Polyethylene glycol bowel preparation does not eliminate the risk of acute renal failure: a population-based case-crossover study

Association Between Influenza Vaccination and Acute Kidney Injury Among the Elderly: A Self-Controlled Case Series

BACKGROUND

Several cases of renal complications, including acute kidney injury (AKI), after influenza vaccination have been reported, but the association remains unproven. We evaluated the association between influenza vaccination and AKI occurrence among the Korean elderly in the 2018-2019 and 2019-2020 seasons.

METHODS

We used a large database combining vaccination registration data from the Korea Disease Control and Prevention Agency and claims data from the National Health Insurance Service. The study subjects were patients hospitalized with AKI for the first-time following vaccination among those who received one influenza vaccine in the 2018-2019 or 2019-2020 season. Only those aged 65 or older at the date of vaccination were included. We performed a self-controlled case series study, designating the risk period as 1 to 28 days post-vaccination and the observation period as each influenza season. The adjusted incidence rate ratio (aIRR) was calculated by adjusting for nephrotoxic drug use and influenza infection that may influence AKI occurrence using a conditional Poisson regression model.

RESULTS

A total of 16 713 and 16 272 AKI events were identified during the 2018-2019 and 2019-2020 seasons, respectively. The aIRR for AKI was 0.83 (95% confidence interval [CI] = 0.79-0.87) in the 2018-2019 season. The aIRR for the 2019-2020 influenza season was similar to the 2018-2019 season (aIRR = 0.86; 95% CI = 0.82-0.90).

CONCLUSIONS

Influenza vaccination is associated with a lower risk of AKI in the elderly over 65. This evidence supports the recommendation of annual influenza vaccination for the elderly. Further studies are needed to determine the biological mechanisms linking the influenza vaccine and AKI.

Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature

Adequate bowel cleansing is critical for a high-quality colonoscopy because it affects diagnostic accuracy and adenoma detection. Nevertheless, almost a quarter of procedures are still carried out with suboptimal preparation, resulting in longer procedure times, higher risk of complications, and higher likelihood of missing lesions. Current guidelines recommend high-volume or low-volume polyethylene glycol (PEG)/non-PEG-based split-dose regimens. In patients who have had insufficient bowel cleansing, the colonoscopy should be repeated the same day or the next day with additional bowel cleansing as a salvage option. A strategy that includes a prolonged low-fiber diet, a split preparation regimen, and a colonoscopy within 5 h of the end of preparation may increase cleansing success rates in the elderly. Furthermore, even though no specific product is specifically recommended in the other cases for difficult-to-prepare patients, clinical evidence suggests that 1-L PEG plus ascorbic acid preparation are associated with higher cleansing success in hospitalized and inflammatory bowel disease patients. Patients with severe renal insufficiency (creatinine clearance < 30 mL/min) should be prepared with isotonic high volume PEG solutions. Few data on cirrhotic patients are currently available, and no trials have been conducted in this population. An accurate characterization of procedural and patient variables may lead to a more personalized approach to bowel preparation, especially in patients undergoing resection of left colon lesions, where intestinal preparation has a poor outcome. The purpose of this review was to summarize the evidence on the risk factors influencing the quality of bowel cleansing in difficult-to-prepare patients, as well as strategies to improve colonoscopy preparation in these patients.

Bowel Preparation and Subsequent Colonoscopy Is Associated with the Risk of Atrial Fibrillation: A Population-Based Case-Crossover Study

This study aimed to clarify the association of the risk of atrial fibrillation (AF) with bowel preparation and subsequent colonoscopy through population-based case-crossover analysis. Patients who developed new-onset AF after undergoing colonoscopy following bowel preparation were included. For each patient, one hazard period and four control periods were matched at specified time windows. Among 189,613 patients with AF, 84 patients (mean age: 72.4 years) finally met the inclusion criteria. Most patients used polyethylene glycol (PEG)-based solutions (2 L PEG + ascorbic acid (n = 56), 4 L PEG (n = 21)) as purgatives and had hypertension (n = 75). A significant association of bowel preparation and colonoscopy with AF occurrence was found in all time windows. The proportion of patients with bowel preparation and colonoscopy was higher during the hazard period than during the control periods. In the 1-, 2-, 4-, 8-, and 12-week time windows, the proportions were 11.9% vs. 4.2%, 13.1% vs. 4.8%, 16.7% vs. 6.3%, 28.6% vs. 11.9%, and 29.8% vs. 14.0%, and the odd ratios (ORs) were 3.11, 3.01, 3.00, 2.96, and 2.61, respectively. Bowel preparation and undergoing colonoscopy was associated with the risk of AF and this examination need to be performed with caution especially in elderly patients with hypertension.

Toxicity Assessment of Mesoporous Silica Nanoparticles upon Intravenous Injection in Mice: Implications for Drug Delivery

Nanoparticles are popular tools utilized to selectively deliver drugs and contrast agents for identification and treatment of disease. To determine the usefulness and translational potential of mesoporous silica nanoparticles (MSNs), further evaluations of toxicity are required. MSNs are among the most utilized nano-delivery systems due to ease of synthesis, pore structure, and functionalization. This study aims to elucidate toxicity as a result of intravenous injection of 25 nm MSNs coated with chitosan (C) or polyethylene glycol (PEG) in mice. Following acute and chronic injections, blood was evaluated for standard blood chemistry and complete blood count analyses. Blood chemistry results primarily indicated that no abnormalities were present following acute or chronic injections of MSNs, or C/PEG-coated MSNs. After four weekly administered treatments, vital organs showed minor exacerbation of pre-existing lesions in the 35KPEG-MSN and moderate exacerbation of pre-existing lesions in uncoated MSN and 2KPEG-MSN treatment groups. In contrast, C-MSN treatment groups had minimal changes compared to controls. This study suggests 25 nm MSNs coated with chitosan should elicit minimal toxicity when administered as either single or multiple intravenous injections, but MSNs coated with PEG, especially 2KPEG may exacerbate pre-existing vascular conditions. Further studies should evaluate varying sizes and types of nanoparticles to provide a better overall understanding on the relation between nanoparticles and in vivo toxicity.

A comparison between limited bowel preparation and comprehensive bowel preparation in radical cystectomy with ileal urinary diversion: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Our aim is to evaluate the value of limited bowel preparation (LBP) in radical cystectomy (RC) with ileal urinary diversion (IUD).

METHODS

A systematic literature search was conducted on electronic database up to February 2020. All data were analyzed using RevMan5 (version 5.3). A subgroup analysis comparing the efficacy of CBP and no bowel preparation (NBP) was also performed.

RESULTS

Six randomized controlled trials (RCTs) including 743 patients were finally enrolled for statistical analysis. According to the meta-analysis, there was no significant difference between LBP group and comprehensive bowel preparation (CBP) group, concerning operative time (p = 0.79), length of stay (p = 0.46), the time to first toleration of clear liquids (p = 0.95), and overall complications (p = 0.29). However, the time to first bowel activity (SMD: - 0.77, 95% CI - 1.47 to - 0.07, p = 0.03), risk of fever (RR: 0.53, 95% CI 0.33-0.85, p = 0.008), time to first flatus (SMD: - 1.06, 95% CI - 2.02 to - 0.10, p = 0.03), and risk of wound healing disorders (RR: 0.65, 95% CI 0.44-0.95, p = 0.03) were significantly lower in LBP group compared with CBP group. Subgroup analysis showed a significant lower risk of wound healing disorders in favor of NBP (RR: 0.50, 95% CI 0.29-0.87, p = 0.01).

CONCLUSIONS

Current evidence indicated that LBP protocols might accelerate recovery of gastrointestinal function, promote wound healing, and reduce the risk of fever without increasing complications in patients undergoing RC with IUD. Besides, bowel preparation also did not hinder wound healing. Further, well-designed RCTs conducted by experienced surgeons are warranted before making the final clinical guidelines.

Risk of Renal Injury After the Use of Polyethylene Glycol for Outpatient Colonoscopy: A Prospective Observational Study

GOAL

The goal of this study was to estimate the risk of renal injury after the use of 3-L polyethylene glycol (PEG) before outpatient colonoscopy.

BACKGROUND

Population-based studies showed that the use of PEG was associated with renal injury, but this association has not been confirmed by prospective study.

STUDY

Patients ≥40 years of age with an estimated glomerular filtration rate ≥30 mL/min were screened for enrollment. Laboratory data were collected before, during, and after the colonoscopies. Patients with a ≥30% increase in baseline serum creatinine levels were followed until a peak level was detected. Renal injury included acute renal dysfunction (ARD) and acute kidney injury (AKI), defined as a 30% to 49% increase and ≥50% increase in creatinine levels compared with the baseline, respectively.

RESULTS

A total of 1163 patients (mean age, 55.7 y) completed the study. Baseline and first postcolonoscopy laboratory data were obtained an average of 17.0 days before and 17.3 days after the colonoscopies were performed, respectively. Renal injury was identified in 32 patients; 26 patients (2.2%) had ARD, and 6 patients (0.5%) had AKI. All patients with renal injury recovered fully during follow-up. In the subgroup analysis, the use of nonsteroidal anti-inflammatory drugs (NSAIDs) before colonoscopy was statistically associated with the development of AKI (odds ratio, 6.5; 95% confidence interval, 1.2-35.5; P=0.03).

CONCLUSIONS

This prospective study showed that the use of PEG was associated with a small risk of renal injury. NSAIDs use was statistically associated with AKI in the context of colonoscopy for which PEG was used for bowel preparation.

Acute kidney injury following implementation of an enhanced recovery after surgery (ERAS) protocol in colorectal surgery

PURPOSE

Fluid management within Enhanced Recovery After Surgery (ERAS) protocols is designed to maintain a euvolemic state avoiding the negative sequelae of hypervolemia or hypovolemia. We sought to determine the effect of a recent ERAS protocol implementation on kidney function and on the incidence of postoperative acute kidney injury (AKI).

METHODS

A total of 132 elective colorectal resections performed using our ERAS protocol were compared to a propensity-matched group prior to ERAS implementation. Fluid balance, urine output, creatinine, and blood urea nitrogen (BUN) were recorded for all patients, and the incidence of AKI was determined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

Implementation of our ERAS protocol decreased average postoperative length of hospital stay (5.5 vs 7.7 days, p < 0.0001) and time to return of bowel function (2.5 vs 4.1 days, p < 0.0001). The rate of postoperative AKI increased following implementation of the protocol (11.4 vs 2.3%, p < 0.0001). However, by the time of discharge, the average creatinine of ERAS patients who had experienced AKI had returned to their preoperative baseline values (p = 0.9037). Significant univariate predictors of AKI in ERAS patients were longer operative times (p < 0.01) and the diagnosis of diverticulitis (p < 0.01). Within our ERAS patients, AKI was associated with a prolonged postoperative length of hospital stay (p < 0.01).

CONCLUSIONS

Despite the proven benefits of the Enhanced Recovery After Surgery (ERAS) protocols, care should be taken during protocol implementation to monitor for and to prevent acute kidney injury.

Reducing hospital admissions of healthy children with functional constipation: a quality initiative

Functional constipation (FC) is a common medical problem in children, with minimal risk of long-term complications. We determined that a large number of children were being admitted to our children’s hospital for FC in which there was no neurological or anatomical cause. Our hospital experienced a patient complication in which a patient died after inpatient treatment of FC. Subsequently, we developed a standardised approach to determine when paediatric patients needed hospitalisation for FC, as well as to develop a regimented outpatient therapeutic approach for such children to prevent hospitalisation. Our quality improvement initiative resulted in a large decrease in the number of children with FC admitted into the hospital as well as a decrease in the number of children needing faecal disimpaction in the operating room. Our quality improvement process can be used to decrease hospitalisations, decrease healthcare costs and improve patient care for paediatric FC.

Risk factors for and the prevention of acute kidney injury after abdominal surgery

Postoperative acute kidney injury in patients undergoing abdominal surgery is not rare and often results in bad outcomes for patients. The incidence of postoperative acute kidney injury is hard to evaluate reliably due to its non-unified definitions in different studies. Risk factors for acute kidney injury specific to abdominal surgery include preoperative renal insufficiency, intraabdominal hypertension, blood transfusion, bowel preparation, perioperative dehydration, contrast agent and nephrotoxic drug use. Among these, preoperative renal insufficiency is the strongest predictor of acute kidney injury. The peri-operative management of high-risk patients should include meticulous selection of fluid solutions. Balanced crystalloid solutions and albumin are generally thought to be relatively safe, while the safety of hydroxyethyl starch solutions has been controversial. The purpose of the present review is to discuss the current knowledge regarding postoperative acute kidney injury in abdominal surgical settings to help surgeons make better decisions concerning the peri-operative management.

The management of 'hard-to-prepare' colonoscopy patients

Effective bowel cleansing is crucial for high quality colonoscopy. A notable portion of patients still present with low quality bowel preparation prior to their colonoscopy, compromising the overall quality of their colonoscopy. Areas covered: This review focuses on the main strategies that can improve the cleansing quality with a special interest on those clinical conditions that have been associated with a poor bowel preparation quality, such as patients with chronic constipation, history of bowel resection, liver cirrhosis, diabetes mellitus and chronic kidney disease. The review provides a practical and evidence-based approach to help clinicians in the management of 'hard-to-prepare' patients. Expert commentary: In the past few years, the quality of colonoscopy has become a hot topic and bowel cleansing is a crucial part of it; however, the approach to patients with an increased risk of poor bowel preparation quality is still not always supported by high-quality evidence, since most of these patients are routinely excluded from the clinical studies. Trials focused on this subgroup of patients are recommended to provide tailored bowel preparation regimens and guarantee high-quality procedures.

Bowel Preparation Is Associated with Reduced Morbidity in Elderly Patients Undergoing Elective Colectomy

BACKGROUND

Bowel preparation in elderly patients is associated with physiologic derangements that may result in postoperative complications. The aim of this study is to determine the impact of bowel preparation on postoperative outcomes in elderly patients.

METHODS

Patients age 75 years and older who underwent elective colectomy were identified from the 2012-2014 American College of National Surgical Quality Improvement Program (ACS-NSQIP database). Patients were grouped into no bowel preparation, mechanical bowel preparation (MBP), oral antibiotic preparation (OABP), or combined MBP + OABP. Logistic regression modeling was conducted to calculate risk-adjusted 30-day outcomes.

RESULTS

There were 4829 patients included in the analysis. Morbidity was 34.3% in no bowel prep, 32.4% in MBP, 24.8% in OABP, and 24.6% in MBP + OABP groups (p < 0.001). The MBP + OABP group compared with no bowel prep was associated with reduced rates of anastomotic leak, ileus, superficial surgical site infection (SSI), organ space SSI, respiratory compromise, and reduced length of stay. There was no difference in the rate of acute kidney injury between the groups.

CONCLUSION

MBP + OABP was associated with reduced morbidity compared with no bowel preparation in elderly patients undergoing elective colorectal resection. MBP alone was not associated with differences in outcomes compared with no bowel preparation. The use of MBP + OABP is safe and effective in elderly patients undergoing elective colectomy.

Does 2 L Polyethylene Glycol Plus Ascorbic Acid Increase the Risk of Renal Impairment Compared to 4 L Polyethylene Glycol?

BACKGROUND

The use of polyethylene glycol (PEG)-based solutions is the gold standard for bowel preparation. However, PEG use might be associated with the risk of acute kidney injury.

AIMS

We aimed to compare the safety of 2 L PEG plus ascorbic acid (AA) versus 4 L PEG.

METHODS

Health examinees that underwent colonoscopy and blood tests on the same day at our center were included in this retrospective study. All subjects were prescribed either 2 L PEG plus AA or 4 L PEG for the bowel preparation prior to the colonoscopy. The incidences of electrolyte imbalance and renal impairment after colonic preparation were investigated. Renal impairment was determined if the subject's estimated glomerular filtration rate was measured less than 60 mL/min/1.73 m².

RESULTS

Of the 29,789 cases, 14,790 received 2 L PEG plus AA (group A) and 14,999 received 4 L PEG (group B) for colonic preparation. Renal impairment occurred more commonly in group A (n = 467, 3.2 %) than in group B (n = 189, 1.3 %). Electrolyte changes such as hypernatremia and hyperkalemia were more common in group A than group B, whereas hyponatremia, hypokalemia, and hypophosphatemia were more common in group B than group A. Old age, male sex, and the use of 2 L PEG plus AA were independent risk factors for renal impairment.

CONCLUSIONS

The evidence strongly suggests that acute kidney injury is more likely to occur when 2 L PEG plus AA is used for the bowel preparation than when 4 L PEG is used.

CLINICAL TRIAL REGISTRATION NUMBER

KCT0001703.

Endoscopy in the elderly: risks, benefits, and yield of common endoscopic procedures

There has been limited research examining the risks, benefits, and use of common endoscopic procedures in the elderly. Furthermore, gastroenterology training programs do not routinely incorporate elderly concerns when dealing with common gastrointestinal issues. There exists a broad array of endoscopic procedures with varying inherent risks that must be weighed with each elderly patient in mind. This article discusses the benefits and drawbacks of the most common procedures and indications for endoscopy including upper endoscopy, colonoscopy, endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, percutaneous endoscopic gastrostomy, and deep enteroscopy.

How we can measure quality in colonoscopy?

Measuring quality is a current need of medical services either to assess their cost-effectiveness or to identify discrepancies requiring refinement. With the advent of bowel cancer screening and increasing patient awareness of bowel symptoms, there has been an unprecedented increase in demand for colonoscopy. Consequently, there is an expanding open-discussion on missed rates of cancer or precancerous polyps during diagnostic/screening colonoscopy and on the rate of adverse events related to therapeutic colonoscopy. Delivering a quality colonoscopy service is therefore a healthcare priority. Colonoscopy is a multi-step process and therefore assessment of all aspects of the procedure must be addressed. Quality in colonoscopy refers to a combination of many patient-centered technical and non-technical skills and knowledge aiming to patient's safety and satisfaction through a continuous effort for improvement. The benefits of this endless process are hiding behind small details which can eventually make the difference in colonoscopy. Identifying specific quality metrics help to define and shape an optimal service and forms a secure basis of improvement. Τhis paper does not aim to give technical details on how to perform colonoscopy but to summarize what to measure and when, in accordance with the current identified quality indicators and standards for colonoscopy.

Consensus guidelines for the use of bowel preparation prior to colonic diagnostic procedures: colonoscopy and small bowel video capsule endoscopy

BACKGROUND

Adequate bowel preparation prior to colonic diagnostic procedures is essential to ensure adequate visualisation.

SCOPE

This consensus aims to provide guidance as to the appropriate use of bowel preparation for a range of defined clinical circumstances. A consensus group from across Europe was convened and met to discuss appropriate bowel preparation. The use of polyethylene glycol (PEG), sodium picosulphate and sodium phosphate (NaP), together with other agents, prokinetics and simethicone, in colonoscopy and small bowel video capsule endoscopy were considered. A systematic review of the literature was carried out and additional unpublished data was obtained from the members of the consensus group where required. Recommendations were graded according to the level of evidence.

FINDINGS

PEG-based regimens are recommended first line for both procedures, since their use is supported by good efficacy and safety data. Sodium-picosulphate-based regimens are recommended second line as their cleansing efficacy appears less than PEG-based regimens. NaP is not recommended for bowel cleansing due to the potential for renal damage and other adverse events. However, the use of NaP is acceptable in patients in whom PEG or sodium picosulphate is ineffective or not tolerated. NaP should not be used in patients with chronic kidney disease, pre-existing electrolyte disturbances, congestive heart failure, cirrhosis or a history of hypertension. The timing of the dose, dietary restrictions, use in special patient groups and recording of the quality of bowel preparation are also considered for patients undergoing colonoscopy. During the development of the guidelines the European Society of Gastrointestinal Endoscopy (ESGE) issued guidance on bowel preparation for colonoscopy. The ESGE guidelines and these consensus guidelines share many recommendations; differences between the guidelines are reviewed.

CONCLUSION

The use of bowel preparation should be tailored to the individual patient and their specific clinical circumstances.