Accuracy of a new transmittance-reflectance pulse oximetry sensor in critically ill neonates.

OBJECTIVE: To test the accuracy of a new pulse oximeter sensor based on transmittance and reflectance. This sensor makes transillumination of tissue unnecessary and allows measurements on the hand, forearm, foot, and lower limb. DESIGN: Prospective, open, nonrandomized criterion standard study. SETTING: Neonatal intensive care unit, tertiary care center. PATIENTS: Sequential sample of 54 critically ill neonates (gestational age 27 to 42 wks; postnatal age 1 to 28 days) with arterial catheters in place. MEASUREMENTS AND MAIN RESULTS: A total of 99 comparisons between pulse oximetry and arterial saturation were obtained. Comparison of femoral or umbilical arterial blood with transcutaneous measurements on the lower limb (n = 66) demonstrated an excellent correlation (r2 = .96). The mean difference was +1.44% +/- 3.51 (SD) % (range -11% to +8%). Comparison of the transcutaneous values with the radial artery saturation from the corresponding upper limb (n = 33) revealed a correlation coefficient of 0.94 with a mean error of +0.66% +/- 3.34% (range -6% to +7%). The mean difference between noninvasive and invasive measurements was least with the test sensor on the hand, intermediate on the calf and arm, and greatest on the foot. The mean error and its standard deviation were slightly larger for arterial saturation values < 90% than for values > or = 90%. CONCLUSION: Accurate pulse oximetry saturation can be acquired from the hand, forearm, foot, and calf of critically ill newborns using this new sensor.

Fractional hepatic de novo lipogenesis in healthy subjects during near-continuous oral nutrition and bed rest: a comparison with published data in artificially fed, critically ill patients.

BACKGROUND AND AIMS: In critically ill patients, fractional hepatic de novo lipogenesis increases in proportion to carbohydrate administration during isoenergetic nutrition. In this study, we sought to determine whether this increase may be the consequence of continuous enteral nutrition and bed rest. We, therefore, measured fractional hepatic de novo lipogenesis in a group of 12 healthy subjects during near-continuous oral feeding (hourly isoenergetic meals with a liquid formula containing 55% carbohydrate). In eight subjects, near-continuous enteral nutrition and bed rest were applied over a 10 h period. In the other four subjects, it was extended to 34 h. Fractional hepatic de novo lipogenesis was measured by infusing(13) C-labeled acetate and monitoring VLDL-(13)C palmitate enrichment with mass isotopomer distribution analysis. Fractional hepatic de novo lipogenesis was 3.2% (range 1.5-7.5%) in the eight subjects after 10 h of near continuous nutrition and 1.6% (range 1.3-2.0%) in the four subjects after 34 h of near-continuous nutrition and bed rest. This indicates that continuous nutrition and physical inactivity do not increase hepatic de novo lipogenesis. Fractional hepatic de novo lipogenesis previously reported in critically ill patients under similar nutritional conditions (9.3%) (range 5.3-15.8%) was markedly higher than in healthy subjects (P&lt;0.001). These data from healthy subjects indicate that fractional hepatic de novo lipogenesis is increased in critically ill patients.

Diagnostic accuracy of G-CSF, IL-8, and IL-1ra in critically ill children with suspected infection.

OBJECTIVE: To elucidate the diagnostic accuracy of granulocyte colony-stimulating factor (G-CSF), interleukin-8 (IL-8), and interleukin-1 receptor antagonist (IL-1ra) in identifying patients with sepsis among critically ill pediatric patients with suspected infection. DESIGN AND SETTING: Nested case-control study in a multidisciplinary neonatal and pediatric intensive care unit (PICU) PATIENTS: PICU patients during a 12-month period with suspected infection, and plasma available from the time of clinical suspicion (254 episodes, 190 patients). MEASUREMENTS AND RESULTS: Plasma levels of G-CSF, IL-8, and IL-1ra. Episodes classified on the basis of clinical and bacteriological findings into: culture-confirmed sepsis, probable sepsis, localized infection, viral infection, and no infection. Plasma levels were significantly higher in episodes of culture-confirmed sepsis than in episodes with ruled-out infection. The area under the receiver operating characteristic curve was higher for IL-8 and G-CSF than for IL-1ra. Combining IL-8 and G-CSF improved the diagnostic performance, particularly as to the detection of Gram-negative sepsis. Sensitivity was low (<50%) in detecting Staphylococcus epidermidis bacteremia or localized infections. CONCLUSIONS: In this heterogeneous population of critically ill children with suspected infection, a model combining plasma levels of IL-8 and G-CSF identified patients with sepsis. Negative results do not rule out S. epidermidis bacteremia or locally confined infectious processes. The model requires validation in an independent data-set.

Quantifying uncertainty: physicians' estimates of infection in critically ill neonates and children.

To determine the diagnostic accuracy of physicians' prior probability estimates of serious infection in critically ill neonates and children, we conducted a prospective cohort study in 2 intensive care units. Using available clinical, laboratory, and radiographic information, 27 physicians provided 2567 probability estimates for 347 patients (follow-up rate, 92%). The median probability estimate of infection increased from 0% (i.e., no antibiotic treatment or diagnostic work-up for sepsis), to 2% on the day preceding initiation of antibiotic therapy, to 20% at initiation of antibiotic treatment (P&lt;.001). At initiation of treatment, predictions discriminated well between episodes subsequently classified as proven infection and episodes ultimately judged unlikely to be infection (area under the curve, 0.88). Physicians also showed a good ability to predict blood culture-positive sepsis (area under the curve, 0.77). Treatment and testing thresholds were derived from the provided predictions and treatment rates. Physicians' prognoses regarding the presence of serious infection were remarkably precise. Studies investigating the value of new tests for diagnosis of sepsis should establish that they add incremental value to physicians' judgment.

Enteral nutrition in critically ill patients with severe hemodynamic failure after cardiopulmonary bypass.

BACKGROUND & AIMS: The study was designed to investigate and quantify nutritional support, and particularly enteral nutrition (EN), in critically ill patients with severe hemodynamic failure. METHODS: Prospective, descriptive study in a surgical intensive care unit (ICU) in a university teaching hospital: patients aged 67+/-13 yrs (mean+/-SD) admitted after cardiac surgery with extracorporeal circulation, staying 5 days in the ICU with acute cardiovascular failure. Severity of disease was assessed with SAPS II, and SOFA scores. Variables were energy delivery and balance, nutrition route, vasopressor doses, and infectious complications. Artificial feeding delivered according to ICU protocol. EN was considered from day 2-3. Energy target was set 25 kcal/kg/day to be reached stepwise over 5 days. RESULTS: Seventy out of 1114 consecutive patients were studied, aged 67+/-17 years, and staying 10+/-7 days in the ICU. Median SAPS II was 43. Nine patients died (13%). All patients had circulatory failure: 18 patients required intra-aortic balloon-pump support (IABP). Norepinephrine was required in 58 patients (83%). Forty patients required artificial nutrition. Energy delivery was very variable. There was no abdominal complication related to EN. As a mean, 1360+/-620 kcal/kg/day could be delivered enterally during the first 2 weeks, corresponding to 70+/-35% of energy target. Enteral nutrient delivery was negatively influenced by increasing dopamine and norepinephrine doses, but not by the use of IABP. CONCLUSION: EN is possible in the majority of patients with severe hemodynamic failure, but usually results in hypocaloric feeding. EN should be considered in patients with careful abdominal and energy monitoring.

Metabolic effects of parenteral nutrition enriched with n-3 polyunsaturated fatty acids in critically ill patients

BACKGROUND & AIMS: n-3 fatty acids are expected to downregulate the inflammatory responses, and hence may decrease insulin resistance. On the other hand, n-3 fatty acid supplementation has been reported to increase glycemia in type 2 diabetes. We therefore assessed the effect of n-3 fatty acids delivered with parenteral nutrition on glucose metabolism in surgical intensive care patients. METHODS: Twenty-four surgical intensive care patients were randomized to receive parenteral nutrition providing 1.25 times their fasting energy expenditure, with 0.25 g of either an n-3 fatty acid enriched-or a soy bean-lipid emulsion. Energy metabolism, glucose production, gluconeogenesis and hepatic de novo lipogenesis were evaluated after 4 days. RESULTS: Total energy expenditure was significantly lower in patients receiving n-3 fatty acids (0.015+/-0.001 vs. 0.019+/-0.001 kcal/kg/min with soy bean lipids (P<0.05)). Glucose oxidation, lipid oxidation, glucose production, gluconeogenesis, hepatic de novo lipogenesis, plasma glucose, insulin and glucagon concentrations did not differ (all P>0.05) in the 2 groups. CONCLUSIONS: n-3 fatty acids were well tolerated in this group of severely ill patients. They decreased total energy expenditure without adverse metabolic effects.

Should Hyperglycemia in Critically Ill Children Be Treated?

Introduction: In adults, strict control of hyperglycemia reduces mortality and morbidity. There is controversy in medical patients and neurological patients who can suffer of neuroglucopenia. Objectives: To determine prevalence and prognostic significance of hyperglycemia among critically ill non-diabetic children. To evaluate which patients will best benefit of insulin treatment. Methods: Retrospective study using blood glucose levels (GLUC: 9015 values, 923 patients) in our PICU from 01.2003 to 12.2005. 11 Patients with DKA were excluded. Overall PICU mortality was 3.7%. Hyperglycemia was defined at 6.1 mmol/L and different cutoff values (6.1, 8.3 and 11.1 mmol/l) were analyzed for glycemia at admission (GLUC). Sustained hyperglycemia was evaluated with the area under the curve normalized per hour (48h-AUC/h) for the first 48 h. The prevalence of hypo (_3mmol/L), hyperglycemia and PICU death were analyzed. Results: Trough the use of different cutoff values (_6.1, _8.3 and _11.1 mmol/l), prevalence of hyperglycemia at admission was 31.8 %, 16.8% and 10.3%; associated mortality was 2.8%, 4.0% and 15.2% respectively, significantly correlated to cutoff values (r_0.95, p_0.05). Prevalence of hypoglycemia at admission was low (0.9% with no death). 48h-AUC(mmol/L/h) was computed in 747 children (30 deaths). Prevalence of hyperglycemic 48h-AUC values was 47.5%, 17.3% and 4.0% with a respective mortality of 3.4%, 6.3% and 20.7% (r_0.97, p_0.03). For those with high GLUC and high 48h-AUC (_ 11.1 mmol/L) mortality was high (31.5%), but it decrease dramatically to 5.5% when 48h-AUC decrease spontaneously to values _8.3 mmol/L/h. Finally, when patients with severe neurological lesions (GCS_3, n_22) where excluded, increased mortality was observed only for GLUC (n_ 86) and 48h-AUC (n_26) higher than 11.1 mmol/L. Conclusions: Hyperglycemia at admission and even more sustained hyperglycemia (AUC) are highly correlated to mortality in PICU. But children who will have benefit of insulin therapy represent only 3% of our population, much lower than for adults.

Progression rate of self-propelled feeding tubes in critically ill patients.

OBJECTIVE: Gaining postpyloric access in ventilated, sedated ICU patients usually requires time-consuming procedures such as endoscopy. Recently, a feeding tube has been introduced that migrates spontaneously into the jejunum in surgical patients. The study aimed at assessing the rate of migration of this tube in critically ill patients. DESIGN: Prospective descriptive trial. SETTING: Surgical ICU in a tertiary University Hospital. PATIENTS: One hundred and five consecutive surgical ICU patients requiring enteral feeding were enrolled, resulting in 128 feeding-tube placement attempts. METHODS: A self-propelled tube was used and followed up for 3 days: progression was assessed by daily contrast-injected X-ray. Severity of illness was assessed with SAPS II and organ failure assessed with SOFA score. RESULTS: The patients were aged 55+/-19 years (mean+/-SD) with SAPS II score of 45+/-18. Of the 128 tube placement attempts, 12 could not be placed in the stomach; eight were accidentally pulled out while in gastric position due to the necessity to avoid fixation during the progression phase. Among organ failures, respiratory failure predominated, followed by cardiovascular. By day 3, the postpyloric progression rate was 63/128 tubes (49%). There was no association between migration and age, or SAPS II score, but the progression rate was significantly poorer in patients with hemodynamic failure. Use of norepinephrine and morphine were negatively associated with tube progression (P<0.001), while abdominal surgery was not. In ten patients, jejunal tubes were placed by endoscopy. CONCLUSION: Self-propelled feeding tubes progressed from the stomach to the postpyloric position in 49% of patients, reducing the number of endoscopic placements: these tubes may facilitate enteral nutrient delivery in the ICU.

Impact of infection on the prognosis of critically ill cirrhotic patients: results from a large worldwide study.

BACKGROUND: Infections are a leading cause of death in patients with advanced cirrhosis, but there are relatively few data on the epidemiology of infection in intensive care unit (ICU) patients with cirrhosis. AIMS: We used data from the Extended Prevalence of Infection in Intensive Care (EPIC) II 1-day point-prevalence study to better define the characteristics of infection in these patients. METHODS: We compared characteristics, including occurrence and types of infections in non-cirrhotic and cirrhotic patients who had not undergone liver transplantation. RESULTS: The EPIC II database includes 13,796 adult patients from 1265 ICUs: 410 of the patients had cirrhosis. The prevalence of infection was higher in cirrhotic than in non-cirrhotic patients (59 vs. 51%, P < 0.01). The lungs were the most common site of infection in all patients, but abdominal infections were more common in cirrhotic than in non-cirrhotic patients (30 vs. 19%, P < 0.01). Infected cirrhotic patients more often had Gram-positive (56 vs. 47%, P < 0.05) isolates than did infected non-cirrhotic patients. Methicillin-resistant Staphylococcus aureus (MRSA) was more frequent in cirrhotic patients. The hospital mortality rate of cirrhotic patients was 42%, compared to 24% in the non-cirrhotic population (P < 0.001). Severe sepsis and septic shock were associated with higher in-hospital mortality rates in cirrhotic than in non-cirrhotic patients (41% and 71% vs. 30% and 49%, respectively, P < 0.05). CONCLUSIONS: Infection is more common in cirrhotic than in non-cirrhotic ICU patients and more commonly caused by Gram-positive organisms, including MRSA. Infection in patients with cirrhosis was associated with higher mortality rates than in non-cirrhotic patients.

Recommendations on the use of EEG monitoring in critically ill patients: consensus statement from the neurointensive care section of the ESICM.

OBJECTIVES: Recommendations for EEG monitoring in the ICU are lacking. The Neurointensive Care Section of the ESICM assembled a multidisciplinary group to establish consensus recommendations on the use of EEG in the ICU. METHODS: A systematic review was performed and 42 studies were included. Data were extracted using the PICO approach, including: (a) population, i.e. ICU patients with at least one of the following: traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, stroke, coma after cardiac arrest, septic and metabolic encephalopathy, encephalitis, and status epilepticus; (b) intervention, i.e. EEG monitoring of at least 30 min duration; (c) control, i.e. intermittent vs. continuous EEG, as no studies compared patients with a specific clinical condition, with and without EEG monitoring; (d) outcome endpoints, i.e. seizure detection, ischemia detection, and prognostication. After selection, evidence was classified and recommendations developed using the GRADE system. RECOMMENDATIONS: The panel recommends EEG in generalized convulsive status epilepticus and to rule out nonconvulsive seizures in brain-injured patients and in comatose ICU patients without primary brain injury who have unexplained and persistent altered consciousness. We suggest EEG to detect ischemia in comatose patients with subarachnoid hemorrhage and to improve prognostication of coma after cardiac arrest. We recommend continuous over intermittent EEG for refractory status epilepticus and suggest it for patients with status epilepticus and suspected ongoing seizures and for comatose patients with unexplained and persistent altered consciousness. CONCLUSIONS: EEG monitoring is an important diagnostic tool for specific indications. Further data are necessary to understand its potential for ischemia assessment and coma prognostication.

A combined ear sensor for pulse oximetry and carbon dioxide tension monitoring: accuracy in critically ill children.

IMPLICATIONS: A new combined ear sensor was tested for accuracy in 20 critically ill children. It provides noninvasive and continuous monitoring of arterial oxygen saturation, arterial carbon dioxide tension, and pulse rate. The sensor proved to be clinically accurate in the tested range.