Effect of conscious sedation on cardiac autonomic regulation during colonoscopy

Combination of syringaresinol-di-O-β-D-glucoside and chlorogenic acid shows behavioral pharmacological anxiolytic activity and activation of hippocampal BDNF-TrkB signaling

Mental stress, such as anxiety and conflict, causes physiological changes such as dysregulation of autonomic nervous activity, depression, and gastric ulcers. It also induces glucocorticoid production and changes in hippocampal brain-derived neurotrophic factor (BDNF) levels. We previously reported that Acanthopanax senticosus HARMS (ASH) exhibited anxiolytic activity. Thus, we attempted to identify the anxiolytic constituents of ASH and investigated its influence on hippocampal BDNF protein expression in male Sprague Dawley rats administered chlorogenic acid (CHA), ( +)-syringaresinol-di-O-β-D-glucoside (SYG), or a mixture of both (Mix) for 1 week using the open field test (OFT) and improved elevated beam walking (IEBW) test. As with ASH and the benzodiazepine anxiolytic cloxazolam (CLO), Mix treatment significantly increased locomotor activity in the OFT. CHA and Mix increased the time spent in the open arm in the IEBW test. SYG and Mix treatment inhibited the significant increase in normalized low-frequency power, indicative of sympathetic nervous activity, and significant decrease in normalized high-frequency power, indicative of parasympathetic nervous activity, as observed in the IEBW test. SYG and Mix treatment significantly increased hippocampal BDNF protein expression. The combination of CHA and SYG possibly induces anxiolytic behavior and modulates autonomic regulation, activates hippocampal BDNF signaling as with ASH.

Pre-endoscopic tachycardia predicts increased sedation dose and lower adenoma detection rate in patients undergoing endoscopic procedures: a case control study

BACKGROUND

Tachycardia prior to endoscopic procedures is commonly encountered which reflect patient anxiety status. Despite this frequent occurrence, it is unclear if in a patient with tachycardia sedation dose should be modified. The aim of our study was to assess the effect of pre-endoscopic tachycardia on sedation dose.

METHODS

A retrospective analysis of all patients who underwent upper endoscopy and colonoscopy at EMMS Nazareth hospital were performed. We excluded patients with diseases and medications affecting the heart rate.

RESULTS

A total of 2855 patients were included in the study. Two-hundred and thirty-seven patients had tachycardia before endoscopy (8.3%, group A) as compared to 2618 (group B) patients who had heart rate ≤100 beats per minute. The mean dosage of propofol in group A was significantly higher (62.6±33.2 mg vs. 57.4±29.9 mg) than in group B (P=0.01). There was no difference in the cecal intubation rate among the two groups (P=0.9). Notably, the adenoma detection rate was significantly lower among group A patients as compared to group B (13.6% vs. 22.8%, P=0.02) patients. There were no sedation related complications.

CONCLUSIONS

Tachycardia prior to endoscopic procedures was associated with higher sedative dosage and lower adenoma detection rate, however no major complications were recorded. These data should be taken into consideration to optimize procedure quality.

Midazolam for sedation before procedures

BACKGROUND

Midazolam is used for sedation before diagnostic and therapeutic medical procedures. It is an imidazole benzodiazepine that has depressant effects on the central nervous system (CNS) with rapid onset of action and few adverse effects. The drug can be administered by several routes including oral, intravenous, intranasal and intramuscular.

OBJECTIVES

To determine the evidence on the effectiveness of midazolam for sedation when administered before a procedure (diagnostic or therapeutic).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL to January 2016), MEDLINE in Ovid (1966 to January 2016) and Ovid EMBASE (1980 to January 2016). We imposed no language restrictions.

SELECTION CRITERIA

Randomized controlled trials in which midazolam, administered to participants of any age, by any route, at any dose or any time before any procedure (apart from dental procedures), was compared with placebo or other medications including sedatives and analgesics.

DATA COLLECTION AND ANALYSIS

Two authors extracted data and assessed risk of bias for each included study. We performed a separate analysis for each different drug comparison.

MAIN RESULTS

We included 30 trials (2319 participants) of midazolam for gastrointestinal endoscopy (16 trials), bronchoscopy (3), diagnostic imaging (5), cardioversion (1), minor plastic surgery (1), lumbar puncture (1), suturing (2) and Kirschner wire removal (1). Comparisons were: intravenous diazepam (14), placebo (5) etomidate (1) fentanyl (1), flunitrazepam (1) and propofol (1); oral chloral hydrate (4), diazepam (2), diazepam and clonidine (1); ketamine (1) and placebo (3); and intranasal placebo (2). There was a high risk of bias due to inadequate reporting about randomization (75% of trials). Effect estimates were imprecise due to small sample sizes. None of the trials reported on allergic or anaphylactoid reactions. Intravenous midazolam versus diazepam (14 trials; 1069 participants)There was no difference in anxiety (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.39 to 1.62; 175 participants; 2 trials) or discomfort/pain (RR 0.60, 95% CI 0.24 to 1.49; 415 participants; 5 trials; I² = 67%). Midazolam produced greater anterograde amnesia (RR 0.45; 95% CI 0.30 to 0.66; 587 participants; 9 trials; low-quality evidence). Intravenous midazolam versus placebo (5 trials; 493 participants)One trial reported that fewer participants who received midazolam were anxious (3/47 versus 15/35; low-quality evidence). There was no difference in discomfort/pain identified in a further trial (3/85 in midazolam group; 4/82 in placebo group; P = 0.876; very low-quality evidence). Oral midazolam versus chloral hydrate (4 trials; 268 participants)Midazolam increased the risk of incomplete procedures (RR 4.01; 95% CI 1.92 to 8.40; moderate-quality evidence). Oral midazolam versus placebo (3 trials; 176 participants)Midazolam reduced pain (midazolam mean 2.56 (standard deviation (SD) 0.49); placebo mean 4.62 (SD 1.49); P < 0.005) and anxiety (midazolam mean 1.52 (SD 0.3); placebo mean 3.97 (SD 0.44); P < 0.0001) in one trial with 99 participants. Two other trials did not find a difference in numerical rating of anxiety (mean 1.7 (SD 2.4) for 20 participants randomized to midazolam; mean 2.6 (SD 2.9) for 22 participants randomized to placebo; P = 0.216; mean Spielberger's Trait Anxiety Inventory score 47.56 (SD 11.68) in the midazolam group; mean 52.78 (SD 9.61) in placebo group; P > 0.05). Intranasal midazolam versus placebo (2 trials; 149 participants)Midazolam induced sedation (midazolam mean 3.15 (SD 0.36); placebo mean 2.56 (SD 0.64); P < 0.001) and reduced the numerical rating of anxiety in one trial with 54 participants (midazolam mean 17.3 (SD 18.58); placebo mean 49.3 (SD 29.46); P < 0.001). There was no difference in meta-analysis of results from both trials for risk of incomplete procedures (RR 0.14, 95% CI 0.02 to 1.12; downgraded to low-quality evidence).

AUTHORS' CONCLUSIONS

We found no high-quality evidence to determine if midazolam, when administered as the sole sedative agent prior to a procedure, produces more or less effective sedation than placebo or other medications. There is low-quality evidence that intravenous midazolam reduced anxiety when compared with placebo. There is inconsistent evidence that oral midazolam decreased anxiety during procedures compared with placebo. Intranasal midazolam did not reduce the risk of incomplete procedures, although anxiolysis and sedation were observed. There is moderate-quality evidence suggesting that oral midazolam produces less effective sedation than chloral hydrate for completion of procedures for children undergoing non-invasive diagnostic procedures.

Comparison of the Effect of Electrical Stimulations on the Chin Skin on Autonomic Nervous Activities During Propofol Sedation With or Without Midazolam

PURPOSE

The aim of this study was to compare the effect of electrical stimulations on the chin skin on autonomic nervous activities evaluated by use of power spectrum analysis of heart rate (HR) variability during intravenous sedation using propofol with or without midazolam.

MATERIALS AND METHODS

Thirty-eight healthy adult male volunteers underwent intravenous sedation with midazolam and propofol (group MP) and with propofol alone (group P) in a randomized crossover manner. In group MP, the participants received midazolam (0.04 mg/kg) and a target-controlled infusion of propofol with a predicted blood concentration of 1.0 μg/mL. In group P, the predicted blood concentration of propofol was maintained at 1.5 μg/mL. The observed variables were bispectral index value, systolic blood pressure, HR, high-frequency component (HF), low-frequency component (LF), and LF/HF ratio. Measurements were conducted over 100-second periods and carried out before, during, and after emergence from sedation by administering 0.2 mg of flumazenil. The paired t test, Wilcoxon t test, repeated-measures analysis of variance, and Friedman χ(2) r test were used for statistical analyses.

RESULTS

The mean age and body weight of the participants were 24.6 ± 2.8 years and 67.0 ± 7.9 kg, respectively. Bispectral index values, systolic blood pressure, and HR showed similar changes in both groups. The LF/HF ratio in group MP during sedation was lower than that before sedation; it also was lower than that in group P during sedation.

CONCLUSIONS

Intravenous sedation with a combination of midazolam and propofol inhibited sympathetic nervous activation induced by electrical stimulations to a greater extent than that with propofol alone.

Autonomic nervous responses in colorectal polypectomy: Randomized controlled trial comparing air and carbon dioxide insufflation

BACKGROUND AND AIM

Carbon dioxide (CO2) insufflation devices are commonly used for endoscopic examination and treatment. In this prospective randomized controlled trial (RCT), we compared patient acceptance, cardiovascular tolerance,and autonomic nervous responses between patients receiving air insufflation and CO2 insufflation.

METHODS

We initially enrolled 170 patients and, of these, 158 patients in total were analyzed (air group, 83; CO2 group, 75). Autonomic nervous responses were evaluated by analysis of heart rate variability (HRV). Primary end point was superiority in the effects of CO2 insufflation on the autonomic nervous system by HRV analysis.

RESULTS

Visual analog scale disclosed significantly less abdominal pain and abdominal fullness with CO2. Percentage heart rate change rate at 1 h and 4 h after the procedure was also significantly lower in the CO2 group than in the air group (1 h after: P < 0.01, 4 h after: P < 0.05). Comparison based on age showed that % heart rate change was significantly lower in the younger CO2 patients (just after colonoscopy and 1 h after: P < 0.01, 4 h after: P < 0.05), but this difference was not apparent in an older group of patients.

CONCLUSIONS

This is the first RCT showing that colorectal polypectomy using CO2 insufflation significantly decreases abdominal pain and abdominal fullness common in such patients with lowered stress to the autonomous nervous system. The effects using CO2 insufflation on the sympathetic nervous system also seemed to be more prominent among younger patients.

Effect of music in endoscopy procedures: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Endoscopies are common clinical examinations that are somewhat painful and even cause fear and anxiety for patients. We performed this systematic review and meta-analysis of randomized controlled trials to determine the effect of music on patients undergoing various endoscopic procedures.

METHODS

We searched the Cochrane Library, Issue 6, 2013, PubMed, and EMBASE databases up to July 2013. Randomized controlled trials comparing endoscopies, with and without the use of music, were included. Two authors independently abstracted data and assessed risk of bias. Subgroup analyses were performed to examine the impact of music on different types of endoscopic procedures.

RESULTS

Twenty-one randomized controlled trials involving 2,134 patients were included. The overall effect of music on patients undergoing a variety of endoscopic procedures significantly improved pain score (weighted mean difference [WMD] = -1.53, 95% confidence interval [CI] [-2.53, -0.53]), anxiety (WMD = -6.04, 95% CI [-9.61, -2.48]), heart rate (P = 0.01), arterial pressure (P < 0.05), and satisfaction score (SMD = 1.83, 95% CI [0.76, 2.91]). Duration of the procedure (P = 0.29), except for gastrointestinal endoscopy (P = 0.03), and sedative or analgesic medication dose (P = 0.23, P = 0.12, respectively) were not significantly decreased in the music group, compared with the control group. Furthermore, music had little effect for patients undergoing colposcopy and bronchoscopy in the subanalysis.

CONCLUSION

Our meta-analysis suggested that music may offer benefits for patients undergoing endoscopy, except in colposcopy and bronchoscopy.

Patient-controlled analgesia and sedation with alfentanyl versus fentanyl for colonoscopy: a randomized double blind study

STUDY OBJECTIVE

The aim of this study was to evaluate whether sedo-analgesia with alfentanyl/fentanyl, using a patient-controlled analgesia (PCA) pump, may have positive outcomes in terms of safety, postprocedural workload, and expectations of the colonoscopist, nurse, and patients in elective colonoscopy.

PATIENTS

One hundred American Society of Anesthesiology physical status I and II adult patients.

INTERVENTIONS

Patients were randomized in a double-blind trial to receive either alfentanyl (n=50) or fentanyl (n=50) by PCA, and incremental doses of midazolam.

MEASUREMENTS

Patient expectations were assessed using hemodynamic variables, willingness to have a repeat colonoscopy in the same way, adverse events, discomfort scores, and patient/operator/nurse satisfaction associated with sedo-analgesia.

RESULT

All patients in both groups had adequate sedo-analgesia with high satisfaction and willingness scores. There were no serious adverse effects and except for a few events, no required medication. The total sedation times were shorter in the alfentanyl group compared with the fentanyl group.

CONCLUSIONS

PCA and sedation with alfentanyl and fentanyl for colonoscopy are safe, feasible, and acceptable to most patients. However, shorter sedation times make alfentanyl more attractive for postprocedural workload.

Midazolam more effectively suppresses sympathetic activations and reduces stress feelings during mental arithmetic task than propofol

PURPOSE

The aim of the present study was to examine the effect of intravenous midazolam and propofol sedation on autonomic nervous activities during psychological stress, and whether these results are associated with changes in subjective stress feelings.

MATERIALS AND METHODS

Seven healthy male volunteers were included in a randomized crossover manner. The heart rate (HR), HR variability, arterial oxygen saturation, and bispectral index value were continuously monitored. A mental arithmetic task for 7 minutes was given with or without intravenous sedation with midazolam or propofol. A bispectral index value of 75 to 85 and an Observer's Assessment of Alertness/Sedation score of 4 were the targeted sedation level in both groups. HR variability was assessed using the power spectral analysis (low-frequency [LF] and high-frequency [HF] components and LF/HF ratio). The faces anxiety scale was used to grade their stress feelings after each mental arithmetic task.

RESULTS

During the mental arithmetic task with intravenous sedation, no differences were found in the bispectral index values, arterial oxygen saturation, or the results of the mental arithmetic task between the 2 groups. The HR, LF/HF ratio, and normalized unit LF increased, and the normalized unit HF decreased in both groups. However, the percentage of changes in LF/HF ratio, normalized unit LF, and normalized unit HF were smaller in the midazolam group. In addition, the reduction in faces anxiety scale was greater in the midazolam group.

CONCLUSIONS

These results suggest that midazolam more effectively suppresses sympathetic nervous activation and reduces subjective stress feelings during a mental arithmetic task than propofol.

Cardiovascular manifestations of sedatives and analgesics in the critical care unit

There are numerous sedatives and analgesics used in critical care medicine today; these medications are used on critically ill patients, many of whom have heart disease, including coronary artery disease or congestive heart failure. The purpose of this review is to recognize the effects of these medications on the heart. Studies that evaluated the effects of sedatives and analgesics on normal individuals or on those with heart disease were reviewed. Current choices for sustained sedation in the critically ill include the benzodiazepines, morphine, propofol, and etomidate. Each of these medications has their particular advantages and disadvantages. Benzodiazepines provide the greatest amnesia and cardiovascular safety but they can cause significant hypotension in the hemodynamically unstable patient. Morphine provides analgesia and cardioprotective activity after ischemia, although the large observational study CRUSADE showed increased mortality rate in those patients with non-ST segment elevation myocardial infarction who received morphine. Propofol is the most easily titratable drug with cardioprotective features, but its use must be accompanied with great attention to possible development of propofol infusion syndrome, which is a deadly disease, especially in patients with head injury and those with septic shock receiving vasopressors. Etomidate has a rapid onset effect and short period of action with great hemodynamic stability even in patients with shock and hypovolemia, but the incidence of adrenal insufficiency during infusion, not bolus doses, may cause deterioration in the circulatory stability. In conclusion, the sedatives and analgesics mentioned here have characteristics that give them a cardiovascular safety profile useful in critically ill patients. However, use of these drugs on an individual basis is dependent on each agent's safety and efficacy.

Cardiac autonomic regulation during gastroscopy

BACKGROUND

Gastroscopy is sometimes associated with adverse cardiovascular events.

AIMS

We evaluated the effects of sedation and pharyngeal anaesthesia on cardiac autonomic regulation during gastroscopy.

PATIENTS

Two hundred thirteen outpatients undergoing gastroscopy.

METHODS

The patients were assigned to 4 groups: (1) sedation with intravenous midazolam and placebo throat spray (midazolam group), (2) placebo sedation and pharyngeal anaesthesia with lidocaine (lidocaine group), (3) placebo sedation and placebo throat spray (placebo group), and (4) no intravenous cannula nor throat spray (control group). Continuous electrocardiogram was recorded. Heart rate variability was assessed; the powers of low frequency (0.04-0.15 Hz) and high frequency (0.15-0.40 Hz) components as well as total power (0.0-0.4 Hz) were calculated.

RESULTS

Gastroscopy was associated with a decrease in high frequency normalized units, increases in low frequency normalized units and low frequency/high frequency ratio indicating activation of sympathetic and withdrawal of vagal modulation. Sympathetic activation resulted in a decrease in total power and all components of heart rate variability. The decrease was most prominent in the midazolam treated patients (p<0.001 vs the lidocaine group and p<0.01 vs placebo and control groups during the postendoscopy phase).

CONCLUSION

Gastroscopy induces a shift towards dominance of the sympathetic modulation of the heart. Premedication with midazolam potentiates this shift.

Effect of music on procedure time and sedation during colonoscopy: A meta-analysis

AIM: To integrate results from different studies in examining the effectiveness of music in reducing the procedure time and the amount of sedation used during colonoscopic procedure.

METHODS: An electronic search in various databases was performed to identify related articles. Study quality was evaluated by the Jadad’s scale. The random effect model was used to pool the effect from individual trials and the Cohen Q-statistic was used to determine heterogeneity. Egger’s regression was used to detect publication bias.

RESULTS: Eight studies with 722 subjects were included in this meta-analysis. The combined mean difference for the time taken for the colonoscopy procedure between the music and control groups was -2.84 with 95% CI (-5.61 to -0.08), implying a short time for the music group. The combined mean difference for the use of sedation was -0.46 with 95%CI (-0.91 to -0.01), showing a significant reduction in the use of sedation in the music group. Heterogeneity was observed in both analyses but no publication bias was detected.

CONCLUSION: Listening to music is effective in reducing procedure time and amount of sedation during colonoscopy and should be promoted.

Cardiovascular considerations in patients undergoing gastrointestinal endoscopy

Gastrointestinal endoscopies are common procedures for diagnosis and treatment. Patients with various cardiovascular conditions can undergo these procedures, including those patients with acute myocardial infarction, but appropriate precautions need to be maintained, especially with procedure-induced autonomic nervous system pertubations that can affect heart rate and blood pressure. In this article, treatment recommendations are included for those patients undergoing endoscopy who are receiving anticoagulation and for those who are at risk for bacterial endocarditis.

Predictors of failed colonoscopy in nonagenarians: a single-center experience

BACKGROUND AND STUDY AIMS

Data on the yield of conventional colonoscopy in very old patients remain limited. The aim of the study was to evaluate the outcome of colonoscopy in nonagenarian patients.

PATIENTS AND METHODS

The safety, success rate to complete colonoscopy and findings of colonoscopies performed during the last 5 years in our center were compared between 41 nonagenarians (group 1) and 2 control groups: 50 consecutive patients aged 70 to 79 years (group 2) and 50 consecutive patients aged 50 to 59 years (group 3). Serum hemoglobin, albumin, patients' source, indications for and colonoscopies findings were retrieved for the total study cohort and comorbidities, mental and functional states for group 1 only. Reasons for colonoscopy failure and predictive factors for failed colonoscopy were analyzed. Chi-square test was used to detect differences in categorical variables by failure or age group. Failure was modeled using logistic regression analyses, and odds ratios with 95% confidence intervals were calculated. All tests were 2-sided and considered significant at P<0.05.

RESULTS

Failed colonoscopy was significantly more prevalent in group 1. The main reason for it was bad preparation. Malignant tumors were significantly more frequently observed in the elderly (groups 1 and 2) than in the younger age group. No complications during and 48 hours postcolonoscopy were observed in all study participants. In univariate analyses in group 1 mental and functional states were inversely and low serum hemoglobin and albumin levels were positively, significantly associated with failure to complete colonoscopy. In multivariate logistic regression analyses, only functional state retained significance as a predictor of failed colonoscopy (odds ratio 5.6, 95% confidence interval 1.5-21.06, P=0.01).

CONCLUSIONS

Colonoscopy in nonagenarians is a safe procedure; however, it carries a significantly higher failure rate. Functional decline was found to be a significant predictive factor for failed colonoscopy.

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

In this study, we evaluated safety and recovery using a patient maintained, target controlled infusion of propofol for sedation in 20 patients undergoing colonoscopy. Using a handset with a two-minute lockout interval, patients could make 0.2 micro g.ml(-1) increments to an initial target plasma concentration of 1 micro g.ml(-1) up to a maximum 4.5 micro g.ml(-1). Four patients became oversedated but required no airway or circulatory interventions. Subjects had a significant reduction in mean (SD) heart rate: 78.7 (15) vs. 69.8 (13.5) (p < 0.001) and in systolic blood pressure 121.1 (13.2) mmHg vs. 96.5 (8.6) mmHg (p < 0.001). Choice reaction time testing 15 min after colonoscopy showed a significant median (IQR [range]) rise of 162 (- 16, 383.3 [-199-859]) ms (p < 0.05). Six patients had faster reaction times postcolonoscopy. All patients denied unpleasant recall and were satisfied with the system. Although oversedation was a problem in this model, we conclude that patient maintained propofol sedation could be possible for colonoscopy.

Heart rate variability in critical illness and critical care

Although the rhythm of a healthy heart is clinically described as regular, the rate is variable. Studies of diverse populations have led to several generalizations about heart rate variability (HRV): (1) HRV is physiologic and normally declines with age, (2) acute changes in HRV are associated with several disease processes that require critical care, (3) measures of HRV can be used to describe the status of critically ill patients, and (4) measures of HRV can be used to predict events subsequent to at least one type of critical illness, myocardial infarction. This brief review considers the mechanisms underlying HRV, the measures that are used to describe HRV, and recent information regarding the use of HRV measures as predictive tools in critical care. The reviewers' opinion is that real-time analysis of HRV in critical illness may provide caregivers with additional information about patient status, effects of intervention, and prognosis.