The effect of restrictive compared to liberal intravenous fluid volume on hypotension in adults undergoing major abdominal surgery.

In a cardiac output (CO) sub-study of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial, it was shown that restrictive fluid management was associated with lower cardiac index at the end of surgery. However, the association of the fluid protocol with intraoperative blood pressure was less clear. This paper primarily compares rates of hypotension between the two fluid regimens. The haemodynamic effects of these protocols may increase our understanding of perioperative fluid prescription. Using a data set of arterial pressure and cardiac output measurements, this observational cohort study primarily compares intraoperative hypotension rates defined by a mean arterial pressure < 65 mmHg between liberal and restrictive fluid protocols. Secondary analyses explore predictors of invasive mean arterial pressure and doppler-derived cardiac output, including fluid volume regimens and surgical duration. 105 patients had a combined total of 835 haemodynamic data capture events from the beginning to the end of the surgery. Here we report that a restrictive regimen is not associated with a greater proportion of participants who experience at least one episode of hypotension than the liberal regimen 64.1% vs. 61.5% (mean difference 2.6%, 95% CI - 15.9% to 21%, p = 0.78). Duration of surgery was associated with an increased risk of hypotension (OR 1.05, 1 to 1.1, p = 0.038). A fluid restriction protocol compared to liberal fluid administration is not associated with lower blood pressure.

Antimicrobial stewardship program for gastrointestinal surgeries at a Vietnamese tertiary hospital.

Background: Antimicrobial Stewardship Programs (ASP) have been applied widely in high-resource countries to prevent surgical site infections (SSI). Evidence favoring ASP interventions (ASPi) in gastrointestinal surgeries from low and middle-income countries has been limited, especially in antimicrobial prophylaxis. We aimed to investigate this gap at a Vietnamese tertiary hospital. Methods: We conducted a retrospective cohort study on patients undergoing clean-contaminated surgeries in 2015 who received standard of care (SoC) or SoC + ASPi. Primary outcome was 30-day SSI incidence. Secondary outcomes included length of stay (LoS) after surgery (days), cost of antibiotics, and cost of treatment (USD). Results were controlled for multiplicity and reported with treatment effect and 95% confidence interval (95%CI). A predictive model was built and cross-validated to detect patients at high risk of SSI. Results: We included 395 patients for analysis (48.1% being female, mean age 49.4 years). Compared to patients receiving SoC, those with SoC + ASPi had a lower incidence of 30-day SSI (-8.8, 95%CI: -16.0 to -1.6, p = 0.042), shorter LoS after surgery (-1.1 days, 95%CI: -1.8 to -0.4, p = 0.004), and lower cost of antibiotics (-37.3 USD, 95%CI: -59.8 to -14.8, p = 0.012) and treatment (-191.1 USD, 95%CI: -348.4 to -33.8, p = 0.042). We estimated that by detecting patients at high risk of SSI with the predictive model and providing prophylactic measures, we could save 398120.7 USD per 1,000 cases of SSI. Conclusion: We found that ASPi were associated with a reduction in risks of SSI, hospital stays, and cost of antibiotics/treatment in a Vietnamese tertiary hospital.

Effects of antivirals on patients with COVID-19 breakthrough.

BACKGROUND: Antivirals have been given widely for patients with COVID-19 breakthrough in Asian countries, creating a "black market" for unapproved and unprescribed medications. More evidence is needed to clarify the benefits of antivirals in these settings. METHODS: We conducted a random-sampling retrospective cohort study at a general hospital in Vietnam. We recruited patients with mild-to-moderate COVID-19 breakthrough who were given either standard of care (SoC) alone or SoC + antiviral. Primary outcome was residual respiratory symptoms that lasted > 7 days. Secondary outcome was long COVID-19, diagnosed by specialized physicians. We used logistic regression to measure odds ratio (OR), in addition to a sensitivity and subgroup analyses to further explore the results. RESULTS: A total of 142 patients (mean age 36.2 ± 9.8) were followed. We recorded residual symptoms in 27.9% and 20.3% of the SoC and SoC + antiviral group, while the figures for long COVID-19 were 11.8% and 8.1%, respectively. Antiviral use was not significantly associated with lower the risks of residual symptoms (OR = 0.51, 95% CI: 0.22-1.20, p = 0.12) or long COVID-19 (OR = 0.55, 95% CI: 0.16-1.90, p = 0.35). The sensitivity and subgroup analyses did not show any significant differences between the study groups (all p > 0.05). CONCLUSION: Antivirals were not associated with faster resolution of respiratory symptoms or lower risks of long COVID-19. Further studies should focus on different antivirals to confirm their effects on different sub-populations. Meanwhile, antivirals should only be used in very high-risk patients to avoid excessive costs and harms.

Current status of Helicobacter pylori resistance to clarithromycin and levofloxacin in Vietnam: Results from molecular analysis of gastric biopsy specimens.

OBJECTIVES: The management of Helicobacter pylori in Vietnam is becoming progressively more difficult due to increasing antibiotic resistance, particularly to clarithromycin (CLR) and levofloxaxin (LVX). In Vietnam, the selection of an H. pylori eradication regimen is predominantly based on empirical evidence. However, molecular analysis aimed at identifying H. pylori antibiotic-resistant genotypes is a promising method in antibiotic susceptibility testing. In this study, we aimed to determine the rates of genotypic H. pylori resistance to CLR and LVX by using DNA strip technology in Vietnam. METHODS: We performed DNA-strip technology-based testing on 112 patients with H. pylori-positive gastroduodenal diseases to detect 23S rRNA and gyrA mutations. RESULTS: Helicobacter pylori genotypic resistance to CLR and LVX was evident in 81.3% and 53.6% of the patients, respectively, and dual resistance was observed in 48.2%. The 23S rRNA A2142G and A2143G mutations accounted for 1.8% and 79.5% of cases, respectively. The gyrA N87K, D91N, D91G, and D91Y mutations were present in 37.5%, 11.6%, 5.4%, and 5.4% of patients, respectively. All four gyrA mutations were observed in both the naïve and failure patients. We further found an association between the 23S rRNA A2143G mutation and a history of CLR use as well as between the gyrA N87K mutation and a history of LVX use. CONCLUSIONS: We found a very high prevalence of H. pylori resistance to CLR and LVX and dual resistance to these antibiotics in Vietnam. The application of molecular assays is feasible and may improve the management of H. pylori infection in Vietnam.

Impact of the COVID-19 Pandemic on the Severity and Early Postoperative Outcomes of Acute Appendicitis.

Background The coronavirus disease 2019 (COVID-19) pandemic caused changes in surgical practice. For acute appendicitis (AA), measures to control the pandemic might hinder patients from seeking medical care timely, resulting in increasing severity, postoperative complications, and mortality. This study aimed to investigate whether the COVID-19 pandemic had a negative impact on the severity and postoperative outcomes of patients with AA. Methodology We retrospectively reviewed medical records of AA patients treated operatively at Nhan Dan Gia Dinh Hospital hospital from June 1st to September 30th in three consecutive years: pre-pandemic (2019)/Group 1, minor waves (2020)/Group 2, and major wave (2021)/Group 3 (2021). Data were collected focusing on the duration of symptoms, severity of AA, time from admission to operation, postoperative complications, and mortality. Results There were 1,055 patients, including 452 patients in Group 1, 409 in Group 2, and 194 in Group 3. The overall number of patients decreased mainly in non-complicated AA. The percentages of hospital admission after 24 hours gradually increased (20.8%, 27.9%, and 43.8%, p < 0.05). The percentages of complicated AA in Group 2 and Group 3 were statistically higher than in Group 1 (39% and 55% vs. 31%, p < 0.05). Waiting time for operation increased to five hours during the major wave. Laparoscopic appendectomy was performed in 98-99% of AA patients during the pandemic, with an early postoperative complication rate of 5-9% and a mortality rate of 0.2-1%. Conclusions Although the percentages of hospital admission after 24 hours and complicated AA increased, laparoscopic appendectomy was still feasible and effective and should be maintained as the standard management for AA during the COVID-19 pandemic.

An extremely rare missense mutation of the androgen receptor gene in a Vietnamese family with complete androgen insensitivity syndrome.

We report a Vietnamese family with complete androgen insensitivity syndrome that included several phenotypic females who have a 46,XY karyotype with an extremely rare mutation of the androgen receptor gene. The proband was a 27-year-old phenotypic adult female referred to our department for karyotyping due to primary amenorrhea. Ultrasound examination revealed a small uterus. Chromosomal analysis showed a 46,XY karyotype. A polymerase chain reaction assay revealed the presence of the sex-determining region Y gene. Next-generation sequencing detected the NM_000044.6(AR):c.2170C>T(p.Pro274Ser) mutation, which was confirmed by Sanger sequencing. There is only one previous report of this mutation in a child with complete androgen insensitivity syndrome. In the family presented in this study, there were four more phenotypic adult females with primary amenorrhea and a phenotypic female infant with testes in the inguinal canals. The infant (first cousin once removed of the proband) presented with inguinal hernia/swelling in a phenotypic female and one of the four abovementioned adults had similar genetic analysis results. This is the second report of a missense mutation NM 000044.6(AR):c.2170C>T in the world and the first study to document a pedigree consisting of several individuals with CAIS as a result of this mutation. The presence of a tiny uterus in the proband, which is a rare occurrence in complete androgen insensitivity syndrome, is a unique clinical indicator of the disorder's variable expressivity.

Clinical use of remdesivir in COVID-19 treatment: a retrospective cohort study.

OBJECTIVES: This study investigated remdesivir's clinical use to provide direct evidence of effectiveness for a low-middle income Asian setting. DESIGN: A one-to-one propensity score matching retrospective cohort study. SETTING: A tertiary hospital with COVID-19 treatment facilities in Vietnam. PARTICIPANTS: A total of 310 patients in standard of care (SoC) group were matched with 310 patients in SoC+remdesivir (SoC+R) group. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was time to critical progression, defined as all-cause mortality or critical illness. The secondary outcomes were length of oxygen therapy/ventilation and need for invasive mechanical ventilation. Outcome reports were presented as HR, OR or effect difference with 95% CI. RESULTS: Patients receiving remdesivir had a lower risk for mortality or critical illness (HR=0.68, 95% CI 0.47 to 0.96, p=0.030). Remdesivir was not associated with a shorter length of oxygen therapy/ventilation (effect difference -0.17 days, 95% CI -1.29 to 0.96, p=0.774). The need for invasive mechanical ventilation was lower in SoC+R group (OR=0.57, 95% CI 0.38 to 0.86, p=0.007). CONCLUSIONS: This study's results showing remdesivir's benefits in non-critical patients with COVID-19 may be extrapolated to other similar low-middle income countries, allowing more regimens for limited resource areas and reducing poor outcomes and equity gap worldwide.

Validation of the Vietnamese version of the low anterior resection syndrome score questionnaire.

Purpose: The aim of this study was to validate the low anterior resection syndrome (LARS) score questionnaire in the Vietnamese language among Vietnamese patients who underwent sphincter-preserving surgery for rectal cancer. Methods: The LARS score questionnaire was translated from English into Vietnamese and then back-translated as recommended internationally. From January 2018 to December 2020, 93 patients who underwent sphincter-preserving surgery completed the Vietnamese version of the LARS score questionnaire together with an anchored question assessing the influence of bowel function on quality of life (QoL). To validate test-retest reliability, patients were requested to answer the LARS score questionnaire twice. Results: Ninety-three patients completed the LARS score questionnaire, of whom 89 responded twice. The patients who responded twice were included in the analysis of test-retest reliability. Fifty-eight patients had a "major" LARS score. The LARS score was able to discriminate between patients who were obese and those who were not (P<0.001) and between the low anterior resection and anterior resection procedures (P<0.001). Age and sex were not associated with higher LARS scores (P=0.975). There was a perfect fit between the QoL category question and the LARS score in 56.2% of cases, and a moderate fit was found in 42.7% of cases, showing reasonable convergent validity. The test-retest reliability of 89 patients showed a high intraclass correlation coefficient. Conclusion: The Vietnamese version of the LARS score questionnaire is a valid tool for measuring LARS.

An Extremely Rare SRD5A2 Gene c.485A>C Mutation in a Compound Heterozygous Newborn with Disorders of Sex Development First Identified in Vietnam.

SRD5A2 (steroid 5-alpha-reductase 2) mutation, which impairs 5α-reductase-2 enzyme activity, is among the causes of 46,XY disorders of sex development (DSD). Here, we report a rare pathogenic mutation NM_000348.4:c.485A>C (NP_000339.2:p.His162Pro) of SRD5A2 gene in a compound heterozygous state first identified in a Vietnamese newborn with 5α-reductase-2 enzyme deficiency. We also first submitted this rare mutation to ClinVar database (VCV000973099.1). The patient presented with hyperpigmented labia-majora-like bifid scrotum, clitoris-like phallus, perineoscrotal hypospadias, and blind-ending vagina. The other mutation NM_000348.4:c.680G>A (NP_000339.2:p.Arg227Gln) was reported previously. This compound heterozygous mutation was first detected by next-generation sequencing. By Sanger sequencing, we confirmed that the c.485A>C mutation was maternal inherited, whereas the c.680G>A mutation was paternal inherited. Up to date, this is the first report of this rare compound heterozygous state of SRD5A2 c.485A>C and c.680G>A mutations in patients with 46,XY DSD generally as well as in Vietnamese population particularly and is also the second report in the world carrying the pathogenic mutation NM_000348.4:c.485A>C (NP_000339.2:p.His162Pro). Our finding has enriched the understanding of the spectrum of SRD5A2 variants and phenotypic correlation in Asian patients with 46,XY DSD.

Laparoscopic Hartmann reversal: experiences from a developing country.

PURPOSE: Laparoscopic surgery is considered a promising approach for Hartmann reversal but is also a complicated major surgical procedure. We conducted a retrospective analysis at a city hospital in Vietnam to evaluate the treatment technique and outcomes of laparoscopic Hartmann reversal (LHR). METHODS: A colorectal surgery database in 5 years between 2015 and 2019 (1,175 cases in total) was retrieved to collect 35 consecutive patients undergoing LHR. RESULTS: The patients had a median age of 61 years old. The median operative time was 185 minutes. All the procedures were first attempted laparoscopically with a conversion rate of 20.0% (7 of 35 cases). There was no intraoperative complication. Postoperative mortality and morbidity were 0 and 11.4% (2 medical, 1 deep surgical site infection, and 1 anastomotic leak required reoperation) respectively. The median time to first bowel activity was 2.8 days and median length of hospital stay was 8 days. CONCLUSION: When performed by skilled surgeons, LHR is a feasible and safe operation with acceptable morbidity rate.

Repatriation operation in South Australia during the COVID-19 pandemic: initial planning and preparedness.

ABSTRACT: With COVID-19 affecting millions of people around the globe, quarantine of international arrivals is a critical public health measure to prevent further disease transmission in local populations. This measure has also been applied in the repatriation of citizens, undertaken by several countries as an ethical obligation and legal responsibility. This article describes the process of planning and preparing for the repatriation operation in South Australia during the COVID-19 pandemic. Interagency collaboration, development of a COVID-19 testing and quarantining protocol, implementing infection prevention and control, and building a specialised health care delivery model were essential aspects of the repatriation operational planning, with a focus on maintaining dignity and wellbeing of the passengers as well as on effective prevention of COVID-19 transmission. From April 2020 to mid-February 2021, more than 14,000 international arrivals travellers have been repatriated under the South Australian repatriation operations. This paper has implications to inform ongoing repatriation efforts in Australia and overseas in a pandemic situation.

Effect of fluid strategy on stroke volume, cardiac output, and fluid responsiveness in adult patients undergoing major abdominal surgery: a sub-study of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial.

BACKGROUND: We designed a prospective sub-study of the larger Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial to measure differences in stroke volume and other haemodynamic parameters at the end of the intraoperative fluid protocols. The haemodynamic effects of the two fluid regimens may increase our understanding of the observed perioperative outcomes. METHODS: Stroke volume and cardiac output were measured with both an oesophageal Doppler ultrasound monitor and arterial pressure waveform analysis. Stroke volume variation, pulse pressure variation, and plethysmographic variability index were also obtained. A passive leg raise manoeuvre was performed to identify fluid responsiveness. RESULTS: Analysis of 105 patients showed that the primary outcome, Doppler monitor-derived stroke volume index, was higher in the liberal group: restrictive 38.5 (28.6-48.8) vs liberal 44.0 (34.9-61.9) ml m-2; P=0.043. Similarly, there was a higher cardiac index in the liberal group: 2.96 (2.32-4.05) vs 2.42 (1.94-3.26) L min-1 m-2; P=0.015. Arterial-pressure-based stroke volume and cardiac index did not differ, nor was there a significant difference in stroke volume variation, pulse pressure variation, or plethysmographic variability index. The passive leg raise manoeuvre showed fluid responsiveness in 40% of restrictive and 30% of liberal protocol patients (not significant). CONCLUSIONS: The liberal fluid group from the RELIEF trial had significantly higher Doppler ultrasound monitor-derived stroke volume and cardiac output compared with the restrictive fluid group at the end of the intraoperative period. Measures of fluid responsiveness did not differ significantly between groups. CLINICAL TRIAL REGISTRATION: ACTRN12615000125527.

Aerosolisation in endonasal endoscopic pituitary surgery.

PURPOSE: To determine the particle size, concentration, airborne duration and spread during endoscopic endonasal pituitary surgery in actual patients in a theatre setting. METHODS: This observational study recruited a convenience sample of three patients. Procedures were performed in a positive pressure operating room. Particle image velocimetry and spectrometry with air sampling were used for aerosol detection. RESULTS: Intubation and extubation generated small particles (< 5 µm) in mean concentrations 12 times greater than background noise (p < 0.001). The mean particle concentrations during endonasal access were 4.5 times greater than background (p = 0.01). Particles were typically large (> 75 µm), remained airborne for up to 10 s and travelled up to 1.1 m. Use of a microdebrider generated mean aerosol concentrations 18 times above baseline (p = 0.005). High-speed drilling did not produce aerosols greater than baseline. Pituitary tumour resection generated mean aerosol concentrations less than background (p = 0.18). Surgical drape removal generated small and large particles in mean concentrations 6.4 times greater than background (p < 0.001). CONCLUSION: Intubation and extubation generate large amounts of small particles that remain suspended in air for long durations and disperse through theatre. Endonasal access and pituitary tumour resection generate smaller concentrations of larger particles which are airborne for shorter periods and travel shorter distances.

An experience in prenatal diagnosis via QF-PCR of a female child with a 9.9 Mb pure deletion at 18p11.32-11.22.

Quantitative Fluorescent - Polymerase Chain Reaction (QF-PCR) is a rapid prenatal diagnosis test for 21, 18, 13 and sex chromosomal aneuploidy detection. However, it could not detect partial trisomy or partial monosomy of those chromosomes. Here, we report a 19-month-old Vietnamese female with a 9.9 Mb pure deletion of chromosome 18 at 18p11.32-11.22 confirmed by next generation sequencing. The patient was short statured with facial dysmorphic features as well as motor skill and speech delays. First trimester screening showed high risk of trisomy 21 with only increased nuchal translucency (NT 3.9 mm) by ultrasound as an indication. Prenatal diagnosis by QF-PCR from amniotic DNA revealed normal disomy. Noticeably, two short tandem repeat (STR) markers D18S391 and D18S976 located on 18p exhibited uninformative patterns (one peak). Thus, our case suggested that the combination of both D18S391 and D18S976 markers with uninformative patterns in QF-PCR for prenatal diagnosis and increased NT in the first trimester ultrasound may be a significant indication of 18p monosomy.

Anaesthetists' attitudes towards attending the funerals of their patients: A cross-sectional study among Australian and New Zealand anaesthetists.

A patient's death can pose significant stress on the family and the treating anaesthetist. Anaesthetists' attitudes about the benefits of and barriers to attending a patient's funeral are unknown. Therefore, we performed a prospective, cross-sectional study to ascertain the frequency of anaesthetists' attendance at a patient's funeral and their perceptions about the benefits and barriers. The primary aim was to investigate the attitudes of anaesthetists towards attending the funeral of a patient. The secondary aims were to examine the perceived benefits of and barriers to attending the funeral and to explore the rate of bonds being formed between anaesthetists, patients and families. Of the 424 anaesthetists who completed the survey (response rate 21.2%), 25 (5.9%) had attended a patient's funeral. Of the participants, 364 (85.9%) rarely formed special bonds with patients or their families; 233 (55%) believed that forming a special bond would increase the likelihood of their attendance. Showing respect to patients or their families was the most commonly perceived benefit of attending a funeral. Participants found expression of personal grief and caring for the patient at the end-of-life and beyond beneficial to themselves and the family. Fear of their attendance being misinterpreted or perceived as not warranted by the family as well as time restraints were barriers for their attendance. Most anaesthetists had never attended a patient's funeral. Few anaesthetists form close relationships with patients or their families. Respect, expression of grief and caring beyond life were perceived benefits of attendance. Families misinterpreting the purpose of attendance or not expecting their attendance and time restraints were commonly perceived barriers. Trial registration: ACTRN 12618000503224.

Emergency surgery for obstructed colorectal cancer in Vietnam.

BACKGROUND: The benefit of one-stage surgery in emergency surgery for obstructing colorectal cancer (oCRC) by colorectal surgeons has increased during the last century but little is known about the outcomes of this technique conducted by general surgeons in developing countries. This retrospective study was to evaluate the outcomes of emergency surgery for oCRC in a general surgery unit. METHODS: A retrospective review of data from 1175 patients who underwent colorectal surgery between January 2013 and January 2018 was performed. Among these, a total of 186 patients with oCRC who underwent surgery within 24 h of hospital admission were analyzed. For patients with resectable right-sided oCRC, one-stage surgery was performed. For left-sided oCRC, primary anastomosis was mainly attempted; otherwise, a stoma was formed. The rates of primary resection, PRa, stoma, mortality, and morbidity were evaluated. RESULTS: Among 186 patients, oCRC involving the right colon, left colon, and rectum were found in 33.3%, 59.1% and 7.5% respectively. Primary resection and anastomosis were performed in 100%, 44.7%, and 0% of patients with oCRC in the right colon, left colon, and rectum respectively. The complication incidence based on Clavien-Dindo grade III or higher was 16.1% and the mortality rate was 7.5%. The median length of hospital stay was 8.5 days, ranging from 2 to 70 days. CONCLUSION: General surgeons with colorectal surgery experience can still manage oCRC effectively. Primary resection and anastomosis for left-sided oCRC is safe in selective patients. The emergency surgery for oCRC could be benefit with the participation of colorectal surgeons.

The cardiovascular effects of crystalloid administration in endoscopy patients.

Intravenous fluids are commonly administered for patients having colonoscopy despite relatively little data to support this practice. It is unclear what, if any, effect crystalloid administration has on stroke volume and cardiac output in patients who are fasting and have had bowel preparation agents. We aimed to assess the physiological effect of 10 ml/kg of crystalloid administration in colonoscopy patients on haemodynamic parameters including stroke volume, stroke volume variation and cardiac output, as measured with transthoracic echocardiography. Our secondary aims were to determine whether stroke volume variation predicted fluid responsiveness in gastrointestinal endoscopy patients and whether these haemodynamic measures are different in fasting patients with bowel preparation (colonoscopy patients) compared to fasting patients alone (gastroscopy patients). We recruited 54 patients having elective gastrointestinal endoscopy (25 colonoscopy, 29 gastroscopy). All patients had stroke volume, cardiac output and stroke volume variation measured with transthoracic echocardiography at baseline. In colonoscopy patients, stroke volume, cardiac output and stroke volume variation were remeasured after 10 ml/kg of intravenous crystalloid. Administration of 10 ml/kg of crystalloid increases stroke volume by 19.6 ml ( p < 0.00005) and cardiac output by 0.81 l/min ( p < 0.001). Stroke volume variation reduced from 23% to 14% after fluid administration ( p < 0.0011). The optimum threshold of stroke volume variation to predict fluid responsiveness was 21% with a sensitivity of 77.8% and specificity of 62.5%. Administration of 10 ml/kg of crystalloid increases stroke volume and cardiac output, and reduces stroke volume variation in fasting elective colonoscopy patients.

Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial: study protocol for a multicentre international trial of cardiac output-guided fluid therapy with low-dose inotrope infusion compared with usual care in patients undergoing major elective gastrointestinal surgery.

INTRODUCTION: Postoperative morbidity and mortality in older patients with comorbidities undergoing gastrointestinal surgery are a major burden on healthcare systems. Infections after surgery are common in such patients, prolonging hospitalisation and reducing postoperative short-term and long-term survival. Optimal management of perioperative intravenous fluids and inotropic drugs may reduce infection rates and improve outcomes from surgery. Previous small trials of cardiac-output-guided haemodynamic therapy algorithms suggested a modest reduction in postoperative morbidity. A large definitive trial is needed to confirm or refute this and inform widespread clinical practice. METHODS: The Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial is a multicentre, international, parallel group, open, randomised controlled trial. 2502 high-risk patients undergoing major elective gastrointestinal surgery will be randomly allocated in a 1:1 ratio using minimisation to minimally invasive cardiac output monitoring to guide protocolised administration of intravenous fluid combined with low-dose inotrope infusion, or usual care. The trial intervention will be carried out during and for 4 hours after surgery. The primary outcome is postoperative infection of Clavien-Dindo grade II or higher within 30 days of randomisation. Participants and those delivering the intervention will not be blinded to treatment allocation; however, outcome assessors will be blinded when feasible. Participant recruitment started in January 2017 and is scheduled to last 3 years, within 50 hospitals worldwide. ETHICS/DISSEMINATION: The OPTIMISE II trial has been approved by the UK National Research Ethics Service and has been approved by responsible ethics committees in all participating countries. The findings will be disseminated through publication in a widely accessible peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: ISRCTN39653756.