Research

Fung R, Stellios J, Bannon PG, Ananda A, Forrest P

Anaesth Intensive Care 2017 01;45(1):88-91

PMID: 28072940

Abstract

We describe the use of peripheral veno-venous extracorporeal membrane oxygenation (VV ECMO) and high-flow nasal oxygen as procedural support in a patient undergoing debulking of a malignant tumour of the lower airway. Due to the significant risk of complete airway obstruction upon induction of anaesthesia, ECMO was established while the patient was awake, and was maintained without systemic anticoagulation to minimise the risk of intraoperative bleeding. This case illustrates that ECMO support with high-flow nasal oxygen can be considered as part of the algorithm for airway management during surgery for subtotal lower airway obstruction, as it may be the only viable option for maintaining adequate gas exchange.

Dennis M, McCanny P, D’Souza M, Forrest P, Burns B, Lowe DA, Gattas D, Scott S, Bannon P, Granger E, Pye R, Totaro R,

Int. J. Cardiol. 2017 Mar;231:131-136

PMID: 27986281

Abstract

AIM: To describe the ECPR experience of two Australian ECMO centres, with regards to survival and neurological outcome, their predictors and complications.

METHODS: Retrospective observational study of prospectively collected data on all patients who underwent extracorporeal cardiopulmonary resuscitation (ECPR) at two academic ECMO referral centres in Sydney, Australia.

MEASUREMENTS AND MAIN RESULTS: Thirty-seven patients underwent ECPR, 25 (68%) were for in-hospital cardiac arrests. Median age was 54 (IQR 47-58), 27 (73%) were male. Initial rhythm was ventricular fibrillation or pulseless ventricular tachycardia in 20 patients (54%), pulseless electrical activity (n=14, 38%), and asystole (n=3, 8%). 27 (73%) arrests were witnessed and 30 (81%) patients received bystander CPR. Median time from arrest to initiation of ECMO flow was 45min (IQR 30-70), and the median time on ECMO was 3days (IQR 1-6). Angiography was performed in 54% of patients, and 27% required subsequent coronary intervention (stenting or balloon angioplasty 24%). A total of 13 patients (35%) survived to hospital discharge (IHCA 33% vs. OHCA 37%). All survivors were discharged with favourable neurological outcome (Cerebral Performance Category 1 or 2). Pre-ECMO lactate level was predictive of mortality OR 1.35 (1.06-1.73, p=0.016).

CONCLUSIONS: In selected patients with refractory cardiac arrest, ECPR may provide temporary support as a bridge to intervention or recovery. We report favourable survival and neurological outcomes in one third of patients and pre-ECMO lactate levels predictive of mortality. Further studies are required to determine optimum selection criteria for ECPR.

McBride KE, Young JM, Bannon PG, Solomon MJ

ANZ J Surg 2017 Jan;87(1-2):70-75

PMID: 27880987

Abstract

BACKGROUND: To undertake a comprehensive needs assessment to determine the baseline of surgical research activity at a tertiary referral hospital in Sydney, Australia.

METHOD: The comprehensive needs assessment comprised three components: a retrospective audit of the hospital ethics committee records to identify surgical research activity; a survey of all 17 surgical departments about the availability of 10 potential research resources and a survey of surgical staff to ascertain perceptions of research culture at the organizational, team and individual levels.

RESULTS: Of all research studies submitted to the hospital ethics committee in a 2-year period, only 9% were identified as surgical studies. Among the 17 surgical departments, there was wide variation in activity with only four defined as being ‘research active’. On average, 52% of potential resources for surgical research were found to be in place within surgical departments. Only five departments were considered to be adequately research resourced (≥75% potential resources in place). Surgical research culture was rated ‘moderate’ at the organizational and team level, and ‘low’ at the individual level. Medical staff rated research capacity significantly higher at the team and individual levels compared to nursing staff.

CONCLUSION: Collectively, the baseline results indicate there is considerable opportunity to enhance surgical research at the hospital level and to use this information to guide new and innovative approaches in the future.

Lal S, Turner L, Powell C, Wilson M, Bannon P

Int. J. Cardiol. 2016 Nov;222:671-3

PMID: 27522375

Abstract

Villanueva C, Doyle M, Parikh R, Manganas C

J Patient Saf 2016 Sep;

PMID: 27653495

Abstract

OBJECTIVES: The aim of this study was to identify the degree of awareness of the current guidelines and common practices for pleural drain insertion.

METHODS: A 10-item questionnaire was sent electronically to junior physicians from 4 different hospitals in the South Eastern Sydney and Illawarra Shoalhaven Local Health District. Participants were asked to give their level of experience and management practices for chest drain insertion.

RESULTS: A total of 94 junior medical officers from 4 hospitals in the district completed the survey. More than 20% had never inserted a chest drain at the time; 72% had primarily learned from bedside teaching and peer learning, but 11% had no training at all. More than 50% of physicians felt that the biggest threat to the procedure was their own lack of confidence for drain insertion. Despite current guidelines, 25% insert chest drains routinely without the aid of ultrasound. A third of interviewees were aware of local guidelines but had not read them. Most physicians (86%) believe that formal standardized training should be available for junior physicians.

CONCLUSIONS: Our findings demonstrate the ongoing need for improved procedural training in chest drain insertion, with emphasis on mandatory thoracic ultrasound. We consider it important to continue to raise concern and awareness that chest drain insertion is not a harmless procedure, and further physician procedural competence is required.

Rajaratnam K, Tak C, Alexander S, Passage J

Innovations (Phila) 2016 May-Jun;11(3):219-21

PMID: 27532301

Abstract

A 69-year-old man underwent minimal incision mitral valve repair for severe symptomatic mitral regurgitation. The echocardiography showed that he had normal left ventricular function with a moderately to severely dilated left atrium, a mildly dilated right atrium, and a large patent foramen ovale. The multistage venous cannulation was very challenging because we could not negotiate the guide wire from the inferior vena cava via the right atrium into the superior vena cava. Despite several attempts, the guide wire would pass into the patent foramen ovale. Methods that we routinely attempt with difficult cannulations such as withdrawing and reinserting, twisting, and to-and-fro movements did not result in success. Eventually, we attempted a novel maneuver, the modified “Valsalva maneuver,” that worked incredibly well.

Verrelli DI, Qian Y, Wilson MK, Wood J, Savage C

Interact Cardiovasc Thorac Surg 2016 Sep;23(3):410-5

PMID: 27241047

Abstract

OBJECTIVES: Tremor may be expected to interfere with the performance of fine motor tasks such as surgery. While tremor is readily quantified in inactive subjects, it is more challenging to measure tremor as the subjects perform complex tasks. The objective of this work was to quantify tremor during the performance of a realistic simulated surgery.

METHODS: Our novel surgical simulator incorporates a force sensor that allows identification and quantification of the intraoperative effects of tremor on the manipulandum. We have collected preliminary data from trainees and experienced surgeons carrying out multiple simulated anastomoses on silicone vessels, mimicking a procedure such as distal coronary anastomosis. We calculated transient and overall tremor intensity, and tested for a hypothesized ‘learning effect’.

RESULTS: Several of the recordings of intraoperative force data manifested distinctive features corresponding to substantial oscillation in the range of 8-12 Hz. We attribute this to enhanced physiological tremor. These early results indicate a significant reduction in the transmission of surgeon’s tremor to the operative field from the first attempt to later attempts (P = 0.039, standardized effect size = 0.91), which may be associated with increasing confidence.

CONCLUSIONS: This new method does not just quantify tremor, but quantifies the transmission of tremor to a manipulandum in the operative field during high-fidelity simulated coronary surgery. This may be used to assess and provide feedback on the performance of trainees and experienced surgeons, along with other fields in which fine motor skills are of vital importance.

Robertson EN, van der Linde D, Sherrah AG, Vallely MP, Wilson M, Bannon PG, Jeremy RW

Int. J. Cardiol. 2016 Oct;220:43-51

PMID: 27372041

Abstract

BACKGROUND: Non-syndromal thoracic aortic aneurysm and dissection (ns-TAAD) is a genetic aortopathy, with uncertain incidence. This study documented the incidence of ns-TAAD and outcomes of family screening over 15years.

METHODS: Consecutive series of 2385 patients with aortic disease in prospective registry (2000 to 2014), including 675 undergoing surgery. Diagnosis of ns-TAAD included family history, aortic imaging, tissue pathology and mutation testing. Screening was offered to relatives of ns-TAAD probands, with follow-up for affected individuals.

RESULTS: There were 270 ns-TAAD probands (74% males), including 116 (43%) presenting with aortic dissection. Among surgical cases, a diagnosis of ns-TAAD was established for 116 (17%). Age of probands was 50.4±14.1years, with aortic diameter of 51±12mm. Screening of 581 at-risk relatives identified 216 new ns-TAAD cases (detection rate=37%). Among 71 probands with known family history, screening identified 130 new affected relatives and among 53 probands with no family history, screening identified 86 new affected relatives. Mean age of new affected relatives at diagnosis was 44±18years, with aortic diameter of 42±7mm, including 42 with diameter>50mm. Ten-year mortality was similar for probands without dissection (7.7±3.1%) and new affected relatives (11.4±4.0%) but greater for probands surviving initial dissection (27.6±7.8%, p=0.003).

CONCLUSIONS: Up to 1 in 6 patients undergoing aortic surgery have features of ns-TAAD, frequently presenting as aortic dissection but at later age than other genetic aortopathies. Family screening identifies affected relatives in up to half of ns-TAAD probands, many of whom already have significant aortic dilatation.

Yoon PD, Byrom M, Lukins H

J Card Surg 2016 Aug;31(8):531-2

PMID: 27349604

Abstract

Edelman JJ, Okiwelu N, Anvardeen K, Joshi P, Murphy B, Sanders LH, Newman MA, Passage J

Heart Lung Circ 2016 Dec;25(12):1240-1244

PMID: 27423976

Abstract

BACKGROUND: Massive pulmonary embolism is a poorly tolerated condition. Treatment options in this condition include anticoagulation and primary reperfusion therapy – systemic thrombolysis, catheter based treatments or surgical embolectomy. There is little data on the relative efficacy of each treatment.

METHODS: The preoperative characteristics and outcomes of patients referred for surgical embolectomy between 2000-2014 was reviewed. Echocardiography was performed in the majority of patients before and after surgery.

RESULTS: Thirty-seven patients underwent pulmonary embolectomy between 2000-2014. One patient died within 30 days, another before leaving hospital. All other patients were alive at the time of follow-up (survival 94.6% at median 36 months). Median ventilation time was 24hours. Median hospital length of stay was 10.5 days. There was echocardiographic evidence of severe right ventricular strain (increased size and decreased function) before surgery, which was significantly improved to within the normal range by discharge, and follow-up.

CONCLUSIONS: Surgical embolectomy is a safe procedure, with low mortality, improved postoperative right ventricular function and pulmonary pressure, and good long-term outcome. Early relief of a large proportion of the clot burden can be life-saving. There should be consideration for its use as an initial treatment strategy in patients with massive or submassive pulmonary embolus with a large burden of proximal clot. A multidisciplinary approach for the treatment of these patients is required.