Recovery of driving skills after endoscopy under propofol sedation: a prospective pilot study to assess the driving skills after endoscopic sedation using driving simulation

BACKGROUND

Patients are recommended not to drive for at least the first 24 h after endoscopy with propofol sedation. However, the evidence underlying these recommendations is scarce. We hypothesized that after endoscopic procedures performed under propofol sedation, the subject's driving ability was restored in less than 24 h.

METHODS

We prospectively enrolled thirty patients between 20 and 70 years possessing a legitimate driver's license scheduled for endoscopy at our hospital. The sample chosen was a convenience sample. Gastroscopy or colonoscopy was performed with propofol sedation. Before and after endoscopy, the investigator drove the subjects to the laboratory to assess their driving skills using a driving simulation system, which employs 3 driving scenarios designed by professional transportation researchers. The blood propofol concentration was estimated before endoscopy, and 2 and 4 h after endoscopy. The primary outcome was the time required for subjects to recover their driving ability after propofol sedation. The secondary outcome was the blood propofol concentration before and after endoscopic procedures under propofol anesthesia.

RESULTS

Thirty volunteers participated in the study and 18 of them completed all the interventions. In the low-risk S-curve scene, the mean acceleration, lane deviation, and number of deviations from the path at baseline (0.016 cm/s2, 42.50 cm, and 0.83, respectively) were significantly less than that at post-2 h (0.029 cm/s2, P = 0.001; 53.80 cm, P = 0.014; 2.06, P = 0.022). In the moderate-(overtaking) and high-risk (emergency collision avoidance) scenes, the tested parameters at baseline and post-2 h were statistically comparable. In the low-, moderate-, and high-risk scenes the tested parameters at baseline and post-4 h were statistically comparable. The total range of propofol was 120-280 mg.The mean blood concentration of propofol at post-2 h was 0.81 ± 0.40 µg/mL, and at post-4 h was below the limit of detection.

CONCLUSION

After endoscopy performed under propofol sedation, subjects' driving abilities were completely restored at 4 h when tested on a simulator.

Impact of High-Flow Nasal Cannula Oxygenation on the Prevention of Hypoxia During Endoscopic Retrograde Cholangiopancreatography in Elderly Patients: A Randomized Clinical Trial

BACKGROUND

Hypoxia is the most frequently occurring adverse effect during endoscopic retrograde cholangiopancreatography (ERCP) under sedation; thus, oxygen must be properly supplied to prevent a reduction of oxygen saturation. In this study, we intend to verify the preventive effect for hypoxia during ERCP, using a high-flow nasal cannula (HFNC), in elderly patients.

METHODS

As a multicenter prospective randomized trial, patients who underwent ERCP with propofol-based sedation were randomly assigned into two groups: Patients in the HFNC group were supplied with oxygen via an HFNC, and those in the standard nasal cannula group were supplied with oxygen via a low-flow nasal cannula. The co-primary end points were the lowest oxygen saturation rate and hypoxia during the overall procedure.

RESULTS

A total of 187 patients (HFNC group: 95; standard nasal cannula group: 92) were included in the analysis. Unexpected hypoxia events were more frequently observed among patients in the standard nasal cannula group than among patients in the HFNC group (13% vs. 4%, odds ratio 3.41, 95% confidence interval 1.06-11.00, p = 0.031). The mean of the lowest oxygen saturation rate during ERCP was significantly lower in the standard nasal cannula group than in the HFNC group (95% vs. 97%, p = 0.002).

CONCLUSION

Oxygen supplementation with an HFNC can prevent oxygen desaturation and hypoxia events in patients undergoing ERCP under sedation. Trial registration Clinical Research Information Service (CRIS; KCT0004960).

Regional entropy of functional imaging signals varies differently in sensory and cognitive systems during propofol-modulated loss and return of behavioral responsiveness

The level and richness of consciousness depend on information integration in the brain. Altered interregional functional interactions may indicate disrupted information integration during anesthetic-induced unconsciousness. How anesthetics modulate the amount of information in various brain regions has received less attention. Here, we propose a novel approach to quantify regional information content in the brain by the entropy of the principal components of regional blood oxygen-dependent imaging signals during graded propofol sedation. Fifteen healthy individuals underwent resting-state scans in wakeful baseline, light sedation (conscious), deep sedation (unconscious), and recovery (conscious). Light sedation characterized by lethargic behavioral responses was associated with global reduction of entropy in the brain. Deep sedation with completely suppressed overt responsiveness was associated with further reductions of entropy in sensory (primary and higher sensory plus orbital prefrontal cortices) but not high-order cognitive (dorsal and medial prefrontal, cingulate, parietotemporal cortices and hippocampal areas) systems. Upon recovery of responsiveness, entropy was restored in the sensory but not in high-order cognitive systems. These findings provide novel evidence for a reduction of information content of the brain as a potential systems-level mechanism of reduced consciousness during propofol anesthesia. The differential changes of entropy in the sensory and high-order cognitive systems associated with losing and regaining overt responsiveness are consistent with the notion of "disconnected consciousness", in which a complete sensory-motor disconnection from the environment occurs with preserved internal mentation.

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.

Propofol Compared to Midazolam Sedation and to General Anesthesia for Percutaneous Microwave Ablation in Patients with Hepatic Malignancies: A Single-Center Comparative Analysis of Three Historical Cohorts

Purpose

In percutaneous ablation procedures, periprocedural pain, unrest and respiratory concerns can be detrimental to achieve a safe and efficacious ablation and impair treatment outcome. This study aimed to compare the association between anesthetic technique and local disease control in patients undergoing percutaneous microwave ablation (MWA) of colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC).

Materials and Methods

This IRB-exempted single-center comparative, retrospective analysis of three cohorts analyzed 90 patients treated for hepatic malignancies from January 2013 until September 2018. The local tumor progression-free survival (LTPFS), safety and periprocedural pain perception were assessed using univariate and multivariate Cox proportional hazard regression analyses to correct for potential confounders.

Results

In 114 procedures (22 general anesthesia; 32 midazolam; 60 propofol), 171 liver tumors (136 CRLM; 35 HCC) were treated with percutaneous MWA. Propofol and general anesthesia were superior to midazolam/fentanyl sedation regarding LTPFS (4/94 [4.3%] vs. 19/42 [45.2%] vs. 2/35 [5.7%]; P < 0.001, respectively). Local tumor progression rate was 14.6% (25/171). Eighteen tumors (72.0%) were retreated by ablation. Of them, 14 (78%) were previously treated with midazolam. Propofol versus midazolam (P < 0.001), general anesthesia versus midazolam (P = 0.016), direct postprocedural visual analog pain score above 5 (P = 0.050) and more than one tumor per procedure (P = 0.045) were predictors for LTPFS. Multivariate analysis revealed that propofol versus midazolam (HR 7.94 [95% CI 0.04–0.39; P < 0.001]) and general anesthesia versus midazolam (HR 6.33 [95% CI 0.04–0.69; P = 0.014]) were associated with LTPFS. Pain during and directly after treatment was significantly worse in patients who received midazolam sedation (P < 0.001).

Conclusions

Compared to propofol and general anesthesia, midazolam/fentanyl sedation was associated with an increased periprocedural perception of pain and lower local tumor progression-free survival. To reduce the number of repeat procedures required to eradicate hepatic malignancies, general anesthesia and propofol sedation should be favored over midazolam.

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.

Judicial Precedent-Based Clinical Practice Guidelines of Propofol in Sedative Esthetic Surgery

BACKGROUND

Propofol is has been widely used for sedation in the field of esthetic surgery because of its favorable pharmacokinetic profile. Propofol sedation-induced side effects are rare. However, when present, they can be serious. The number of malpractice claims associated with propofol sedation has increased in recent years. This study aims to show which procedures lead to the most claims in the field of esthetic surgery through a review of Korean precedents.

METHODS

Thirteen precedent cases of propofol sedation in the field of esthetic surgery were collected between 2000 and 2016. We analyzed the type of procedure, administration route, anesthesia provider, complications, timing of damaging events, average indemnification, plaintiff's (patients) winning rate, ratio and the reason of limitation of liability and the key factors affecting the judgement in these cases.

RESULTS

Most plaintiffs were women, and in most cases (11/13, 73.3%), the times of the damaging events were in maintenance and the anesthesia provider was the surgeon. The most common complication related to propofol sedation was hypoxic brain damage. Among the 13 cases, 12 were won by the plaintiff. The mean claim settlement was 339,455,814 KRW (USD 301,792.15). The key factors affecting the judgement were administration method and staff, monitoring method, preparation of emergency kit, response to emergencies, transfer to a higher-level hospital, detailed medical recording about event and informed consent.

CONCLUSION

The number of claims owing to propofol sedation after esthetic surgery is increasing. Close monitoring during the operation, immediate reaction to an event and thorough medical records were main key factors that influenced the judgement. Preoperative explanation about the possibility of complications was important. The findings will help surgeons achieve high patient satisfaction and reduce liability concerns.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

No increased risk of perforation during colonoscopy in patients undergoing propofol versus traditional sedation: A meta-analysis

BACKGROUND AND AIMS

The safety of propofol sedation during colonoscopy remains unclear, and we performed a meta-analysis to assess the risk of perforation in patients undergoing propofol vs. traditional sedation.

METHODS

MEDLINE, CBM, VIP, CNKI, and Wanfang databases were searched up to December 2016. Two reviewers independently assessed abstract of those searched articles. Data about perforation condition in propofol and traditional sedation groups were extracted and combined using the random effects model.

RESULTS

A total of 19 studies were included in the current meta-analysis. Compared to traditional sedation, propofol sedation did not increase the risk of perforation (RD = - 0.00, 95% CI - 0.00~0.00, p = 0.98; subgroup analysis: OR = 1.30, 95% CI 0.83~2.05, p = 0.25).

CONCLUSION

This meta-analysis suggested that propofol sedation did not increase the risk of perforation compared to traditional sedation during colonoscopy.

Propofol attenuates low-frequency fluctuations of resting-state fMRI BOLD signal in the anterior frontal cortex upon loss of consciousness

Recent studies indicate that spontaneous low-frequency fluctuations (LFFs) of resting-state functional magnetic resonance imaging (rs-fMRI) blood oxygen level-dependent (BOLD) signals are driven by the slow (<0.1Hz) modulation of ongoing neuronal activity synchronized locally and across remote brain regions. How regional LFFs of the BOLD fMRI signal are altered during anesthetic-induced alteration of consciousness is not well understood. Using rs-fMRI in 15 healthy participants, we show that during administration of propofol to achieve loss of behavioral responsiveness indexing unconsciousness, the fractional amplitude of LFF (fALFF index) was reduced in comparison to wakeful baseline in the anterior frontal regions, temporal pole, hippocampus, parahippocampal gyrus, and amygdala. Such changes were absent in large areas of the motor, parietal, and sensory cortices. During light sedation characterized by the preservation of overt responsiveness and therefore consciousness, fALFF was reduced in the subcortical areas, temporal pole, medial orbital frontal cortex, cingulate cortex, and cerebellum. Between light sedation and deep sedation, fALFF was reduced primarily in the medial and dorsolateral frontal areas. The preferential reduction of LFFs in the anterior frontal regions is consistent with frontal to sensory-motor cortical disconnection and may contribute to the suppression of consciousness during general anesthesia.

Case of Vasovagal Syncope With Asystole Associated With Propofol Sedation

Few cases of bradycardic complications occurring under intravenous sedation have been reported. Here, we report a case of vasovagal syncope with asystole (7.2 seconds) associated with propofol sedation.

Propofol and non-propofol based sedation for outpatient colonoscopy-prospective comparison of depth of sedation using an EEG based SEDLine monitor

Propofol is a popular anesthetic sedative employed in colonoscopy. It is known to increase the patient satisfaction and improve throughput. However, there are concerns among the clinicians with regard to the depth of sedation, as a deeper degree of sedation is known to increase the incidence of aspiration and other adverse events. So we planned to compare the depth of sedation between propofol and non-propofol based sedation in patients undergoing outpatient colonoscopy, as measured by an electroencephalogram (EEG) based monitor SEDLine monitor (SedlineInc., San Diego, CA). The non-randomized prospective observational study was performed in the outpatient gastroenterology suite of the Hospital of the University of Pennsylvania, Philadelphia. Patients included ASA class I-III aged more than 18 years scheduled for colonoscopy under Propofol or non-propofol based sedation. After an institutional review board approval, a written consent was obtained from prospective patients. Sedation (propofol or non-propofol based) was administered by either a certified nurse anesthetist under the supervision of an anesthesiologist (propofol) or a registered endoscopy nurse under the guidance of the endoscopist performing the procedure (non-propofol sedation). Depth of sedation was measured with an EEG based SEDLine monitor. The sedation providers were blinded to the patient state index-the indicator of depth of sedation. PSI (patient state index-SEDLine reading) was documented at colonoscope insertion, removal and at the return of verbal responsiveness after colonoscope withdrawal. Sedation spectrum was retrieved from the data stored on the SEDLine monitor. Patients sedated with propofol experience significantly deeper degrees of sedation at all times during the procedure. Additionally, during significant part of the procedure, they are at PSI levels associated with deep general anesthesia. The group that received propofol was more deeply sedated and had lower PSI values. Lighter propofol titration protocols may lead to improved patient care such as lowering risk of aspiration and hypotension. The role of processed EEG monitors such as the SEDLine monitor to improve sedation protocols remains to be determined. Trial registration We obtained an ethical clearance from the Institute. No trial registration was mandated, as no interventional drug or investigational device were used during the study.

Sevoflurane versus propofol sedation during periocular anesthetic injections in oculoplastic procedures: An open-label randomized comparison

PURPOSE

The purpose of the current investigation was to make an objective controlled comparison of pain tolerance, patient satisfaction and potential complications during the injection of local anesthesia in oculoplastic procedures under short-term sedation using inhalational versus parenteral sedatives.

METHODS

This was an open-label, randomized clinical trial where patients were randomized to 3 groups. Group I: Sedation with intravenous propofol. Group II: Sedation with inhaled sevoflurane. Group 3: Control group receiving no sedation.

RESULTS

A total of 396 patients were randomly assigned, and 375 were included in the final analysis. Study groups were similar in age, gender, and distribution of operative procedures performed. There was no statistically significant difference in the adjusted primary composite outcome measure between propofol and sevoflurane (pain scores and patient satisfaction). Significantly more patients in group I required restraining during periocular injections than group II or III (p < 0.001). Significantly more patients sneezed in group I than group II (p < 0.001) and none in the control group. Three patients in group II suffered severe excitation-disinhibition during emergence from sedation which was rapidly reversible, and 3 more suffered a severe bout of postoperative nausea and vomiting (PONV).

CONCLUSION

Sevoflurane and propofol during periocular anesthetic injections produce an equally favorable experience. Sevoflurane is introduced painlessly, and offers better patient control with less induction of the sneezing reflex which may provide a higher safety profile, however short-term aggression/disinhibition and PONV may be an issue in some patients.

Increased precuneus connectivity during propofol sedation

Using functional magnetic resonance imaging in human participants, we show that sedation by propofol to the point of lost overt responsiveness during the performance of an auditory verbal memory task unexpectedly increases functional connectivity of the precuneus with cortical regions, particularly the dorsal prefrontal and visual cortices. After recovery of consciousness, functional connectivity returns to a pattern similar to that observed during the wakeful baseline. In the context of a recent proposal that highlights the uncoupling of consciousness, connectedness, and responsiveness in general anesthesia, the increased precuneus functional connectivity under propofol sedation may reflect disconnected endogenous mentation or dreaming that continues at a reduced level of metabolic activity.

Combined Spinal Epidural Anaesthesia with BiPAP-Three Case Reports

SUMMARY

We report three cases where BiPAP (bi-level positive airway pressure) was used with CSEA (combined spinal epidural anaesthesia) to over come the hypoventilation due to preoperative poor respiratory reserves and additive effect of sedation. Combination of BiPAP with spinal, epidural and CSEA have been used successfully in patients of severe COPD (chronic obstructive pulmonary disease) for various surgical procedures. This combination provides safe alternative to conventional general anaesthesia, as it avoids need for postoperative ventilatory support and its deleterious effects.