Clinical validation of a computerized algorithm to determine mean systemic filling pressure.

Mean systemic filling pressure (Pms) is a promising parameter in determining intravascular fluid status. Pms derived from venous return curves during inspiratory holds with incremental airway pressures (Pms-Insp) estimates Pms reliably but is labor-intensive. A computerized algorithm to calculate Pms (Pmsa) at the bedside has been proposed. In previous studies Pmsa and Pms-Insp correlated well but with considerable bias. This observational study was performed to validate Pmsa with Pms-Insp in cardiac surgery patients. Cardiac output, right atrial pressure and mean arterial pressure were prospectively recorded to calculate Pmsa using a bedside monitor. Pms-Insp was calculated offline after performing inspiratory holds. Intraclass-correlation coefficient (ICC) and assessment of agreement were used to compare Pmsa with Pms-Insp. Bias, coefficient of variance (COV), precision and limits of agreement (LOA) were calculated. Proportional bias was assessed with linear regression. A high degree of inter-method reliability was found between Pmsa and Pms-Insp (ICC 0.89; 95%CI 0.72-0.96, p = 0.01) in 18 patients. Pmsa and Pms-Insp differed not significantly (11.9 mmHg, IQR 9.8-13.4 vs. 12.7 mmHg, IQR 10.5-14.4, p = 0.38). Bias was -0.502 ± 1.90 mmHg (p = 0.277). COV was 4% with LOA -4.22 - 3.22 mmHg without proportional bias. Conversion coefficient Pmsa âž” Pms-Insp was 0.94. This assessment of agreement demonstrates that the measures Pms-Insp and the computerized Pmsa-algorithm are interchangeable (bias -0.502 ± 1.90 mmHg with conversion coefficient 0.94). The choice of Pmsa is straightforward, it is non-interventional and available continuously at the bedside in contrast to Pms-Insp which is interventional and calculated off-line. Further studies should be performed to determine the place of Pmsa in the circulatory management of critically ill patients. ( www.clinicaltrials.gov ; TRN NCT04202432, release date 16-12-2019; retrospectively registered).Clinical Trial Registration www.ClinicalTrials.gov , TRN: NCT04202432, initial release date 16-12-2019 (retrospectively registered).

Intelligent checklists improve checklist compliance in the intensive care unit: a prospective before-and-after mixed-method study.

BACKGROUND: We examined whether a context and process-sensitive 'intelligent' checklist increases compliance with best practice compared with a paper checklist during intensive care ward rounds. METHODS: We conducted a single-centre prospective before-and-after mixed-method trial in a 35 bed medical and surgical ICU. Daily ICU ward rounds were observed during two periods of 8 weeks. We compared paper checklists (control) with a dynamic (digital) clinical checklist (DCC, intervention). The primary outcome was compliance with best clinical practice, measured as the percentages of checked items and unchecked critical items. Secondary outcomes included ICU stay and the usability of digital checklists. Data are presented as median (interquartile range). RESULTS: Clinical characteristics and severity of critical illness were similar during both control and intervention periods of study. A total of 36 clinicians visited 197 patients during 352 ward rounds using the paper checklist, compared with 211 patients during 366 ward rounds using the DCC. Per ICU round, a median of 100% of items (94.4-100.0) were completed by DCC, compared with 75.1% (66.7-86.4) by paper checklist (P=0.03). No critical items remained unchecked by the DCC, compared with 15.4% (8.3-27.3) by the paper checklist (P=0.01). The DCC was associated with reduced ICU stay (1 day [1-3]), compared with the paper checklist (2 days [1-4]; P=0.05). Usability of the DCC was judged by clinicians to require further improvement. CONCLUSIONS: A digital checklist improved compliance with best clinical practice, compared with a paper checklist, during ward rounds on a mixed ICU. CLINICAL TRIAL REGISTRATION: NCT03599856.

Acute isotonic hyponatremia after single dose histidine-tryptophan-ketoglutarate cardioplegia: an observational study.

INTRODUCTION: Histidine-tryptophan-ketoglutarate cardioplegia is used for prolonged myocardial protection in complex cardiac surgery. Administration leads to acute hyponatremia in a majority of patients, because of its low sodium concentration (15 mmol/L). However, histidine-tryptophan-ketoglutarate solution's osmolality is slightly hypertonic (310 mOsm/kg). Hypothesized was that acute isotonic hyponatremia will be induced, which does not need to be corrected with hypertonic saline. METHODS: Cardiac surgery patients who received histidine-tryptophan-ketoglutarate cardioplegia were included in this prospective single center study. Serial blood samples were taken from each patient at five different time points: after induction of anesthesia (T1) and 10 minutes (T2), 6 hours (T3), 12 hours (T4), and 18 hours (T5) after administration of histidine-tryptophan-ketoglutarate cardioplegia, respectively. Blood samples were analyzed for sodium concentration, osmolality, and acid-base balance. RESULTS: Twenty-five patients were included. Median blood sodium levels decreased from 140 [138-141] at T1 to 128 [125-130] mmol/L at T2 (p < 0.001). At T3, T4, and T5, median blood sodium concentrations were 136 [134-138], 139 [137-140], and 140 [137-142] mmol/L, respectively. Median osmolality was 289 [286-293] at T1 and increased to 296 [291-299] mOsm/kg (p < 0.001) at T2. At T3, T4, and T5, osmolality was 298 [292-302], 298 [294-304], and 300 [297-306] mOsm/kg, respectively. Median pH decreased from 7.38 [7.36-7.40] at T1 to 7.30 [7.27-7.32] at T2 (p < 0.001). CONCLUSION: Administration of histidine-tryptophan-ketoglutarate cardioplegia during cardiac surgery leads to acute moderate to severe isotonic hyponatremia, which resolves spontaneously in the first 18 hours perioperatively. Correction with hypertonic saline is not necessary.

Fully automated postoperative ventilation in cardiac surgery patients: a randomised clinical trial.

BACKGROUND: Ensuring that lung-protective ventilation is achieved at scale is challenging in perioperative practice. Fully automated ventilation may be more effective in delivering lung-protective ventilation. Here, we compared automated lung-protective ventilation with conventional ventilation after elective cardiac surgery in haemodynamically stable patients. METHODS: In this single-centre investigator-led study, patients were randomly assigned at the end of cardiac surgery to receive either automated (adaptive support ventilation) or conventional ventilation. The primary endpoint was the proportion of postoperative ventilation time characterised by exposure to predefined optimal, acceptable, and critical (injurious) ventilatory parameters in the first three postoperative hours. Secondary outcomes included severe hypoxaemia (Spo2 <85%) and resumption of spontaneous breathing. Data are presented as mean (95% confidence intervals [CIs]). RESULTS: We randomised 220 patients (30.4% females; age: 62-76 yr). Subjects randomised to automated ventilation (n=109) spent a 29.7% (95% CI: 22.1-37.4) higher mean proportion of postoperative ventilation time receiving optimal postoperative ventilation after surgery (P<0.001) compared with subjects receiving conventional postoperative ventilation (n=111). Automated ventilation also reduced the proportion of postoperative ventilation time that subjects were exposed to injurious ventilatory settings by 2.5% (95% CI: 1-4; P=0.003). Severe hypoxaemia was less likely in subjects randomised to automated ventilation (risk ratio: 0.26 [0.22-0.31]; P<0.01). Subjects resumed spontaneous breathing more rapidly when randomised to automated ventilation (hazard ratio: 1.38 [1.05-1.83]; P=0.03). CONCLUSIONS: Fully automated ventilation in haemodynamically stable patients after cardiac surgery optimised lung-protective ventilation during postoperative ventilation, with fewer episodes of severe hypoxaemia and an accelerated resumption of spontaneous breathing. CLINICAL TRIAL REGISTRATION: NCT03180203.

Impact of the Advanced Practice Provider in Adult Critical Care: A Systematic Review and Meta-Analysis.

OBJECTIVES: To evaluate the effects on quality and efficiency of implementation of the advanced practice provider in critical care. DATA SOURCES: PubMed, Embase, The Cochrane Library, and CINAHL were used to extract articles regarding advanced practice providers in critical care. STUDY SELECTION: Articles were selected when reporting a comparison between advanced practice providers and physician resident/fellows regarding the outcome measures of mortality, length of stay, or specific tasks. Descriptive studies without comparison were excluded. The methodological quality of the included studies was rated using the Newcastle-Ottawa scale. The agreement between the reviewers was assessed with Cohen's kappa. A meta-analysis was constructed on mortality and length of stay. DATA EXTRACTION AND SYNTHESIS: One-hundred fifty-six studies were assessed by full text. Thirty comparative cohort studies were selected and analyzed. These compared advanced practice providers with physician resident/fellows. All studies comprised adult intensive care. Most of the included studies showed a moderate to good quality. Over time, the study designs advanced from retrospective designs to include prospective and comparative designs. DATA SYNTHESIS: Four random effects meta-analyses on length of stay and mortality were constructed from the available studies. These meta-analyses showed no significant difference between performance of advanced practice providers on the ICU and physician residents/fellows on the ICU, suggesting the quality of care of both groups was equal. Mean difference for length of stay on the ICU was 0.34 (95% CI, -0.31 to 1.00; I = 99%) and for in hospital length of stay 0.02 (95% CI, -0.85 to 0.89; I = 91%); whereas the odds ratio for ICU mortality was 0.98 (95% CI, 0.81-1.19; I = 37.3%) and for hospital mortality 0.92 (95% CI, 0.79-1.07; I = 28%). CONCLUSIONS: This review and meta-analysis shows no differences between acute care given by advanced practice providers compared with physician resident/fellows measured as length of stay or mortality. However, advanced practice providers might add value to care in several other ways, but this needs further study.

Impact of postoperative renal replacement therapy on long-term outcome after cardiac surgery increases with age.

BACKGROUND AND AIM OF THE STUDY: In the present study, we investigated the survival of patients who received postoperative renal replacement therapy (RRT) after cardiac surgery. We specifically focused on factors predicting long-term outcome in elderly patients. METHODS: Data of all patients that received unintentional renal replacement therapy following cardiac surgery between 2004 and 2010 were analyzed. Logistic- and Cox regression analyses were performed to detect the predictors of early and late mortality, respectively. RESULTS: During the study period, 11,899 patients underwent cardiac surgery in our center. Post-operative RRT was performed in 138 patients (1.2%). In this group of patients, 30-day mortality included 72 patients (52%) and the total overall mortality included 107 patients (77.5%). Regression analyses revealed that age predicted 30-day mortality (odds ratio = 1.08 [1.03 to 1.12]) as well as late mortality (odds ratio = 1.05 [1.02 to 1.07]. CONCLUSIONS: Patients requiring RRT after cardiac surgery have a poor prognosis with a high mortality. Older age predicted both 30-day and late mortality in these patients.

Effects of decontamination of the oropharynx and intestinal tract on antibiotic resistance in ICUs: a randomized clinical trial.

IMPORTANCE: Selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) are prophylactic antibiotic regimens used in intensive care units (ICUs) and associated with improved patient outcome. Controversy exists regarding the relative effects of both measures on patient outcome and antibiotic resistance. OBJECTIVE: To compare the effects of SDD and SOD, applied as unit-wide interventions, on antibiotic resistance and patient outcome. DESIGN, SETTING, AND PARTICIPANTS: Pragmatic, cluster randomized crossover trial comparing 12 months of SOD with 12 months of SDD in 16 Dutch ICUs between August 1, 2009, and February 1, 2013. Patients with an expected length of ICU stay longer than 48 hours were eligible to receive the regimens, and 5881 and 6116 patients were included in the clinical outcome analysis for SOD and SDD, respectively. INTERVENTIONS: Intensive care units were randomized to administer either SDD or SOD. MAIN OUTCOMES AND MEASURES: Unit-wide prevalence of antibiotic-resistant gram-negative bacteria. Secondary outcomes were day-28 mortality, ICU-acquired bacteremia, and length of ICU stay. RESULTS: In point-prevalence surveys, prevalences of antibiotic-resistant gram-negative bacteria in perianal swabs were significantly lower during SDD compared with SOD; for aminoglycoside resistance, average prevalence was 5.6% (95% CI, 4.6%-6.7%) during SDD and 11.8% (95% CI, 10.3%-13.2%) during SOD (P < .001). During both interventions the prevalence of rectal carriage of aminoglycoside-resistant gram-negative bacteria increased 7% per month (95% CI, 1%-13%) during SDD (P = .02) and 4% per month (95% CI, 0%-8%) during SOD (P = .046; P = .40 for difference). Day 28-mortality was 25.4% and 24.1% during SOD and SDD, respectively (adjusted odds ratio, 0.96 [95% CI, 0.88-1.06]; P = .42), and there were no statistically significant differences in other outcome parameters or between surgical and nonsurgical patients. Intensive care unit-acquired bacteremia occurred in 5.9% and 4.6% of the patients during SOD and SDD, respectively (odds ratio, 0.77 [95% CI, 0.65-0.91]; P = .002; number needed to treat, 77). CONCLUSIONS AND RELEVANCE: Unit-wide application of SDD and SOD was associated with low levels of antibiotic resistance and no differences in day-28 mortality. Compared with SOD, SDD was associated with lower rectal carriage of antibiotic-resistant gram-negative bacteria and ICU-acquired bacteremia but a more pronounced gradual increase in aminoglycoside-resistant gram-negative bacteria. TRIAL REGISTRATION: trialregister.nlIdentifier: NTR1780.

Advanced practice providers versus medical residents as leaders of rapid response teams: A 12-month retrospective analysis.

PURPOSE: In a time of worldwide physician shortages, the advanced practice providers (APPs) might be a good alternative for physicians as the leaders of a rapid response team. This retrospective analysis aimed to establish whether the performance of APP-led rapid response teams is comparable to the performance of rapid response teams led by a medical resident of the ICU. MATERIAL AND METHODS: In a retrospective single-center cohort study, the electronic medical record of a tertiary hospital was queried during a 12-months period to identify patients who had been visited by our rapid response team. Patient- and process-related outcomes of interventions of rapid response teams led by an APP were compared with those of teams led by a medical resident using various parameters, including the MAELOR tool, which measures the performance of a rapid response team. RESULTS: In total, 179 responses of the APP-led teams were analyzed, versus 275 responses of the teams led by a resident. Per APP, twice as many calls were handled than per resident. Interventions of teams led by APPs, and residents did not differ in number of admissions (p = 0.87), mortality (p = 0.8), early warning scores (p = 0.2) or MAELOR tool triggering (p = 0.19). Both groups scored equally on time to admission (p = 0.67) or time until any performed intervention. CONCLUSION: This retrospective analysis showed that the quality of APP-led rapid response teams was similar to the quality of teams led by a resident. These findings need to be confirmed by prospective studies with balanced outcome parameters.

Advanced Practice Providers as Leaders of a Rapid Response Team: A Prospective Cohort Study.

In view of the shortage of medical staff, the quality and continuity of care may be improved by employing advanced practice providers (APPs). This study aims to assess the quality of these APPs in critical care. In a large teaching hospital, rapid response team (RRT) interventions led by APPs were assessed by independent observers and intensivists and compared to those led by medical residents MRs. In addition to mortality, the MAELOR tool (assessment of RRT intervention), time from RRT call until arrival at the scene and time until completion of clinical investigations were assessed. Process outcomes were assessed with the crisis management skills checklist, the Ottawa global rating scale and the Mayo high-performance teamwork scale. The intensivists assessed performance with the handoff CEX recipient scale. Mortality, MAELOR tool, time until arrival and clinical investigation in both groups were the same. Process outcomes and performance observer scores were also equal. The CEX recipient scores, however, showed differences between MRs and APPs that increased with experience. Experienced APPs had significantly better situational awareness, better organization, better evaluations and better judgment than MRs with equal experience (p < 0.05). This study shows that APPs perform well in leading an RRT and may provide added quality over a resident. RRTs should seriously consider the deployment of APPs instead of junior clinicians.

Effect of Automated Closed-loop ventilation versus convenTional VEntilation on duration and quality of ventilation in critically ill patients (ACTiVE) - study protocol of a randomized clinical trial.

BACKGROUND: INTELLiVENT-Adaptive Support Ventilation (ASV) is a fully automated closed-loop mode of ventilation for use in critically ill patients. Evidence for benefit of INTELLiVENT-ASV in comparison to ventilation that is not fully automated with regard to duration of ventilation and quality of breathing is largely lacking. We test the hypothesis that INTELLiVENT-ASV shortens time spent on a ventilator and improves the quality of breathing. METHODS: The "Effects of Automated Closed-loop VenTilation versus Conventional Ventilation on Duration and Quality of Ventilation" (ACTiVE) study is an international, multicenter, two-group randomized clinical superiority trial. In total, 1200 intensive care unit (ICU) patients with an anticipated duration of ventilation of > 24 h will be randomly assigned to one of the two ventilation strategies. Investigators screen patients aged 18 years or older at start of invasive ventilation in the ICU. Patients either receive automated ventilation by means of INTELLiVENT-ASV, or ventilation that is not automated by means of a conventional ventilation mode. The primary endpoint is the number of days free from ventilation and alive at day 28; secondary endpoints are quality of breathing using granular breath-by-breath analysis of ventilation parameters and variables in a time frame of 24 h early after the start of invasive ventilation, duration of ventilation in survivors, ICU and hospital length of stay (LOS), and mortality rates in the ICU and hospital, and at 28 and 90 days. DISCUSSION: ACTiVE is one of the first randomized clinical trials that is adequately powered to compare the effects of automated closed-loop ventilation versus conventional ventilation on duration of ventilation and quality of breathing in invasively ventilated critically ill patients. The results of ACTiVE will support intensivist in their choices regarding the use of automated ventilation. TRIAL REGISTRATION: ACTiVE is registered in clinicaltrials.gov (study identifier: NCT04593810 ) on 20 October 2020.

[Limited use of extracorporeal CO2 removal]. / Extracorporele CO2-verwijdering beperkt toegepast.

Extracorporeal CO2 removal is a low-flow technique in which a pump, a membrane lung and sweepgas, remove CO2 from a patient. This facilitates protective, invasive ventilation in patients with severe hypercapnia, for example in ARDS. Although the physiological concept has been proven many times, the indication area has remained limited to only seriously ill, highly complex patients. Because of this and the relatively high number of contraindications and complications, the use of this technique is limited to Intensive Care.

Treatment of hypophosphatemia in the intensive care unit: a review.

INTRODUCTION: Currently no evidence-based guideline exists for the approach to hypophosphatemia in critically ill patients. METHODS: We performed a narrative review of the medical literature to identify the incidence, symptoms, and treatment of hypophosphatemia in critically ill patients. Specifically, we searched for answers to the questions whether correction of hypophosphatemia is associated with improved outcome, and whether a certain treatment strategy is superior. RESULTS: Incidence: hypophosphatemia is frequently encountered in the intensive care unit; and critically ill patients are at increased risk for developing hypophosphatemia due to the presence of multiple causal factors. SYMPTOMS: hypophosphatemia may lead to a multitude of symptoms, including cardiac and respiratory failure. TREATMENT: hypophosphatemia is generally corrected when it is symptomatic or severe. However, although multiple studies confirm the efficacy and safety of intravenous phosphate administration, it remains uncertain when and how to correct hypophosphatemia. OUTCOME: in some studies, hypophosphatemia was associated with higher mortality; a paucity of randomized controlled evidence exists for whether correction of hypophosphatemia improves the outcome in critically ill patients. CONCLUSIONS: Additional studies addressing the current approach to hypophosphatemia in critically ill patients are required. Studies should focus on the association between hypophosphatemia and morbidity and/or mortality, as well as the effect of correction of this electrolyte disorder.

Physicians' and nurses' opinions on selective decontamination of the digestive tract and selective oropharyngeal decontamination: a survey.

INTRODUCTION: Use of selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) in intensive care patients has been controversial for years. Through regular questionnaires we determined expectations concerning SDD (effectiveness) and experience with SDD and SOD (workload and patient friendliness), as perceived by nurses and physicians. METHODS: A survey was embedded in a group-randomized, controlled, cross-over multicenter study in the Netherlands in which, during three 6-month periods, SDD, SOD or standard care was used in random order. At the end of each study period, all nurses and physicians from participating intensive care units received study questionnaires. RESULTS: In all, 1024 (71%) of 1450 questionnaires were returned by nurses and 253 (82%) of 307 by physicians. Expectations that SDD improved patient outcome increased from 71% and 77% of respondents after the first two study periods to 82% at the end of the study (P = 0.004), with comparable trends among nurses and physicians. Nurses considered SDD to impose a higher workload (median 5.0, on a scale from 1 (low) to 10 (high)) than SOD (median 4.0) and standard care (median 2.0). Both SDD and SOD were considered less patient friendly than standard care (medians 4.0, 4.0 and 6.0, respectively). According to physicians, SDD had a higher workload (median 5.5) than SOD (median 5.0), which in turn was higher than standard care (median 2.5). Furthermore, physicians graded patient friendliness of standard care (median 8.0) higher than that of SDD and SOD (both median 6.0). CONCLUSIONS: Although perceived effectiveness of SDD increased as the trial proceeded, both among physicians and nurses, SOD and SDD were, as compared to standard care, considered to increase workload and to reduce patient friendliness. Therefore, education about the importance of oral care and on the effects of SDD and SOD on patient outcomes will be important when implementing these strategies. TRIAL REGISTRATION: ISRCTN35176830.

Procedures Performed by Advanced Practice Providers Compared With Medical Residents in the ICU: A Prospective Observational Study.

To assess the frequency and safety of procedures performed by advanced practice providers and medical residents in a mixed-bed ICU. DESIGN: A prospective observational study where consecutive invasive procedures were studied over a period of 1 year and 8 months. The interventions were registered anonymously in an online database. Endpoints were success rate at first attempt, number of attempts, complications, level of supervision, and teamwork. SETTING: A 33-bedded mixed ICU. SUBJECTS: Advanced practice providers and medical residents. INTERVENTIONS: Registration of the performance of tracheal intubation, central venous and arterial access, tube thoracostomies, interhospital transportation, and electrical cardioversion. MEASUREMENT AND MAIN RESULTS: A full-time advanced practice provider performed an average of 168 procedures and a medical resident an average of 68. The advanced practice provider inserted significant more radial, brachial, and femoral artery catheters (66% vs 74%, p = 0.17; 15% vs 12%, p = 0.14; 18% vs 14%, p = 0.14, respectively). The median number of attempts needed to successfully insert an arterial catheter was lower, and the success rate at first attempt was higher in the group treated by advanced practice providers (1.30 [interquartile range, 1-1.82] vs 1.53 [interquartile range, 1-2.27], p < 0.0001; and 71% vs 54%, p < 0.0001). The advanced practice providers inserted more central venous catheters (247 vs 177) with a lower median number of attempts (1.20 [interquartile range, 1-1.71] vs 1.33 [interquartile range, 1-1.86]) and a higher success rate at first attempt (81% vs 70%; p < 0.005). The number of intubations by advanced practice providers was 143 and by medical residents was 115 with more supervision by the advanced practice provider (10% vs 0%; p = 0.01). Team performance, as reported by nursing staff, was higher during advanced practice provider procedures compared with medical resident procedures (median, 4.85 [interquartile range, 4.85-5] vs 4.73 [interquartile range, 4.22-5]). Other procedures were also more often performed by advanced practice providers. The complication rate in the advanced practice provider-treated patient group was lower than that in the medical resident group. CONCLUSIONS: Advanced practice providers in critical care performed procedures safe and effectively when compared with medical residents. Advanced practice providers appear to be a valuable addition to the professional staff in critical care when it comes to invasive procedures.

Characteristics and outcome of patients admitted to the ICU following bariatric surgery.

BACKGROUND: This study evaluates the characteristics and outcome of patients admitted to the ICU following bariatric surgery. METHODS: Descriptive study. A review of a prospectively collected database of our bariatric surgery procedures from 2003 until 2006 was performed. The study was performed in a tertiary level, mixed medical and surgical, adult ICU of a large referral hospital. RESULTS: Of the 265 patients undergoing bariatric surgery (mainly gastroplasties and Roux-en-Y gastric bypasses), 22 (8%) were admitted to the ICU, of which 14 (64%) were on an elective basis and eight (36%) emergently. Hospital length of stay (LOS) for all patients was 4.5 days and ICU LOS was 12 days. Most elective admissions were standard procedure because of obstructive sleep apnea (OSA) or super obesity, with a median ICU stay of 1 day. Emergent admissions were mainly done after emergent surgery due to surgical complications and had a median ICU stay of 8 days. Only two patients needed intensive care for more than 3 days. There were no deaths during ICU stay. CONCLUSIONS: The ICU admission rate in our report is 8%. This study showed that 32 ICU days are needed per 100 diverse bariatric procedures. Most patients are admitted to the ICU for only a few days and the majority of the admissions is planned.

Determinants of tidal volumes with adaptive support ventilation: a multicenter observational study.

INTRODUCTION: In the present study, we investigated the behavior of adaptive support ventilation (ASV) in patients after cardiothoracic surgery. We determined tidal volumes (Vt) and factors that influence Vt with this mode of microprocessor-controlled mechanical ventilation (MV). METHODS: This was a prospective, multicenter, observational study in three Dutch intensive care units over a 5-mo period. MV data were collected during steady-state after arrival in the intensive care unit. RESULTS: Data were collected for 346 consecutive patients after cardiothoracic surgery: 262 patients weaned with ASV, and 84 patients weaned with pressure-controlled/pressure-support MV. With ASV the mean (+/- sd) Vt expressed per kilogram actual body weight was 7.1 +/- 1.6 mL. Expressed per kilogram ideal body weight (IBW), Vt was 8.3 +/- 1.5 mL. In patients with a correctly set body weight (SBW) (i.e., the IBW), Vt was 8.1 +/- 1.4 mL/kg. With pressure-controlled/pressure-support-MV Vt was 7.3 +/- 1.4 mL/kg IBW (P < 0.001 vs ASV). Multivariate logistic regression analysis showed Vt with ASV to be dependent on only two parameters: respiratory rate and the correctness of SBW. CONCLUSIONS: Vt with ASV seems to be dependent on two parameters: respiratory rate and the correctness of SBW. The first factor is not clinically important because respiratory rate is automatically chosen by the microprocessor. The second factor is clinically important because it is the only factor that can be influenced by the operator. Our data show the importance of setting the correct weight with ASV. With ASV, Vt are >8 mL/kg IBW in a substantial number of patients. Randomized clinical trials should be performed to compare ASV with other ventilation modes.

Epidemiology of acute lung injury and acute respiratory distress syndrome in The Netherlands: a survey.

BACKGROUND: The characteristics, incidence and risk factors for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) may depend on definitions and geography. METHODS: A prospective, 3-day point-prevalence study was performed by a survey of all intensive care units (ICU) in the Netherlands (n=96). Thirty-six ICU's responded (37%), reporting on 266 patients, of whom 151 were mechanically ventilated. The questionnaire included criteria and potential risk factors for ALI/ARDS, according to the North American-European Consensus Conference (NAECC) or the lung injury score (LIS>or=2.5). RESULTS: Agreement between definitions was fair (kappa 0.31-0.42, P=0.001). ALI/ARDS was characterized, regardless of definition, by radiographic densities, low oxygenation ratios, high inspiratory O(2) and airway pressure requirements. Depending on definitions, ALI and ARDS accounted for about 12-33% and 7-9% of ICU admissions per year, respectively, constituting 21-58% (ALI) and 13-16% (ARDS) of all mechanically ventilated patients. The annual incidences of ALI and ARDS are 29.3 (95%CI 18.4-40.1) and 24.0 (95%CI 14.2-33.8) by NAECC, respectively, and are, respectively, 83.6 (95%CI 65.3-101.9) and 20.9 (95%CI 11.7-30.1) by LIS per 100,000. Risk factors for ALI/ARDS were aspiration, pneumonia, sepsis and chronic alcohol abuse (the latter only by NAECC). CONCLUSION: The effect of definitions of ALI/ARDS on mechanical ventilation in the Netherlands is small. Nevertheless, the incidence of ALI/ARDS may be higher than in other European countries but lower than in the USA, and the incidence of ALI by LIS may overestimate compared to that by NAECC. Aspiration, pneumonia, sepsis and chronic alcohol abuse are major risk factors, largely independent of definitions.

Clinical outcome of immunonutrition in a heterogeneous intensive care population.

OBJECTIVE: To study the effect of a high-protein enteral formula enriched with arginine, glutamine, and antioxidants and containing omega3 fatty acids and a mixture of fibers, on the clinical outcome of a heterogeneous intensive care (ICU) population. DESIGN AND SETTING: A randomized, prospective, double blind, controlled, two-center clinical trial in two intensive care units in The Netherlands. PATIENTS AND PARTICIPANTS: A total of 597 adult ICU patients expected to require enteral tube feeding for more than 2 days were randomized to receive immunonutrition or an isocaloric control formula. INTERVENTIONS: Patients received either the immunonutrition or the control feed. MEASUREMENTS AND RESULTS: Intention-to-treat and per-protocol analyses showed no statistically significant difference in clinical outcome parameters between the two groups. Results of the intention-to-treat analysis in control vs. immunonutrition were: median ICU length of stay in days, 8.0 (IQR 5.0-16.0) vs. 7.0 (4.0-14.0); median hospital length of stay in days, 20.0 (IQR 10.0-34.0) vs. 20.0 (10.0-35.0); median days of ventilation, 6.0 (IQR 3.0-12.0) vs. 6.0 (IQR 3.0-12.0); ICU mortality, 26.8% vs. 28.2%; in-hospital mortality, 36.4% vs. 38.5%; infectious complications, 41.7% vs. 43.0%. CONCLUSIONS: The results of this largest randomized, controlled trial found that in the general ICU population immunonutrition has no beneficial effect on clinical outcome parameters. These results are consistent with the literature that is currently available.