Surgery (Austin & Northern Health) - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 10 of 18
  • 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
    Complete opioid transition to sublingual Buprenorphine after abdominal surgery is associated with significant reductions in opioid requirements, but not reduction in hospital length of stay: a retrospective cohort study
    Heldreich, C ; Ganatra, S ; Lim, Z ; Meyer, I ; Hu, R ; Weinberg, L ; Tan, CO (BMC, 2022-01-21)
    BACKGROUND: The use of sublingual buprenorphine (SLBup) for acute pain after major abdominal surgery may offer the potential advantages of unique analgesic properties and more reliable absorption during resolving ileus. We hypothesized that complete opioid transition to SLBup rather than oral oxycodone (OOxy) in the early postoperative period after major abdominal surgery would reduce hospital length of stay, and acute pain and total OMEDD (Oral Morphine Equivalent Daily Dose) requirements in the first 24 h from post-parenteral opioid transition. METHODS: We reviewed 146 patients who had undergone elective and emergency abdominal surgery under our quaternary referral centre's Upper Gastro-Intestinal and Colo-Rectal Surgical Units 6 months before and after the introduction of complete postoperative transition to sublingual buprenorphine, rather than oral oxycodone, in July 2017. Our primary endpoint was 24-hourly post-transition OMEDDs; secondary endpoints were 24-hourly post-transition Mean NRS-11 pain scores on movement (POM) and length of hospital stay (LOS). Univariate analysis and linear multivariate regression analyses were used to quantify effect size and identify surgical, patient & other analgesic factors associated with these outcome measures. RESULTS: Patients transitioning to SLBup had reduced 24-hourly post-transition OMEDD requirements on postoperative day 2 (POD) (26 mg less, p = 0.04) and NRS-11 POM at POD1 (0.7 NRS-11 units less, p = 0.01). When adjusting for patient, surgical and special analgesic factors, SLBup was associated with a similar reduction in OMEDDs (Unstandardised beta-coefficient -26 mg, p = 0.0001), but not NRS-11 POM (p = 0.47) or hospital LOS (p = 0.16). CONCLUSIONS: Our change of practice from use of OOxy to SLBup as primary transition opioid from patient-controlled analgesia delivered full opioid agonists was associated with a clinically significant decrease in 24-hourly post-parenteral opioid transition OMEDDs and improved NRS-11 POM, but without an association with hospital LOS after major abdominal surgery. Further prospective randomized work is required to confirm these observed associations and impact on other important patient-centred outcomes.
  • Item
    Thumbnail Image
    The ALOHA trial: (intra-articular local anaesthetic in hip arthroscopy)-a three-arm randomized trial comparing pre-emptive, high- and low-dose intra-articular local anaesthetic in hip arthroscopy
    Tan, CO ; Tran, P ; Chong, YM ; Howard, W ; Weinberg, L (OXFORD UNIV PRESS, 2020-12)
    Abstract Pain after hip arthroscopy is variable and can be severe despite multimodal analgesia. Intra-articular local anaesthetic (IALA) may reduce acute postoperative pain after hip arthroscopy. However, neither its optimum dose nor timing of administration have been systematically evaluated. In 132 patients, a double-blinded, three-arm randomized controlled trial comparing IALA used during hip arthroscopy was conducted comparing 100 mg ropivacaine given at the end of the procedure (Group L, lose dose), 200 mg ropivacaine at the end of the procedure (Group H, high dose) and 100 mg of ropivacaine given at the beginning and end of the procedure (Group P, pre-emptive). There were no statistically significant differences between the three groups for Numerical Rating Scale-11 pain scores in the recovery room [mean (standard deviation): Group L—2.2 (1.9); Group H—2.3 (2.1); Group P—2.7 (2.5); lowest P = 0.6], or post-recovery room Visual Analogue Scale pain scores at 2, 4 and 6 h. There were also no significant differences in antiemetic usage and requirement for rescue fascia iliaca blockade between the three groups. Compared to a single 100 mg dose of ropivacaine at the end of the procedure, we were unable to demonstrate any advantage of either a higher dose IALA or a pre-emptive dose IALA when multimodal analgesia is used.
  • Item
    Thumbnail Image
    High Frequency, Low Background Rate Extrapleural Programmed Intermittent Bolus Ropivacaine Provides Superior Analgesia Compared with Continuous Infusion for Acute Pain Management Following Thoracic Surgery: A Retrospective Cohort Study.
    Bishop, B ; Pearce, B ; Willshire, L ; Kilpin, M ; Howard, W ; Weinberg, L ; Tan, C (Briefland, 2019-10)
    BACKGROUND: Thoracic surgery often results in severe postoperative pain. Regional analgesia via surgically placed extrapleural local anaesthetic (LA) and continuous infusion (CI) is an effective technique, however usually requires supplemental opioid to achieve satisfactory patient analgesia. We hypothesized that high frequency, low background rate extrapleural programmed intermittent boluses (PIB) of LA by could achieve superior patient analgesia and reduced oral morphine equivalent daily dosage (OMEDD) requirements for up to 3 days after thoracic surgery vs. CI. METHODS: We retrospectively analysed data from 84 adult patients receiving extrapleural analgesia after thoracic surgery in a single tertiary teaching hospital. The primary outcome measure was the effect of PIB vs. CI on maximum daily 11-point numerical rating scale (NRS-11) ratings as determined by multivariate linear regression analysis, corrected for OMEDD use, total daily LA dose, surgery type, age, opioid type, and use of ketamine analgesia. Secondary outcome measures were the effect on OMEDD use, the effect of total 'rescue' LA boluses, and univariate analyses of the above outcomes and variables. RESULTS: PIB on day 0, and a higher proportion of LA given as rescue boluses on day 1 were associated with reduced maximum NRS-11 ratings [standardized/ [unstandardized] beta coefficient -0.34/ [-0.92 NRS-11 if PIB] (P = 0.007); and -0.26/ [-0.029 NRS-11 per mg/kg extrapleural ropivacaine] (P = 0.03)], respectively. Only patient age was associated with reduced OMEDD use [day 0: -0.58/ [-4.4 OMEDDs per year of age] (P ≤ 0.005); day 1: -0.49/ [-3.56 OMEDDs per year of age] (P ≤ 0.005); day 2: -0.32/ [-1.9 OMEDDs per year of age] (P = 0.04)]. OMEDD use on day 2, however, was associated with slightly higher maximum NRS-11 ratings [+0.28/ +0.006 NRS-11 per mg OMEDD (P = 0.036)]. On univariate analysis, PIB patients achieved the largest difference in OMEDD use [-98 mg (95% CI -73 to -123 mg)] and NRS-11 ratings [-1.1 (-0.4 to -1.8)] against CI patients on day 3. CONCLUSIONS: Use of high frequency, low background rate PIB extrapleural LA after thoracic surgery appears to have a modest beneficial effect on acute pain, but not OMEDD use, over CI when adjusted for patient, surgical and other analgesic factors after thoracic surgery. Further work is required to elucidate the potential magnitude of effect that extrapleural LA given by PIB over CI can achieve.
  • Item
    Thumbnail Image
    Airway strategies for lung isolation in a patient with high-velocity nail gun injuries to the right cardiac ventricle and floor of the mouth: a case report.
    Lim, H ; Weinberg, L ; Tan, CO ; Tay, S ; Kolivas, C ; Peyton, P (Springer Science and Business Media LLC, 2013-05-28)
    INTRODUCTION: We report a case of deliberate self-harm in which three three-inch nails were fired from a nail gun resulting in mandibular fixation and two penetrating injuries to the right cardiac ventricle. This combination of high-velocity penetrating injury has not been previously described. CASE PRESENTATION: A 69-year-old Caucasian man with a medical history of chronic depression was brought to hospital after a failed suicide attempt. The attempt consisted of self-asphyxiation with car exhaust fumes and shooting himself thrice with a three-inch nail gun. He sustained a penetrating nail injury to the floor of his mouth, effectively pinning his mouth closed, and penetrating injuries to the right ventricular free wall and at the junction of the right atrioventricular septum. The patient required emergency surgery with requirements for thoracotomy and sternotomy, lung isolation and cardiopulmonary bypass. CONCLUSIONS: This is the first reported case of a combination high-velocity penetrating nail gun injury to the face and the right cardiac ventricle. This rare case offers airway strategies to accommodate the surgical requirement for lung separation for penetrating chest trauma in a patient with iatrogenically limited mouth opening.
  • Item
    Thumbnail Image
    The impact of fluid intervention on complications and length of hospital stay after pancreaticoduodenectomy (Whipple's procedure)
    Weinberg, L ; Wong, D ; Karalapillai, D ; Pearce, B ; Tan, CO ; Tay, S ; Christophi, C ; McNicol, L ; Nikfarjam, M (BIOMED CENTRAL LTD, 2014-05-14)
    BACKGROUND: There is limited information on the impact on perioperative fluid intervention on complications and length of hospital stay following pancreaticoduodenectomy. Therefore, we conducted a detailed analysis of fluid intervention in patients undergoing pancreaticoduodenectomy at a university teaching hospital to test the hypothesis that a restrictive intravenous fluid regime and/or a neutral or negative cumulative fluid balance, would impact on perioperative complications and length of hospital stay. METHODS: We retrospectively obtained demographic, operative details, detailed fluid prescription, complications and outcomes data for 150 consecutive patients undergoing pancreaticoduodenectomy in a university teaching hospital. Prognostic predictors for length of hospital stay and complications were determined. RESULTS: One hundred and fifty consecutive patients undergoing pancreaticoduodenectomy were evaluated between 2006 and 2012. The majority of patients were, middle-aged, overweight and ASA class III. Postoperative complications were frequent and occurred in 86 patients (57%). The majority of complications were graded as Clavien-Dindo Class 2 and 3. Postoperative pancreatic fistula occurred in 13 patients (9%), and delayed gastric emptying occurred in 25 patients (17%). Other postoperative surgical complications included sepsis (22%), bile leak (4%), and postoperative bleeding (2%). Serious medical complications included pulmonary edema (6%), myocardial infarction (8%), cardiac arrhythmias (13%), respiratory failure (8%), and renal failure (7%). Patients with complications received a higher median volume of intravenous therapy and had higher cumulative positive fluid balances. Postoperative length of stay was significantly longer in patients with complications (median 25 days vs. 10 days; p < 0.001). After adjustment for covariates, a fluid balance of less than 1 litre on postoperative day 1 and surgeon caseloads were associated with the development of complications. CONCLUSIONS: In the context of pancreaticoduodenectomy, restrictive perioperative fluid intervention and negative cumulative fluid balance were associated with fewer complications and shorter length of hospital stay. These findings provide good opportunities to evaluate strategies aimed at improving perioperative care.
  • Item
    Thumbnail Image
    Postoperative wristwatch-induced compressive neuropathy of the hand: a case report.
    Weinberg, L ; Spanger, M ; Tan, C ; Nikfarjam, M (Springer Science and Business Media LLC, 2015-06-16)
    INTRODUCTION: Postoperative peripheral nerve injuries are well-recognised complications of both surgery and anaesthesia and a leading cause of litigation claims. We present a rare cause of compressive sensory and motor neuropraxia of the median, ulnar and radial nerves of the right hand resulting from a wristwatch that was worn on the first postoperative night following minor surgery. Mechanisms of this compressive neuropathy are discussed, with specific recommendations made regarding the wearing of wristwatches, jewellery and constrictive clothing in the immediate postoperative period. CASE PRESENTATION: A 12-year-old white boy presented with a complete glove and stocking sensory and motor neuropathy involving his right hand from a wristwatch that was worn on the first postoperative night following uneventful surgery for a minor procedure. Over the following 12 hours the oedema and erythema resolved with complete return of motor function. After 18 hours, the sensory deficit completely resolved. CONCLUSIONS: Postoperative neuropraxia is often preventable. Paediatric patients, especially if thin, may be particularly susceptible to a compression neuropathy from constrictive clothing or jewellery, in particular circumferential varieties such as wristwatches. These items should not be worn in the immediate postoperative period as pressure on peripheral nerves can result in severe and debilitating nerve injury. Education should be given to all medical staff, carers or parents of children undergoing surgery on the avoidance of wearing wristwatches, jewellery or constrictive clothing in the immediate postoperative period. Early medical evaluation of any postoperative nerve injury is of paramount importance.
  • Item
    Thumbnail Image
    Surgical predictors of acute postoperative pain after hip arthroscopy
    Tan, CO ; Chong, YM ; Tran, P ; Weinberg, L ; Howard, W (BIOMED CENTRAL LTD, 2015-07-02)
    BACKGROUND: Pain following hip arthroscopy is highly variable and can be severe. Little published data exists demonstrating reliable predictors of significant pain after hip arthroscopy. The aim of this study was to identify influence of intraoperative factors (arthroscopic fluid infusion pressure, operative type) on the severity of postoperative pain. METHODS: A retrospective review of 131 patients who had received a variety of arthroscopic hip interventions was performed. A standardized anaesthetic technique was used on all patients and postoperative pain was analysed using recovery pain severity outcomes and analgesic use. A multivariate logistic regression analysis was performed on intraoperative factors including patient age, sex and BMI, arthroscopic infusion pressures (40 vs 80 mm Hg), amount of fluid used, length of surgery and types of arthroscopic interventions performed. Thirty six patients were also prospectively examined to determine arthroscopic fluid infusion rates for 40 and 80 mm Hg infusion pressures. RESULTS: Use of a higher infusion pressure of 80 mm Hg was strongly associated with all pain severity endpoints (OR 2.8 - 8.2). Other significant factors included hip arthroscopy that involved femoral chondro-ostectomy (OR 5.8) and labral repair (OR 7.5). Length of surgery and total amount of infusion fluid used were not associated with increased pain. CONCLUSIONS: 80 mm Hg arthroscopic infusion pressures, femoral chondro-osteoectomy and labral repair are strongly associated with significant postoperative pain, whereas intraoperative infusion volumes or surgical duration are not. Identification of these predictors in individual patients may guide clinical practice regarding the choice of more invasive regional analgesia options. The use of 40 mm Hg arthroscopic infusion pressures will assist in reducing postoperative pain.
  • Item
    Thumbnail Image
    Plasma-Lyte 148: A clinical review.
    Weinberg, L ; Collins, N ; Van Mourik, K ; Tan, C ; Bellomo, R (Baishideng Publishing Group Inc., 2016-11-04)
    AIM: To outline the physiochemical properties and specific clinical uses of Plasma-Lyte 148 as choice of solution for fluid intervention in critical illness, surgery and perioperative medicine. METHODS: We performed an electronic literature search from Medline and PubMed (via Ovid), anesthesia and pharmacology textbooks, and online sources including studies that compared Plasma-Lyte 148 to other crystalloid solutions. The following keywords were used: "surgery", "anaesthesia", "anesthesia", "anesthesiology", "anaesthesiology", "fluids", "fluid therapy", "crystalloid", "saline", "plasma-Lyte", "plasmalyte", "hartmann's", "ringers" "acetate", "gluconate", "malate", "lactate". All relevant articles were accessed in full. We summarized the data and reported the data in tables and text. RESULTS: We retrieved 104 articles relevant to the choice of Plasma-Lyte 148 for fluid intervention in critical illness, surgery and perioperative medicine. We analyzed the data and reported the results in tables and text. CONCLUSION: Plasma-Lyte 148 is an isotonic, buffered intravenous crystalloid solution with a physiochemical composition that closely reflects human plasma. Emerging data supports the use of buffered crystalloid solutions in preference to saline in improving physicochemical outcomes. Further large randomized controlled trials assessing the comparative effectiveness of Plasma-Lyte 148 and other crystalloid solutions in measuring clinically important outcomes such as morbidity and mortality are needed.