-maintained sedation system for delivering propofol to the predicted effect-site concentration rather than plasma concentration. To assess its efficacy and safety, 20 healthy volunteers deliberately attempted to over-sedate themselves using the system. The new effect-site concentration driven system delivered sedation successfully, and more rapidly than its predecessor. Fifteen volunteers ended the study when the system automatically reduced the effect-site concentration after 6 min of no button presses despite verbal contact and maintenance of arterial oxygen saturation (at effect-site concentration 1.8-3.8 microg x ml(-1)). Four out of 20 volunteers ended with minor arterial desaturation (lowest 88% at effect-site concentration 2.6-3.4 microg x ml(-1)). One volunteer ended after loss of verbal contact at effect-site concentration 3.4 microg x ml(-1). Further modification of the system's design is necessary before it can be recommended for routine practice.