Critical Care - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 8 of 8
  • Item
    Thumbnail Image
    Intraoperative low tidal volume ventilation and the risk of ICD-10 coded delirium and the use for antipsychotic medications
    Karalapillai, D ; Weinberg, L ; Serpa Neto, A ; Peyton, PJ ; Ellard, L ; Hu, R ; Pearce, B ; Tan, C ; Story, D ; O'Donnell, M ; Hamilton, P ; Oughton, C ; Galtieri, J ; Appu, S ; Wilson, A ; Eastwood, G ; Bellomo, R ; Jones, DA (BMC, 2022-05-16)
    BACKGROUND: Low tidal volume (VT) ventilation and its associated increase in arterial carbon dioxide (PaCO2) may affect postoperative neurologic function. We aimed to test the hypothesis that intraoperative low VT ventilation affect the incidence of postoperative ICD-10 coded delirium and/or the need for antipsychotic medications. METHODS: This is a post-hoc analysis of a large randomized controlled trial evaluating low vs. conventional VT ventilation during major non-cardiothoracic, non-intracranial surgery. The primary outcome was the incidence of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay, and the absolute difference with its 95% confidence interval (CI) was calculated. RESULTS: We studied 1206 patients (median age of 64 [55-72] years, 59.0% males, median ARISCAT of 26 [19-37], and 47.6% of ASA 3). ICD-10 coded delirium and /or antipsychotic medication use was diagnosed in 11.2% with similar incidence between low and conventional VT ventilation (11.1% vs. 11.3%; absolute difference, -0.24 [95%CI, -3.82 to 3.32]; p = 0.894). There was no interaction between allocation group and type of surgery. CONCLUSION: In adult patients undergoing major surgery, low VT ventilation was not associated with increased risk of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay. TRIAL REGISTRATION: ANZCTR Identifier: ACTRN12614000790640 .
  • Item
    Thumbnail Image
    Intra-operative ventilator mechanical power as a predictor of postoperative pulmonary complications in surgical patients A secondary analysis of a randomised clinical trial
    Karalapillai, D ; Weinberg, L ; Neto A, S ; Peyton, P ; Ellard, L ; Hu, R ; Pearce, B ; Tan, CO ; Story, D ; O'Donnell, M ; Hamilton, P ; Oughton, C ; Galtieri, J ; Wilson, A ; Eastwood, G ; Bellomo, R ; Jones, DA (LIPPINCOTT WILLIAMS & WILKINS, 2022-01)
    BACKGROUND: Studies in critically ill patients suggest a relationship between mechanical power (an index of the energy delivered by the ventilator, which includes driving pressure, respiratory rate, tidal volume and inspiratory pressure) and complications. OBJECTIVE: We aimed to assess the association between intra-operative mechanical power and postoperative pulmonary complications (PPCs). DESIGN: Post hoc analysis of a large randomised clinical trial. SETTING: University-affiliated academic tertiary hospital in Melbourne, Australia, from February 2015 to February 2019. PATIENTS: Adult patients undergoing major noncardiothoracic, nonintracranial surgery. INTERVENTION: Dynamic mechanical power was calculated using the power equation adjusted by the respiratory system compliance (CRS). Multivariable models were used to assess the independent association between mechanical power and outcomes. MAIN OUTCOME MEASURES: The primary outcome was the incidence of PPCs within the first seven postoperative days. The secondary outcome was the incidence of acute respiratory failure. RESULTS: We studied 1156 patients (median age [IQR]: 64 [55 to 72] years, 59.5% men). Median mechanical power adjusted by CRS was 0.32 [0.22 to 0.51] (J min-1)/(ml cmH2O-1). A higher mechanical power was also independently associated with increased risk of PPCs [odds ratio (OR 1.34, 95% CI, 1.17 to 1.52); P < 0.001) and acute respiratory failure (OR 1.40, 95% CI, 1.21 to 1.61; P < 0.001). CONCLUSION: In patients receiving ventilation during major noncardiothoracic, nonintracranial surgery, exposure to a higher mechanical power was independently associated with an increased risk of PPCs and acute respiratory failure. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry no: 12614000790640.
  • Item
    Thumbnail Image
    Peri-operative lidocaine infusion for open radical prostatectomy - a reply
    Weinberg, L ; Story, D ; Gordon, I ; Christophi, C (WILEY-BLACKWELL, 2016-10)
  • Item
    Thumbnail Image
    Sodium bicarbonate infusion in patients undergoing orthotopic liver transplantation: a single center randomized controlled pilot trial
    Weinberg, L ; Broad, J ; Pillai, P ; Chen, G ; Nguyen, M ; Eastwood, GM ; Scurrah, N ; Nikfarjam, M ; Story, D ; McNicol, L ; Bellomo, R (WILEY-BLACKWELL, 2016-05)
    BACKGROUND: Liver transplantation-associated acute kidney injury (AKI) carries significant morbidity and mortality. We hypothesized that sodium bicarbonate would reduce the incidence and/or severity of liver transplantation-associated AKI. METHODS: In this double-blinded pilot RCT, adult patients undergoing orthotopic liver transplantation were randomized to an infusion of either 8.4% sodium bicarbonate (0.5 mEq/kg/h for the first hour; 0.15 mEq/kg/h until completion of surgery); (n = 30) or 0.9% sodium chloride (n = 30). PRIMARY OUTCOME: AKI within the first 48 h post-operatively. RESULTS: There were no significant differences between the two treatment groups with regard to baseline characteristics, model for end-stage liver disease and acute physiology and chronic health evaluation (APACHE) II scores, and pre-transplantation renal function. Intra-operative factors were similar for duration of surgery, blood product requirements, crystalloid and colloid volumes infused and requirements for vasoactive therapy. Eleven patients (37%) in the bicarbonate group and 10 patients (33%) in the sodium chloride group developed a post-operative AKI (p = 0.79). Bicarbonate infusion attenuated the degree of immediate post-operative metabolic acidosis; however, this effect dissipated by 48 h. There were no significant differences in ventilation hours, ICU or hospital length of stay, or mortality. CONCLUSIONS: The intra-operative infusion of sodium bicarbonate did not decrease the incidence of AKI in patients following orthotopic liver transplantation.
  • Item
    Thumbnail Image
    Associations between preoperative anaemia and hospital costs following major abdominal surgery: cohort study
    Meyerov, J ; Louis, M ; Lee, DK ; Fletcher, L ; Banyasz, D ; Miles, LF ; Ma, R ; Tosif, S ; Koshy, AN ; Story, DA ; Bellomo, R ; Weinberg, L (OXFORD UNIV PRESS, 2021-03)
    BACKGROUND: Determining the cost-effectiveness and sustainability of patient blood management programmes relies on quantifying the economic burden of preoperative anaemia. This retrospective cohort study aimed to evaluate the hospital costs attributable to preoperative anaemia in patients undergoing major abdominal surgery. METHODS: Patients who underwent major abdominal surgery between 2010 and 2018 were included. The association between preoperative patient haemoglobin (Hb) concentration and hospital costs was evaluated by curve estimation based on the least-square method. The in-hospital cost of index admission was calculated using an activity-based costing methodology. Multivariable regression analysis and propensity score matching were used to estimate the effects of Hb concentration on variables related directly to hospital costs. RESULTS: A total of 1286 patients were included. The median overall cost was US $18 476 (i.q.r.13 784-27 880), and 568 patients (44.2 per cent) had a Hb level below 13.0 g/dl. Patients with a preoperative Hb level below 9.0 g/dl had total hospital costs that were 50.6 (95 per cent c.i. 14.1 to 98.9) per cent higher than those for patients with a preoperative Hb level of 9.0-13.0 g/dl (P < 0.001), 72.5 (30.6 to 128.0) per cent higher than costs for patients with a Hb concentration of 13.1-15.0 g/dl (P < 0.001), and 62.4 (21.8 to 116.7) per cent higher than those for patients with a Hb level greater than 15.0 g/dl (P < 0.001). Multivariable general linear modelling showed that packed red blood cell (PRBC) transfusions were a principal cost driver in patients with a Hb concentration below 9.0 g/dl. CONCLUSION: Patients with the lowest Hb concentration incurred the highest hospital costs, which were strongly associated with increased PRBC transfusions. Costs and possible complications may be decreased by treating preoperative anaemia, particularly more severe anaemia.
  • Item
    Thumbnail Image
    Functional evaluation and practice survey to guide purchasing of intravenous cannulae
    Tay, S ; Spain, B ; Morandell, K ; Gilson, J ; Weinberg, L ; Story, D (BIOMED CENTRAL LTD, 2013-12-24)
    BACKGROUND: There are wide variations in the physical designs and attributes between different brands of intravenous cannulae that makes product selection and purchasing difficult. In a systematic assessment to guide purchasing, we assessed two cannulae - Cannula P and I. We proposed that the results of in-vitro performance testing of the cannulae would be associated with preference after clinical comparison. METHODS: We designed an observer-blinded randomised head-to-head trial between the 18, 20 and 22 gauge versions of Cannula P and I. Our primary end-point was pressure (mmHg) generated during various flow rates and our secondary end-point was the force (Newton) required to slide the catheter away from the needle. This was followed by a prospective electronic survey following a two-week clinical trial period. RESULTS: The mean difference in resistance between Cannula P and I was: 307 mmHg.L-1.hr-1 (95% CI: 289-325, p < 0.001) for 22G; 135 mmHg.L-1.hr-1 (95% CI: 125-144, p < 0.001) for 20G; and 27 mmHg.L-1.hr-1 (95% CI: 26-28, p < 0.001) for 18G. The mean difference in the force needed to displace the catheter away from its needle was: 1.41 N (95% CI: 1.09-1.73, p < 0.001) for 22G; 0.19 N (95% CI: -0.04-0.41, p = 0.12) for 20G; and 1.96 N (95% CI: 1.40-2.52, p < 0.001) for 18G. After a trial period, all 16 anaesthetist who had used both cannulae preferred Cannula I to P. CONCLUSIONS: The evaluation process described here could help hospitals improve efficient product selection and purchasing decisions for intravenous cannulae.
  • Item
    Thumbnail Image
    Attitudes of anesthetists towards an anesthesia-led nurse practitioner model for low-risk colonoscopy procedures: a cross-sectional survey
    Weinberg, L ; Grover, H ; Cowie, D ; Langley, E ; Heland, M ; Story, DA (BMC, 2020-03-17)
    BACKGROUND: The mounting pressure on the Australian healthcare system is driving a continual exploration of areas to improve patient care and access and to maximize utilization of our workforce. We hypothesized that there would be support by anesthetists employed at our hospital for the design, development, and potential implementation of an anesthesia-led nurse practitioner (NP) model for low-risk colonoscopy patients. METHODS: We conducted a cross-sectional, mixed methods study to ascertain the attitudes and acceptability of anesthetists towards a proposed anesthesia-led NP model for low-risk colonoscopy patients. An online survey using commercial software and theoretical questions pertaining to participants' attitudes towards an anesthesia-led NP model was e-mailed to consultant anesthetists. Participants were also invited to participate in a voluntary 20-min face-to-face interview. RESULTS: A total of 60 survey responses were received from a pool of 100 anesthetists (response rate = 60%, accounting for 8.04% margin of error). Despite the theoretical benefits of improved patient access to colonoscopy services, most anesthetists were not willing to participate in the supervision and training of NPs. The predominant themes underlying their lack of support for the program were a perception that patient safety would be compromised compared to the current model of anesthesia-led care, the model does not meet the Australian and New Zealand College of Anesthetists guidelines for procedural sedation and analgesia, and the program may be a public liability prone to litigation in the event of an adverse outcome. Concerns about consumer acceptance and cost-effectiveness were also raised. Finally, participants thought the model should be pilot tested to better understand consumer attitudes, logistical feasibility, patient and proceduralist attitudes, clinical governance, and, importantly, patient safety. CONCLUSIONS: Most anesthetists working in a single-center university hospital did not support an anesthesia-led NP model for low-risk colonoscopy patients. Patient safety, violations of the current Australian and New Zealand College of Anesthetists guidelines on procedural sedation, and logistical feasibility were significant barriers to the acceptance of the model. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, 12619001036101.
  • Item
    Thumbnail Image
    Restrictive intraoperative fluid optimisation algorithm improves outcomes in patients undergoing pancreaticoduodenectomy: A prospective multicentre randomized controlled trial
    Weinberg, L ; Ianno, D ; Churilov, L ; Chao, I ; Scurrah, N ; Rachbuch, C ; Banting, J ; Muralidharan, V ; Story, D ; Bellomo, R ; Christophi, C ; Nikfarjam, M ; Hills, RK (PUBLIC LIBRARY SCIENCE, 2017-09-07)
    We aimed to evaluate perioperative outcomes in patients undergoing pancreaticoduodenectomy with or without a cardiac output goal directed therapy (GDT) algorithm. We conducted a multicentre randomised controlled trial in four high volume hepatobiliary-pancreatic surgery centres. We evaluated whether the additional impact of a intraoperative fluid optimisation algorithm would influence the amount of fluid delivered, reduce fluid related complications, and improve length of hospital stay. Fifty-two consecutive adult patients were recruited. The median (IQR) duration of surgery was 8.6 hours (7.1:9.6) in the GDT group vs. 7.8 hours (6.8:9.0) in the usual care group (p = 0.2). Intraoperative fluid balance was 1005mL (475:1873) in the GDT group vs. 3300mL (2474:3874) in the usual care group (p<0.0001). Total volume of fluid administered intraoperatively was also lower in the GDT group: 2050mL (1313:2700) vs. 4088mL (3400:4525), p<0.0001 and vasoactive medications were used more frequently. There were no significant differences in proportions of patients experiencing overall complications (p = 0.179); however, fewer complications occurred in the GDT group: 44 vs. 92 (Incidence Rate Ratio: 0.41; 95%CI 0.24 to 0.69, p = 0.001). Median (IQR) length of hospital stay was 9.5 days (IQR: 7.0, 14.3) in the GDT vs. 12.5 days in the usual care group (IQR: 9.0, 22.3) for an Incidence Rate Ratio 0.64 (95% CI 0.48 to 0.85, p = 0.002). In conclusion, using a surgery-specific, patient-specific goal directed restrictive fluid therapy algorithm in this cohort of patients, can justify using enough fluid without causing oedema, yet as little fluid as possible without causing hypovolaemia i.e. "precision" fluid therapy. Our findings support the use of a perioperative haemodynamic optimization plan that prioritizes preservation of cardiac output and organ perfusion pressure by judicious use of fluid therapy, rational use of vasoactive drugs and timely application of inotropic drugs. They also suggest the need for further larger studies to confirm its findings.