Patient-administered nitrous oxide/oxygen inhalation provides safe and effective analgesia for percutaneous liver biopsy: a randomized placebo-controlled trial

Nitrous Oxide to Reduce Wound Care-Related Pain in Adults: A Systematic Review and Meta-Analysis

Significance: As an essential procedure, wound care comes with acute pain, which is short but high in intensity, causing patients to fear and affecting subsequent treatment. Nitrous oxide (N2O) is used to relieve pain related to wound care; however, evidence regarding its application is conflicting. Thus, this systematic review and meta-analysis was performed to evaluate the efficacy of N2O in wound care-related pain. Recent Advances: Randomized controlled trials that investigated the effect of N2O in adults undergoing wound care were systematically searched from PubMed, Embase, the Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov up to February 2023. The primary outcome was the pain score. Secondary outcomes included patients' satisfaction and side effects. Critical Issues: Through screening the 265 identified articles, seven and six studies were finally included in the systematic review and meta-analysis, respectively. Pooled analysis suggested that there was no significant difference in reducing wound care-related pain between the N2O group and the control group (mean difference [MD], -0.02, 95% confidence interval [CI], -1.46, 1.42; p = 0.98, I2 = 96%). Subgroup analyses indicated that there was a significant difference in favor of N2O for burns, not for ulcers, and N2O was superior to oxygen and similar to topical or intravenous anesthesia. There was no significant difference in patients' satisfaction or the incidence of side effects between groups. Future Directions: This review suggests that N2O might be effective for pain management in patients undergoing wound care. Caution must be taken when interpreting these results due to the high risk of biased methods in the included studies.

Nonalcoholic Fatty Liver Disease in Patients with Type 2 Diabetes: Screening, Diagnosis, and Treatment

Nonalcoholic fatty liver disease (NAFLD), recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD) affects ~70% of patients with type 2 diabetes (T2D), with ~20% showing signs of advanced liver fibrosis. Patients with T2D are at an increased risk of developing cirrhosis, liver failure, and hepatocellular carcinoma and their liver-related mortality is doubled compared with non-diabetic individuals. Nonetheless, the condition is frequently overlooked and disease awareness is limited both among patients and among physicians. Given recent epidemiological evidence, clinical practice guidelines recommend screening for NAFLD/MASLD and advanced liver fibrosis in patients with T2D. While many drugs are currently being tested for the treatment of NAFLD/MASLD, none of them have yet received formal approval from regulatory agencies. However, several classes of antidiabetic drugs (namely pioglitazone, sodium-glucose transporter 2 inhibitors, glucagon-like peptide 1 receptor agonists, and multi-agonists) have shown favorable effects in terms of liver enzymes, liver fat content and, in some occasions, on histologic features such as inflammation and fibrosis. Therefore, diabetologists have the opportunity to actively treat NAFLD/MASLD, with a concrete possibility of changing the natural history of the disease. In the present narrative review, we summarize evidence and clinical recommendations for NAFLD/MAFLD screening in the setting of T2D, as well as on the effect of currently available glucose-lowering drugs on hepatic endpoints.

Efficacy of nitrous oxide in adults undergoing puncture biopsy: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Nitrous oxide (N2O) with rapid analgesic effect is often used to relieve pain induced by diagnostic procedures. This review was conducted to evaluate the efficacy and safety of N2O in patients undergoing puncture biopsy.

METHODS

We systematically searched PubMed, Embase, the Cochrane Library, Web of Science, Scopus and the ClinicalTrials.gov up to March, 2022. Randomized controlled trials (RCTs) were included if they investigated the effect of N2O in adults undergoing puncture biopsy. The primary outcome was pain score. Secondary outcomes included anxiety score, patient satisfaction and side effects.

RESULTS

Twelve RCTs with 1070 patients were included in the qualitative review, of which eleven RCTs were included in the meta-analysis. Pooled analysis suggested that compared with the controls (placebo, lidocaine and midazolam), N2O had better analgesic effect (MD -1.12, 95% CI -2.12 to -0.13, P = 0.03; I2 = 94%). In addition, N2O significantly alleviated patient anxiety (MD = -1.79, 95% CI -2.41 to -1.18, P<0.00001; I2 = 0%) and improved patient satisfaction (MD 1.81, 95% CI 0.11 to 3.50, P = 0.04; I2 = 92%). There was no significant difference regrading the risk of nausea (RR 2.56; 95% CI 0.70 to 9.31, P = 0.15; I2 = 0%), headache (RR 0.62, 95% CI 0.17 to 2.33, P = 0.48; I2 = 46%), dizziness (RR 1.80, 95% CI 0.63 to 5.13, P = 0.27; I2 = 0%) or euphoria (RR 2.67, 95% CI 0.81 to 8.79, P = 0.11; I2 = 8%) between the N2O group and the control group.

CONCLUSION

The present review suggested that N2O might be effective for pain management in patients undergoing puncture biopsy.

Comparative Assessment of Anxiety during Inferior Alveolar Nerve Block under Nitrous Oxide + Oxygen and Oxygen Inhalation Sedation in Children Aged 3-12 Years: A Randomized Clinical Trial

Aim

A comparative evaluation of children's anxiety with the use of nitrous oxide-oxygen (N2O-O2) inhalation sedation during the administration of inferior alveolar nerve block (IANB).

Materials and methodology

A total of 60 children between 3 and 12 years of age, with Frankl's behavior rating of 2-3 requiring IANB for any dental procedure were enrolled in this randomized clinical study. Group I (n = 30) received N2O and oxygen inhalation sedation at a concentration in the range of 25-50%, whereas group II (n = 30) received 100% O2 as a placebo. The physiological parameters like pulse rate, respiration, blood pressure, and O2 saturation were measured at the baseline, intraoperatively [during and after administration of local anesthesia (LA)] and postoperatively after the termination of the gases in both groups. The sedation level was measured intraoperatively (before administration of LA) using the Ramsay Sedation Score (RSS). The discomfort and anxiety were measured at the baseline, intraoperatively, and postoperatively using the Face, Legs, Activity, Cry, Consolability (FLACC) behavior scale. The data were evaluated using the statistical software International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) statistics 20.0.

Results

There was a significant difference in the FLACC scores between the two groups, intraoperatively (p-value-0.002), and postoperatively (p-value-0.049). The mean of the RSS for group I was 2.80 + 1.03, and for group II was 1.80 + 0.81. All the physiological parameters recorded were within the normal range.

Conclusion

The use of N2O-O2 inhalation improved the anxiety levels in children while receiving the IANB and showed significant anxiolytic and sedative effects as compared to O2 inhalation.

Clinical significance

Nitrous oxide-oxygen (N2O-O2) inhalation can be used as a nonpharmacological behavior management adjunct for invasive treatments for children with utmost comfort for the child.

How to cite this article

Thomas PS, Dave BH, Shah DJ, et al. Comparative Assessment of Anxiety during Inferior Alveolar Nerve Block under Nitrous Oxide + Oxygen and Oxygen Inhalation Sedation in Children Aged 3-12 Years: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2023;16(1):30-36.

"Wet Heparin" and "Wet Saline" EUS-Guided Liver Biopsy Techniques Both Provide High Rates of Specimen Adequacy for Benign Parenchymal Liver Disease

BACKGROUND

Endoscopic ultrasound-guided liver biopsy (EUS-LB) has emerged as a viable mean to obtain core tissue, but the optimal tools and techniques are still an area of active investigation.

AIMS

(1) To compare tissue adequacy using "wet saline" (WS) vs. "wet heparin" (WH) technique (2) To compare post-procedure pain between EUS-LB and percutaneous liver biopsy (PLB).

METHODS

Retrospective review of consecutive patients who underwent EUS-LB and PLB for benign parenchymal liver disease between May 2017 to October 2019 at a single tertiary veterans affairs medical center.

RESULTS

About 257 biopsies from 217 patients were included. Among the 102 EUS-LB specimens, 53 were obtained using WS technique and 49 were obtained using WH technique. Specimen adequacy was similar in both groups. Median Aggregate Specimen Length (ASL) and length of longest piece did not differ significantly between WS and WH groups. Clots were present more frequently in the WS group. Among patients who underwent EUS-LB of both right and left liver lobes, an adequate biopsy was obtained in 85% of patients in the WS group and 96% of patients in the WH group. The percentage of patients experiencing immediate post-procedure pain was higher with PLB compared to EUS-LB, but these results were not statistically significant.

CONCLUSIONS

Both WS and WH EUS-LB techniques can offer high rates of specimen adequacy with low rates of pain and other post-procedure complications.

Impact of non-invasive biomarkers on hepatology practice: Past, present and future

Over the last two decades, there have been tremendous advances in the non-invasive diagnosis and risk stratification of chronic liver diseases (CLDs). Non-invasive approaches are based on the quantification of biomarkers in serum samples or on the measurement of liver stiffness, using either ultrasound- or magnetic resonance-based elastography techniques. The fibrosis-4 index (non-patented) and enhanced liver fibrosis test (patented) are the most widely adopted serum markers, whereas vibration-controlled transient elastography is the most widely adopted elastography technique. In this review, we discuss the role of non-invasive tests in the current era, as well as their accuracy and how their use in clinical practice has changed the practice of hepatology, including identification of early cirrhosis in patients with risk factors for CLD, diagnosis of portal hypertension, establishing prognosis in compensated cirrhosis, guiding antiviral treatment, and screening for fibrosis and cirrhosis in primary care.

Prospective comparison of transient elastography, MRI and serum scores for grading steatosis and detecting non-alcoholic steatohepatitis in bariatric surgery candidates

Background & Aims

Tools for the non-invasive diagnosis of non-alcoholic steatohepatitis (NASH) in morbidly obese patients with suspected non-alcoholic fatty liver disease (NAFLD) are an unmet clinical need. We prospectively compared the performance of transient elastography, MRI, and 3 serum scores for the diagnosis of NAFLD, grading of steatosis and detection of NASH in bariatric surgery candidates.

Methods

Of 186 patients screened, 152 underwent liver biopsy, which was used as a reference for NAFLD (steatosis [S]>5%), steatosis grading and NASH diagnosis. Biopsies were read by a single expert pathologist. MRI-based proton density fat fraction (MRI-PDFF) was measured in an open-bore, vertical field 1.0T scanner and controlled attenuation parameter (CAP) was measured by transient elastography, using the XL probe. Serum scores (SteatoTest, hepatic steatosis index and fatty liver index) were also calculated.

Results

The applicability of MRI was better than that of FibroScan (98% vs. 79%; p <0.0001). CAP had AUROCs of 0.83, 0.79, 0.73 and 0.69 for S>5%, S>33%, S>66% and NASH, respectively. Transient elastography had an AUROC of 0.80 for significant fibrosis (F0-F1 vs. F2-F3). MRI-PDFF had AUROCs of 0.97, 0.95, 0.92 and 0.84 for S>5%, S>33%, S>66% and NASH, respectively. When compared head-to-head in the 97 patients with all valid tests available, MRI-PDFF outperformed CAP for grading steatosis (S>33%, AUROC 0.97 vs. 0.78; p <0.0003 and S>66%, AUROC 0.93 vs. 0.75; p = 0.0015) and diagnosing NASH (AUROC 0.82 vs. 0.68; p = 0.0056). When compared in "intention to diagnose" analysis, MRI-PDFF outperformed CAP, hepatic steatosis index and fatty liver index for grading steatosis (S>5%, S>33% and S>66%).

Conclusion

MRI-PDFF outperforms CAP for diagnosing NAFLD, grading steatosis and excluding NASH in morbidly obese patients undergoing bariatric surgery.

Lay summary

Non-invasive tests for detecting fatty liver and steatohepatitis, the active form of the disease, have not been well studied in obese patients who are candidates for bariatric surgery. The most popular tests for this purpose are Fibroscan, which can be used to measure the controlled attenuation parameter (CAP), and magnetic resonance imaging, which can be used to measure the proton density fat fraction (MRI-PDFF). We found that, when taking liver biopsy as a reference, MRI-PDFF performed better than CAP for detecting and grading fatty liver as well as excluding steatohepatitis in morbidly obese patients undergoing bariatric surgery.

Effects of Different Recovery Positions on the Postpercutaneous Liver Biopsy Complications: A Metaanalysis

Objective: We aim to evaluate the effects of different recovery positions on the adverse events and the patient acceptability in those who underwent percutaneous liver biopsy (PLB). Methods: A literature search was conducted in the Cochrane Library, Embase, Scopus, PubMed, CNKI, Sinomed, and Wanfang databases. The time for the article extraction was until July 2020. The articles were screened by two independent researchers, together with the bias risk evaluation and data extraction. The RevMan 5.4 software was utilized for the metaanalysis. Results: Finally, two articles involving 180 subjects were eligible for this study. Metaanalysis showed that at T0, the alternation between right-side and combined position (CRP) would induce an elevation of post-PLB pain compared with the dorsal/supine position (SRP) [WMD = -2.00, 95% CI (-3.54, -0.47), p = 0.01]. There were no statistical differences in the postoperative pain among the CRP, SRP, and right-side position (RRP). The patient acceptability of SRP and RRP was higher than that of the CRP. Finally, two eligible studies were included, which showed no incidence of pneumothorax and abdominal bleeding. Conclusions: CRP would induce post-PLB pain at T0. SRP was the most acceptable position for the cases that underwent PLB. There were no statistical differences in the incidence of pneumothorax and abdominal bleeding. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020196633.

Current state of endohepatology: Diagnosis and treatment of portal hypertension and its complications with endoscopic ultrasound

The diagnosis and management of cirrhosis and portal hypertension (PH) with its complications including variceal hemorrhage, ascites, and hepatic encephalopathy continues to evolve. Although there are established “standards of care” in liver biopsy and measurement of PH, gastric varices remain an area without a universally accepted therapeutic approach. The concept of “Endo Hepatology” has been used to describe of the applications of endoscopic ultrasound (EUS) to these challenges. EUS-liver biopsy (EUS-LB) offers an alternative to percutaneous and transjuglar liver biopsy without compromising safety or efficacy, and with added advantages including the potential to reduce sampling error by allowing biopsies in both hepatic lobes. Furthermore, EUS-LB can be performed during the same procedure as EUS-guided portal pressure gradient (PPG) measurements, allowing for the collection of valuable diagnostic and prognostic data. EUS-guided PPG measurements provide an appealing alternative to the transjugular approach, with proposed advantages including the ability to directly measure portal vein pressure. In addition, EUS-guided treatment of gastric varices (GV) offers several possible advantages to current therapies. EUS-guided treatment of GV allows detailed assessment of the vascular anatomy, similar efficacy and safety to current therapies, and allows the evaluation of treatment effect through doppler ultrasound visualization. The appropriate selection of patients for these procedures is paramount to ensuring generation of useful clinical data and patient safety.

A portable single-sided magnetic-resonance sensor for the grading of liver steatosis and fibrosis

Low-cost non-invasive diagnostic tools for staging the progression of non-alcoholic chronic liver failure from fatty liver disease to steatohepatitis are unavailable. Here, we describe the development and performance of a portable single-sided magnetic-resonance sensor for grading liver steatosis and fibrosis using diffusion-weighted multicomponent T2 relaxometry. In a diet-induced mouse model of non-alcoholic fatty liver disease, the sensor achieved overall accuracies of 92% (Cohen's kappa, κ = 0.89) and 86% (κ = 0.78) in the ex vivo grading of steatosis and fibrosis, respectively. Localization of the measurements in living mice through frequency-dependent spatial encoding led to an overall accuracy of 87% (κ = 0.81) for the grading of steatosis. In human liver samples, the sensor graded steatosis with an overall accuracy of 93% (κ = 0.88). The use of T2 relaxometry as a sensitive measure in fully automated low-cost magnetic-resonance devices at the point of care would alleviate the accessibility and cost limits of magnetic-resonance imaging for diagnosing liver disease and assessing liver health before liver transplantation.

Impact of Opioid Analgesia and Inhalation Sedation Kalinox on Pain and Radial Artery Spasm during Transradial Coronary Angiography

With respect to the transfemoral approach, transradial procedures enable a drastic reduction of bleeding events and are associated with a reduction of mortality. Radial artery spasm (RAS) is one of the most common complications and may lead to patient discomfort and procedural failure. Currently, there is no consensus on the optimal sedation protocol to avoid RAS. The aim of this study was to investigate the respective impact of opioids analgesia and inhalation sedation with a 50% nitrous oxide/oxygen premix (Kalinox) on pain and occurrence of RAS during transradial coronary procedures. Consecutive patients undergoing transradial coronary angiography were prospectively enrolled in one, single center observational study (Nouvel Hôpital Civil, Strasbourg, France). Patients received opioids analgesia or inhalation sedation with Kalinox. The primary endpoints of the study were the incidence of a pain scale ≥5/10 and the occurrence of RAS. The secondary endpoints were the incidence of side effects. A total of 325 patients were enrolled (185 in the opioids analgesia group, 140 in the Kalinox group). RAS and pain scale ≥5 rates were not significantly different in the opioids analgesia and Kalinox groups (respectively 13.5% vs. 10.0% and 16.2% vs. 11.4%). Headache was more frequently observed in the Kalinox group (6.4% vs. 0.0%; p = 0.002). By multivariate analysis, female gender, BMI <25 kg/m², puncture difficulty, the use of plastic needle and 6F sheath were identified as independent predictors of RAS. Procedural inhalation sedation by Kalinox is as safe as opioids analgesia during transradial coronary angiography.

Early preoperative versus postoperative administration of meloxicam in pain control, patient global status improvement, knee function recovery of arthroscopic knee surgery

BACKGROUND

This study aimed to investigate the efficacy and safety between early preoperative administration and postoperative administration of oral meloxicam in patients underwent arthroscopic knee surgery (AKS).

METHODS

Totally 296 patients with the intention to undergo AKS were recruited and randomly allocated as 1:1 ratio into early preoperative analgesia (EPA) group and postoperative analgesia (POA) group. Pain visual analog scale (VAS) score and severity (at rest and at flexion), patient global assessment (PGA) score, the consumption of rescue analgesia (pethidine), and adverse events were evaluated during the perioperation. And knee range of motion (ROM), International Knee Documentation Committee (IKDC) score, and Lysholm score were assessed at baseline and at 3 months after AKS.

RESULTS

Both pain VAS score and severity (at rest and at flexion) were decreased at 4, 8, and 12 hours, but similar at -24, -2, 24, 36, and 48 hours after AKS in EPA group compared with POA group. Besides, PGA score was lower at 4, 8, 12, and 24 hours, but similar at -24, -2, 36, and 48 hours after AKS in EPA group compared with POA group. As to the consumption of pethidine in perioperative period, it was decreased in EPA group compared with POA group. No difference was observed in knee ROM, IKDC score, Lysholm score, and adverse effects between EPA group and POA group.

CONCLUSION

Early preoperative administration of meloxicam was a superior approach in pain control compared with postoperative administration in treating patients underwent AKS.

Analgesia effect of premixed nitrous oxide/oxygen during the rehabilitation after total knee arthroplasty: a study protocol for a randomized controlled trial

Background

The morbidity of knee arthritis is increasing among aged people and total knee arthroplasty has been its mainstream treatment to date. Postoperative rehabilitation is an important part of the procedure. However, the intense pain during the functional exercise involved has always been a challenge for both patients and health care professionals. The aim of this study is to test the analgesic effect of a mixture of nitrous oxide/oxygeb (1:1) inhalation for patients who are doing functional exercise 1 month after total knee arthroplasty.

Methods/design

This double-blind, randomized, placebo-controlled study will be implemented in the Rehabilitation Department in the General Hospital of Ningxia Medical University. Patients aged between 50 and 75 years who underwent a primary unilateral total knee arthroplasty are eligible for inclusion. The key exclusion criteria include: epilepsy, pulmonary embolism, intestinal obstruction, aerothorax. The treatment group (A) will receive a pre-prepared nitrous oxide/oxygen mixture plus conventional treatment (no analgesics), and the control group (B) will receive oxygen plus conventional treatment (no analgesics). Patients, physicians, therapists, and data collectors are all blind to the experiment. Assessments will be taken immediately after functional exercise begins (T0), 5 min (T1) after functional exercise begins, and 5 min after functional exercise has finished (T2). Patients will be randomly allocated between a treatment group (A) and a control group (B) in a ratio of 1:1. Primary outcome, including pain severity in the procedure, will be taken for each group. Secondary outcomes include blood pressure, heart rate, oxygen saturation, side effects, knee joint range of motion, Knee Society Score (KSS), rescue analgesia need, and satisfaction from both therapists and patients.

Discussion

This study will focus on exploring a fast and efficient analgesic for patients who are doing functional exercise after total knee arthroplasty. Our previous studies suggested that the prefixed nitrous oxide/oxygen mixture was an efficacious analgesic for the management of burn-dressing pain and breakthrough cancer pain. The results of this study should provide a more in-depth insight into the effects of this analgesic method. If this treatment proves successful, it could be implemented widely for patients doing functional exercise in the rehabilitation department.

Trial registration

ChiCTR-INR-17012891. Registered on 6 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3472-7) contains supplementary material, which is available to authorized users.

Characterization and evaluation of liver fibrosis grade in patients with chronic hepatitis B virus infection and normal transaminases

Background/Aims

The objective of our study was to determine the epidemiological, laboratory, and serological characteristics of patients with chronic hepatitis B virus (HBV) infection and normal transaminases. The study also aimed to evaluate liver damage by measuring the liver fibrosis (LF) grade and to identify possible factors associated with the presence of fibrosis.

Methods

A retrospective observational study was conducted in patients with chronic HBV infection and classified as inactive carriers or immune-tolerant. Epidemiological variables of age, sex, immigrant, alcohol consumption, and body mass index (BMI), as well as virological variables (HBV DNA) and transaminase level were collected throughout the follow-up. The LF grade was evaluated by transient elastography. The cutoff value for significant fibrosis (SF) was liver stiffness ≥7.9 kPa.

Results

A total of 214 patients were included in the analysis, and 62% of them had a BMI ≥25 kg/m². During follow-up, 4% of patients showed transaminase elevation (<1.5 times normal). Most patients had a viral DNA level <2,000 IU/mL (83%). Data on LF were available in 160 patients; of these, 14% had SF, 9% F3, and 6% F4. The variables associated with the presence of SF were transaminase alteration during follow-up, as 23% of patients with SF had elevated transaminases versus 3% of patients without SF (P<0.005), and BMI, as the vast majority of patients with SF (88%) had a BMI ≥25 kg/m² versus 56% of patients without SF (P<0.05).

Conclusions

In patients with chronic HBV infection and normal transaminases, liver damage does not seem to be related to DNA levels, alcohol consumption, or immigrant status. SF seems to be associated with transaminase alteration during follow-up and elevated BMI. It is therefore recommended to measure LF grade with validated non-invasive methods in such patients.

Comparison of the effect of region-of-interest methods using gadoxetic acid-enhanced MR imaging with diffusion-weighted imaging on staging hepatic fibrosis

OBJECTIVE

To evaluate the utility of T1 mapping on gadoxetic acid-enhanced MRI and DWI for staging liver fibrosis and assess the influence of ROI positioning on interobserver variability, T1 relaxation time and ADC value.

METHODS

This retrospective study was approved by the institutional review board and included 150 patients (mean age 58 years old; 91 men and 59 women). Liver fibrosis stages (S) were histopathologically determined. T1 relaxation time and ADC value of liver were measured by three distinct ROI protocols (the whole left lobe liver, the whole right lobe liver and the individual ROIs). T1 relaxation time measurements were compared with ADC values according to S scores. Interobserver variability for the T1 relaxation times and ADC values by the three distinct ROI protocols was analyzed by calculating the ICC.

RESULTS

T1 relaxation time measurements by the three distinct ROI protocols on severe fibrosis stage were significantly higher than the relative values on mild fibrosis stage. The mean ADC values on severe fibrosis stage showed no significantly different when measured by means of the whole right lobe liver (p = 0.057) and the individual ROIs (p = 0.10), compared with the relative values on mild fibrosis stage. AUCs of T1 relaxation time and ADC value by the means of the three distinct ROI protocols were 0.614, 0.676, 0.677 and 0.656, 0.585, 0.575 for identification of severe fibrosis stage. The interobserver reproducibility was excellent for measuring the right lobe liver T1 relaxation time and the individual ROIs T1 relaxation time (ICC 0.814, 0.883, respectively).

CONCLUSIONS

T1 relaxation time measurements by means of the three distinct ROI protocols on gadoxetic acid-enhanced MR imaging were a potential biomarker in staging of hepatic fibrosis, which were more accuracy than DWI-ADC measurements. The more reproducible results were obtained when measuring T1 relaxation time of the whole right lobe liver and the individual ROIs.

Nitrous oxide-based techniques versus nitrous oxide-free techniques for general anaesthesia

BACKGROUND

Nitrous oxide has been used for over 160 years for the induction and maintenance of general anaesthesia. It has been used as a sole agent but is most often employed as part of a technique using other anaesthetic gases, intravenous agents, or both. Its low tissue solubility (and therefore rapid kinetics), low cost, and low rate of cardiorespiratory complications have made nitrous oxide by far the most commonly used general anaesthetic. The accumulating evidence regarding adverse effects of nitrous oxide administration has led many anaesthetists to question its continued routine use in a variety of operating room settings. Adverse events may result from both the biological actions of nitrous oxide and the fact that to deliver an effective dose, nitrous oxide, which is a relatively weak anaesthetic agent, needs to be given in high concentrations that restrict oxygen delivery (for example, a common mixture is 30% oxygen with 70% nitrous oxide). As well as the risk of low blood oxygen levels, concerns have also been raised regarding the risk of compromising the immune system, impaired cognition, postoperative cardiovascular complications, bowel obstruction from distention, and possible respiratory compromise.

OBJECTIVES

To determine if nitrous oxide-based anaesthesia results in similar outcomes to nitrous oxide-free anaesthesia in adults undergoing surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014 Issue 10); MEDLINE (1966 to 17 October 2014); EMBASE (1974 to 17 October 2014); and ISI Web of Science (1974 to 17 October 2014). We also searched the reference lists of relevant articles, conference proceedings, and ongoing trials up to 17 October 2014 on specific websites (http://clinicaltrials.gov/, http://controlled-trials.com/, and http://www.centerwatch.com).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing general anaesthesia where nitrous oxide was part of the anaesthetic technique used for the induction or maintenance of general anaesthesia (or both) with any general anaesthesia using a volatile anaesthetic or propofol-based maintenance of anaesthesia but no nitrous oxide for adults undergoing surgery. Our primary outcome was inhospital case fatality rate. Secondary outcomes were complications and length of stay.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the outcome data. We used meta-analysis for data synthesis. Heterogeneity was examined with the Chi² test and by calculating the I² statistic. We used a fixed-effect model if the measure of inconsistency was low for all comparisons (I² statistic < 50%); otherwise we used a random-effects model for measures with high inconsistency. We undertook subgroup analyses to explore inconsistency and sensitivity analyses to evaluate whether the results were robust. We assessed the quality of evidence of the main outcomes using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

MAIN RESULTS

We included 35 trials (13,872 adult participants). Seven included studies were at low risk of bias. We identified eight studies as awaiting classification since we could not obtain the full texts, and had insufficient information to include or exclude them. We included data from 24 trials for quantitative synthesis. The results of meta-analyses showed that nitrous oxide-based techniques increased the incidence of pulmonary atelectasis (odds ratio (OR) 1.57, 95% confidence interval (CI) 1.18 to 2.10, P = 0.002), but had no effects on the inhospital case fatality rate, the incidence of pneumonia, myocardial infarction, stroke, severe nausea and vomiting, venous thromboembolism, wound infection, or the length of hospital stay. The sensitivity analyses suggested that the results of the meta-analyses were all robust except for the outcomes of pneumonia, and severe nausea and vomiting. Two trials reported length of intensive care unit (ICU) stay but the data were skewed so were not pooled. Both trials reported that nitrous oxide-based techniques had no effects on the length of ICU stay. We rated the quality of evidence for two outcomes (pulmonary atelectasis, myocardial infarction) as high, four outcomes (inhospital case fatality rate, stroke, venous thromboembolism, length of hospital stay) as moderate, and three (pneumonia, severe nausea and vomiting, wound infection rate) as low.

AUTHORS' CONCLUSIONS

Given the evidence from this Cochrane review, the avoidance of nitrous oxide may be reasonable in participants with pre-existing poor pulmonary function or at high risk of postoperative nausea and vomiting. Since there are eight studies awaiting classification, selection bias may exist in our systematic review.

Use of pethidine for percutaneous liver biopsy - a randomised, placebo-controlled, double blind study

BACKGROUND

Percutaneous liver biopsy (PLB) is the "gold standard" in the diagnosis of liver diseases. A pilot trial has shown pethidine may reduce anxiety and the need for post-procedural pain relief. The aim of this study was to investigate the role of pre-procedural pethidine.

METHODS

A double-blinded, randomized, placebo-controlled trial was conducted to assess the need for pethidine prior to PLB. 98 patients were randomly assigned to receive either 50 mg pethidine i.v. (n = 48), or an equal volume of 0.9% normal saline (n = 50). PLB was performed with ultrasound guidance after adequate local anaesthesia with xylocaine. Patients were asked to self-evaluate pain experienced using a visual analogue score (0-10) immediately and an hour after PLB. Patients were then followed up 24 hours after the procedure to assess their pain score, retrospective pain score and willingness to have a repeat procedure.

RESULTS

Pethidine administration resulted in significantly lower pain scores (0.60 ± 0.1 vs 1.2 ± 0.2, p = 0.006) and required less analgesia (0% vs 10%, p = 0.03) immediately after PLB in comparison to the placebo group. There was no significant difference in the pain score and analgesia requirement one hour after the procedure, the pain score at 24 hours after procedure and retrospective pain score. 94% of all patients of either group are willing to under go a repeat liver biopsy (NS).

CONCLUSIONS

The administration of pethidine routinely prior to PLB reduces the immediate post procedural pain but has no lasting effect and does not influence the patients' decision making process for future investigations.

TRIAL REGISTRATION

ACTRN12614001194651 , 13 November 2014.

[Liver biopsy in Dakar: indications, complications and diagnostic contribution--about 70 cases]

Introduction

Les objectifs de notre travail étaient de déterminer les indications, les complications et l'apport diagnostique de la ponction biopsie hépatique (PBH) transpariétale.

Méthodes

Il s'agissait d'une étude rétrospective descriptive allant du janvier 2006 à décembre 2010, réalisée dans le service de Médecine Interne de l'hôpital de Pikine de Dakar. Etaient inclus, tous les malades ayant subi une biopsie hépatique, en ambulatoire ou en hospitalisation. Etaient exclus, tous les patients qui ont bénéficié d'une PBH dont les résultats n'ont pas été retrouvés. Les données suivantes étaient étudié: l’âge, le sexe, les indications, la taille du fragment biopsique, Le nombre de carottes, les complications, la comparaison des diagnostics pré biopsiques avec les comptes rendus histologiques.

Résultats

Ont été colligées 70 patients atteints d'hépatopathie chronique ayant bénéficiés d'une PBH. Il s'agissait de 46 hommes (65.71%) et 24 femmes (34.29%). L’âge moyen des patients était de 36 ans. Les PBH étaient réalisées en ambulatoire chez 58 patients (82.86%) et chez 12 malades hospitalisés (17,14%). Les indications étaient dominées par les hépatites virales chroniques dans 62,86% (44cas), suivi des processus tumoraux du foie dans 24.29% (17 cas). Les complications survenues chez 15 patients (21.43%) étaient représentées de 14 cas de douleur (20%) et d'un cas de malaise vagal (1.43%). Les 70 PBH effectuées ont ramené une carotte dans 35,71% des cas, 2 à 6 carottes dans 32,87% des cas. La longueur moyenne des fragments biopsiques était de 22 ±8 mm. Soixante-six résultats étaient interprétables et 4 non interprétables soit une performance diagnostique de 94,29%.

Conclusion

La PBH est de pratique sure, avec un respect des contres indications et une bonne maitrise de la technique. Son acceptabilité a été bonne dans notre pratique et sa rentabilité diagnostique excellente. Elle devrait être beaucoup plus vulgarisée dans notre pays, comme alternative aux moyens d'exploration non invasive.

Non-invasive assessment of liver fibrosis in chronic hepatitis C

Quantification of hepatic fibrosis is of critical importance in chronic hepatitis C not only for prognosis, but also for antiviral treatment indication. Two end points are clinically relevant: detection of significant fibrosis (indication for antiviral treatment) and detection of cirrhosis (screening for eosphageal varices and hepatocellular carcinoma). Until recently, liver biopsy was considered the reference method for the evaluation of liver fibrosis. Limitations of liver biopsy (invasiveness, sampling error, and inter-observer variability) have led to the development of non-invasive methods. Currently available methods rely on two different approaches: a "biological" approach based on the dosage of serum fibrosis biomarkers; and a "physical" approach based on the measurement of liver stiffness, using transient elastography (TE). This review is aimed at discussing the advantages and limits of non-invasive methods and liver biopsy and the perspectives for their rational use in clinical practice in the management of patients with chronic hepatitis C.

Involvement of the protein kinase Cγ isoform in development of tolerance to nitrous oxide–induced antinociception in mice

Prolonged exposure to nitrous oxide (N2O) results in development of acute tolerance to its antinociceptive effect. Cross-tolerance to N2O-induced antinociception is also observed in morphine-tolerant animals. Despite increasing evidence of tolerance development to N2O-induced antinociception, the details of the mechanisms that underlie this tolerance remain unknown. The present study was conducted to investigate the involvement of brain protein kinase C (PKC) isoform in these two types of tolerance to N2O-induced antinociception in mice. Prolonged exposure (41 min in total, including 30 min pre-exposure and 11 min of antinociceptive testing) to 70% N2O produced a reduction in N2O-induced antinociception, indicating development of acute tolerance. The prolonged exposure to 70% N2O caused an activation of PKCgamma isoform in the brain, but not the PKCepsilon isoform. Pretreatment with a PKCgamma-antisense oligonucleotide but not the corresponding mismatch oligonucleotide (i.c.v.) prevented the development of acute tolerance to N2O-induced antinociception. Chronic morphine treatment (10 mg/kg, s.c., b.i.d. for 5 days) resulted in development of tolerance to morphine-induced antinociception and cross-tolerance to N2O-induced antinociception. The development of tolerance to morphine and cross-tolerance to N2O were both inhibited by pretreatment with PKC inhibitor, chelerythrine (1 nmol, i.c.v.). Morphine-tolerant mice showed an activation of PKC within the brain, which was suppressed by pretreatment with chelerythrine (1 nmol, i.c.v.). Thus, activation of brain PKC, in particular, the PKCgamma isoform, appears to play an important role in the development of both acute tolerance and cross-tolerance to N2O-induced antinociception in mice.

Tolerability of an equimolar mix of nitrous oxide and oxygen during painful procedures in very elderly patients

BACKGROUND AND OBJECTIVE

Although an equimolar mix of nitrous oxide-oxygen (N(2)O/O(2)) [Kalinox] is widely used as an analgesic, there have been few specific studies of this product in the elderly. In this article, we investigate the tolerability of this equimolar mix in very elderly patients undergoing painful procedures.

METHODS

This was a prospective, observational study of patients hospitalised in the geriatric short-stay unit of a teaching hospital between July 2001 and September 2003. All patients aged >/=80 years who were scheduled for invasive care procedures were eligible for inclusion. Sixty-two patients were recruited and underwent a total of 68 procedures. The procedures were divided into four classes based on the degree of pain they were expected to cause and their duration. Patients received the equimolar N(2)O/O(2) mix (Kalinox) for 5 minutes before the beginning of the procedure and throughout its duration. The inhaled treatment was administered via a high-concentration mask. Assessments were carried out during the inhalation and over the 15 minute period following inhalation. The primary endpoint of the study was tolerability of the equimolar N(2)O/O(2) mix, and all adverse events were recorded. Secondary endpoints were the efficacy of the product (assessed on a verbal rating scale and/or the Doloplus scale), its ease of use and its acceptability to patients and staff.

RESULTS

Fourteen patients (22.6%) each reported at least one adverse event: impaired hearing (n = 1), altered perception of the environment (n = 8), anxiety (n = 1), headache (n = 3) and drowsiness at the end of the procedure (n = 2). All these disorders subsided rapidly after treatment was completed.

CONCLUSION

This study shows the favourable tolerability of the equimolar N(2)O/O(2) mix in very elderly subjects, which makes this product a valuable tool for the management of acute pain in this age group.

A systematic review of the safety of analgesia with 50% nitrous oxide: can lay responders use analgesic gases in the prehospital setting?

A safe and effective form of pain relief would be an advantage in the prehospital treatment of patients experiencing extreme pain. Although used by many emergency medical services, 50% nitrous oxide (an inhaled analgesic known to have good pain relief properties) is not widely used by volunteer and semiprofessional organisations. This review aimed to determine whether 50% nitrous oxide is safe for use by first responders who are not trained as emergency medical technicians. A thorough search of the literature identified 12 randomised controlled trials investigating the use of 50% nitrous oxide (as compared with placebo or conventional analgesic regimens) in a range of conditions. The outcomes analysed for this review were: adverse events, recovery time, and need for additional medication. None of the studies compared the treatments in the prehospital setting; children were well represented. Adverse effects were rare and significant adverse outcomes such as hypotension and oxygen desaturation could not be attributed to nitrous oxide. Compared with patients receiving conventional analgesia, those receiving 50% nitrous oxide did not require additional medication any more frequently and had a faster recovery from sedative effects. The low incidence of significant adverse events from 50% nitrous oxide suggests that this agent could be used safely by lay responders.

Prospective randomized trial of post-liver biopsy recovery positions: does positioning really matter?

GOALS

The goal of this study was to compare three commonly practiced post-liver biopsy recovery postures with respect to pain levels and overall patient acceptability.

BACKGROUND

Percutaneous liver biopsy is a valuable procedure used in the diagnosis, prognosis, and treatment of liver diseases. No standardized recovery posture exists, and no studies have been performed to compare these different recovery techniques.

STUDY

Ninety adult patients were randomized into three arms of the study: right-side (R), supine (S), and combination (C) groups. A validated Visual Analogue Scale (VAS) was given to patients to grade the pain and discomfort experienced during recovery intervals as well as to grade the overall acceptability of the biopsy experience.

RESULTS

Immediately following liver biopsy, more pain was experienced by patients randomized to R with a mean VAS score of 26.5 of 100, compared with 14.2 (P = 0.026) and 12.1 (P = 0.009) for C and S groups, respectively. At the end of recovery, there was no difference among the three groups. The mean acceptability score was 89.2 of 100 for C versus 94.5 for S (P = 0.047) and 94.8 for R (P = 0.046).

CONCLUSION

This study is the first to examine differing post-liver biopsy techniques. When three commonly practiced recovery positions, C, R, and S, are compared, C was the least acceptable position. Patients should be placed in position R or S during recovery.

Influence of operator experience on performance of ultrasound-guided percutaneous liver biopsy

The purpose was to evaluate the influence of radiologist's experience on the diagnostic yield and complications of a percutaneous liver biopsy (PLB) method. Six hundred patients underwent an ultrasound-guided PLB by an inexperienced operator in 25.2% of cases (experience of less than 15 percutaneous liver biopsies performed alone--group I) or by an experienced operator (experience of more than 150 percutaneous liver biopsies--group II). The two groups were well-matched with respect to sex, age, percentage with viral hepatitis without histological cirrhosis, number of needle passes, history of liver biopsy and pain before the biopsy. A histological diagnosis was available in 97.3% of cases without any significant difference between the two groups ( P=0.25). However, group II samples were significantly longer and contained more portal tracts ( P=0.01). Pain was mild immediately and 6 h after the biopsy, without significant difference between both groups. Eight vasovagal reactions (five in group II) and one arteriobiliary fistula (in group II) occurred. With the method of PLB used for this study, operator's experience did not influence either the final histological diagnosis or the degree of pain suffered.

Prevalence and characteristics of pain induced by percutaneous liver biopsy

Percutaneous needle liver biopsy is an important procedure for the diagnosis and evaluation of liver disease and is frequently associated with pain. In this prospective study, we investigated the prevalence and characteristics of this pain syndrome. Fifty-four subjects, who underwent liver biopsy under ultrasound guidance, received 5 mg of diazepam orally 1 h before the procedure and local infiltration with 10 mL of 2% lidocaine just before needle insertion. Outcome measures included the visual analog scale for measuring pain intensity over 24 h, pain localization on a body scheme, and the Spielberger questionnaire for measuring anxiety levels. Forty-seven (84%) of the 54 respondents reported pain 30 min after the biopsy (visual analog scale, 4.2 +/- 0.5; mean +/- SEM), and 21 (39%) reported pain at the 24-h time point. Biopsy site pain was reported by 9 subjects, right shoulder pain by 14, and pain at both sites by 24. Higher pain intensities were reported by women and by subjects with higher anxiety levels. This study indicates that liver biopsy is a painful condition in most patients. Mild anxiolytic treatment plus local anesthetic infiltration seem to produce insufficient analgesia, thus indicating that a more profound analgesic treatment is required for better control of this pain.

IMPLICATIONS

Percutaneous liver biopsy is a painful procedure in most patients. Mild anxiolytic treatment plus local anesthetic infiltration seem to produce insufficient analgesia. A more profound analgesic treatment is required for better control of this pain.