Breaches of pre-medical emergency team call criteria in an Australian hospital.

Objectives and outcomes: To evaluate the 24hrs before medical emergency team (MET) calls to examine: 1) the frequency, nature, and timing of pre-MET criteria breaches; 2) differences in characteristics and outcomes between patients who did and didn't experience pre-MET breaches. Design: Retrospective observational study November 2020-June 2021. Setting: Tertiary referral Australian hospital. Participants: Adults (≥18 years) experiencing MET calls. Results: Breaches in pre-MET criteria occurred prior to 1886/2255 (83.6%) MET calls, and 1038/1281 (81.0%) of the first MET calls. Patients with pre-MET breaches were older (median [IQR] 72 [57-81] vs 66 [56-77] yrs), more likely to be admitted from home (87.8% vs 81.9%) and via the emergency department (73.0% vs 50.2%), but less likely to be for full resuscitation after (67.3% vs 76.5%) the MET. The three most common pre-MET breaches were low SpO2 (48.0%), high pulse rate (39.8%), and low systolic blood pressure (29.0%) which were present for a median (IQR) of 15.4 (7.5-20.8), 13.2 (4.3-21.0), and 12.6 (3.5-20.1) hrs before the MET call, respectively. Patients with pre-MET breaches were more likely to need intensive care admission within 24 h (15.6 vs 11.9%), have repeat MET calls (33.3 vs 24.7%), and die in hospital (15.8 vs 9.9%). Conclusions: Four-fifths of MET calls were preceded by pre-MET criteria breaches, which were present for many hours. Such patients were older, had more limits of treatment, and experienced worse outcomes. There is a need to improve goals of care documentation and pre-MET management of clinical deterioration.

Accuracy of non-invasive body temperature measurement methods in critically ill patients: a prospective, bicentric, observational study.

Objective: The accuracy of different non-invasive body temperature measurement methods in intensive care unit (ICU) patients is uncertain. We aimed to study the accuracy of three commonly used methods. Design: Prospective observational study. Setting: ICUs of two tertiary Australian hospitals. Participants: Critically ill patients admitted to the ICU. Interventions: Invasive (intravascular and intra-urinary bladder catheter) and non-invasive (axillary chemical dot, tympanic infrared, and temporal scanner) body temperature measurements were taken at study inclusion and every 4 hours for the following 72 hours. Main outcome measures: Accuracy of non-invasive body temperature measurement methods was assessed by the Bland-Altman approach, accounting for repeated measurements and significant explanatory variables that were identified by regression analysis. Clinical adequacy was set at limits of agreement (LoA) of 1°C compared with core temperature. Results: We studied 50 consecutive critically ill patients who were mainly admitted to the ICU after cardiac surgery. From over 375 observations, invasive core temperature (mostly pulmonary artery catheter) ranged from 33.9°C to 39°C. On average, the LoA between invasive and non-invasive measurements methods were about 3°C. The temporal scanner showed the worst performance in estimating core temperature (bias, 0.66°C; LoA, -1.23°C, +2.55°C), followed by tympanic infrared (bias, 0.44°C; LoA, -1.73°C, +2.61°C) and axillary chemical dot methods (bias, 0.32°C; LoA, -1.64°C, +2.28°C). No methods achieved clinical adequacy even accounting for significant explanatory variables. Conclusions: The axillary chemical dot, tympanic infrared and temporal scanner methods are inaccurate measures of core temperature in ICU patients. These non-invasive methods appeared unreliable for use in ICU patients.

Accuracy of non-invasive body temperature measurement methods in adult patients admitted to the intensive care unit: a systematic review and meta-analysis.

Objective: Non-invasive thermometers are widely used in both clinical practice and trials to estimate core temperature. We aimed to investigate their accuracy and precision in patients admitted to the intensive care unit (ICU). Study design: Systematic review and meta-analysis. Data sources: We searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials to identify all relevant studies from 1966 to 2017. We selected published trials that reported the accuracy and precision of non-invasive peripheral thermometers (index test) in ICU patients compared with intravascular temperature measurement (reference test). The extracted data included the study design and setting, authors, study population, devices, and body temperature measurements. Methods: Two reviewers performed the initial search, selected studies, and extracted data. Study quality was assessed using the QUADAS-2 tool. Pooled estimates of the mean bias between index and reference tests and the standard deviation of mean bias were synthesised using DerSimonian and Laird random effects meta-analyses. Results: We included 13 cohort studies (632 patients, 105 375 measurements). Axillary, tympanic infrared and zero heat flux thermometers all underestimated intravascular temperature. Only oesophageal measurements showed clinically acceptable accuracy. We found an insufficient number of studies to assess precision for any technique. Study heterogeneity was high (99-100%). Risk of bias for the index test was unclear, mostly because of no device calibration or control for confounders. Conclusions: Compared with the gold standard of intravascular temperature measurement, non-invasive peripheral thermometers have low accuracy. This makes their clinical and trial-related use in ICU patients unreliable and potentially misleading.

Haemodynamic effect of a 20% albumin fluid bolus in post-cardiac surgery patients.

OBJECTIVE: To study the cardiovascular effect over 30 minutes following the end of fluid bolus therapy (FBT) with 20% albumin in patients after cardiac surgery. DESIGN: Prospective observational study. SETTING: Intensive care unit of a tertiary university-affiliated hospital. PARTICIPANTS: Twenty post-cardiac surgery mechanically ventilated patients with a clinical decision to administer FBT. INTERVENTION: FBT with a 100 mL bolus of 20% albumin. MAIN OUTCOME MEASURES: Cardiac index (CI) response was defined by a ≥ 15% increase, while mean arterial pressure (MAP) response was defined by a ≥ 10% increase. RESULTS: The most common indication for FBT was hypotension (40%). Median duration of infusion was 7 minutes (interquartile range [IQR], 3-9 min). At the end of FBT, five patients (25%) showed a CI response, which increased to almost half in the following 30 minutes and dissipated in one patient. MAP response occurred in 11 patients (55%) and dissipated in five patients (45%) by a median of 6 minutes (IQR, 6-10 min). CI and MAP responses coexisted in four patients (20%). An intrabolus MAP response occurred in 17 patients (85%) but dissipated in 11 patients (65%) within a median of 7 minutes (IQR, 2-11 min). On regression analysis, faster fluid bolus administration predicted MAP increase at the end of the bolus. CONCLUSION: In post-cardiac surgery patients, CI response to 20% albumin FBT was not congruous with MAP response over 30 minutes. Although hypotension was the main indication for FBT and a MAP response occurred in most of patients, such response was maximal during the bolus, dissipated in a few minutes, and was dissociated from the CI response.

A Pilot Randomized Controlled Study of Mild Hypercapnia During Cardiac Surgery With Cardiopulmonary Bypass.

OBJECTIVES: To test whether targeted therapeutic mild hypercapnia (TTMH) would attenuate cerebral oxygen desaturation detected using near-infrared spectroscopy during cardiac surgery requiring cardiopulmonary bypass (CPB). DESIGN: Randomized controlled trials. SETTING: Operating rooms and intensive care unit of tertiary hospital. PARTICIPANTS: The study comprised 30 patients undergoing cardiac surgery with CPB. INTERVENTIONS: Patients were randomly assigned to receive either standard carbon dioxide management (normocapnia) or TTMH (target arterial carbon dioxide partial pressure between 50 and 55 mmHg) throughout the intraoperative period and postoperatively until the onset of spontaneous ventilation. MEASUREMENTS AND MAIN RESULTS: Relevant biochemical and hemodynamic variables were measured, and cerebral tissue oxygen saturation (SctO2) was monitored with near-infrared spectroscopy. Patients were followed-up with neuropsychological testing. Patient demographics between groups were compared using the Fisher exact and Mann-Whitney tests, and SctO2 between groups was compared using repeated measures analysis of variance. The median patient age was 67 years (interquartile range [IQR] 62-72 y), and the median EuroSCORE II was 1.1. The median CPB time was 106 minutes. The mean intraoperative arterial carbon dioxide partial pressure for each patient was significantly higher with TTMH (52.1 mmHg [IQR 49.9-53.9 mmHg] v 40.8 mmHg [IQR 38.7-41.7 mmHg]; p < 0.001) as was pulmonary artery pressure (23.9 mmHg [IQR 22.4-25.3 mmHg] v 18.5 mmHg [IQR 14.8-20.7 mmHg]; p = 0.004). There was no difference in mean percentage change in SctO2 during CPB in the control group for both hemispheres (left: -6.7% v -2.3%; p = 0.110; right: -7.9% v -1.0%; p = 0.120). Compliance with neuropsychological test protocols was poor. However, the proportion of patients with drops in test score >20% was similar between groups in all tests. CONCLUSIONS: TTMH did not increase SctO2 appreciably during CPB but increased pulmonary artery pressures before and after CPB. These findings do not support further investigation of TTMH as a means of improving SctO2 during and after cardiac surgery requiring CPB.

Conservative versus conventional oxygen therapy for cardiac surgical patients: A before-and-after study.

Avoiding hypoxaemia is considered crucial in cardiac surgery patients admitted to the intensive care unit (ICU). However, avoiding hyperoxaemia may also be important. A conservative approach to oxygen therapy may reduce exposure to hyperoxaemia without increasing the risk of hypoxaemia. Using a before-and-after design, we evaluated the introduction of conservative oxygen therapy (target SpO2 88%-92% using the lowest FiO2) for cardiac surgical patients admitted to the ICU. We studied 9041 arterial blood gas (ABG) datasets: 4298 ABGs from 245 'conventional' and 4743 ABGs from 298 'conservative' oxygen therapy patients. During mechanical ventilation (MV) and while in the ICU, compared to the conventional group, conservative group patients had significantly lower FiO2 exposure and PaO2 values ( P < 0.001 for each). Accordingly, using the mean PaO2 during MV, more conservative group patients were classified as normoxaemic (226 versus 62 patients, P < 0.01), fewer as hyperoxaemic (66 versus 178 patients, P < 0.01) and no patient in either group as hypoxaemic or severely hypoxaemic. Moreover, more ABG samples were hyperoxaemic or severely hyperoxaemic during conventional treatment ( P < 0.001). Finally, there was no difference in ICU or hospital length of stay, ICU or hospital mortality or 30-day mortality between the groups. Our findings support the feasibility and physiological safety of conservative oxygen therapy in patients admitted to ICU after cardiac surgery.

The normal cardiac index in older healthy individuals: a scoping review.

OBJECTIVE: Despite the growing number of older patients having major surgery, the normal resting values for the cardiac index of older patients remain unclear. We aim to derive a normative value for such patients. DESIGN: Scoping review. DATA SOURCES: We searched MEDLINE, EMBASE and CENTRAL for studies reporting measured values of cardiac output or cardiac index in healthy, older humans at rest. RESULTS: We retrieved 5340 citations and assessed 412 fulltext articles for eligibility. Twenty-nine studies, published between 1964 and 2017, met our inclusion criteria. Overall, the mean cardiac index in healthy volunteers over 60 years of age was reported between 2.1 and 3.2 L/min/m2 and the mean cardiac output was between 3.1 and 6.4 L/min. A yearly decline in cardiac index (between 3.5 and 8 mL/min/m2 per year) was reported in some but not all studies. Only one study measured the cardiac index in nine people over 80 years of age. CONCLUSIONS: The normal range of the cardiac index in older patients may be lower than previously reported. Its rate of decline with age is uncertain, but likely between 3.5 and 8 mL/min/m2 per year. Data on the normal cardiac index in people older than 80 years are scant.

Prediction of tracheostomy in critically ill trauma patients: a systematic review.

BACKGROUND: Tracheostomy is relatively common in mechanically ventilated patients in the intensive care unit (ICU). The prediction of which patients will receive a tracheostomy is crucial to both clinical decision making and the design of targeted interventional trials of its timing. OBJECTIVES: We aimed to systematically review the literature to ascertain whether useful predictors of eventual tracheostomy can be identified, with a particular focus on trauma patients. DATA SOURCES AND REVIEW METHODS: We searched three electronic databases to identify all studies of any design evaluating potential predictors of tracheostomy in mechanically ventilated ICU patients. Bias was assessed using the Quality in Prognosis Studies tool. RESULTS: Of 140 potentially eligible studies, we identified 12 relevant observational studies recruiting a total of 119 945 mechanically ventilated patients, of whom 14 080 (11.7%) received a tracheostomy. Seven studies were performed in trauma populations and included 24 858 patients, of whom 6140 (24.7%) received a tracheostomy. Factors predictive of receiving a tracheostomy in the trauma population included patient factors (age and comorbidities), diagnostic factors (injury type and injury severity score), and intervention factors (craniotomy or laparotomy). Profound clinical and methodological heterogeneity prevented meaningful metaanalysis. Significantly, more predictors were present on the day of admission in trauma populations than in non-trauma patients with brain injury and in other populations (89.7% v 73.3% v 25.0%). CONCLUSION: There are a number of clinical factors associated with subsequent tracheostomy in mechanically ventilated patients, in particular trauma patients. Given the need to prevent patients from receiving an unnecessary tracheostomy, these findings indicate that better predictive models are needed before the conduct of interventional trials. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO registry no. CRD42018084987.

Small volume resuscitation with 20% albumin in intensive care: physiological effects : The SWIPE randomised clinical trial.

PURPOSE: We set out to assess the resuscitation fluid requirements and physiological and clinical responses of intensive care unit (ICU) patients resuscitated with 20% albumin versus 4-5% albumin. METHODS: We performed a randomised controlled trial in 321 adult patients requiring fluid resuscitation within 48 h of admission to three ICUs in Australia and the UK. RESULTS: The cumulative volume of resuscitation fluid at 48 h (primary outcome) was lower in the 20% albumin group than in the 4-5% albumin group [median difference - 600 ml, 95% confidence interval (CI) - 800 to - 400; P < 0.001]. The 20% albumin group had lower cumulative fluid balance at 48 h (mean difference - 576 ml, 95% CI - 1033 to - 119; P = 0.01). Peak albumin levels were higher but sodium and chloride levels lower in the 20% albumin group. Median (interquartile range) duration of mechanical ventilation was 12.0 h (7.6, 33.1) in the 20% albumin group and 15.3 h (7.7, 58.1) in the 4-5% albumin group (P = 0.13); the proportion of patients commenced on renal replacement therapy after randomization was 3.3% and 4.2% (P = 0.67), respectively, and the proportion discharged alive from ICU was 97.4% and 91.1% (P = 0.02). CONCLUSIONS: Resuscitation with 20% albumin decreased resuscitation fluid requirements, minimized positive early fluid balance and was not associated with any evidence of harm compared with 4-5% albumin. These findings support the safety of further exploration of resuscitation with 20% albumin in larger randomised trials. TRIAL REGISTRATION: http://www.anzctr.org.au . Identifier ACTRN12615000349549.

Body temperature measurement methods and targets in Australian and New Zealand intensive care units.

OBJECTIVE: In Australian and New Zealand (ANZ) intensive care units (ICUs), the preferred measurement methods and targets for temperature remain uncertain, but are crucial for future interventional studies. We aimed to investigate the reported use of temperature measurement methods and targets in ANZ ICUs. DESIGN, SETTINGS AND PARTICIPANTS: Structured online questionnaire delivered via the email list of the Australian and New Zealand Intensive Care Society Clinical Trials Group. MAIN OUTCOME MEASURES: Measurements methods and targets for temperature in ANZ ICUs. RESULTS: Of 209 respondents, 130 were nurses (62.2%) and 79 were doctors (37.8%). Only 21.5% of the respondents reported having a unit protocol for measuring body temperature. However, invasive temperature measurement methods were preferred by doctors (69.8% v 55.3%) and non-invasive methods by nurses (29.9% v 44.2%). Moreover, among non-invasive methods, tympanic measurement was preferred by doctors (66.0% v 26.9%) and axillary by nurses (11.7% v 51.9%). Both professions reported a wide range of temperature thresholds that they believed required cooling interventions, but 16.7% of doctors and 42.4% of nurses reported that, in patients with cardiac arrest, they would actively cool patients only if the temperature was ≥ 38°C. CONCLUSION: In ANZ ICUs, preferred temperature measurement methods and targets are typically not governed by protocol, vary greatly and differ between doctors and nurses. Targeted temperature management after cardiac arrest is not fully established. Future studies of the comparative accuracy of non-invasive temperature measurements methods and practice in patients with cardiac arrest appear important.

Ventilation management in Victorian intensive care unit patients without acute respiratory distress syndrome.

BACKGROUND: The setting of tidal volume (VT) during controlled mechanical ventilation (CMV) in critically ill patients without acute respiratory distress syndrome (ARDS) is likely important but currently unknown. We aimed to describe current CMV settings in intensive care units (ICUs) across Victoria. METHODS: We performed a multicentre, prospective, observational study. We collected clinical, ventilatory and arterial blood gas data twice daily for 7 days. We performed subgroup analysis by sex and assessment of arterial partial pressure of carbon dioxide (PaCO2) management where hypercapnia was potentially physiologically contraindicated. RESULTS: We recorded 453 observational sets in 123 patients across seven ICUs. The most commonly selected initial VT was 500 mL (33%), and this proportion did not differ according to sex (32% male, 34% female). Moreover, 38% of patients were exposed to initial VT per predicted body weight (VT-PBW) > 8.0 mL/kg. VT-PBW in this range were more likely to occur in females, those with a lower height, lower ideal body weight or in those for whom hypercapnia was potentially physiologically contraindicated. As a consequence, females were more frequently exposed to a lower PaCO2 and higher pH. CONCLUSIONS: In adults without ARDS undergoing CMV in Australian ICUs, the initial VT was a stereotypical 500 mL in one-third of participants, irrespective of sex. Moreover, around 40% of patients were exposed to an initial VT-PBW > 8.0 mL/kg. Finally, women were more likely to be exposed to a high VT and hyperventilation.

Repeated sensor use for regional cerebral oxygenation measurements by near-infrared spectroscopy: a technical report.

OBJECTIVE: Near-infrared spectroscopy (NIRS) has been used in clinical practice to assess regional cerebral tissue oxygen saturation (StcO2). There is no evidence whether repeated use of the same sensor affects StcO2 measurements. We aimed to assess whether there was a significant systematic decrease or increase in StcO2 when NIRS sensors were reused. DESIGN: Participants were divided into three groups (A, B and C). StcO2 was recorded over 5 minutes daily for 5 days in Groups A and B ("new-sensor" [NS] period; sensor age, 1-5 days) and in Groups A and C, with the sensor previously used for A ("extended-use" [EU] period; sensor age, 6-10 days). SETTING: Single-centre, university hospital, intensive care unit. PARTICIPANTS: Healthy volunteers. MAIN OUTCOME MEASURES: StcO2 change within and between study periods. RESULTS: In 13 participants (9 male; median age, 30 years), the range of median StcO2 values per day was 65-72%. In the NS period, there were no changes in right-sided StcO2, and left-sided StcO2 showed no systematic or progressive patterns of increase or decrease when comparing Day 1 with subsequent days. There were no differences when comparing Day 1 with subsequent days (up to Day 10) in the EU period or between the NS and EU periods for left or right StcO2. CONCLUSIONS: Repeated use of NIRS sensors measured StcO2 in different individuals for up to 10 days. There were no significant, systematic, persistent or progressive changes in StcO2 with extended use over time. Our findings suggest that StcO2 does not change with sensor reuse for up to 10 days.

Liberal Glucose Control in ICU Patients With Diabetes: A Before-and-After Study.

OBJECTIVES: To assess the feasibility, biochemical efficacy, and safety of liberal versus conventional glucose control in ICU patients with diabetes. DESIGN: Prospective, open-label, sequential period study. SETTING: A 22-bed mixed ICU of a tertiary hospital in Australia. PATIENTS: We compared 350 consecutive patients with diabetes admitted over 15 months who received liberal glucose control with a preintervention control population of 350 consecutive patients with diabetes who received conventional glucose control. INTERVENTIONS: Liberal control patients received insulin therapy if glucose was greater than 14 mmol/L (target: 10-14 mmol/L [180-252 mg/dL]). Conventional control patients received insulin therapy if glucose was greater than 10 mmol/L (target: 6-10 mmol/L [108-180 mg/dL]). MEASUREMENTS AND MAIN RESULTS: We assessed separation in blood glucose, insulin requirements, occurrence of hypoglycemia (blood glucose ≤ 3.9 mmol/L [70 mg/dL]), creatinine and white cell count levels, and clinical outcomes. The median (interquartile range) time-weighted average blood glucose concentration was significantly higher in the liberal control group (11.0 mmol/L [8.7-12.0 mmol/L]; 198 mg/dL [157-216 mg/dL]) than in the conventional control group (9.6 mmol/L [8.5-11.0 mmol/L]; 173 mg/dL [153-198 mg/dL]; p < 0.001). Overall, 132 liberal control patients (37.7%) and 188 conventional control patients (53.7%) received insulin in ICU (p < 0.001). Hypoglycemia occurred in 6.6% and 8.6%, respectively (p = 0.32). Among 314 patients with glycated hemoglobin A1c greater than or equal to 7%, hypoglycemia occurred in 4.1% and 9.6%, respectively (p = 0.053). Trajectories of creatinine and white cell count were similar in the groups. In multivariable analyses, we found no independent association between glucose control and mortality, duration of mechanical ventilation, or ICU-free days to day 30. CONCLUSIONS: In ICU patients with diabetes, during a period of liberal glucose control, insulin administration, and among patients with hemoglobin A1c greater than or equal to 7%, the prevalence of hypoglycemia was reduced, without negatively affecting serum creatinine, the white cell count response, or other clinical outcomes. (Trial Registration: Australian New Zealand Clinical Trials Registry; ACTRN12615000216516).

Does Fluid Type and Amount Affect Kidney Function in Critical Illness?

Acute kidney injury (AKI) is common, although commonly used clinical diagnostic markers are imperfect. Intravenous fluid administration remains a cornerstone of therapy worldwide, but there is minimal evidence of efficacy for the use of fluid bolus therapy outside of specific circumstances, and emerging evidence associates fluid accumulation with worse renal outcomes and even increased mortality among critically ill patients. Artificial colloid solutions have been associated with harm, and chloride-rich solutions may adversely affect renal function. Large trials to provide guidance regarding the optimal fluid choices to prevent or ameliorate AKI, and promote renal recovery, are urgently required.

Interobserver agreement for post mortem renal histopathology and diagnosis of acute tubular necrosis in critically ill patients.

BACKGROUND: The renal histopathology of critically ill patients dying with acute kidney injury (AKI) in intensive care units of high income countries remains uncertain. METHODS: Retrospective observational assessment of interobserver agreement in the reporting of renal post mortem histopathology, and the ability of pathologists blinded to the clinical context to independently identify the presence of pre-mortem AKI from digital images of histological sections from 34 critically ill patients dying in teaching hospitals in Australia and Canada. RESULTS: We identified a heterogeneous cohort with a median age of 65 years (interquartile range [IQR], 56.5-77), APACHE II score of 27 (IQR, 19-33), and sepsis as the most common admission diagnosis (12/34; 35%). The most common proximate causes of death were cardiovascular (19/34; 56%) and respiratory (7/34; 21%) failure. AKI was common, with 23 patients (68%) developing RIFLE-F AKI, and 21 patients (62%) receiving renal replacement therapy. Structured reporting for tubular inflammation showed excellent agreement (kappa = 1), but no other subdomain demonstrated better than moderate agreement (kappa < 0.6). Only fair agreement (55.9% of cases; kappa = 0.23) was demonstrated on the diagnosis of moderate to severe acute tubular necrosis (ATN). Pathologist A predicted RIFLE-I or worse AKI with the diagnosis of ATN, with an overall accuracy of 61.8%; pathologist B predicted AKI with an accuracy of 35.3%. CONCLUSIONS: Post mortem assessment of the renal histopathology in critically ill patients is neither robust nor reproducible; independent pathologists agree poorly on the diagnosis of ATN, and their structural assessment appears dissociated from ante-mortem renal function.

Defining fluid removal in the intensive care unit: A national and international survey of critical care practice.

DESIGN AND OBJECTIVES: To identify and compare how intensive care unit specialists in the United Kingdom and Australia and New Zealand self-reportedly define, assess and manage fluid overload in critically ill patients using a structured online questionnaire. RESULTS: We assessed 219 responses. Australia and New Zealand and United Kingdom intensive care unit specialists reported using clinical examination findings, bedside tools and radiological features to assess fluid status, diagnose fluid overload and initiate fluid removal in the critically ill. An elevated central venous pressure is not regarded as helpful in diagnosing fluid overload and targeting a clinician-set fluid balance is the most popular management strategy. Renal replacement therapy is used ahead of more diuretic therapy in patients who are oligo/anuric, or when diuretic therapy has not generated an adequate response. CONCLUSIONS: This self-reported account of practice by United Kingdom and Australia and New Zealand intensivists demonstrates that fluid overload remains poorly defined with variability in both management and practice.

Near-Infrared Spectroscopy in Adult Cardiac Surgery Patients: A Systematic Review and Meta-Analysis.

OBJECTIVES: To identify the normal baseline preoperative range of cerebral tissue oxygen saturation (SctO2) derived using near-infrared spectroscopy (NIRS) and the efficacy of perioperative interventions designed to modulate SctO2 in cardiac surgical patients. DESIGN: Systematic review and meta-analysis of relevant randomized controlled trials (RCTs) extracted from the Medline, Embase, and Cochrane Central Register of Controlled Trials databases. SETTING: Hospitals performing cardiac surgery. PARTICIPANTS: The study comprised 953 participants from 11 RCTs. INTERVENTIONS: Interventions included the following: (1) SctO2 monitoring protocol compared with no monitoring; (2) use of cardiopulmonary bypass (CPB) compared with no CPB; (3) normothermic CPB compared with hypothermic CPB; (4) glyceryl trinitrate during surgery compared with placebo; (5) midazolam during induction of anesthesia compared with propofol; (6) sevoflurane anesthesia compared with total intravenous anesthesia; (7) sevoflurane anesthesia compared with propofol-based anesthesia; and (8) norepinephrine during CPB compared with phenylephrine. MEASUREMENTS AND MAIN RESULTS: Eleven RCTs with 953 participants measured baseline preoperative SctO2 using NIRS. The pooled mean baseline SctO2 was 66.4% (95% CI 65.0-67.7), generating a reference range of 51.0% to 81.8%. Four interventions (1, 3, 4, and 6 described in the Interventions section above) increased intraoperative SctO2 across the majority of reported time points. Postoperative follow-up of SctO2 occurred in only 1 study, and postoperative cognitive assessment correlating SctO2 with cognitive function was applied in only 4 studies using variable methodology. CONCLUSIONS: The authors have established that reference values for baseline NIRS-derived SctO2 in cardiac surgery patients are varied and have identified interventions that modulate SctO2. This information opens the door to standardized research and interventional studies in this field.

Magnesium status and magnesium therapy in cardiac surgery: A systematic review and meta-analysis focusing on arrhythmia prevention.

PURPOSE: To investigate magnesium as prophylaxis or treatment of postoperative arrhythmias in cardiac surgery (CS) patients. To assess impact on biochemical and patient-centered outcomes. MATERIALS AND METHODS: We searched MEDLINE, CENTRAL and EMBASE electronic databases from 1975 to October 2015 using terms related to magnesium and CS. English-Language RCTs were included involving adults undergoing CS with parenterally administered magnesium to treat or prevent arrhythmias, compared to control or standard antiarrythmics. We extracted incidence of postoperative arrhythmias, termination following magnesium administration and secondary outcomes (including mortality, length of stay, hemodynamic parameters, biochemistry). RESULTS: Thirty-five studies were included, with significant methodological heterogeneity. Atrial fibrillation (AF) was most commonly reported, followed by ventricular, supraventricular and overall arrhythmia frequency. Magnesium appeared to reduce AF (RR 0.69, 95% confidence interval (95%CI) 0.56-0.86, p=0.002), particularly postoperatively (RR 0.51, 95%CI 0.34-0.77, p=0.003) for longer than 24h. Maximal benefit was seen with bolus doses up to 60mmol. Magnesium appeared to reduce ventricular arrhythmias (RR=0.46, 95%CI 0.24-0.89, p=0.004), with a trend to reduced overall arrhythmias (RR=0.80, 95%CI 0.57-1.12, p=0.191). We found no mortality effect or significant increase in adverse events. CONCLUSIONS: Magnesium administration post-CS appears to reduce AF without significant adverse events. There is limited evidence to support magnesium administration for prevention of other arrhythmias.

Survival and functional outcomes of patients with metastatic solid organ cancer admitted to the intensive care unit of a tertiary centre.

OBJECTIVE: Metastatic solid organ cancer is associated with a poor prognosis, and admission of patients with these cancers to the intensive care unit remains a dilemma. We aimed to assess outcomesin a cohort of these patients who were admitted to the ICU of a general tertiary centre. DESIGN, SETTING AND PATIENTS: A retrospective observational study of patients with incurable metastatic solid organ malignancies who had unplanned admission to a tertiary hospital ICU between 1 January 2010 and 30 June 2015. MAIN OUTCOME MEASURES: Survival outcomes up to 1 year after ICU admission, and functional outcomes as measured by Eastern Cooperative Oncology Group (ECOG) grade up to 3 months after ICU discharge. We also determined rates of advance care planning documentation. RESULTS: A total of 101 patients were treated in the ICU during the study period. Hospital, 30-day and 1-year mortality rates were 35%, 41% and 77%, respectively, and the median survival was 2.3 months (95% CI, 1.1-3.9 months). On multivariable analysis, lowest albumin level (hazard ratio [HR], 1.10; 95% CI, 1.04-1.15) and highest white cell count (HR, 1.03; 95% CI, 1.00-1.07) were significant, although they were marginal predictors of poorer overall survival. Higher ECOG grade showed a trend towards significance (HR, 1.60; 95% CI, 0.94-2.73; P = 0.08). In patients alive and assessable at 1 month, 17/31 (55%) had functionally declined. At 3 months, 15/22 surviving patients (68%) had returned to their baseline, pre-ICU admission ECOG grade. Ninety per cent had no advance care directive and twothirds did not have a medical enduring power of attorney. CONCLUSIONS: Survival is poor in patients with metastatic cancer after emergent ICU admission, although functional state is often recovered by 3 months in surviving patients. Albumin level, white cell count and ECOG grade are simple prognostic markers of survival.