K. Espersen

Randomized evaluation of pulse oximetry in 20,802 patients. II: Perioperative events and postoperative complications

BackgroundThe authors describe the effect of pulse oximetry monitoring on the frequency of unanticipated perl-operative events, changes In patient care, and the rate of postoperative complications in a prospective randomized study. MethodsThe study Included 20,802 surgical patients in Denmark randomly assigned to be monitored or not with pulse oximetry In the operating room (OR) and postanesthesla care unit (PACU). ResultsDuring anesthesia and in the PACU, significantly more patients in the oximetry group had at least one respiratory event than did the control patients. This was the result of a 19-fold Increase in the incidence of diagnosed hypoxemia in the oximetry group than in the control group in both the OR and PACU (P < 0.00001). In the OR, cardiovascular events were observed In a similar number of patients in both groups, except myocardial ischemia (as denned by angina or ST-seg-ment depression), which was detected in 12 patients in the oximetry group and In 26 patients in the control group (P < 0.03). Several changes in PACU care were observed in association with the use of pulse oximetry. These Included higher flow rate of supplemental oxygen (P < 0.00001), Increased use of supplemental oxygen at discharge (P < 0.00001), and increased use of naloxone (P < 0.02). The rate of changes in patient care as a consequence of the oximetry monitoring Increased as the American Society of Anesthesiologists physical status worsened (P < 0.00001). One or more postoperative complications occurred in 10% of the patients in the oximetry group and in 9.4% in the control group (difference not significant). The two groups did not differ significantly in cardiovascular, respiratory, neurologic, or Infectious complications. The duration of hospital stay was a median of 5 days in both groups (difference not significant). An equal number of in-hospital deaths were registered in the two groups. Questionnaires, completed by the anesthesiologists at the five partlc

Procalcitonin increase in early identification of critically ill patients at high risk of mortality.

Objective:To investigate day-by-day changes in procalcitonin and maximum obtained levels as predictors of mortality in critically ill patients. Design:Prospective observational cohort study. Setting:Multidisciplinary intensive care unit at Rigshospitalet, Copenhagen University Hospital, a tertiary reference hospital in Denmark. Patients:Four hundred seventy-two patients with diverse comorbidity and age admitted to this intensive care unit. Interventions:Equal in all patient groups: antimicrobial treatment adjusted according to the procalcitonin level. Measurements and Main Results:Daily procalcitonin measurements were carried out during the study period as well as measurements of white blood cell count and C-reactive protein and registration of comorbidity. The primary end point was all-cause mortality in a 90-day follow-up period. Secondary end points were mortality during the stay in the intensive care unit and in a 30-day follow-up period. A total of 3,642 procalcitonin measurements were evaluated in 472 critically ill patients. We found that a high maximum procalcitonin level and a procalcitonin increase for 1 day were independent predictors of 90-day all-cause mortality in the multivariate Cox regression analysis model. C-reactive protein and leukocyte increases did not show these qualities. The adjusted hazard ratio for procalcitonin increase for 1 day was 1.8 (95% confidence interval 1.3–2.7). The relative risk for mortality in the intensive care unit for patients with an increasing procalcitonin was as follows: after 1 day increase, 1.8 (95% confidence interval 1.4–2.4); after 2 days increase, 2.2 (95% confidence interval 1.6–3.0); and after 3 days increase: 2.8 (95% confidence interval 2.0–3.8). Conclusions:A high maximum procalcitonin level and a procalcitonin increase for 1 day are early independent predictors of all-cause mortality in a 90-day follow-up period after intensive care unit admission. Mortality risk increases for every day that procalcitonin increases. Levels or increases of C-reactive protein and white blood cell count do not seem to predict mortality.

Randomized evaluation of pulse oximetry in 20,802 patients: I. Design, demography, pulse oximetry failure rate, and overall complication rate.

BackgroundAlthough pulse oximetry is currently In widespread use, there are few data documenting Improvement in patient outcome as a result of the use of oximetry. The authors describe the study design, patient demographic findings, data validation, pulse oximetry failure rate, and overall postoperative complication rates in the first large prospective randomized multicenter clinical trial on perloperative pulse oximetry monitoring. Methods;In five Danish hospitals, by random assignment, monitoring did or did not include pulse oximetry for patients 18 yr of age and older, whether scheduled for elective or emergency operations, or for regional or general anesthesia, except during cardiac and neurosurgical procedures. Operational definitions were established for perioperative events and postoperative complications. The data were collected preoperatively, during anesthesia, in the postanesthesia care unit, and until the day of discharge from the hospital or the seventh postoperative day. ResultsOf 20,802 patients, 10,312 were assigned to the oximetry group and 10,490, to the control group. In general, the demographic data, patient factors, and anesthetic agents used were distributed evenly. A slight intergroup difference was found in the distribution of age, duration of surgery, some types of surgery, and some types of anesthesia. The total failure rate of the oximetry was 2.5%, but it increased to 7.2% in patients with American Society of Anesthesiologists physical status 4 (P < 0.00001). In 14.9% of the patients, one or more events occurred in the operating room and 13.5% in the postanesthesia care unit. The overall postoperative complication rate was 9.7%. The total rates of cardiovascular and respiratory complications were 2.78% and 3.50%, respectively. Within the

Provision of protein and energy in relation to measured requirements in intensive care patients

BACKGROUND & AIMS Adequacy of nutritional support in intensive care patients is still a matter of investigation. This study aimed to relate mortality to provision, measured requirements and balances for energy and protein in ICU patients. DESIGN Prospective observational cohort study of 113 ICU patients in a tertiary referral hospital. RESULTS Death occurred earlier in the tertile of patients with the lowest provision of protein and amino acids. The results were confirmed in Cox regression analyses which showed a significantly decreased hazard ratio of death with increased protein provision, also when adjusted for baseline prognostic variables (APACHE II, SOFA scores and age). Provision of energy, measured resting energy expenditure or energy and nitrogen balance was not related to mortality. The possible cause-effect relationship is discussed after a more detailed analysis of the initial part of the admission. CONCLUSION In these severely ill ICU patients, a higher provision of protein and amino acids was associated with a lower mortality. This was not the case for provision of energy or measured resting energy expenditure or energy or nitrogen balances. The hypothesis that higher provision of protein improves outcome should be tested in a randomised trial.

The early IL-6 and IL-10 response in trauma is correlated with injury severity and mortality

Background: Trauma has previously been shown to influence interleukin (IL)‐6 and IL‐10 levels, but the association of injury severity and mortality with IL‐6 and IL‐10 responses in the early phase of accidental trauma remains to be investigated. We wished to describe serum levels of IL‐6 and IL‐10 in the first 24 h after trauma and to assess the relationship with severity of injury and mortality.

Hypocoagulability, as evaluated by thrombelastography, at admission to the ICU is associated with increased 30-day mortality.

Thrombelastography (TEG), a cell-based whole blood assay, may better reflect haemostatic competence than conventional coagulation assays and this was therefore evaluated including the clot forming parameters: R, angle and maximal amplitude in patients at ICU admission. This was a prospective, observational study of patients admitted to a general ICU at a tertiary care university hospital with an expected stay of more than 24 h. Blood samples for TEG and standard coagulation analysis were obtained at admission. The APACHE II and sequential organ failure assessment (SOFA) scores and 30-day mortality were recorded. At ICU admission, 106 patients (42%) showed hypocoagulability as evaluated by TEG and these patients had higher first day SOFA score (P < 0.0001) and higher 30-days (42 vs. 13%, P < 0.0001) mortality than patients presenting with a normal TEG. In 30-day survivors, admission platelet count (P = 0.05), angle (P < 0.001) and maximal amplitude (P = 0.001) were higher and R decreased (P = 0.0013) compared with nonsurvivors. Hypocoagulability at admission as evaluated by TEG was an independent risk factor for 30-day mortality [adjusted odds ratio (OR) 3.5; 95% confidence interval (CI) 1.7–7.1]. Hypocoagulability as evaluated by TEG was frequent at admission in general ICU patients and associated with a higher rate of ventilator treatment, higher rate of renal replacement therapy and a higher use of blood products. Hypocoagulability is an independent risk factor for 30-day mortality.

Dopamine, Dobutamine, and Dopexamine A Comparison of Renal Effects in Unanesthetized Human Volunteers

BackgroundRecently, dopexamine(DX), which acts via adrenergic (β2and dopaminergic DA1 receptors, has been introduced in the treatment of low cardiac output states. However, the renal effects of DX have not been compared to those produced by equipotent inotropic doses of dopamine (DA), which predominantly stimulates DA1 and DA2 receptors, and of do-butamine (DB), which stimulates β, but not DA receptors. The current study tested the null hypothesis that, with equal increases in cardiac output, DX, DA, and DB would have similar effects on renal function. MethodsEach drug was given for 2 h on three different occasions to eight normal subjects in doses adjusted to produce a similar 30–35% Increase in cardiac output. Effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) were measured as renal clearances of l31I-hippuran and 99mTc-DTPA, respectively. Lithium clearance (CLI) was used as an Index of proximal tubular outflow. ResultsDoses of DA, DX, and DB were 2.90 ± 0.19, 1–00 ± 0.02, and 4.92 ± 0.40 μg · kg−1 · min−1 respectively. Dopamine and DX increased ERPF by 23% and 10%, respectively, whereas ERPF remained unchanged during DB. The Increase in ERPF was smaller during DX compared with DA. The GFR remained unchanged during DA and DB, but increased during DX (7%). The CLi Increased by 35% and 30% during DA and DX, respectively, but was not changed by DB. Calculated absolute proximal reabsorption rate (APR = GFR – CLi) decreased by 13% during DA, but remained unchanged during DB and DX. Dopamine Increased sodium clearance (CNa) by 103%, but the changes during DX and DB were not significant. Only DA decreased fractional distal reabsorption (FDRNa = 1 – CNa/CLi). ConclusionsThe findings are consistent with a specific, renal-vasodilating effect of DA and DX. However, in the current doses, this effect of DX was of lesser magnitude compared with that of DA. Only DA significantly Increased CNa, and the decreases In APR and FDRNa indicate that an effect on tubular reabsorption rate contributed to the natriuresis.

Retrospective evaluation of a decision support system for controlled mechanical ventilation

Management of mechanical ventilation in intensive care patients is complicated by conflicting clinical goals. Decision support systems (DSS) may support clinicians in finding the correct balance. The objective of this study was to evaluate a computerized model-based DSS for its advice on inspired oxygen fraction, tidal volume and respiratory frequency. The DSS was retrospectively evaluated in 16 intensive care patient cases, with physiological models fitted to the retrospective data and then used to simulate patient response to changes in therapy. Sensitivity of the DSS’s advice to variations in cardiac output (CO) was evaluated. Compared to the baseline ventilator settings set as part of routine clinical care, the system suggested lower tidal volumes and inspired oxygen fraction, but higher frequency, with all suggestions and the model simulated outcome comparing well with the respiratory goals of the Acute Respiratory Distress Syndrome Network from 2000. Changes in advice with CO variation of about 20% were negligible except in cases of high oxygen consumption. Results suggest that the DSS provides clinically relevant and rational advice on therapy in agreement with current ‘best practice’, and that the advice is robust to variation in CO.

Decision support of inspired oxygen fraction using a model of oxygen transport

Abstract Setting inspired oxygen fraction (FiO 2 ) is a complicated balance between ensuring adequate oxygenation and minimizing the risk of lung damage. This paper presents a retrospective test of a model-based decision support system (INVENT) for advising on FiO 2 levels in intensive care patients. Clinically determined FiO 2 levels and the resulting blood oxygenation are compared with INVENT determined FiO levels and model simulated blood oxygenation. The results indicate that INVENT can maintain an acceptable level of oxygenation using similar or more appropriate levels of FiO compared to clinical practice.

Minimal modeling of pulmonary gas exchange of oxygen and carbon dioxideΓçömodeling complexity required in intensive care patients

ESICM LIVES 2011 24th Annual Congress Berlin, Germany 1–5 October 2011 This supplement issue of the official ESICM/ESPNIC journal Intensive Care Medicine contains abstracts of scientific papers presented at the 24th Annual Congress of the European Society of Intensive Care Medicine. The abstracts appear in order of presentation from Monday 3 October to Wednesday 5 October 2011. The same abstract numbering is used in the Congress Final Programme. 24th ANNUAL CONGRESS, ICC—BERLIN–GERMANY, 1–5 OCTOBER 2011Background: Vγ9/Vδ2 T cells are a minor subset of T cells in human blood and differ from other T cells by their immediate responsiveness to microbes. Vγ9/Vδ2 T cells interact with monocytes and become activated by microbial-derived HMB-PP, an essential metabolite produced by a large range of pathogens, which in turn leads to substantial cytokine secretion and the generation of inflammatory response1. Objective: To investigate if infections caused by HMBPP+ve organisms carry higher risk of death in ICU patients. Methods: Retrospective analysis of data collected in the clinical information system of a university and a non-university hospital between 2009-10. Microbiology data was retrieved from the respective databases and paired with patient level data. Microbiologically significant infection was defined as either bacteremia or respiratory secretion cultures with organism concentration > 105 CFU with appropriate clinical manifestations. For statistical analysis Mann-Whitney U test and Chi-square test was used. Results: We identified 3186 patients with 409 clinically significant microbiology cultures. HMBPP+ve pathogens were identified in 227, HMBPP-ve in 182 occasions. Significantly higher ICU mortality was observed with HMBPP+ve infections 60/227 HMBPP+ve vs 33/182 HMBPP –ve, respectively p=0.047 APACHE II LOS Ventilator days Inotropic support (days) HMBPP+ve 18 (9) 7.9 (14) 3 (6) 1 (3) HMBPP-ve 16.5 (8) 6.9 (11) 3 (6) 0.5 (3) Data presented as median and (interquartile range) No significant differences in APACHE II, length of stay, length of advanced respiratory and cardiovascular support was observed. Conclusion: This report is the first to confirm that infection caused by HMBPP+ pathogens carries higher risk of death in ICU patients. This was not attribute to baseline differences as demonstrated by similar APACHE II scores in the HMBPP+ve and –ve group. The exact mechanism behind this phenomenon is unclear, but it has been postulated that a rapid and HMB-PP-dependent crosstalk between the patients Vγ9/Vδ2 T cells and autologous monocytes results in the immediate production of inflammatory mediators. Disproportionate monocyte-γδ T cell crosstalk may result in excessive production of inflammatory mediators, possibly explaining why episodes of HMB-PP+ve sepsis are associated with increased risk of death. Further studies are warranted to investigate this pathway.