Sustainability of clinical pathway guided care in cardiac surgery ICU patients; 9-years experience in over 7500 patients.

OBJECTIVE: To determine trends over time regarding inclusion of post-operative cardiac surgery intensive care unit (ICU) patients in a clinical pathway (CP), and the association with clinical outcome. DESIGN: Retrospective cohort study. SETTING: ICU of an academic hospital. PARTICIPANTS: All cardiac surgery patients operated between 2007 and 2015. MEASURES AND RESULTS: A total of 7553 patients were operated. Three patient groups were identified: patients treated according to CP (n = 6567), patients excluded from the CP within the first 48 h (n = 633) and patients never included in CP (n = 353). Patients treated according to CP increased significantly over time from 74% to 95% and the median Log EuroSCORE (predicted mortality score) in this group increased significantly over time (P = 0.016). In-hospital length of stay (LOS) decreased in all groups, but significantly in CP group (P < 0.001). Overall, the in-hospital, and 1-year mortality decreased from 1.5 to 1.1% and 3.7 to 2.9%, respectively (both P < 0.05). Patients with a Log EuroSCORE >10 were more likely excluded from CP (P < 0.001), but, if included in CP, these patients had a significantly shorter Intensive Care stay and in-hospital stay compared to excluded patients with a Log EuroSCORE >10 (both P < 0.001). CONCLUSIONS: The use of a CP for all post-operative cardiac surgery patients in the ICU is sustainable. While more complex patients were treated according to the CP, clinical outcome improved in the CP group.

Effect of Haloperidol on Survival Among Critically Ill Adults With a High Risk of Delirium: The REDUCE Randomized Clinical Trial.

Importance: Results of studies on use of prophylactic haloperidol in critically ill adults are inconclusive, especially in patients at high risk of delirium. Objective: To determine whether prophylactic use of haloperidol improves survival among critically ill adults at high risk of delirium, which was defined as an anticipated intensive care unit (ICU) stay of at least 2 days. Design, Setting, and Participants: Randomized, double-blind, placebo-controlled investigator-driven study involving 1789 critically ill adults treated at 21 ICUs, at which nonpharmacological interventions for delirium prevention are routinely used in the Netherlands. Patients without delirium whose expected ICU stay was at least a day were included. Recruitment was from July 2013 to December 2016 and follow-up was conducted at 90 days with the final follow-up on March 1, 2017. Interventions: Patients received prophylactic treatment 3 times daily intravenously either 1 mg (n = 350) or 2 mg (n = 732) of haloperidol or placebo (n = 707), consisting of 0.9% sodium chloride. Main Outcome and Measures: The primary outcome was the number of days that patients survived in 28 days. There were 15 secondary outcomes, including delirium incidence, 28-day delirium-free and coma-free days, duration of mechanical ventilation, and ICU and hospital length of stay. Results: All 1789 randomized patients (mean, age 66.6 years [SD, 12.6]; 1099 men [61.4%]) completed the study. The 1-mg haloperidol group was prematurely stopped because of futility. There was no difference in the median days patients survived in 28 days, 28 days in the 2-mg haloperidol group vs 28 days in the placebo group, for a difference of 0 days (95% CI, 0-0; P = .93) and a hazard ratio of 1.003 (95% CI, 0.78-1.30, P=.82). All of the 15 secondary outcomes were not statistically different. These included delirium incidence (mean difference, 1.5%, 95% CI, -3.6% to 6.7%), delirium-free and coma-free days (mean difference, 0 days, 95% CI, 0-0 days), and duration of mechanical ventilation, ICU, and hospital length of stay (mean difference, 0 days, 95% CI, 0-0 days for all 3 measures). The number of reported adverse effects did not differ between groups (2 [0.3%] for the 2-mg haloperidol group vs 1 [0.1%] for the placebo group). Conclusions and Relevance: Among critically ill adults at high risk of delirium, the use of prophylactic haloperidol compared with placebo did not improve survival at 28 days. These findings do not support the use of prophylactic haloperidol for reducing mortality in critically ill adults. Trial Registration: clinicaltrials.gov Identifier: NCT01785290.

The Influence of End-of-Life Care on Organ Donor Potential.

Many patients with acute devastating brain injury die outside intensive care units and could go unrecognized as potential organ donors. We conducted a prospective observational study in seven hospitals in the Netherlands to define the number of unrecognized potential organ donors outside intensive care units, and to identify the effect that end-of-life care has on organ donor potential. Records of all patients who died between January 2013 and March 2014 were reviewed. Patients were included if they died within 72 h after hospital admission outside the intensive care unit due to devastating brain injury, and fulfilled the criteria for organ donation. Physicians of included patients were interviewed using a standardized questionnaire regarding logistics and medical decisions related to end-of-life care. Of the 5170 patients screened, we found 72 additional potential organ donors outside intensive care units. Initiation of end-of-life care in acute settings and lack of knowledge and experience in organ donation practices outside intensive care units can result in under-recognition of potential donors equivalent to 11-34% of the total pool of organ donors. Collaboration with the intensive care unit and adjusting the end-of-life path in these patients is required to increase the likelihood of organ donation.

Estimation of extravascular lung water using the transpulmonary ultrasound dilution (TPUD) method: a validation study in neonatal lambs.

Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accurate measurement of EVLW in these patients is limited due to the lack of bedside methods. The aim of this pilot study was to investigate the reliability of the transpulmonary ultrasound dilution (TPUD) technique as a possible method for estimating EVLW in a neonatal animal model. Pulmonary edema was induced in 11 lambs by repeated surfactant lavages. In between the lavages, EVLW indexed by bodyweight was estimated by TPUD (EVLWItpud) and transpulmonary dye dilution (EVLWItpdd) (n = 22). Final EVLWItpud measurements were also compared with EVLWI estimations by gold standard post mortem gravimetry (EVLWIgrav) (n = 6). EVLWI was also measured in two additional lambs without pulmonary edema. Bland-Altman plots showed a mean bias between EVLWItpud and EVLWItpdd of -3.4 mL/kg (LOA ± 25.8 mL/kg) and between EVLWItpud and EVLWIgrav of 1.7 mL/kg (LOA ± 8.3 mL/kg). The percentage errors were 109 and 43 % respectively. The correlation between changes in EVLW measured by TPUD and TPDD was r2 = 0.22. Agreement between EVLWI measurements by TPUD and TPDD was low. Trending ability to detect changes between these two methods in EVLWI was questionable. The accuracy of EVLWItpud was good compared to the gold standard gravimetric method but the TPUD lacked precision in its current prototype. Based on these limited data, we believe that TPUD has potential for future use to estimate EVLW after adaptation of the algorithm. Larger studies are needed to support our findings.

Crew Resource Management in the Intensive Care Unit: a prospective 3-year cohort study.

BACKGROUND: Human factors account for the majority of adverse events in both aviation and medicine. Human factors awareness training entitled "Crew Resource Management (CRM)" is associated with improved aviation safety. We determined whether implementation of CRM impacts outcome in critically ill patients. METHODS: We performed a prospective 3-year cohort study in a 32-bed ICU, admitting 2500-3000 patients yearly. At the end of the baseline year, all personnel received CRM training, followed by 1 year of implementation. The third year was defined as the clinical effect year. All 7271 patients admitted to the ICU in the study period were included. The primary outcome measure was ICU complication rate. Secondary outcome measures were ICU and hospital length of stay, and standardized mortality ratio. RESULTS: Occurrence of serious complications was 67.1/1000 patients and 66.4/1000 patients during the baseline and implementation year respectively, decreasing to 50.9/1000 patients in the post-implementation year (P = 0.03). Adjusted odds ratios for occurrence of complications were 0.92 (95% CI 0.71-1.19, P = 0.52) and 0.66 (95% CI 0.51-0.87, P = 0.003) in the implementation and post-implementation year. The incidence of cardiac arrests was 9.2/1000 patients and 8.3/1000 patients during the baseline and implementation year, decreasing to 3.5/1000 patients (P = 0.04) in the post-implementation year, while cardiopulmonary resuscitation success rate increased from 19% to 55% and 67% (P = 0.02). Standardized mortality ratio decreased from 0.72 (95% CI 0.63-0.81) in the baseline year to 0.60 (95% CI 0.53-0.67) in the post-implementation year (P = 0.04). CONCLUSION: Our data indicate an association between CRM implementation and reduction in serious complications and lower mortality in critically ill patients.

Resveratrol attenuates NF-κB-binding activity but not cytokine production in mechanically ventilated mice.

BACKGROUND: Mechanical ventilation (MV) can result in inflammation and subsequent lung injury. Toll-like receptor (TLR)4 and NF-κB are proposed to play a crucial role in the MV-induced inflammatory response. Resveratrol (RVT) exhibits anti-inflammatory effects in vitro and in vivo supposedly by interfering with TLR4 signaling and NF-κB. In the present study, we investigated the role of RVT in MV-induced inflammation in mice. METHODS: RVT (10 mg/kg, 20 mg/kg and 40 mg/kg) or vehicle was intraperitoneally administered 1 h before start of MV (4 h, tidal volume 8 ml/kg, positive end-expiratory pressure 1,5 cmH2 O and FiO2 0.4). Blood and lungs were harvested for cytokine analysis. DNA binding activity of transcription factor NF-κB was measured in lung homogenates. RESULTS: MV resulted in elevated pulmonary concentrations of IL-1ß, IL-6, keratinocyte-derived chemokine (KC) and NF-κB DNA-binding activity. RVT at 10, 20 and 40 mg/kg reduced NF-κB's DNA-binding activity following MV compared with ventilated controls. However, no differences in cytokine release were found between RVT-treated and control ventilated mice. Similarly, in plasma, MV resulted in elevated concentrations of TNF-α, KC and IL-6, but RVT did not affect cytokine levels. CONCLUSIONS: RVT abrogates the MV-induced increase in pulmonary NF-κB activity but does not attenuate cytokine levels. This implies a less prominent role for NF-κB in MV-induced inflammation than previously assumed.

Vitamin D status is not associated with inflammatory cytokine levels during experimental human endotoxaemia.

Vitamin D has been shown to modulate innate immune responses in vitro and ex vivo; however, human in-vivo data are lacking. At high latitudes, seasonal vitamin D deficiency is common due to alternating ultraviolet (UV)-B radiation exposure. In the present study, we investigated whether levels of 25 hydroxyvitamin D(3) [25(OH)D(3) ] and its active metabolite 1,25 dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ] are subject to seasonal variation and whether plasma levels of these vitamin D metabolites correlate with the in-vivo cytokine response during experimental human endotoxaemia [administration of lipopolysaccharide (LPS) in healthy volunteers]. Plasma levels of 25(OH)D(3) and 1,25(OH)(2) D(3) were determined in samples obtained just prior to administration of an intravenous bolus of 2 ng/kg LPS (derived from Escherichia coli O:113) in 112 healthy male volunteers. In the same subjects, plasma levels of the inflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were analysed serially after endotoxin administration. Plasma levels of 1,25(OH)(2) D(3) , but not 25(OH)D(3) , were subject to significant seasonal variation, with lower levels in autumn and winter. 25(OH)D(3) and 1,25(OH)(2) D(3) levels did not correlate with plasma cytokine responses. Furthermore, 25(OH)D(3) deficient subjects (< 50 nmol/l) displayed an identical cytokine response compared with sufficient subjects. In conclusion, plasma levels of vitamin D are not correlated with the LPS-induced TNF, IL-6 and IL-10 cytokine response in humans in vivo. These findings question the direct role of vitamin D in modulation of the innate immune response.

Transpulmonary thermodilution cardiac output measurement is not affected by severe pulmonary oedema: a newborn animal study.

BACKGROUND: The transpulmonary thermodilution (TPTD) technique is widely used in clinical practice for measuring cardiac output (CO). This study was designed to investigate the influence of various levels of pulmonary oedema on the reliability of CO measurements by the TPTD method. METHODS: In 11 newborn lambs pulmonary oedema was induced using a surfactant washout technique. Serial CO measurements using TPTD (CO(TPTD)) were performed at various amounts of lung water. Simultaneously, CO was measured by an ultrasound flow probe around the main pulmonary artery (CO(MPA)) and used as the standard reference. CO was divided by the body surface area to calculate cardiac index (CI). Data were analysed using correlational statistics and Bland-Altman analysis. RESULTS: One lamb died prematurely. A total of 56 measurements in 10 lambs were analysed with a median CI(MPA) of 2.95 (IQR 1.04) litre min(-1) m(-2). Mean percentage increase in extravascular lung water (EVLW) between the start and the end of the study was 126.4% (SD 40.4). Comparison of the two CO methods showed a mean bias CI of -0.16 litre min(-1) m(-2) (limits of agreement ±0.73 litre min(-1) m(-2)) and a percentage error of 23.8%. Intraclass correlation coefficients were 0.91 (95% CI 0.81-0.95) for absolute agreement and 0.92 (95% CI 0.87-0.95) for consistency. Acceptable agreement was confirmed by a tolerability-agreement ratio of 0.39. The within-subject correlation between the amount of EVLWI and the bias between the two methods was not significant (-0.02; P=0.91). CONCLUSIONS: CO measurements by the transpulmonary thermodilution technique over a wide range of CI values are not affected by the presence of high EVLWI. The slight underestimation of the CO is independent of the amount of pulmonary oedema.

Decontamination of the digestive tract and oropharynx in ICU patients.

BACKGROUND: Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting. METHODS: We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance. RESULTS: A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively. CONCLUSIONS: In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Dynamic indices do not predict volume responsiveness in routine clinical practice.

BACKGROUND: Dynamic indices, including pulse pressure, systolic pressure, and stroke volume variation (PPV, SPV, and SVV), are accurate predictors of fluid responsiveness under strict conditions, for example, controlled mechanical ventilation using conventional tidal volumes (TVs) in the absence of cardiac arrhythmias. However, in routine clinical practice, these prerequisites are not always met. We evaluated the effect of regularly used ventilator settings, different calculation methods, and the presence of cardiac arrhythmias on the ability of dynamic indices to predict fluid responsiveness in sedated, mechanically ventilated patients. METHODS: We prospectively evaluated 47 fluid challenges in 29 consecutive cardiac surgery patients. Patients were divided into different groups based on TV. Dynamic indices were calculated in various ways: calculation over 30 s, breath-by-breath (with and without excluding arrhythmias), and with correction for TV. RESULTS: The predictive value was optimal in the group ventilated with TVs >7 ml kg(-1) with correction for TV, calculated breath-by-breath, and with exclusion of arrhythmias [area under the curve (AUC)=0.95, 0.93, and 0.90 for PPV, SPV, and SVV, respectively]. Including patients ventilated with lower TVs decreased the predictive value of all dynamic indices, while calculating dynamic indices over 30 s and not excluding cardiac arrhythmias further reduced the AUC to 0.51, 0.63, and 0.51 for PPV, SPV, and SVV, respectively. CONCLUSIONS: PPV, SPV, and SVV are the only reliable predictors of fluid responsiveness under strict conditions. In routine clinical practice, factors including low TV, cardiac arrhythmias, and the calculation method can substantially reduce their predictive value.

Cardiac output can be measured with the transpulmonary thermodilution method in a paediatric animal model with a left-to-right shunt.

BACKGROUND: The transpulmonary thermodilution (TPTD) technique for measuring cardiac output (CO) has never been validated in the presence of a left-to-right shunt. METHODS: In this experimental, paediatric animal model, nine lambs with a surgically constructed aorta-pulmonary left-to-right shunt were studied under various haemodynamic conditions. CO was measured with closed and open shunt using the TPTD technique (CO(TPTD)) with central venous injections of ice-cold saline. An ultrasound transit time perivascular flow probe around the main pulmonary artery served as the standard reference measurement (CO(MPA)). RESULTS: Seven lambs were eligible for further analysis. Mean (sd) weight was 6.6 (1.6) kg. The mean CO(MPA) was 1.21 litre min(-1) (range 0.61-2.06 l min(-1)) with closed shunt and 0.93 litre min(-1) (range 0.48-1.45 litre min(-1)) with open shunt. The open shunt resulted in a mean Q(p)/Q(s) ratio of 1.8 (range 1.6-2.4). The bias between the two CO methods was 0.17 litre min(-1) [limits of agreement (LOA) of 0.27 litre min(-1)] with closed shunt and 0.14 litre min(-1) (LOA of 0.32 litre min(-1)) with open shunt. The percentage errors were 22% with closed shunt and 34% with open shunt. The correlation (r) between the two methods was 0.93 (P<0.001) with closed shunt and 0.86 (P<0.001) with open shunt. The correlation (r) between the two methods in tracking changes in CO (ΔCO) during the whole experiment was 0.94 (P<0.0001). CONCLUSIONS: The TPTD technique is a feasible method of measuring CO in paediatric animals with a left-to-right shunt.

Non-invasive measurement of pulse pressure variation and systolic pressure variation using a finger cuff corresponds with intra-arterial measurement.

BACKGROUND: Pulse pressure variation (PPV) and systolic pressure variation (SPV) are reliable predictors of fluid responsiveness in patients undergoing controlled mechanical ventilation. Currently, PPV and SPV are measured invasively and it is unknown if an arterial pressure (AP) signal obtained with a finger cuff can be used as an alternative. The aim of this study was to validate PPV and SPV measured using a finger cuff. METHODS: Patients receiving mechanical ventilation under sedation after cardiac artery bypass graft (CABG) surgery were included after arrival on the intensive care unit. AP was measured invasively in the radial artery and non-invasively using the finger cuff of the Nexfin™ monitor. I.V. fluid challenges were administered according to clinical need. The mean value of PPV and SVV was calculated before and after administration of a fluid challenge. Agreement of the calculated PPV and SPV from both methods was assessed using the Bland-Altman analysis. RESULTS: Nineteen patients were included and 28 volume challenges were analysed. Correlation between the two methods for PPV and SPV [mean (sd)=6.9 (4.3)% and 5.3 (2.6)%, respectively] was r=0.96 (P<0.0001) and r=0.95 (P<0.0001), respectively. The mean bias was -0.95% for PPV and -0.22% for SPV. Limits of agreement were -4.3% and 2.4% for PPV and -2.2% and 1.7% for SPV. The correlation between changes in PPV and SPV as a result of volume expansion measured by the two different methods was r=0.88 (P<0.0001) and r=0.87 (P<0.0001), respectively. CONCLUSIONS: In patients receiving controlled mechanical ventilation after CABG, PPV and SPV can be measured reliably non-invasively using the inflatable finger cuff of the Nexfin™ monitor.

α7 nicotinic acetylcholine receptor agonist GTS-21 attenuates ventilator-induced tumour necrosis factor-α production and lung injury.

BACKGROUND: Mechanical ventilation (MV) induces an inflammatory response that can lead to lung injury. The vagus nerve can limit the inflammatory response through the cholinergic anti-inflammatory pathway. We evaluated the effects of stimulation of the cholinergic anti-inflammatory pathway with the selective partial α7 nicotinic acetylcholine receptor (α7nAChR) agonist GTS-21 on inflammation and lung injury induced by MV using clinically relevant ventilator settings. Furthermore, we investigated whether altering endogenous cholinergic signalling, by administration of the non-specific nAChR antagonist mecamylamine and the peripherally acting acetylcholinesterase inhibitor neostigmine, modulates the MV-induced inflammatory response. METHODS: C57BL6 mice were injected i.p. with either the selective α7nAChR agonist GTS-21 (8 mg kg(-1)), the acetylcholinesterase inhibitor neostigmine (80 µg kg(-1)), the nAChR antagonist mecamylamine (1 mg kg(-1)), or a placebo; followed by 4 h of MV (8 ml kg(-1), 1.5 cm H(2)O PEEP). RESULTS: MV resulted in release of cytokines in plasma and lungs compared with unventilated mice. Lung and plasma levels of tumour necrosis factor (TNF)-α, but not of interleukin-10, were lower in GTS-21-treated animals compared with placebo (P<0.05). In addition, GTS-21 lowered the alveolar-arterial gradient, indicating improved lung function (P=0.04). Neither neostigmine nor mecamylamine had an effect on MV-induced inflammation or lung function. CONCLUSIONS: MV with clinically relevant ventilator settings results in pulmonary and systemic inflammation. Stimulation of the cholinergic anti-inflammatory pathway with GTS-21 attenuates MV-induced release of TNF-α, which was associated with reduced lung injury. Modulation of endogenous cholinergic signalling did not affect the MV-induced inflammatory response. Selective stimulation of the cholinergic anti-inflammatory pathway may represent new treatment options for MV-induced lung injury.

A point-of-care thoracic ultrasound protocol for hospital medical emergency teams (METUS) improves diagnostic accuracy.

BACKGROUND: Point-of-care ultrasound (POCUS) has proven itself in many clinical situations. Few data on the use of POCUS during Medical Emergency Team (MET) calls exist. In this study, we hypothesized that the use of POCUS would increase the number of correct diagnosis made by the MET and increase MET's certainty. METHODS: Single-center prospective observational study on adult patients in need for MET assistance. Patients were included in blocks (weeks). During even weeks, the MET physician performed a clinical assessment and registered an initial diagnosis. Subsequently, the POCUS protocol was performed and a second diagnosis was registered (US+). During uneven weeks, no POCUS was performed (US-). A blinded expert reviewed the charts for a final diagnosis. The number of correct diagnoses was compared to the final diagnosis between both groups. Physician's certainty, mortality and possible differences in first treatment were also evaluated. RESULTS: We included 100 patients: 52 in the US + and 48 in the US- group. There were significantly more correct diagnoses in the US+ group compared to the US- group: 78 vs 51% (P  = 0.006). Certainty improved significantly with POCUS (P  <  0.001). No differences in 28-day mortality and first treatment were found. CONCLUSIONS: The use of thoracic POCUS during MET calls leads to better diagnosis and increases certainty. TRIAL REGISTRATION: ClinicalTrials.gov. Registered 12 July 2017, NCT03214809 https://www.clinicaltrials.gov/ct2/show/NCT03214809?term=metus&cntry=NL&draw=2&rank=1.

Shared decision-making in the ICU from the perspective of physicians, nurses and patients: a qualitative interview study.

OBJECTIVE: To identify views, experiences and needs for shared decision-making (SDM) in the intensive care unit (ICU) according to ICU physicians, ICU nurses and former ICU patients and their close family members. DESIGN: Qualitative study. SETTING: Two Dutch tertiary centres. PARTICIPANTS: 19 interviews were held with 29 participants: seven with ICU physicians from two tertiary centres, five with ICU nurses from one tertiary centre and nine with former ICU patients, of whom seven brought one or two of their close family members who had been involved in the ICU stay. RESULTS: Three themes, encompassing a total of 16 categories, were identified pertaining to struggles of ICU physicians, needs of former ICU patients and their family members and the preferred role of ICU nurses. The main struggles ICU physicians encountered with SDM include uncertainty about long-term health outcomes, time constraints, feeling pressure because of having final responsibility and a fear of losing control. Former patients and family members mainly expressed aspects they missed, such as not feeling included in ICU treatment decisions and a lack of information about long-term outcomes and recovery. ICU nurses reported mainly opportunities to strengthen their role in incorporating non-medical information in the ICU decision-making process and as liaison between physicians and patients and family. CONCLUSIONS: Interviewed stakeholders reported struggles, needs and an elucidation of their current and preferred role in the SDM process in the ICU. This study signals an essential need for more long-term outcome information, a more informal inclusion of patients and their family members in decision-making processes and a more substantial role for ICU nurses to integrate patients' values and needs in the decision-making process.

Three bedside techniques to quantify dynamic pulmonary hyperinflation in mechanically ventilated patients with chronic obstructive pulmonary disease.

BACKGROUND: Dynamic pulmonary hyperinflation may develop in patients with chronic obstructive pulmonary disease (COPD) due to dynamic airway collapse and/or increased airway resistance, increasing the risk of volutrauma and hemodynamic compromise. The reference standard to quantify dynamic pulmonary hyperinflation is the measurement of the volume at end-inspiration (Vei). As this is cumbersome, the aim of this study was to evaluate if methods that are easier to perform at the bedside can accurately reflect Vei. METHODS: Vei was assessed in COPD patients under controlled protective mechanical ventilation (7 ± mL/kg) on zero end-expiratory pressure, using three techniques in a fixed order: (1) reference standard (Veireference): passive exhalation to atmosphere from end-inspiration in a calibrated glass burette; (2) ventilator maneuver (Veimaneuver): measuring the expired volume during a passive exhalation of 45s using the ventilator flow sensor; (3) formula (Veiformula): (Vt × Pplateau)/(Pplateau - PEEPi), with Vt tidal volume, Pplateau is plateau pressure after an end-inspiratory occlusion, and PEEPi is intrinsic positive end-expiratory pressure after an end-expiratory occlusion. A convenience sample of 17 patients was recruited. RESULTS: Veireference was 1030 ± 380 mL and had no significant correlation with Pplateau (r2 = 0.06; P = 0.3710) or PEEPi (r2 = 0.11; P = 0.2156), and was inversely related with Pdrive (calculated as Pplateau -PEEPi) (r2 = 0.49; P = 0.0024). A low bias but rather wide limits of agreement and fairly good correlations were found when comparing Veimaneuver and Veiformula to Veireference. Vei remained stable during the study period (low bias 15 mL with high agreement (95% limits of agreement from - 100 to 130 mL) and high correlation (r2 = 0.98; P < 0.0001) between both measurements of Veireference). CONCLUSIONS: In patients with COPD, airway pressures are not a valid representation of Vei. The three techniques to quantify Vei show low bias, but wide limits of agreement.

Increased sodium intake and decreased sodium excretion in ICU-acquired hypernatremia: A prospective cohort study.

PURPOSE: To provide more in-depth insight in the development of early ICU-acquired hypernatremia in critically ill patients based on detailed, longitudinal and quantitative data. MATERIALS AND METHODS: A comparative analysis was performed using prospectively collected data of ICU patients. All patients requiring ICU admission for more than 48 h between April and December 2018 were included. For this study, urine samples were collected daily and analyzed for electrolytes and osmolality. Additionally, plasma osmolality analyses were performed. Further data collection consisted of routine laboratory results, detailed fluid balances and medication use. RESULTS: A total of 183 patient were included for analysis, of whom 38% developed ICU-acquired hypernatremia. Whereas the hypernatremic group was similar to the non-hypernatremic group at baseline and during the first days, hypernatremic patients had a significantly higher sodium intake on day 2 to 5, a lower urine sodium concentration on day 3 and 4 and a worse kidney function (plasma creatinine 251 versus 71.9 µmol/L on day 5). Additionally, hypernatremic patients had higher APACHE IV scores (67 versus 49, p < 0.05) and higher ICU (23 versus 12%, p = 0.07) and 90-day mortality (33 versus 14%, p < 0.01). CONCLUSIONS: Longitudinal analysis shows that the development of early ICU-acquired hypernatremia is preceded by increased sodium intake, decreased renal function and decreased sodium excretion.

Continuous non-invasive finger arterial pressure monitoring reflects intra-arterial pressure changes in children undergoing cardiac surgery.

BACKGROUND: Continuous non-invasive measurement of finger arterial pressure (FAP) is a reliable technology in adults. FAP is measured with an inflatable cuff around the finger and simultaneously converted to a reconstructed brachial artery pressure waveform (reBAP) by the Nexfin™ device. We assessed the adequacy of a prototype device (Nexfin-paediatric), designed for a paediatric population, for detecting rapid arterial pressure changes in children during cardiac surgery. METHODS: Thirteen anaesthetized children with a median age of 11 months (2 months-7 yr) undergoing congenital cardiac surgery were included in the study. reBAP and intra-arterial pressure (IAP) were recorded simultaneously during the surgical procedure. To assess the accuracy of reBAP in tracking arterial pressure changes, the four largest IAP variations within a 5 min time interval were identified from each procedure. These variations were compared offline with reBAP during a 10 s control period before and a 10 s period after an arterial pressure change had occurred. RESULTS: In 10 out of 13 children, a non-invasive arterial pressure recording could be obtained. Therefore, recordings from these 10 children were eligible for further analysis, resulting in 40 data points. The correlation coefficient between reBAP and IAP in tracking mean arterial pressure (MAP) changes was 0.98. reBAP followed changes in IAP with a mean bias for systolic, diastolic arterial pressure, and MAP of 0.0 mm Hg (sd 5.8), 0.1 (sd 2.8), and 0.19 (sd 2.7), respectively. CONCLUSIONS: The prototype device closely follows arterial pressure changes in children. However, in a considerable number of attempts, obtaining a signal was time-consuming or unsuccessful. This technique seems promising but requires further technical development.

Recruitment pattern of the diaphragm and extradiaphragmatic inspiratory muscles in response to different levels of pressure support.

BACKGROUND: Inappropriate ventilator assist plays an important role in the development of diaphragm dysfunction. Ventilator under-assist may lead to muscle injury, while over-assist may result in muscle atrophy. This provides a good rationale to monitor respiratory drive in ventilated patients. Respiratory drive can be monitored by a nasogastric catheter, either with esophageal balloon to determine muscular pressure (gold standard) or with electrodes to measure electrical activity of the diaphragm. A disadvantage is that both techniques are invasive. Therefore, it is interesting to investigate the role of surrogate markers for respiratory dive, such as extradiaphragmatic inspiratory muscle activity. The aim of the current study was to investigate the effect of different inspiratory support levels on the recruitment pattern of extradiaphragmatic inspiratory muscles with respect to the diaphragm and to evaluate agreement between activity of extradiaphragmatic inspiratory muscles and the diaphragm. METHODS: Activity from the alae nasi, genioglossus, scalene, sternocleidomastoid and parasternal intercostals was recorded using surface electrodes. Electrical activity of the diaphragm was measured using a multi-electrode nasogastric catheter. Pressure support (PS) levels were reduced from 15 to 3 cmH2O every 5 min with steps of 3 cmH2O. The magnitude and timing of respiratory muscle activity were assessed. RESULTS: We included 17 ventilated patients. Diaphragm and extradiaphragmatic inspiratory muscle activity increased in response to lower PS levels (36 ± 6% increase for the diaphragm, 30 ± 6% parasternal intercostals, 41 ± 6% scalene, 40 ± 8% sternocleidomastoid, 43 ± 6% alae nasi and 30 ± 6% genioglossus). Changes in diaphragm activity correlated best with changes in alae nasi activity (r2 = 0.49; P < 0.001), while there was no correlation between diaphragm and sternocleidomastoid activity. The agreement between diaphragm and extradiaphragmatic inspiratory muscle activity was low due to a high individual variability. Onset of alae nasi activity preceded the onset of all other muscles. CONCLUSIONS: Extradiaphragmatic inspiratory muscle activity increases in response to lower inspiratory support levels. However, there is a poor correlation and agreement with the change in diaphragm activity, limiting the use of surface electromyography (EMG) recordings of extradiaphragmatic inspiratory muscles as a surrogate for electrical activity of the diaphragm.