Chris Anstey

Nasal high flow oxygen therapy in patients with COPD reduces respiratory rate and tissue carbon dioxide while increasing tidal and end-expiratory lung volumes: a randomised crossover trial

Abstract Patients with COPD using long-term oxygen therapy (LTOT) over 15 h per day have improved outcomes. As inhalation of dry cold gas is detrimental to mucociliary clearance, humidified nasal high flow (NHF) oxygen may reduce frequency of exacerbations, while improving lung function and quality of life in this cohort. In this randomised crossover study, we assessed short-term physiological responses to NHF therapy in 30 males chronically treated with LTOT. LTOT (2–4 L/min) through nasal cannula was compared with NHF at 30 L/min from an AIRVO through an Optiflow nasal interface with entrained supplemental oxygen. Comparing NHF with LTOT: transcutaneous carbon dioxide (TcCO2) (43.3 vs 46.7 mm Hg, p<0.001), transcutaneous oxygen (TcO2) (97.1 vs 101.2 mm Hg, p=0.01), I:E ratio (0.75 vs 0.86, p=0.02) and respiratory rate (RR) (15.4 vs 19.2 bpm, p<0.001) were lower; and tidal volume (Vt) (0.50 vs 0.40, p=0.003) and end-expiratory lung volume (EELV) (174% vs 113%, p<0.001) were higher. EELV is expressed as relative change from baseline (%Δ). Subjective dyspnoea and interface comfort favoured LTOT. NHF decreased TcCO2, I:E ratio and RR, with a concurrent increase in EELV and Vt compared with LTOT. This demonstrates a potential mechanistic rationale behind the improved outcomes observed in long-term treatment with NHF in oxygen-dependent patients. Trial registration number ACTRN12613000028707.

Data quality of the Australia and New Zealand Dialysis and Transplant Registry: a pilot audit.

Most clinical registries in Australia, including the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), do not audit submitted data. Inaccurate data can bias registry analysis. This study aimed to audit data submitted to ANZDATA from a single region.

Transition from heparin to citrate anticoagulation for continuous renal replacement therapy: safety, efficiency, and cost

Regional citrate anticoagulation (RCA) for continuous renal replacement therapy (CRRT) has recently been recommended as first‐line over heparin. Evidence suggests that RCA prolongs filter life and may reduce bleeding risk, but there is little research on the benefits to dialysis dose delivery or cost, or the effectiveness of transitioning to RCA first‐line. The aim of the present study was to assess the effect on dialysis delivery, cost and safety when transitioning from systemic heparin to RCA for first‐line anticoagulation for CRRT. A single‐center, retrospective observational study was conducted from 2006 to 2012, during which a transition from heparin to a simplified RCA protocol occurred. Demographic and dialysis data, pathology results and costs were obtained. Data were analyzed for both heparin and RCA, and for before and after the transition. 166 patients had 992 dialysis days (heparin 334 vs. RCA 658); demographics were well matched; RCA used less filters per day (P = 0.03), had more days when prescribed dialysis was achieved (85% vs. 60%, P < 0.001), and less filter “down‐time” per day (2.4 vs. 6.1 h, P = 0.02). RCA was estimated to cost AU

Speaking valves in tracheostomised ICU patients weaning off mechanical ventilation - do they facilitate lung recruitment?

487 per day, compared to heparin at

Intraoperative Cerebral Perfusion Disturbances During Transcatheter Aortic Valve Replacement

479 per day. When the data were analyzed, comparing before and after the transition, these results remained statistically significant. There was no statistical difference in clinical safety events. Transition to first‐line RCA was safe, provided more time on filter and consumed less filter circuits using a simple and user friendly protocol. The adjusted cost difference appears negligible.

Complementary and alternative medicine use by patients receiving curative-intent chemotherapy.

BackgroundPatients who require positive pressure ventilation through a tracheostomy are unable to phonate due to the inflated tracheostomy cuff. Whilst a speaking valve (SV) can be used on a tracheostomy tube, its use in ventilated ICU patients has been inhibited by concerns regarding potential deleterious effects to recovering lungs. The objective of this study was to assess end expiratory lung impedance (EELI) and standard bedside respiratory parameters before, during and after SV use in tracheostomised patients weaning from mechanical ventilation.MethodsA prospective observational study was conducted in a cardio-thoracic adult ICU. 20 consecutive tracheostomised patients weaning from mechanical ventilation and using a SV were recruited. Electrical Impedance Tomography (EIT) was used to monitor patients’ EELI. Changes in lung impedance and standard bedside respiratory data were analysed pre, during and post SV use.ResultsUse of in-line SVs resulted in significant increase of EELI. This effect grew and was maintained for at least 15 minutes after removal of the SV (p < 0.001). EtCO2 showed a significant drop during SV use (p = 0.01) whilst SpO2 remained unchanged. Respiratory rate (RR (breaths per minute)) decreased whilst the SV was in situ (p <0.001), and heart rate (HR (beats per minute)) was unchanged. All results were similar regardless of the patients’ respiratory requirements at time of recruitment.ConclusionsIn this cohort of critically ill ventilated patients, SVs did not cause derecruitment of the lungs when used in the ventilator weaning period. Deflating the tracheostomy cuff and restoring the airflow via the upper airway with a one-way valve may facilitate lung recruitment during and after SV use, as indicated by increased EELI.Trial registrationAnna-Liisa Sutt, Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12615000589583. 4/6/2015.

Impact of non‐traditional phosphate binders and cinacalcet on haemodialysis patient biochemistry, pill burden and cost

BACKGROUND Transcatheter aortic valve replacement entails profound and unavoidable hemodynamic perturbations that may contribute to the neurological injury associated with the procedure. METHODS Thirty-one patients were monitored with cerebral oximetry as a surrogate marker of perfusion while undergoing transcatheter aortic valve replacement via a transfemoral approach under general anesthesia to detect intraoperative hypoperfusion insult. Serial neurologic, cognitive, and cerebral magnetic resonance imaging assessments were administered to objectively quantify perioperative neurologic injury and ascertain any association with significant cerebral oximetry disturbances. RESULTS Cerebral oximetry reacted promptly to rapid ventricular pacing with significant cerebral desaturation, relative to baseline, of greater than 12% and greater than 20% in 12 of 31 (68%) and 9 of 31 (29%) patients, respectively; or to an absolute measurement of less than 50% in 10 of 31 (33%) patients. Hyperemia occurred immediately following relief of aortic stenosis exceeding baseline by greater than 10% and greater than 20% in 14 of 31 (45%) and 5 of 31 (16%) patients. Postoperative cognitive dysfunction was evident in 3 of 31 (10%) patients and new magnetic resonance imaging-defined ischemic lesions were seen in 17 of 28 (61%) patients. No patient experienced clinically apparent stroke. CONCLUSIONS Cerebral oximetry reacted promptly to rapid ventricular pacing with significant desaturation and hyperemia a common occurrence. However, no association between this intraoperative insult and objective neurologic injury was detected.

Ventilation distribution and lung recruitment with speaking valve use in tracheostomised patient weaning from mechanical ventilation in intensive care

To determine which types of complementary and alternative medicine (CAM) are being used by cancer patients commencing curative‐intent chemotherapy, whether the CAM taken has the potential to affect treatment efficacy, the reasons for patients’ decisions to use CAM and whether these patients would like information on CAM safety with chemotherapy.

A Comparison between Two Dilute Citrate Solutions (15 vs. 18 mmol/l) in Continuous Renal Replacement Therapy: The Base Excess and Renal Substitution Solution Study

Aim:  The Australian Pharmaceutical Benefits Scheme (PBS) commenced cost subsidization for haemodialysis patients of sevelamer in December 2007, cinacalcet in July 2008 and lanthanum in May 2009. To determine the impact of PBS listing of these medications, we performed a single centre cross‐sectional, longitudinal study.

Urine and serum midkine levels in an Australian chronic kidney disease clinic population: an observational study

Purpose Speaking valves (SV) are used infrequently in tracheostomised ICU patients due to concerns regarding their putative effect on lung recruitment. A recent study in cardio‐thoracic population demonstrated increased end‐expiratory lung volumes during and post SV use without examining if the increase in end‐expiratory lung impedance (EELI) resulted in alveolar recruitment or potential hyperinflation in discrete loci. Materials and methods A secondary analysis of Electrical Impedance Tomography (EIT) data from a previous study was conducted. EELI distribution and tidal variation (TV) were assessed with a previously validated tool. A new tool was used to investigate ventilated surface area (VSA) and regional ventilation delay (RVD) as indicators of alveolar recruitment. Results The increase in EELI was found to be uniform with significant increase across all lung sections (p < 0.001). TV showed an initial non‐significant decrease (p = 0.94) with subsequent increase significantly above baseline (p < 0.001). VSA and RVD showed non‐significant changes during and post SV use. Conclusions These findings indicate that hyperinflation did not occur with SV use, which is supported by previously published data on respiratory parameters. These data along with obvious psychological benefits to patients are encouraging towards safe use of SVs in this critically ill cardio‐thoracic patient population. Trial registration: Anna‐Liisa Sutt, Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12615000589583. 4/6/2015. HighlightsUniform increase of end‐expiratory lung volume across ventral‐dorsal and R‐L lung sections with speaking valve use.Data suggests no alveolar hyperinflation associated with speaking valve use.Data are encouraging towards wide use of speaking valves in intensive care.