Radiation Dose and Fluoroscopy Time of Extracranial Carotid Artery Stenting : Elective vs. Emergency Treatment Including Combined Mechanical Thrombectomy in Tandem Occlusion.

PURPOSE: Fluoroscopically guided endovascular carotid artery stenting (CAS) of extracranial carotid stenosis (ECS) is a reasonable alternative to carotid endarterectomy in selected patients. Diagnostic reference levels (DRL) for this common neurointervention have not yet been defined and respective literature data are sparse. We provide detailed dosimetrics for useful expansion of the DRL catalogue. METHODS: A retrospective single-center study of patients undergoing CAS between 2013 and 2021. We analyzed dose area product (DAP) and fluoroscopy time considering the following parameters: indications for CAS, semielective/elective versus emergency including additional mechanical thrombectomy (MT) in extracranial/intracranial tandem occlusion, etiology of ECS (atherosclerotic vs. radiation-induced), periprocedural features, e.g., number of applied stents, percutaneous transluminal angioplasty (PTA) and MT maneuvers, and dose protocol. Local DRL was defined as 75% percentile of the DAP distribution. RESULTS: A total of 102 patients were included (semielective/elective CAS n = 75, emergency CAS n = 8, CAS + MT n = 19). Total median DAP was 78.2 Gy cm2 (DRL 117 Gy cm2). Lowest and highest median dosimetry values were documented for semielective/elective CAS and CAS + MT (DAP 49.1 vs. 146.8 Gy cm2, fluoroscopy time 27.1 vs. 43.8 min; p < 0.005), respectively. Dosimetrics were significantly lower in patients undergoing 0-1 PTA maneuvers compared to ≥ 2 maneuvers (p < 0.05). Etiology of ECS, number of stents and MT maneuvers had no significant impact on dosimetry values (p > 0.05). A low-dose protocol yielded a 33% reduction of DAP. CONCLUSION: This CAS study suggests novel local DRLs for both elective and emergency cases with or without intracranial MT. A dedicated low-dose protocol was suitable for substantial reduction of radiation dose.

Emergency treatment with intravenous infusion of methylene blue followed by oral administration in a cat presented with severe recurrent methemoglobinemia.

OBJECTIVE: To describe the use of IV infusion followed by oral administration of methylene blue (MB) to successfully treat recurrent methemoglobinemia (MetHb) in a young cat. CASE SUMMARY: A 6-month-old male Ragdoll cat presented with recurrent episodes of severe MetHb and was successfully managed with IV infusion of MB followed by a course of oral MB. Although the definitive cause of the patient's MetHb remains unknown, the cat made a full recovery following treatment without developing any significant side effects secondary to therapy and at the time of writing not had any further recurrences. Follow-up at 6 months found the patient in good health and without any long-term consequences. NEW INFORMATION PROVIDED: To the authors' knowledge, this is the first report of a cat presented with severe MetHb quantitatively assessed via co-oximetry and successfully treated with both IV and oral administration of MB.

NaCl 3% Bolus Therapy as Emergency Treatment for Severe Hyponatremia: Comparison of 100 mL vs 250 mL.

CONTEXT: The aim of initial treatment of severe hyponatremia is to rapidly increase serum sodium to reduce the complications of cerebral edema. The optimal strategy to achieve this goal safely is still under debate. OBJECTIVE: To compare the efficacy and safety of 100 and 250 mL NaCl 3% rapid bolus therapy as initial treatment of severe hypotonic hyponatremia. METHODS: Retrospective analysis of patients admitted to a teaching hospital in The Netherlands between 2017 and 2019. The patients were 130 adults with severe hypotonic hyponatremia, defined as serum sodium ≤ 120 mmol/L. A bolus of either 100 mL (n = 63) or 250 mL (n = 67) NaCl 3% was the initial treatment. Successful treatment was defined as a rise in serum sodium ≥ 5 mmol/L within the first 4 hours after bolus therapy. Overcorrection of serum sodium was defined as an increase of more than 10 mmol/L in the first 24 hours. RESULTS: The percentage of patients with a rise in serum sodium ≥5 mmol/L within 4 hours was 32% and 52% after a bolus of 100 and 250 mL, respectively (P = .018). Overcorrection of serum sodium was observed after a median of 13 hours (range 9-17 hours) in 21% of patients in both treatment groups (P = .971). Osmotic demyelination syndrome did not occur. CONCLUSION: Initial treatment of severe hypotonic hyponatremia is more effective with a NaCl 3% bolus of 250 mL than of 100 mL and does not increase the risk of overcorrection.

Emergency treatment of airway obstruction caused by a laryngeal neuroendocrine tumor: A case report.

RATIONALE: Laryngeal obstruction is a life-threatening adverse event that requires urgent and appropriate management, particularly in patients with coexisting cardiopulmonary and brain comorbidities. However, laryngeal obstruction caused by laryngeal neuroendocrine tumors has rarely been reported. PATIENT CONCERNS: Neuroendocrine tumors can cause pathological changes in the neuro-humoral system, and asphyxia caused by airway obstruction has a more adverse effect on patients with neuroendocrine tumors. DIAGNOSES: We report the case of a 64-year-old man with clinical manifestations of dyspnea. Preoperative and intraoperative pathological examination indicated that the patient was diagnosed with life-threatening airway obstruction caused by a laryngeal neuroendocrine tumor, pneumonia, and scoliosis. INTERVENTIONS: The patient underwent laryngeal tumor resection under general anesthesia. He was recovered well and was generally good without the necessity of undergoing radiotherapy and chemotherapy at the 6-months follow-up. OUTCOMES: This case report has provided an emergency treatment strategy associated with awake intubation. We concluded that flexible establishment of an artificial airway, skilled anesthesia and surgical manipulation, and necessary postoperative intensive care are extremely important for improving the prognosis of patients with severely difficult airway. It is noteworthy that the timely adjust for endotracheal intubation strategy according to the patient's response is needed. It is important for the long-term prognosis of patients to avoid the establishment of a traumatic artificial airway and the occurrence of adverse complications. LESSONS: 1. Introduction; 2. Case presentation; 3. Discussion; 4. Conclusion.

Emergency treatment of anaphylaxis: concise clinical guidance.

Anaphylaxis is a serious systemic hypersensitivity reaction that is usually rapid in onset and may cause death. It is characterised by the rapid development of airway and/or breathing and/or circulation problems. Intramuscular adrenaline is the most important treatment, although, even in healthcare settings, many patients do not receive this intervention contrary to guidelines. The Resuscitation Council UK published an updated guideline in 2021 with some significant changes in recognition, management, observation and follow-up of patients with anaphylaxis. This is a concise version of the updated guideline.

Nomogram for Prediction of Postoperative Morbidity in Patients with Colon Cancer Requiring Emergency Therapy.

BACKGROUND Postoperative complications are the major cause of mortality and prolonged hospitalization after emergency surgery for colon cancer. This study aimed to propose an effective nomogram to predict postoperative complications in order to improve the outcomes. MATERIAL AND METHODS We retrospectively analyzed 449 patients who underwent emergency surgery for complicated colon cancer at the County Emergency Hospital Clinic "St. Apostle Andrei" in Galati, in the period from 2008 to 2017. Postoperative complications were intestinal obstruction, leakage, bleeding, peritonitis, wound infection, surgical wound dehiscence, respiratory failure, heart failure, acute renal failure, sepsis, and Clostridium difficile colitis, within a month after surgery. Logistic regression models were used to identify the independent prediction factors, and a nomogram was created, based on the best model. RESULTS A total of 106 patients (21%) presented postoperative complications after emergency surgery for colon cancer; 51 patients (11.36%) died during the postoperative period. After identifying the risk factors through univariate regression analysis, we identified the independent prediction factors in 2 multivariate regression models. The model with the highest accuracy included the following 7 independent prediction factors: Eastern Cooperative Oncology Group performance status, Charlson score, white blood cell count, electrolyte and coagulation disorders, surgery time, and cachexia (P<0.05 for all). This model showed good precision in predicting postoperative complications, with an area under curve of 0.83 and ideal accordance between the predicted and observed probabilities. CONCLUSIONS The nomogram developed in this study, which was based on a multivariate logistic regression model, had good individual prediction of postoperative complications.

Midterm outcomes of emergency surgery for acute type A aortic dissection in octogenarians.

OBJECTIVE: The incidence of elderly patients with acute type A aortic dissection is increasing. A recent analysis of the International Registry of Acute Aortic Dissection failed to show a mortality benefit with surgery compared with medical management in octogenarians. Therefore, we compared our institutional outcomes of emergency surgery for acute type A aortic dissection in octogenarians versus septuagenarians to understand the outcomes of surgical intervention in elderly patients. METHODS: From 2002 to 2017, 70 octogenarians (aged ≥80 years) and 165 septuagenarians (70-79 years) underwent surgery for acute type A aortic dissection (N = 235, total). Quality of life was assessed by the RAND Short Form-36 quality of life survey. Midterm clinical and functional data were obtained retrospectively. RESULTS: At baseline, septuagenarians had a higher prevalence of diabetes (20.6% vs 5.7%, P = .01). The prevalence of cardiopulmonary resuscitation was 4.8% versus 10.0% (P = .24) in septuagenarians and octogenarians. The prevalence of cardiogenic shock was 18.2% versus 27.1% (P = .17). Thirty-day/in-hospital mortality was 21.2% versus 28.6% (P = .29). Multivariable logistic regression identified cardiogenic shock as an independent risk factor for in-hospital mortality (odds ratio, 10.07; 95% confidence interval, 2.30-44.03) in octogenarians. Survival at 5 years was 49.7% (42.1%-58.6%) versus 34.2% (23.9%-48.8%) in septuagenarians and octogenarians, respectively. Responses to the quality of life survey were no different between septuagenarians and octogenarians across all 8 quality of life categories. CONCLUSIONS: Clinical outcomes after surgery for acute type A aortic dissection are similar in octogenarians and septuagenarians. For discharged survivors, quality of life remains favorable and does not differ between the 2 groups.

The new SUMPOT to predict postoperative complications using an Artificial Neural Network.

An accurate assessment of preoperative risk may improve use of hospital resources and reduce morbidity and mortality in high-risk surgical patients. This study aims at implementing an automated surgical risk calculator based on Artificial Neural Network technology to identify patients at risk for postoperative complications. We developed the new SUMPOT based on risk factors previously used in other scoring systems and tested it in a cohort of 560 surgical patients undergoing elective or emergency procedures and subsequently admitted to intensive care units, high-dependency units or standard wards. The whole dataset was divided into a training set, to train the predictive model, and a testing set, to assess generalization performance. The effectiveness of the Artificial Neural Network is a measure of the accuracy in detecting those patients who will develop postoperative complications. A total of 560 surgical patients entered the analysis. Among them, 77 patients (13.7%) suffered from one or more postoperative complications (PoCs), while 483 patients (86.3%) did not. The trained Artificial Neural Network returned an average classification accuracy of 90% in the testing set. Specifically, classification accuracy was 90.2% in the control group (46 patients out of 51 were correctly classified) and 88.9% in the PoC group (8 patients out of 9 were correctly classified). The Artificial Neural Network showed good performance in predicting presence/absence of postoperative complications, suggesting its potential value for perioperative management of surgical patients. Further clinical studies are required to confirm its applicability in routine clinical practice.

The hidden burden of unplanned readmission after emergency general surgery.

BACKGROUND: There are no national studies of nonelective readmissions after emergency general surgery (EGS) diagnoses that track nonindex hospital readmission. We sought to determine the rate of overall and nonindex hospital readmissions at 30 and 90 days after discharge for EGS diagnoses, hypothesizing a significant portion would be to nonindex hospitals. METHODS: The 2013 to 2014 Nationwide Readmissions Database was queried for all patients 16 years or older admitted with an EGS primary diagnosis and survived index hospitalization. Multivariable logistic regression identified risk factors for nonelective 30- and 90-day readmission to index and nonindex hospitals. RESULTS: Of 4,171,983 patients, 13% experienced unplanned readmission at 30 days. Of these, 21% were admitted to a nonindex hospital. By 90 days, 22% experienced an unplanned readmission, of which 23% were to a nonindex hospital. The most common reason for readmission was infection. Publicly insured or uninsured patients accounted for 67% of admissions and 77% of readmissions. Readmission predictors at 30 days included leaving against medical advice (odds ratio [OR], 2.51 [2.47-2.56]), increased length of stay (4-7 days: OR, 1.42 [1.41-1.43]; >7 days: OR, 2.04 [2.02-2.06]), Charlson Comorbidity Index ≥2 (OR, 1.72 [1.71-1.73]), public insurance (Medicare: OR, 1.45 [1.44-1.46]; Medicaid: OR, 1.38 [1.37-1.40]), EGS patients who fell into the "Other" surgical category (OR, 1.42 [1.38-1.48]), and nonroutine discharge. Risk factors for readmission remained consistent at 90 days. CONCLUSION: Given that nonindex hospital EGS readmission accounts for nearly a quarter of readmissions and often related to important benchmarks such as infection, current EGS quality metrics are inaccurate. This has implications for policy, benchmarking, and readmission reduction programs. LEVEL OF EVIDENCE: Epidemiological study, level III.

Understanding the issues experienced by older people undergoing emergency surgery.

The number of older people undergoing surgery in the UK is increasing, partly due to an ageing population and advances in surgical techniques. However, outcomes for older patients who have undergone surgery are suboptimal when compared with younger people, especially following emergency surgery. To minimise the risk of adverse events affecting older people following surgery, it is essential that nurses understand how to manage common challenges for this patient group such as delirium, pain, reduced mobility and inadequate hydration.

Does Coronavirus Disease 2019 (COVID-19) Affect Perioperative Morbidity and Mortality for Patients Requiring Emergency Instrumented Spinal Surgery? A Single-Center Cohort Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic sent shockwaves through health services worldwide. Resources were reallocated. Patients with COVID-19 still required instrumented spinal surgery for emergencies. Clinical outcomes for these patients are not known. The objective of this study was to evaluate the effects of COVID-19 on perioperative morbidity and mortality for patients undergoing emergency instrumented spinal surgery and to determine risk factors for increased morbidity/mortality. METHODS: This retrospective cohort study included 11 patients who were negative for COVID-19 and 8 patients who were positive for COVID-19 who underwent emergency instrumented spinal surgery in 1 hospital in the United Kingdom during the pandemic peak. Data collection was performed through case note review. Patients in both treatment groups were comparable for age, sex, body mass index (BMI), comorbidities, surgical indication, and preoperative neurologic status. Predefined perioperative outcomes were recorded within a 30-day postoperative period. Univariable analysis was used to identify risk factors for increased morbidity. RESULTS: There were no mortalities in either treatment group. Four patients positive for COVID-19 (50%) developed a complication compared with 6 (55%) in the COVID-19-negative group (P > 0.05). The commonest complication in both groups was respiratory infection. Three patients positive for COVID-19 (37.5%) required intensive care unit admission, compared with 4 (36%) in the COVID-19-negative group (P > 0.05). The average time between surgery and discharge was 19 and 10 days in COVID-19-positive and -negative groups, respectively (P = 0.02). In the COVID-19 positive group, smoking, abnormal BMI, preoperative oxygen requirement, presence of fever, and oxygen saturations <95% correlated with increased risk of complications. CONCLUSIONS: Emergency instrumented spinal surgery in patients positive for COVID-19 was associated with increased length of hospital stay. There was no difference in occurrence of complications or intensive care unit admission. Risk factors for increased morbidity in patients with COVID-19 included smoking, abnormal BMI, preoperative oxygen requirement, fever and saturations <95%.

Emergency general surgery: Impact of hospital and surgeon admission case volume on mortality.

BACKGROUND: Emergency general surgery (EGS) is a high-volume and high-risk surgical service. Interhospital variation in EGS outcomes exists, but there is disagreement in the literature as to whether hospital admission volume affects in-hospital mortality. Scotland collects high-quality data on all admitted patients, whether managed operatively or nonoperatively. Our aim was to determine the relationship between hospital admission volume and in-hospital mortality of EGS patients in Scotland. Second, to investigate whether surgeon admission volume affects mortality. METHODS: This national population-level cohort study included EGS patients aged 16 years and older, who were admitted to a Scottish hospital between 2014 and 2018 (inclusive). A logistic regression model was created, with in-hospital mortality as the dependent variable, and admission volume of hospital per year as a continuous covariate of interest, adjusted for age, sex, comorbidity, deprivation, surgeon admission volume, surgeon operative rate, transfer status, diagnosis, and operation category. RESULTS: There were 376,076 admissions to 25 hospitals, which met our inclusion criteria. The EGS hospital admission rate per year had no effect on in-hospital mortality (odds ratio [OR], 1.000; 95% confidence interval [CI], 1.000-1.000). Higher average surgeon monthly admission volume increased the odds of in-hospital mortality (>35 admissions: OR, 1.139; 95% CI, 1.038-1.250; 25-35 admissions: OR, 1.091; 95% CI, 1.004-1.185; <25 admissions was the referent). CONCLUSION: In Scotland, in contrast to other settings, EGS hospital admission volume did not influence in-hospital mortality. The finding of an association between individual surgeons' case volume and in-hospital mortality warrants further investigation. LEVEL OF EVIDENCE: Care management, Level IV.

Validation of the Artificial Intelligence-Based Predictive Optimal Trees in Emergency Surgery Risk (POTTER) Calculator in Emergency General Surgery and Emergency Laparotomy Patients.

BACKGROUND: The Predictive Optimal Trees in Emergency Surgery Risk (POTTER) tool is an artificial intelligence-based calculator for the prediction of 30-day outcomes in patients undergoing emergency operations. In this study, we sought to assess the performance of POTTER in the emergency general surgery (EGS) population in particular. METHODS: All patients who underwent EGS in the 2017 American College of Surgeons NSQIP database were included. The performance of POTTER in predicting 30-day postoperative mortality, morbidity, and 18 specific complications was assessed using the c-statistic metric. As a subgroup analysis, the performance of POTTER in predicting the outcomes of patients undergoing emergency laparotomy was assessed. RESULTS: A total of 59,955 patients were included. Median age was 50 years and 51.3% were women. POTTER predicted mortality (c-statistic = 0.93) and morbidity (c-statistic = 0.83) extremely well. Among individual complications, POTTER had the highest performance in predicting septic shock (c-statistic = 0.93), respiratory failure requiring mechanical ventilation for 48 hours or longer (c-statistic = 0.92), and acute renal failure (c-statistic = 0.92). Among patients undergoing emergency laparotomy, the c-statistic performances of POTTER in predicting mortality and morbidity were 0.86 and 0.77, respectively. CONCLUSIONS: POTTER is an interpretable, accurate, and user-friendly predictor of 30-day outcomes in patients undergoing EGS. POTTER could prove useful for bedside counseling of patients and their families and for benchmarking of EGS care.

Editor's Choice - Systematic Review and Meta-Analysis of the Effect of Weekend Admission on Outcomes for Ruptured Abdominal Aortic Aneurysms: A Call for an Equitable Seven Day Vascular Service.

OBJECTIVE: "The weekend effect" of higher patient mortality when presenting at a weekend compared with a weekday has been established for several conditions. The aim of this study was to investigate whether a weekend effect exists for the emergency condition of ruptured abdominal aortic aneurysm. DATA SOURCES: A review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO registration number CRD42020157484). MEDLINE, EMBASE and CINAHL were searched using the Healthcare Databases Advanced Search interface developed by NICE. REVIEW METHODS: The prognostic factor of interest was weekend admission. The primary outcome of interest was all cause peri-operative mortality, with a secondary outcome of hospital length of stay. A random effects meta-analysis was performed, and the results were reported as summary odds ratio (OR) and 95% confidence interval (CI). RESULTS: Twelve observational cohort studies published between 2001 and 2019 comprising 14 patient cohorts with a total of 95 856 patients were eligible for quantitative synthesis. Patients presenting on a weekend had a significantly higher risk of unadjusted in hospital mortality (OR 1.20, 95% CI 1.10 - 1.31, p < .001). Both the unadjusted 30 day mortality risk (OR 1.16, 95% CI 0.98 - 1.39, p = .090) and unadjusted 90 day mortality risk (OR 1.12, 95% CI 0.90 - 1.40, p = .30) were higher for those presenting at a weekend, but neither reached statistical significance. There was a significantly greater risk of combined unadjusted in hospital, 30 and 90 day mortality for those presenting at a weekend (OR 1.17, 95% CI 1.09 - 1.27, p < .001). Hospital length of stay was not statistically different between groups. CONCLUSION: There is an association between weekend admission and higher mortality in patients presenting with ruptured abdominal aortic aneurysm.

Postoperative complications and mortality following emergency digestive surgery during the COVID-19 pandemic: A multicenter collaborative retrospective cohort study protocol (COVID-CIR).

ABSTRACT: Infection with the SARS-CoV-2 virus seems to contribute significantly to increased postoperative complications and mortality after emergency surgical procedures. Additionally, the fear of COVID-19 contagion delays the consultation of patients, resulting in the deterioration of their acute diseases by the time of consultation. In the specific case of urgent digestive surgery patients, both factors significantly worsen the postoperative course and prognosis. Main working hypothesis: infection by COVID-19 increases postoperative 30-day-mortality for any cause in patients submitted to emergency/urgent general or gastrointestinal surgery. Likewise, hospital collapse during the first wave of the COVID-19 pandemic increased 30-day-mortality for any cause. Hence, the main objective of this study is to estimate the cumulative incidence of mortality at 30-days-after-surgery. Secondary objectives are: to estimate the cumulative incidence of postoperative complications and to develop a specific postoperative risk propensity model for COVID-19-infected patients.A multicenter, observational retrospective cohort study (COVID-CIR-study) will be carried out in consecutive patients operated on for urgent digestive pathology. Two cohorts will be defined: the "pandemic" cohort, which will include all patients (classified as COVID-19-positive or -negative) operated on for emergency digestive pathology during the months of March to June 2020; and the "control" cohort, which will include all patients operated on for emergency digestive pathology during the months of March to June 2019. Information will be gathered on demographic characteristics, clinical and analytical parameters, scores on the usual prognostic scales for quality management in a General Surgery service (POSSUM, P-POSSUM and LUCENTUM scores), prognostic factors applicable to all patients, specific prognostic factors for patients infected with SARS-CoV-2, postoperative morbidity and mortality (at 30 and 90 postoperative days). The main objective is to estimate the cumulative incidence of mortality at 30 days after surgery. As secondary objectives, to estimate the cumulative incidence of postoperative complications and to develop a specific postoperative risk propensity model for SARS-CoV-2 infected patients.The protocol (version1.0, April 20th 2020) was approved by the local Institutional Review Board (Ethic-and-Clinical-Investigation-Committee, code PR169/20, date 05/05/20). The study findings will be submitted to peer-reviewed journals and presented at relevant national and international scientific meetings.ClinicalTrials.gov Identifier: NCT04479150 (July 21, 2020).

Patient Age and Long-term Survival in Colorectal Cancer Patients Who Undergo Emergency Surgery.

BACKGROUND/AIM: Emergency surgery for colorectal cancer (CRC) is a high-risk procedure with high morbidity and mortality rates, especially for older patients. The relationship between patient age status and long-term outcomes is unclear. We hypothesize that patient age might be associated with long-term outcomes in patients with CRC who undergo emergency surgery. PATIENTS AND METHODS: Utilizing a database of CRC patients who received emergency surgery, we examined the prognostic association of patient age. RESULTS: The ≥80-years group was significantly associated with American Society of Anesthesiologists (ASA) physical status, bowel obstruction, N stage, shorter operating time, and less adjuvant chemotherapy (all p<0.03); and also, with shorter recurrence-free survival [multivariable hazard ratio, 2.79; 95% confidence interval, 1.13-7.21; p=0.026]. ASA status and adjuvant chemotherapy were significantly associated with recurrence-free survival (all p<0.03). CONCLUSION: Advanced age is associated with shorter recurrence-free survival in CRC patients who undergo emergency surgery.

Urgent-start peritoneal dialysis versus haemodialysis for people with chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) who require urgent initiation of dialysis but without having a permanent dialysis access have traditionally commenced haemodialysis (HD) using a central venous catheter (CVC). However, several studies have reported that urgent initiation of peritoneal dialysis (PD) is a viable alternative option for such patients. OBJECTIVES: This review aimed to examine the benefits and harms of urgent-start PD compared to HD initiated using a CVC in adults and children with CKD requiring long-term kidney replacement therapy. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 25 May 2020 for randomised controlled trials through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. For non-randomised controlled trials, MEDLINE (OVID) (1946 to 11 February 2020) and EMBASE (OVID) (1980 to 11 February 2020) were searched. SELECTION CRITERIA: All randomised controlled trials (RCTs), quasi-RCTs and non-RCTs comparing urgent-start PD to HD initiated using a CVC. DATA COLLECTION AND ANALYSIS: Two authors extracted data and assessed the quality of studies independently. Additional information was obtained from the primary investigators. The estimates of effect were analysed using random-effects model and results were presented as risk ratios (RR) with 95% confidence intervals (CI). The GRADE framework was used to make judgments regarding certainty of the evidence for each outcome. MAIN RESULTS: Overall, seven observational studies (991 participants) were included: three prospective cohort studies and four retrospective cohort studies. All the outcomes except one (bacteraemia) were graded as very low certainty of evidence given that all included studies were observational studies and few events resulting in imprecision, and inconsistent findings. Urgent-start PD may reduce the incidence of catheter-related bacteraemia compared with HD initiated with a CVC (2 studies, 301 participants: RR 0.13, 95% CI 0.04 to 0.41; I2 = 0%; low certainty evidence), which translated into 131 fewer bacteraemia episodes per 1000 (95% CI 89 to 145 fewer). Urgent-start PD has uncertain effects on peritonitis risk (2 studies, 301 participants: RR 1.78, 95% CI 0.23 to 13.62; I2 = 0%; very low certainty evidence), exit-site/tunnel infection (1 study, 419 participants: RR 3.99, 95% CI 1.2 to 12.05; very low certainty evidence), exit-site bleeding (1 study, 178 participants: RR 0.12, 95% CI 0.01 to 2.33; very low certainty evidence), catheter malfunction (2 studies; 597 participants: RR 0.26, 95% CI: 0.07 to 0.91; I2 = 66%; very low certainty evidence), catheter re-adjustment (2 studies, 225 participants: RR: 0.13; 95% CI 0.00 to 18.61; I2 = 92%; very low certainty evidence), technique survival (1 study, 123 participants: RR: 1.18, 95% CI 0.87 to 1.61; very low certainty evidence), or patient survival (5 studies, 820 participants; RR 0.68, 95% CI 0.44 to 1.07; I2 = 0%; very low certainty evidence) compared with HD initiated using a CVC. Two studies using different methods of measurements for hospitalisation reported that hospitalisation was similar although one study reported higher hospitalisation rates in HD initiated using a catheter compared with urgent-start PD. AUTHORS' CONCLUSIONS: Compared with HD initiated using a CVC, urgent-start PD may reduce the risk of bacteraemia and had uncertain effects on other complications of dialysis and technique and patient survival. In summary, there are very few studies directly comparing the outcomes of urgent-start PD and HD initiated using a CVC for patients with CKD who need to commence dialysis urgently. This evidence gap needs to be addressed in future studies.