Brigit Roberts

Multicentre study of delirium in ICU patients using a simple screening tool.

Traditionally, intensive care unit (ICU) delirium was viewed as benign and was under-diagnosed in the absence of ICU-appropriate screening tools. Research suggests that up to half of all ICU patients experiencing delirium will continue to do so after discharge to the ward, and half of those experiencing delirium in the ward will die within 1 year of delirium diagnosis. ICU-specific screening tools are now available. The purpose of this study was to identify the incidence of delirium in ICU and explore its associations to clinical factors and outcomes. A secondary aim was to evaluate the usefulness of the intensive care delirium screening checklist (ICDSC). A total of 185 patients in six ICUs in Australia and New Zealand were screened for delirium using the ICDSC over two 12-hour periods per day for the duration of their ICU admission. Some 84 patients (45%) developed delirium. Development of delirium was associated with increased severity of illness (acute physiology and chronic health evaluation--APACHE II--and sequential organ failure assessment--SOFA), ICU length of stay (LOS), and use of psycho-active drugs. Delirious patients showed no statistically significant difference in ICU and hospital mortality rates, nor prolonged hospital LOS. The ICDSC was found to be user-friendly. The incidence of delirium, observed characteristics and outcomes for patients admitted to Australian and New Zealand ICUs for > 36 hours without any history of altered mental state fell in the mid-range and were generally consistent with previous literature. An ICU-specific delirium assessment, such as the ICDSC, should be included in routine ICU observations to minimise under-diagnosis of this serious phenomenon.

Decrease in proven ventriculitis by reducing the frequency of cerebrospinal fluid sampling from extraventricular drains

OBJECT Ventriculitis associated with extraventricular drains (EVD) increases rates of morbidity and mortality as well as costs. Surveillance samples of CSF are taken routinely from EVD, but there is no consensus on the optimum frequency of sampling. The goal of this study was to assess whether the incidence of ventriculitis changed when CSF sampling frequency was reduced once every 3 days. METHODS After receiving institutional ethics committee approval for their project, the authors compared a prospective sample of EVD-treated patients (admitted 2008-2009) and a historical comparison group (admitted 2005-2007) at two tertiary hospital ICUs. A broad definition of ventriculitis included suspected ventriculitis (that is, treated with antibiotics for ventriculitis) and proven ventriculitis (positive CSF culture). Adult ICU patients with no preexisting neurological infection were enrolled in the study. After staff was provided with an education package, sampling of CSF was changed from daily to once every 3 days. All other management of the EVD remained unchanged. More frequent sampling was permitted if clinically indicated during the third daily sampling phase. RESULTS Two hundred seven patients were recruited during the daily sampling phase and 176 patients when sampling was reduced to once every 3 days. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was lower for the daily sampling group than for the every-3rd-day group (18.6 vs 20.3, respectively; p < 0.01), but there was no difference in mean age (47 and 45 years, respectively; p = 0.14), male or female sex (61% and 59%, respectively; p = 0.68), or median EVD duration in the ICU (4.9 and 5.8 days, respectively; p = 0.14). Most patients were admitted with subarachnoid hemorrhage (42% in the daily group and 33% in the every-3rd-day group) or traumatic head injuries (29% and 36%, respectively). The incidence of ventriculitis decreased from 17% to 11% overall and for proven ventriculitis from 10% to 3% once sampling frequency was reduced. Sampling of CSF once every 3 days was independently associated with ventriculitis (OR 0.44, 95% CI 0.22-0.88, p = 0.02). CONCLUSIONS Reducing the frequency of CSF sampling to once every 3 days was associated with a significant decrease in the incidence of ventriculitis. The authors suggest that CSF sampling should therefore be performed once every 3 days in the absence of clinical indicators of ventriculitis. Reducing frequency of CSF sampling from EVDs decreased proven ventriculitis.

A double-blind, randomized trial of intravenous versus intramuscular antivenom for Red-back spider envenoming

Objective:  To compare the efficacy of intravenous versus intramuscular antivenom (AV) in the treatment of Red‐back spider (RBS) envenoming.

Matching positive end-expiratory pressure to intra-abdominal pressure improves oxygenation in a porcine sick lung model of intra-abdominal hypertension

IntroductionIntra-abdominal hypertension (IAH) causes atelectasis, reduces lung volumes and increases respiratory system elastance. Positive end-expiratory pressure (PEEP) in the setting of IAH and healthy lungs improves lung volumes but not oxygenation. However, critically ill patients with IAH often suffer from acute lung injury (ALI). This study, therefore, examined the respiratory and cardiac effects of positive end-expiratory pressure in an animal model of IAH, with sick lungs.MethodsNine pigs were anesthetized and ventilated (48 +/- 6 kg). Lung injury was induced with oleic acid. Three levels of intra-abdominal pressure (baseline, 18, and 22 mmHg) were randomly generated. At each level of intra-abdominal pressure, three levels of PEEP were randomly applied: baseline (5 cmH2O), moderate (0.5 × intra-abdominal pressure), and high (1.0 × intra-abdominal pressure). We measured end-expiratory lung volumes, arterial oxygen levels, respiratory mechanics, and cardiac output 10 minutes after each new IAP and PEEP setting.ResultsAt baseline PEEP, IAH (22 mmHg) decreased oxygen levels (-55%, P <0.001) and end-expiratory lung volumes (-45%, P = 0.007). At IAP of 22 mmHg, moderate and high PEEP increased oxygen levels (+60%, P = 0.04 and +162%, P <0.001) and end-expiratory lung volume (+44%, P = 0.02 and +279%, P <0.001) and high PEEP reduced cardiac output (-30%, P = 0.04). Shunt and dead-space fraction inversely correlated with oxygen levels and end-expiratory lung volumes. In the presence of IAH, lung, chest wall and respiratory system elastance increased. Subsequently, PEEP decreased respiratory system elastance by decreasing chest wall elastance.ConclusionsIn a porcine sick lung model of IAH, PEEP matched to intra-abdominal pressure led to increased lung volumes and oxygenation and decreased chest wall elastance shunt and dead-space fraction. High PEEP decreased cardiac output. The study shows that lung injury influences the effects of IAH and PEEP on oxygenation and respiratory mechanics. Our findings support the application of PEEP in the setting of acute lung injury and IAH.

Biopatch--a new concept in antimicrobial dressings for invasive devices.

A randomised controlled trial (RCT) was conducted to assess the reduction in the rate of catheter-related infections associated with the Biopatch dressing (Johnson & Johnson Medical Inc., Arlington, Texas, USA) used for insertion-site management of central venous catheters (CVCs) placed in the intensive care unit. Patients having a CVC placed were randomly assigned to receive either a Biopatch keyhole dressing to the occlusive Opsite IV 3000 (Smith and Nephew Medical Ltd., Hull, UK) (experimental group) or the Opsite IV 3000 alone (control group). There was a very low colonisation rate of CVC tip and skin exit-site swabs in both the experimental group (6 of 17) and the control group (5 of 16). No statistical difference was found between the two groups with regard to CVC or exit-site colonisation. A calculated sample size of 11,000 would be required to statistically demonstrate a 10 per cent reduction in CVC infection rate using the new Biopatch dressing. A much larger RCT would be required to demonstrate the efficacy of this new device.

Matching positive end-expiratory pressure to intra-abdominal pressure prevents end-expiratory lung volume decline in a pig model of intra-abdominal hypertension

Objective:Intra-abdominal hypertension is common in critically ill patients and is associated with increased morbidity and mortality. In a previous experimental study, positive end-expiratory pressures of up to 15 cm H2O did not prevent end-expiratory lung volume decline caused by intra-abdominal hypertension. Therefore, we examined the effect of matching positive end-expiratory pressure to the intra-abdominal pressure on cardio-respiratory parameters. Design:Experimental pig model of intra-abdominal hypertension. Setting:Large animal facility, University of Western Australia. Subjects:Nine anesthetized, nonparalyzed, and ventilated pigs (48 ± 7 kg). Interventions:Four levels of intra-abdominal pressure (baseline, 12, 18, and 22 mm Hg) were generated in a randomized order by inflating an intra-abdominal balloon. At each level of intra-abdominal pressure, three levels of positive end-expiratory pressure were randomly applied with varying degrees of matching the corresponding intra-abdominal pressure: baseline positive end-expiratory pressure (= 5 cm H2O), moderate positive end-expiratory pressure (= half intra-abdominal pressure in cm H2O + 5 cm H2O), and high positive end-expiratory pressure (= intra-abdominal pressure in cm H2O). Measurements:We measured end-expiratory lung volume, arterial oxygen levels, respiratory mechanics, and cardiac output 5 mins after each new intra-abdominal pressure and positive end-expiratory pressure setting. Main Results:Intra-abdominal hypertension decreased end-expiratory lung volume and PaO2 (−49% [p < .001] and −8% [p < .05], respectively, at 22 mm Hg intra-abdominal pressure compared with baseline intra-abdominal pressure) but did not change cardiac output (p = .5). At each level of intra-abdominal pressure, moderate positive end-expiratory pressure increased end-expiratory lung volume (+119% [p < .001] at 22 mm Hg intra-abdominal pressure compared with 5 cm H2O positive end-expiratory pressure) while minimally decreasing cardiac output (−8%, p < .05). High positive end-expiratory pressure further increased end-expiratory lung volume (+233% [p < .001] at 22 mm Hg intra-abdominal pressure compared with 5 cm H2O positive end-expiratory pressure) but led to a greater decrease in cardiac output (−26%, p < .05). Neither moderate nor high positive end-expiratory pressure improved PaO2 (p = .7).Intra-abdominal hypertension decreased end-expiratory transpulmonary pressure but did not alter end-inspiratory transpulmonary pressure. Intra-abdominal hypertension decreased total respiratory compliance through a decrease in chest wall compliance. Positive end-expiratory pressure decreased the respiratory compliance by reducing lung compliance. Conclusions:In a pig model of intra-abdominal hypertension, positive end-expiratory pressure matched to intra-abdominal pressure led to a preservation of end-expiratory lung volume, but did not improve arterial oxygen tension and caused a reduction in cardiac output. Therefore, we do not recommend routine application of positive end-expiratory pressure matched to intra-abdominal pressure to prevent intra-abdominal pressure–induced end-expiratory lung volume decline in healthy lungs.

Commonly applied positive end-expiratory pressures do not prevent functional residual capacity decline in the setting of intra-abdominal hypertension: a pig model

IntroductionIntra-abdominal hypertension is common in critically ill patients and is associated with increased morbidity and mortality. The optimal ventilation strategy remains unclear in these patients. We examined the effect of positive end-expiratory pressures (PEEP) on functional residual capacity (FRC) and oxygen delivery in a pig model of intra-abdominal hypertension.MethodsThirteen adult pigs received standardised anaesthesia and ventilation. We randomised three levels of intra-abdominal pressure (3 mmHg (baseline), 18 mmHg, and 26 mmHg) and four commonly applied levels of PEEP (5, 8, 12 and 15 cmH2O). Intra-abdominal pressures were generated by inflating an intra-abdominal balloon. We measured intra-abdominal (bladder) pressure, functional residual capacity, cardiac output, haemoglobin and oxygen saturation, and calculated oxygen delivery.ResultsRaised intra-abdominal pressure decreased FRC but did not change cardiac output. PEEP increased FRC at baseline intra-abdominal pressure. The decline in FRC with raised intra-abdominal pressure was partly reversed by PEEP at 18 mmHg intra-abdominal pressure and not at all at 26 mmHg intra-abdominal pressure. PEEP significantly decreased cardiac output and oxygen delivery at baseline and at 26 mmHg intra-abdominal pressure but not at 18 mmHg intra-abdominal pressure.ConclusionsIn a pig model of intra-abdominal hypertension, PEEP up to 15 cmH2O did not prevent the FRC decline caused by intra-abdominal hypertension and was associated with reduced oxygen delivery as a consequence of reduced cardiac output. This implies that PEEP levels inferior to the corresponding intra-abdominal pressures cannot be recommended to prevent FRC decline in the setting of intra-abdominal hypertension.

The role of femoral venous pressure and femoral venous oxygen saturation in the setting of intra-abdominal hypertension: a pig model

Femoral venous access is frequently used in critically ill patients. Because raised intra-abdominal pressure (IAP) is also frequently found in this group of patients, we examined the impact of IAP and positive end-expiratory pressure (PEEP) on femoral venous pressure (FVP) and femoral venous oxygen saturation (Sfvo2) in an animal model. Thirteen adult pigs received standardized anesthesia and ventilation. Randomized levels of IAP (3 [baseline], 18, and 26 mmHg) were applied, with levels of PEEP (5, 8, 12, and 15 cmH2O) applied randomly at each IAP level. We measured bladder pressure (IAP), superior vena cava pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, FVP, mixed venous oxygen saturation (Svo2), and Sfvo2. We found that FVP correlated well with IAP (FVP = 4.1 + [0.12 × PEEP] + [1.00 × IAP]; R2 = 0.89, P < 0.001) with a moderate bias and precision of 5.0 and 3.8 mmHg, respectively. Because the level of agreement did not meet the recommendations of the World Society of Abdominal Compartment Syndrome, FVP cannot currently be recommended to measure IAP, and further clinical trials are warranted. However, a raised FVP should prompt the measurement of the bladder pressure. Femoral venous oxygen saturation did correlate neither with Svo2 nor with abdominal perfusion pressure. Therefore, Sfvo2 is of no clinical use in the setting of raised IAP.

Intensive Care Research Coordinators in Australia and New Zealand: A cross-sectional survey of demographics, responsibilities, job satisfaction and importance

INTRODUCTION The achievement of successful clinical research projects depends on multiple team members including Research Coordinators (RCs), who are the link between the researcher and the trial participants. The RCs main responsibility is to ensure that all research is conducted according to the appropriate protocols, regulations and guidelines. AIM Description of demographics, the role and associated responsibilities and assessment of items of importance to, and satisfaction with, various job related items. METHOD An observational web-based cross-sectional study of RCs working in Intensive Care Units (ICU) across Australia and New Zealand. RESULTS Fifty-six participants completed the survey. Forty percent had more than 6 years experience in ICU research and one-third held a Masters Degree. Most respondents performed research related tasks including ethics submission, patient screening, education and data collection. Autonomy and work hours were the most satisfying job characteristics reported and aspects relating to autonomy were most important for the RCs. Inadequate remuneration was of great concern to the participants. CONCLUSION Research Coordinators in Australia and New Zealand have many and varied roles with a significant workload. Unfortunately, the RCs do not feel their employers are adequately remunerating the demand on their time and efforts. The results indicate that RCs enjoy high levels of satisfaction with general conditions and facets of their work and its environment and they remain passionate about their role in the ICU setting.

Commentary on Spilsbury K, Petherick E, Cullum N, Nelson A, Nixon J & Mason S (2008) The role and potential contribution of clinical research nurses to clinical trials. Journal of Clinical Nursing 17, 549–557

version 4.2.5. Available at: http://www.cochrane.org Cooper R, Molan P & Harding KG (2002a) The sensitivity of honey to Gram-positive cocci of clinical significance isolated from wounds. Journal of Applied Microbiology 93, 857–863. Cooper RA, Halas E & Molan P (2002b) The Efficacy of Honey in Inhibiting Strains of Pseudomonas aeruginosa from Infected Burns. Journal of Burn Care and Rehabilitation 23, 366–370. French V, Cooper R & Molan P (2005) The antibacterial activity of honey against coagulase-negative staphylococci. Journal of Antimicrobial Chemotherapy 56, 228–231. Gethin G & Cowman S (2008) Manuka honey vs Hydrogel, a prospective, open label, multicentre randomised controlled trial to compare desloughing efficacy and healing outcomes in venous ulcers. Journal of Clinical Nursing (in press). Gunes U & Eser I (2007) Effectiveness of a honey dressing for healing pressure ulcers. Journal of Wound Ostomy and Continence Nurses Society 34, 184–190. Hejase MJ, Simonin JE, Bihrle R & Coogan CL (1996) Genital Fournier’s gangrene: experience with 38 patients. Urology 47, 734–739. Higgins JPT & Green S (eds) (2005) Cochrane handbook for systematic reviews of interventions. In The Cochrane Library, Issue 3. John Wiley & Sons Ltd, Chichester, pp 79–89. Holland W (2001) Evidence-based medicine: a commentary. Euro Observer (Newsletter of the European Observatory on Health Care System) 3, 1–3. Ingle R, Levin J & Polinder K (2006) Wound healing with honey a randomised controlled trial. South African Medical Journal 96, 831–835. Jadad A (1998) Randomised Controlled Trials. British Medical Journal Books, London. Jull A, Walker N, Parag V, Molan P & Rodgers A (2008) Randomized clinical trial of honey-impregnated dressings for venous leg ulcers. British Journal of Surgery 95, 175–182. Molan P (2006) The evidence supporting the use of honey in as a wound dressing. The International Journal of Lower Extremity Wounds 5, 40–54. Nagane NS, Ganu JV, Bhagwat VR & Subrahmanyam M (2004) Efficacy of topical honey therapy against silver sulphadiazine treatment in burns: a biochemical study. Indian Journal of Clinical Biochemistry 19, 173–176. NHB (2005) Honey, a reference guide to nature’s sweetener. National Honey Board. Available at: http://www.nhb.org. Pocock S (1983) Clinical Trials – A Practical Approach. John Wiley & Sons, Chichester. Subrahmanyam M (1993) Honey as a Surgical Dressing for Burns and Ulcers. The Indian Journal of Surgery 55, 468–473. Subrahmanyam M, Eroglu S, Karacaglan N, Mithat A, Tayfun A & Yildirim S (2003) Free radical control – the main mechanism of action of honey in burns. Annals of Burns & Fire Disasters 16, 1–4. Subrahmanyam M & Ugane SP (2004) Honey dressing beneficial in treatment of Fournier’s gangrene. The Indian Journal of Surgery 66, 75–77. Temnov TA (1944) Bactericidal properties of honey and utilization of honey and other bee-keeping products for the healing of wounds. Bee World 25, 86–87. White J & Doner L (1980) Honey composition and properties. Beekeeping in the United States Agricultural Handbook Number 335. Available at www.beesource.com/pov/usda/beekpUSA.82.htm