Kwok-ming Ho

Benefits and risks of furosemide in acute kidney injury.

Furosemide, a potent loop diuretic, is frequently used in different stages of acute kidney injury, but its clinical roles remain uncertain. This review summarises the pharmacology of furosemide, its potential uses and side effects, and the evidence of its efficacy. Furosemide is actively secreted by the proximal tubules into the urine before reaching its site of action at the ascending limb of loop of Henle. It is the urinary concentrations of furosemide that determine its diuretic effect. The severity of acute kidney injury has a significant effect on the diuretic response to furosemide; a good ‘urinary response’ may be considered as a ‘proxy’ for having some residual renal function. The current evidence does not suggest that furosemide can reduce mortality in patients with acute kidney injury. In patients with acute lung injury without haemodynamic instability, furosemide may be useful in achieving fluid balance to facilitate mechanical ventilation according to the lung‐protective ventilation strategy.

Effect of neuraxial anaesthesia on tumour progression in cervical cancer patients treated with brachytherapy: a retrospective cohort study

BACKGROUND Recent evidence suggests that neuraxial and regional anaesthesia may influence the progression of the underlying malignant disease after surgery. METHODS This retrospective cohort study assessed whether neuraxial anaesthesia would affect the progression of cervical cancer in 132 consecutive patients who were treated with brachytherapy in a tertiary cancer centre in Australia. RESULTS Age, American Society of Anesthesiologists status, International Federation of Gynecologists and Obstetricians (FIGO) cancer staging, invasion into the uterus, tumour volume, and tumour cell types were not significantly different between patients who received neuraxial and general anaesthesia during their first brachytherapy treatment. The use of neuraxial anaesthesia during the first brachytherapy was not associated with a reduced risk of local or systemic recurrence [hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.54-1.67; P=0.863], long-term mortality from tumour recurrence (HR 1.46, 95% CI 0.75-2.84; P=0.265), or all-cause mortality (HR 1.46, 95% CI 0.81-2.61; P=0.209), after adjusting for other prognostic factors. Tumour recurrence and long-term survival were only significantly associated with the tumour cell type, tumour volume, and FIGO tumour staging. Sensitivity analyses using proportions of all brachytherapy sessions performed under neuraxial anaesthesia also did not show any beneficial effects of neuraxial anaesthesia on tumour recurrence and long-term survival. CONCLUSIONS Using neuraxial anaesthesia during brachytherapy for patients with cervical cancer was not associated with a reduced risk of tumour recurrence and mortality when compared with general anaesthesia.

Effect of length of stay in intensive care unit on hospital and long-term mortality of critically ill adult patients

BACKGROUND Critical illness leading to prolonged length of stay (LOS) in an intensive care unit (ICU) is associated with significant mortality and resource utilization. This study assessed the independent effect of ICU LOS on in-hospital and long-term mortality after hospital discharge. METHODS Clinical and mortality data of 22 298 patients, aged 16 yr and older, admitted to ICU between 1987 and 2002 were included in this linked-data cohort study. Coxs regression with restricted cubic spline function was used to model the effect of LOS on in-hospital and long-term mortality after adjusting for age, gender, acute physiology score (APS), maximum number of organ failures, era of admission, elective admission, Charlsons co-morbidity index, and diagnosis. The variability each predictor explained was calculated by the percentage of the chi(2) statistic contribution to the total chi(2) statistic. RESULTS Most hospital deaths occurred within the first few days of ICU admission. Increasing LOS in ICU was not associated with an increased risk of in-hospital mortality after adjusting for other covariates, but was associated with an increased risk of long-term mortality after hospital discharge. The variability on the long-term mortality effect associated with ICU LOS (2.3%) appeared to reach a plateau after the first 10 days in ICU and was not as important as age (35.8%), co-morbidities (18.6%), diagnosis (10.9%), and APS (3.6%). CONCLUSIONS LOS in ICU was not an independent risk factor for in-hospital mortality, but it had a small effect on long-term mortality after hospital discharge after adjustment for other risk factors.

Neurotrauma and the rule of rescue

The rule of rescue describes the powerful human proclivity to rescue identified endangered lives, regardless of cost or risk. Deciding whether or not to perform a decompressive craniectomy as a life-saving or ‘rescue’ procedure for a young person with a severe traumatic brain injury provides a good example of the ethical tensions that occur in these situations. Unfortunately, there comes a point when the primary brain injury is so severe that if the patient survives they are likely to remain severely disabled and fully dependent. The health resource implications of this outcome are significant. By using a web-based outcome prediction model this study compares the long-term outcome and designation of two groups of patients. One group had a very severe injury as adjudged by the model and the other group a less severe injury. At 18 month follow-up there were significant differences in outcome and healthcare requirements. This raises important ethical issues when considering life-saving but non-restorative surgical intervention. The discussion about realistic outcome cannot be dichotomised into simply life or death so that the outcome for the patient must enter the equation. As in other ‘rescue situations’, the utility of the procedure cannot be rationalised on a mere cost–benefit analysis. A compromise has to be reached to determine at what point either the likely outcome would be unacceptable to the person on whom the procedure is being performed or the social utility gained from the rule of rescue intervention fails to justify the utilitarian value and justice of equitable resource allocation.

Use of remifentanil as a sedative agent in critically ill adult patients: a meta-analysis

This meta‐analysis examined the benefits of using remifentanil as a sedative agent in critically ill patients. A total of 11 randomised controlled trials, comparing remifentanil with another opioid or hypnotic agent in 1067 critically ill adult patients, were identified from the Cochrane controlled trials register and EMBASE and MEDLINE databases, and subjected to meta‐analysis. Remifentanil was associated with a reduction in the time to tracheal extubation after cessation of sedation (weighted‐mean‐difference −2.04 h (95% CI −0.39 to −3.69 h); p = 0.02). Remifentanil was, however, not associated with a significant reduction in mortality (relative risk 1.01 (95% CI 0.67–1.52); p = 0.96), duration of mechanical ventilation, length of intensive care unit stay, and risk of agitation (relative risk 1.08 (95% CI 0.64–1.82); p = 0.77) when compared to an alternative sedative or analgesic agent. The current evidence does not support the routine use of remifentanil as a sedative agent in critically ill adult patients.

Effect of an episode of critical illness on subsequent hospitalisation: a linked data study

Healthcare utilisation can affect quality of life and is important in assessing the cost‐effectiveness of medical interventions. A clinical database was linked to two Australian state administrative databases to assess the difference in incidence of healthcare utilisation of 19 921 patients who survived their first episode of critical illness. The number of hospital admissions and days of hospitalisation per patient‐year was respectively 150% and 220% greater after than before an episode of critical illness (assessed over the same time period). This was the case regardless of age or type of surgery (i.e. cardiac vs non‐cardiac). After adjusting for the ageing effect of the cohort as a whole, there was still an unexplained two to four‐fold increase in hospital admissions per patient‐year after an episode of critical illness. We conclude that an episode of critical illness is a robust predictor of subsequent healthcare utilisation.

Incidence and risk factors for intensive care unit admission after bariatric surgery: a multicentre population-based cohort study

BACKGROUND With increasing rates of bariatric surgery and the consequential involvement of increasingly complex patients, uncertainty remains regarding the use of intensive care unit (ICU) services after bariatric surgery. Our objective was to define the incidence, indications, and outcomes of patients requiring ICU admission after bariatric surgery and assess whether unplanned ICU admission could be predicted using preoperative factors. METHODS All adult bariatric surgery patients between 2007 and 2011 in Western Australia were identified from the Department of Health Data Linkage Unit database and merged with a separate database encompassing all subsequent ICU admissions pertaining to bariatric surgery. The minimal and mean follow-up periods were 12 months and 3.4 yr, respectively. RESULTS Of the 12 062 patients who underwent bariatric surgery during the study period, 590 patients (4.9%; 650 ICU admissions) were admitted to an ICU after their bariatric surgery. Patients admitted to the ICU were older (48 vs 43 yr, P<0.001), more likely to be male (49.7 vs 20.2%, P<0.001), and more likely to require revisional bariatric surgery (14.4 vs 7.1%, P<0.001). One hundred and seventy-six patients required an emergent unplanned ICU admission, with 51 requiring multiple ICU admissions. Revisional or open surgery, diabetes mellitus, chronic respiratory disease, and obstructive apnoea were the strongest preoperative factors associated with unplanned ICU admission. CONCLUSIONS Intensive care unit admission after bariatric surgery was uncommon (4.9% of all patients), with 30.9% of all referrals being unplanned. A nomogram and smartphone application based on five important preoperative factors may assist anaesthetists to conduct preoperative planning for high-risk bariatric surgical patients.

Futility and neurotrauma: can we make an objective assessment?

Reflections intensive care physicians as to whether a decompressi craniectomy would be appropriate. The intensivists no that the high ICP was continuing to rise despite maxim therapy and strongly felt that a surgical decompressio should be performed because the patient was otherwi very likely to die. But the neurosurgeons felt that, given severity of the primary injury, the patient was very like How do decisions change if we can assess risk of “unacceptable badness”?

Concentration-dependent effect of hypocalcaemia on in vitro clot strength in patients at risk of bleeding: A retrospective cohort study

It is uncertain whether hypocalcaemia is associated with an increased risk of bleeding. This study assessed the dose‐related relationship between ionised calcium concentrations and in vitro clot strength measured by maximum amplitude (MA) on the thromboelastograph (TEG).

Decompressive craniectomy--a narrative review and discussion.

There continues to be considerable amount of interest in decompressive craniectomy however its use is controversial. It is technically straightforward however it is not without significant complications and although there is currently unequivocal evidence available that it can be a life saving intervention, evidence that outcome is improved over and above standard medical therapy is less forthcoming. This narrative review considers the current role of decompressive craniectomy in the management of neurological emergencies and focuses on four specific questions, namely; (i) Is the decompressive craniectomy a life saving procedure? (ii) Does decompressive craniectomy improve outcome? (iii) Are there any risks associated with decompressive craniectomy? (iv) How do patients feel about their eventual outcome? Finally the future directions for the use of decompressive craniectomy are explored.