The impact of prematurity: a perspective of pediatric intensive care units

OBJECTIVE: To evaluate the relative resource use of pediatric intensive care unit (PICU) patients who had been born prematurely. DESIGN: Nonconcurrent cohort study. SETTING: Consecutive admissions to 16 voluntary PICUs. PATIENTS: A total of 431 formerly premature patients (FPP) and 5,319 nonpremature patients. INTERVENTIONS: None METHODS: Patients with a history of prematurity and a prematurity-related complication or an anatomical deformity were compared for demographic and resource requirements to a group of non-premature patients by a bivariable logistic regression analysis that controlled for age as a co-morbid factor. RESULTS: Compared with other patients, FPP were younger (34.9 +/- 2.2 months vs. 72.4 +/- 1.0 months; p < .001), readmitted to the PICU more often during the same hospitalization (11.1% vs. 5.5%; p < .001), used more chronic technologies (ventilators, gastrostomy tubes, tracheostomy tubes, and parenteral nutrition; 30.3% vs. 5.6%; p < .001), and had longer lengths of stay (5.98 +/-0.59 days vs. 3.56 +/- 0.12 days; p = .004). FPP had significantly higher use of ventilators (45.5% vs. 35.0%; p < .007) and lower use of arterial catheters (27.8% vs. 35.9%, p = .006) and central venous catheters (16.9% vs. 20.9%, p = .026) than nonprematures. The need for other PICU resources, including vasopressors, were similar. CONCLUSIONS: FPP used more chronic and acute care resources than patients who were not prematurely born. Continued improvements in neonatal care will influence change in many aspects of the health care system. This will also affect the delivery of care to the current patient base of the PICU.     

Very early extubation in children after cardiac surgery

OBJECTIVE: Very early extubation of children after cardiac surgery has been suggested as a safe alternative to prolonged postoperative intubation but is still not common practice. Studies of early extubation in children may not have described reasons for failure to extubate, or have included nonbypass or only low-risk repairs. We present our experience with very early extubation in an inclusive group of children after cardiac surgery. DESIGN: Retrospective chart review. SETTING: University hospital operating room and pediatric intensive care unit (ICU). PATIENTS: A total of 102 consecutive children (age <18 yrs) undergoing cardiac surgery requiring cardiopulmonary bypass. MAIN RESULTS: Forty-eight patients were extubated early (88% in the operating room, 12% on arrival in ICU). Patients extubated late were younger (13.8 +/- 26.2 vs. 47.6 +/- 44.5 months), smaller (8.1 +/- 10.7 vs.17.5 +/- 14.2 kg), and had higher ASA scores than patients extubated early (p <.001 for all). The youngest patient extubated early was 2 months old (range, 2-192 months). Paco2 on ICU arrival was higher in the early extubation group (52.4 +/- 6.9 vs. 41.2 +/- 14.7 mm Hg [7.0 +/- 0.9 vs. 5.5 +/- 2.0 kPa], p <.001), and pH was lower (7.27 +/- 0.04 vs. 7.37 +/- 0.16, p <.001). Use of subarachnoid morphine did not affect ability to extubate early. No patients in the early extubation group required special airway support, reintubation, or increased inotropic support after ICU admission. CONCLUSIONS: Successful early extubation of even young children is possible and easily accomplished in most children undergoing cardiopulmonary bypass, even with complex procedures, but advantages of extubation in the operating room vs. immediate ICU extubation remain unclear. Transient mild-to-moderate mixed acidosis is common and requires no treatment. Full implementation requires acceptance by surgical and ICU staffs.     

Lessons learned from the Marmara disaster: Time period under the rubble

OBJECTIVE: To investigate the effect of the time period under the rubble on morbidity and mortality of the crush-syndrome patients after the catastrophic Marmara earthquake that struck northwestern Turkey in August 1999. DESIGN: Observational study. SETTING: Consecutive admissions to emergency and intensive care units of 35 reference hospitals that treated the renal victims. METHODS: Analysis of questionnaires obtained from these hospitals. PATIENTS: A total of 539 of 639 crush-syndrome patients whose time under the rubble was identified in the questionnaires. RESULTS: Mean time under the rubble was 11.7 +/- 14.3 hrs (median, 8 hrs; interquartile range, 6 hrs; range, 0.5-135 hrs). The highest number of patients was entrapped within the 5-8 hrs time stratum, and by the end of 48 hrs, 97% of the victims had been rescued. Nondialyzed victims spent a longer duration under the rubble than dialyzed ones (15.9 +/- 23.1 hrs [median, 7 hrs; interquartile range, 8.5 hrs] vs. 10.3 +/- 9.5 hrs [median, 8 hrs; interquartile range, 6 hrs), p <.001)]. Likewise, in the strata of longer time under the rubble, the percentage of survivors was higher (p =.07). Time under the rubble correlated positively with the number of amputated extremities (p <.001) and admission platelet count (p <.001), and it correlated negatively with admission serum albumin (p <.001). The victims entrapped for >50 hrs (n = 6) were characterized by lower figures of admission blood urea nitrogen (p =.04), serum creatinine (p =.003), hemodialysis sessions, and duration of hemodialysis support (p =.005, for both analyses) compared with victims whose time under the rubble was shorter. CONCLUSION: Rescue efforts should continue at least for 5 days after the disaster. Time under the rubble is not an adverse prognostic indicator of survival or renal dysfunction for the patients of crush syndrome, probably because only the victims with mild or moderate injuries can survive under the rubble for longer durations.     

Endotracheal tube intraluminal volume loss among mechanically ventilated patients

OBJECTIVE: To measure endotracheal tube intraluminal volume loss among mechanically ventilated patients. DESIGN: Prospective observational study. SETTING: Medical intensive care unit (19 beds) of an urban university-affiliated teaching hospital. PATIENTS: A total of 101 patients with acute respiratory failure requiring >24 hrs of mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Acoustic reflectometry was employed to measure the intraluminal volume of 13-cm endotracheal tube segments. The endotracheal tube segment volumes were statistically smaller among endotracheal tubes used in patients compared with unused endotracheal tubes (5.4 +/- 0.7 vs. 6.0 +/- 0.6 mL, p <.001). The average percentage difference in endotracheal tube segment volumes, between the unused endotracheal tubes and the endotracheal tubes used in patients, was 9.8% (range, 0-45.5%). The percentage difference in the endotracheal tube segment volumes increased significantly with increasing duration of tracheal intubation (r2 =.766, p <.001). The minimum diameter of the endotracheal tube segments was also statistically smaller among endotracheal tubes used in patients compared with the unused endotracheal tubes (7.5 +/- 0.4 vs. 6.7 +/- 1.2 mm, p <.001). CONCLUSIONS: Endotracheal tube intraluminal volume loss is common among patients with acute respiratory failure requiring mechanical ventilation and increases with prolonged tracheal intubation.     

Observational study of children admitted to United Kingdom and Republic of Ireland Paediatric Intensive Care Units after out-of-hospital cardiac arrest

AimsTo estimate the prevalence of children admitted after out-of-hospital cardiac arrest (OHCA) to UK and Republic of Ireland (RoI) Paediatric Intensive Care Units (PICUs) and factors associated with mortality to inform future clinical trial feasibility.MethodObservational study using a prospectively collected dataset of the Paediatric Intensive Care Audit Network (PICANet) of 33 UK and RoI PICUs (January 2003 to June 2010). Cases (0 to <16 years), with documented OHCA surviving to PICU admission and requiring mechanical ventilation were included. Main outcomes were prevalence for admission and death within PICU. Factors associated with mortality were examined with multiple logistic regression analysis.Results827 of 111,170 admissions (0.73%; 95% CI [0.48 to 0.98%]) were identified as children admitted following OHCA. PICU mortality for OHCA was 50.5% (418/827). Recruitment into an adequately sized clinical trial would not be feasible with the current prevalence rate. Characteristics at PICU admission associated with increased risk of death included; bilateral unreactive pupils, genetically inherited condition, inter-hospital transfer to PICU, requirement for vasoactive drugs and greater base deficit. Factors associated with reduced risk of death were submersion or a respiratory aetiology and pre-existing respiratory or cardiac conditions.ConclusionsLess than 120 children a year are admitted to PICUs in the UK and RoI after OHCA, limiting options for conducting UK intervention trials. The risk factors associated with mortality identified in this study will allow risk stratification in future studies.     

Noninvasive ventilation to prevent respiratory failure after extubation in high-risk patients

OBJECTIVE: Compared with standard medical therapy (SMT), noninvasive ventilation (NIV) does not reduce the need for reintubation in unselected patients who develop respiratory failure after extubation. The goal of this study was to assess whether early application of NIV, immediately after extubation, is effective in preventing postextubation respiratory failure in an at-risk population. DESIGN: Multiple-center, randomized controlled study. SETTING: Multiple hospitals. PATIENTS: Ninety-seven consecutive patients with similar baseline characteristics, requiring >48 hrs of mechanical ventilation and considered at risk of developing postextubation respiratory failure (i.e., patients who had hypercapnia, congestive heart failure, ineffective cough and excessive tracheobronchial secretions, more than one failure of a weaning trial, more than one comorbid condition, and upper airway obstruction). INTERVENTIONS: After a successful weaning trial, the patients were randomized to receive NIV for > or = 8 hrs a day in the first 48 hrs or SMT. Primary outcome was the need for reintubation according to standardized criteria. Secondary outcomes were intensive care unit and hospital mortality, as well as time spent in the intensive care unit and in hospital. MEASUREMENTS AND MAIN RESULTS: Compared with the SMT group, the NIV group had a lower rate of reintubation (four of 48 vs. 12 of 49; p = .027). The need for reintubation was associated with a higher risk of mortality (p < .01). The use of NIV resulted in a reduction of risk of intensive care unit mortality (-10%, p < .01), mediated by the reduction for the need of reintubation. CONCLUSIONS: NIV was more effective than SMT in preventing postextubation respiratory failure in a population considered at risk of developing this complication.     

Pediatric risk of mortality (PRISM) score

The Pediatric Risk of Mortality (PRISM) score was developed from the Physiologic Stability Index (PSI) to reduce the number of physiologic variables required for pediatric ICU (PICU) mortality risk assessment and to obtain an objective weighting of the remaining variables. Univariate and multivariate statistical techniques were applied to admission day PSI data (1,415 patients, 116 deaths) from four PICUs. The resulting PRISM score consists of 14 routinely measured, physiologic variables, and 23 variable ranges. The performance of a logistic function estimating PICU mortality risk from the PRISM score, age, and operative status was tested in a different sample from six PICUs (1,227 patients, 105 deaths), each PICU separately, and in diagnostic groups using chi-square goodness-of-fit tests and receiver operating characteristic (ROC) analysis. In all groups, the number and distribution of survivors and nonsurvivors in adjacent mortality risk intervals were accurately predicted: total validation group (chi 2(5) = 0.80; p greater than .95), each PICU separately (chi 2(5) range 0.83 to 7.38; all p greater than .10), operative patients (chi 2(5) = 2.03; p greater than .75), nonoperative patients (chi 2(5) = 2.80, p greater than .50), cardiovascular disease patients (chi 2(5) = 4.72; p greater than .25), respiratory disease patients (chi 2(5) = 5.82; p greater than .25), and neurologic disease patients (chi 2(5) = 7.15; p greater than .10). ROC analysis also demonstrated excellent predictor performance (area index = 0.92 +/- 0.02).     

Long-stay patients in the pediatric intensive care unit

OBJECTIVE: Length of stay in the pediatric intensive care unit (PICU) is a reflection of patient severity of illness and health status, as well as PICU quality and performance. We determined the clinical profiles and relative resource use of long-stay patients (LSPs) and developed a prediction model to identify LSPs for early quality and cost saving interventions. DESIGN: Nonconcurrent cohort study. SETTING: A total of 16 randomly selected PICUs and 16 volunteer PICUs. PATIENTS: A total of 11,165 consecutive admissions to the 32 PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: LSPs were defined as patients having a length of stay greater than the 95th percentile (>12 days). Logistic regression analysis was used to determine which clinical characteristics, available within the first 24 hrs after admission, were associated with LSPs and to create a predictive algorithm. Overall, LSPs were 4.7% of the population but represented 36.1% of the days of care. Multivariate analysis indicated that the following factors are predictive of long stays: age <12 months, previous ICU admission, emergency admission, no CPR before admission, admission from another ICU or intermediate care unit, chronic care requirements (total parenteral nutrition and tracheostomy), specific diagnoses including acquired cardiac disease, pneumonia, and other respiratory disorders, having never been discharged from the hospital, need for ventilatory support or an intracranial catheter, and a Pediatric Risk of Mortality III score between 10 and 33. The performance of the prediction algorithm in both the training and validation samples for identifying LSPs was good for both discrimination (area under the receiver operating characteristics curve of 0.83 and 0.85, respectively), and calibration (goodness of fit, p = .33 and p = .16, respectively). LSPs comprised from 2.1% to 8.1% of individual ICU patients and occupied from 15.2% to 57.8% of individual ICU bed days. CONCLUSIONS: LSPs have less favorable outcomes and use more resources than non-LSPs. The clinical profile of LSPs includes those who are younger and those that require chronic care devices. A predictive algorithm could help identify patients at high risk of prolonged stays appropriate for specific interventions.     

Comparison of the performance of two general and three specific scoring systems for meningococcal septic shock in children

OBJECTIVE: To evaluate the performance at admission to the pediatric intensive care unit (PICU) of five severity scores, two general (the Pediatric Risk of Mortality [PRISM] II and III scores) and three specific for meningococcal septic shock (Leclerc, Glasgow Meningococcal Septicemia Prognostic Score [GMSPS], and Gedde-Dahl's MOC score) in children with this condition. DESIGN: Multicenter, retrospective, cohort study. SETTING: The PICUs from four tertiary centers. PATIENTS: Patients were 192 children ranging in age from 1 month to 14 yrs consecutively admitted to the participating PICUs during a period of 12 yrs and 6 months (January 1983 to June 1995), who were diagnosed with presumed or confirmed meningococcal septic shock. Patients with a length of stay <2 hrs were excluded from the study. INTERVENTIONS: Clinical and laboratory data gathered during the first 2 hrs after admission were used to compute the scoring systems tested. MEASUREMENTS AND MAIN RESULTS: There were 66 deaths (34%). Neisseria meningitidis was cultured from 142 (74%) children. GMSPS and PRISM II provided the best discriminative capability, as measured by the area under the receiver operating characteristic curve (SEM): 0.816 (0.036) and 0.803 (0.041), respectively. The other three scores gave lower receiver operating characteristic areas: PRISM III = 0.777 (0.043), MOC = 0.775 (0.037), and Leclerc = 0.661 (0.045). There was a statistically significant difference between the areas under the receiver operating characteristic curve of GMSPS and Leclerc (p < .01) but not between the GMSPS and the remaining three scores. All five scores presented good calibration with no significant differences between observed and predicted mortality (Hosmer-Lemeshow goodness-of-fit test). CONCLUSIONS: The specific GMSPS and the general pediatric severity system PRISM II performed better than the other three scores, being appropriate tools to assess severity of illness at admission to the PICU in children with presumed meningococcal septic shock.     

Incidence and prognosis of early hepatic dysfunction in critically ill patients--a prospective multicenter study

OBJECTIVE: In critically ill patients, hepatic dysfunction is regarded as a late organ failure associated with poor prognosis. We investigated the incidence and prognostic implications of early hepatic dysfunction (serum bilirubin >2 mg/dL within 48 hrs of admission). DESIGN: Prospective, multicenter cohort study. SETTING: Thirty-two medical, surgical, and mixed intensive care units. PATIENTS: A total of 38,036 adult patients admitted consecutively over a period of 4 yrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Excluding patients with preexisting cirrhosis (n = 691; 1.8%) and acute or acute-on-chronic hepatic failure (n = 108, 0.3%), we identified 4,146 patients (10.9%) with early hepatic dysfunction. These patients had different baseline characteristics, longer median intensive care unit stays (5 vs. 3 days; p < .001) and increased hospital mortality (30.4% vs. 16.4%; p < .001). Hepatic dysfunction was also associated with higher observed-to-expected mortality ratios (1.02 vs. 0.91; p < .001). Multiple logistic regression analysis showed an independent mortality risk of hepatic dysfunction (odds ratio, 1.86; 95% confidence interval, 1.71-2.03; p < .001), which exceeded the impact of all other organ dysfunctions. A case-control study further confirmed these results: Patients with early hepatic dysfunction exhibited significantly increased raw and risk-adjusted mortality compared with control subjects. CONCLUSIONS: Our results provide strong evidence that early hepatic dysfunction, occurring in 11% of critically ill patients, presents a specific and independent risk factor for poor prognosis.     

Pattern of spontaneous breathing: potential marker for weaning outcome

OBJECTIVE: To quantitatively assess the spontaneous breathing (SB) pattern, during minimal ventilatory support, of patients who pass or fail weaning trials from mechanical ventilation. DESIGN: A prospective, clinical trial. SETTING: Intensive care unit of a university teaching hospital. PATIENTS: Fifty-two tracheally intubated and hemodynamically stable patients who were judged clinically ready for extubation. METHODS: Using a computerized respiratory profile monitor, continuous respiratory parameters were obtained while patients were receiving four or less synchronized intermittent mandatory (SIMV) breaths and during CPAP trials. Coefficients of variation (CV) of spontaneous tidal volumes and flows during SIMV trials as well as the entropies and dimensions of the breathing patterns during CPAP trials were used to assess the dynamical breathing behaviors of the patients who passed or failed weaning trials. MEASUREMENTS AND RESULTS: Thirty-nine extubations were successful and 13 were not. The CV of the spontaneous tidal volumes (VT) and the spontaneous peak inspiratory flows (PF), the Kolmogorov entropy and the dimension of the SB patterns were compared in the two groups. The CV of VT (9.13 +/- 4.11 vs 26.07 +/- 6.94), the CV of PF (11.63 +/- 4.18 vs 29.88 +/- 12.07), the Kolmogorov entropy (0.09 +/- 0.03 bits/cycle vs 0.39 +/- 0.09 bits/cycle), and the dimension of the SB pattern (1.33 +/- 0.07 vs 3.93 +/- 0.47) were all significantly smaller (P < 0.05) in the successfully extubated group versus the group that failed extubation. CONCLUSION: The spontaneous breathing pattern during minimal mechanical ventilatory support is more chaotic in patients who failed extubation trials compared to patients who passed extubation trials. Thus, we speculate that characterizing the SB pattern during minimal ventilatory support might be a useful tool in differentiating between extubation success and failure.     

Risk factors and outcomes of extubation failure in a South African tertiary paediatric intensive care unit

Background Extubation failure contributes to poor outcome of mechanically ventilated children, yet the prevalence and risk factors have been poorly studied in South African (SA) children. Objectives To determine the prevalence, risk factors and outcomes of extubation failure in an SA paediatric intensive care unit (PICU). Methods This was a prospective, observational study of all mechanically ventilated children admitted to a tertiary PICU in Cape Town, SA. Extubation failure was defined as requiring re-intubation within 48 hours of planned extubation. Results There were 219 episodes of mechanical ventilation in 204 children (median (interquartile range (IQR)) age 8 (1.6 - 44.4) months). Twenty-one of 184 (11.4%) planned extubations (95% confidence interval (CI) 7.2% - 16.9%) failed. Emergency cardiac admissions (adjusted odds ratio (aOR) 7.58 (95% CI 1.90 - 30.29), dysmorphology (aOR 4.90; 95% CI 1.49 - 16.14), prematurity (aOR 4.39; 95% CI 1.24 - 15.57), and ventilation ≥48 hours (aOR 6.42 (95% CI 1.57 - 26.22) were associated with extubation failure. Children who failed extubation had longer durations of ventilation (231 hours (146.0 - 341.0) v. 53 hours (21.7 - 123.0); p<0.0001); longer duration of PICU (15 (9 - 20) days v. 5 (2 - 9) days; p<0.0001) and hospital length of stay (32 (21 - 53) days v. 15 (8 - 27) days; p=0.009); and higher 30-day mortality (28.6% v. 6.7%; p=0.001) than successfully extubated children. Conclusion Extubation failure was associated with significant morbidity and mortality in our setting. Risk factors for extubation failure identified in our context were similar to those reported in other settings. Contributions of the study This study provides novel data on the prevalence, risk factors and outcomes associated with extubation failure in a single-centre South African PICU. The results of this study may help identify high-risk groups for extubation failure within our local context, and forms a basis for practice improvement initiatives aimed at decreasing extubation failure rates and improving outcomes.     

Effect of a nursing-implemented sedation protocol on the duration of mechanical ventilation

OBJECTIVE: To compare a practice of protocol-directed sedation during mechanical ventilation implemented by nurses with traditional non-protocol-directed sedation administration. DESIGN: Randomized, controlled clinical trial. SETTING: Medical intensive care unit (19 beds) in an urban teaching hospital. PATIENTS: Patients requiring mechanical ventilation (n = 321). INTERVENTIONS: Patients were randomly assigned to receive either protocol-directed sedation (n = 162) or non-protocol-directed sedation (n = 159). MEASUREMENTS AND MAIN RESULTS: The median duration of mechanical ventilation was 55.9 hrs (95% confidence interval, 41.0-90.0 hrs) for patients managed with protocol-directed sedation and 117.0 hrs (95% confidence interval, 96.0-155.6 hrs) for patients receiving non-protocol-directed sedation. Kaplan-Meier analysis demonstrated that patients in the protocol-directed sedation group had statistically shorter durations of mechanical ventilation than patients in the non-protocol-directed sedation group (chi-square = 7.00, p = .008, log rank test; chi-square = 8.54, p = .004, Wilcoxon's test; chi-square = 9.18, p = .003, -2 log test). Lengths of stay in the intensive care unit (5.7+/-5.9 days vs. 7.5+/-6.5 days; p = .013) and hospital (14.0+/-17.3 days vs. 19.9+/-24.2 days; p < .001) were also significantly shorter among patients in the protocol-directed sedation group. Among the 132 patients (41.1%) receiving continuous intravenous sedation, those in the protocol-directed sedation group (n = 66) had a significantly shorter duration of continuous intravenous sedation than those in the non-protocol-directed sedation group (n = 66) (3.5+/-4.0 days vs. 5.6+/-6.4 days; p = .003). Patients in the protocol-directed sedation group also had a significantly lower tracheostomy rate compared with patients in the non-protocol-directed sedation group (10 of 162 patients [6.2%] vs. 21 of 159 patients [13.2%], p = .038). CONCLUSIONS: The use of protocol-directed sedation can reduce the duration of mechanical ventilation, the intensive care unit and hospital lengths of stay, and the need for tracheostomy among critically ill patients with acute respiratory failure.     

Serum concentrations of immune parameters during acute cardiogenic pulmonary edema.

OBJECTIVE: To evaluate the effect of acute cardiogenic pulmonary edema on the concentrations of immune parameters in serum. DESIGN: Prospective, controlled study. SETTING: Medical ICU. PATIENTS: Twenty-four consecutive patients with acute pulmonary edema who had significant clinical improvement within 30 mins and did not show any evidence of either tissue damage or infection. For comparison, 25 healthy, age-matched controls and 25 patients with mild chronic heart failure were also studied. INTERVENTIONS: Treatment with oxygen, nitrates, and loop diuretics. MEASUREMENTS: Lymphokines, acute-phase reactants, and cortisol concentrations were measured in serial serum and plasma samples. MAIN RESULTS: Serum concentrations of soluble CD-8 antigen (soluble CD-8) decreased from 928 +/- 124 (SEM) U/mL on admission to 712 +/- 112 and 579 +/- 67 U/mL after 2 and 6 hrs, respectively (p less than .05, p less than .01), and returned to baseline values within 48 hrs (853 +/- 109 U/mL). Concentrations of soluble interleukin-2 receptor increased from 721 +/- 71 to 1078 +/- 112 and 1226 +/- 128 U/mL 12 and 36 hrs, respectively, after admission (p less than .05, p less than .01). Plasma cortisol concentrations were markedly increased on admission (56.9 +/- 4.7 vs. 13.1 +/- 1.3 micrograms/dL after recovery, p less than .001). Increased cortisol concentrations coincided with the nadir of soluble CD-8. Tumor necrosis factor-alpha remained within normal limits in all patients. Neither acute-phase reactants nor angiotensin converting enzyme activity showed significant changes during the observation period. CONCLUSION: The present results indicate significant alterations in the serum concentrations of immune parameters as an effect of an uncomplicated acute cardiogenic pulmonary edema.     

Recruitment maneuvers during prone positioning in patients with acute respiratory distress syndrome

OBJECTIVE: To evaluate the interaction of recruitment maneuvers and prone positioning on gas exchange and venous admixture in patients with early extrapulmonary acute respiratory distress syndrome ventilated with high levels of positive end-expiratory pressure. We hypothesized that a sustained inflation performed after 6 hrs of prone positioning would induce sustained improvement in oxygenation (Pao2/Fio2) and venous admixture. DESIGN: Prospective, interventional study. SETTING: Tertiary care, postoperative intensive care unit. PATIENTS: Fifteen patients with early extrapulmonary acute respiratory distress syndrome. INTERVENTIONS: After 6 hrs of prone positioning, a sustained inflation was performed with 50 cm H2O maintained for 30 secs. Data were recorded in supine position, after 6 hrs of prone positioning, at 3, 30, and 180 mins following the sustained inflation. MEASUREMENTS AND MAIN RESULTS: A response to prone positioning was observed in nine of 15 patients leading to an improvement of Pao2/Fio2 (147 +/- 37 torr vs. 225 +/- 77 torr, p = .005) and venous admixture (35.4 +/- 8.3% vs. 28.9 +/- 9.8%, p = .001). Six patients did not respond to prone positioning. Following the sustained inflation, the responders to prone positioning showed a further increase of Pao2/Fio2 and decrease of venous admixture at 3 mins (Pao2/Fio2, 225 +/- 77 torr vs. 368 +/- 90 torr, p = .018; venous admixture, 28.9 +/- 9.8% vs. 18.9 +/- 6.7%, p = .05). In all six nonresponders to prone positioning, an improvement of Pao2/Fio2 and venous admixture occurred at 3 mins following the sustained inflation (128 +/- 18 torr vs. 277 +/- 59 torr, p = .03; venous admixture, 34.2 +/- 6.0% vs. 23.8 +/- 6.3%, p = .05). The beneficial effects of the sustained inflation remained significantly elevated over 3 hrs in responders and nonresponders to prone positioning. CONCLUSION: In patients with early extrapulmonary acute respiratory distress syndrome, a sustained inflation performed after 6 hrs of prone positioning induced further and sustained improvement of oxygenation and venous admixture in both responders and nonresponders to prone positioning.     

The effect of prompt physician visits on intensive care unit mortality and cost

OBJECTIVE: To determine the effect on mortality, length of stay, and direct variable cost of physician response time to seeing patients after intensive care unit admission. DESIGN: Retrospective analysis of the intensive care unit database. SETTING: Medical center. PATIENTS: Subjects were 840 patients who had complete direct variable cost data and a subset of 316 patients who were matched by propensity scores. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Median time to first visit by a physician was 6 hrs. One hundred thirty-five patients (16.1%) died in hospital compared with 25.0% predicted by Acute Physiology and Chronic Health Evaluation risk (p < .001). Higher Acute Physiology and Chronic Health Evaluation risk, older age, mechanical ventilation on arrival in the intensive care unit, and longer time until seen by a physician were predictors of hospital mortality. Each 1-hr delay in seeing the patient was associated with a 1.6% increased risk of hospital death, which further increased to 2.1% after including propensity score. However, patients seen more promptly (<6 vs. >6 hrs) had greater hospital direct variable cost ($11,992 +/- $12,043 vs. $10,355 +/- $10,368, p = .04), before controlling for acuity of illness and other factors that may have affected time to evaluation. In the subpopulation of propensity-matched patients, patients seen promptly (<6 vs. >6 hrs) had shorter hospital length of stays (11 +/- 11 vs. 13 +/- 14 days, p = .03) but similar direct variable costs ($10,963 +/- 10,778 vs. $13,016 +/- 13,006, p = .16) and similar mortality rates (24 vs. 30, p = .46). CONCLUSIONS: In the total patient population, delay in seeing patients was associated with an increased risk of death. In the propensity-matched patients, promptly seen patients had shorter hospital stays but similar direct variable costs.     

Systemic hemodynamics, gastric intramucosal PCO2 changes, and outcome in critically ill burn patients

OBJECTIVES: To define the hemodynamic and gastric intramucosal PCO2 (PiCO2) changes during the first 48 hrs after burn trauma and to analyze their relationship with outcome. DESIGN: Prospective, observational study in a cohort of consecutively admitted critically ill burn patients. SETTING: Intensive care burn unit in a university hospital. PATIENTS: Forty-two patients with burns covering >20% of body surface area or inhalation injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were monitored with an oximetric pulmonary arterial catheter and a gastric tonometer to measure PiCO2. The difference between arterial and gastric mucosal PCO2 (P[i-a]CO2) was considered indicative of gastric mucosal hypoxia. Hemodynamic and PiCO2 measurements were performed during the first 48 hrs after admission. Patients suffered burns covering 36.1% +/- 14.3% (mean +/- SD) and 45.3% +/- 21.9% of body surface area (survivors and nonsurvivors, respectively). All patients were successfully resuscitated by conventional standards. Nonsurvivors (n = 16) died a median of 17 days after admission. In univariate analysis, the presence of shock during the resuscitation phase, age, mixed venous pH, P[i-a]CO2, right atrial pressure, pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, systemic and pulmonary vascular resistance, left ventricular stroke work index, mixed venous oxygen saturation, and systemic oxygen delivery, consumption, and extraction ratio, measured over the first 12 hrs after admission, were significantly (p < .05) different between survivors and nonsurvivors. These differences disappeared after 12 hrs after admission. Multivariate analysis identified age, percentage body surface area burned, and oxygen delivery index (6 hrs after admission) as factors independently associated with a poor outcome. P[i-a]CO2 (12 hrs after admission) was significantly greater in patients with than in those without inhalation injury (17 +/- 13 torr [2.26 +/- 1.73 kPa] vs. 6 +/- 10 torr [0.79 +/- 1.33 kPa]; p = .005). Patients with a P[i-a]CO2 difference (6 hrs after admission) > or =10 torr (1.33 kPa) had a mortality rate of 56% vs. 25% of those patients with <10 torr (p = .044). CONCLUSIONS: Our data indicate that there are hemodynamic and biochemical changes that occur early after burn trauma that are associated with prognosis after an apparently successful resuscitation. Particularly, a hemodynamic profile characterized by systemic acidosis, low systemic blood flow, and systemic and pulmonary vasoconstriction early after trauma is associated with a poor outcome. Additionally, intestinal mucosal acidosis occurs after burn trauma, is influenced by inhalation injury, and is a variable related to outcome.     

Comparison of two dose regimens of arginine vasopressin in advanced vasodilatory shock

OBJECTIVE: To evaluate the effects of two arginine vasopressin (AVP) dose regimens (0.033 vs. 0.067 IU/min) on treatment efficacy, hemodynamic response, prevalence of adverse events, and changes in laboratory variables. DESIGN: Retrospective, controlled study. PATIENTS: A total of 78 patients with vasodilatory shock (mean norepinephrine dosage, 1.07 microg.kg-1.min-1; 95% confidence interval, 0.82-1.56 microg.kg-1.min-1). INTERVENTIONS: Supplementary infusion of AVP at 0.033 (n = 39) and 0.067 IU/min (n = 39). MEASUREMENTS AND MAIN RESULTS: Cardiocirculatory, laboratory, and clinical variables were evaluated and compared between groups before and at 0.5, 1, 4, 12, 24, 48, and 72 hrs after initiation of AVP. Treatment efficacy was assessed by the increase in mean arterial blood pressure and the extent of norepinephrine reduction during the first 24 hrs of AVP therapy. Standard tests and a mixed-effects model were used for statistical analysis. Although the relative increase in mean arterial pressure was comparable between groups (0.033 vs. 0.067 IU/min: 16.8 +/- 18.4 vs. 21.4 +/- 14.9 mm Hg, p = .24), norepinephrine could be reduced significantly more often in patients receiving 0.067 IU/min. AVP at 0.067 IU/min resulted in a higher mean arterial pressure (p < .001), lower central venous pressure (p = .001), lower mean pulmonary arterial pressure (p = .04), and lower norepinephrine requirements (p < .001) during the 72-hr observation period. Increases in liver enzymes occurred more often in patients treated with 0.033 IU/min (71.8% vs. 28.2%, p < .001). The prevalence of a decrease in cardiac index (69.2% vs. 53.8%, p = .24), decrease in platelet count (94.8% vs. 84.6%, p = .26), and increase in total bilirubin (48.7% vs. 71.8%, p = .06) was not significantly different between groups. Bilirubin levels (3.1 +/- 3.4 vs. 5.2 +/- 5.5 mg/dL, p = .04) and base deficit (-7.2 +/- 4.3 vs. -3.9 +/- 5.9 mmol/L, p = .005) were lower and arterial lactate concentrations higher (76 +/- 67 vs. 46 +/- 38 mg/dL, p < .001) in patients receiving 0.033 IU/min. CONCLUSIONS: AVP dosages of 0.067 IU/min seem to be more effective to reverse cardiovascular failure in vasodilatory shock requiring high norepinephrine dosages than 0.033 IU/min.     

Effect of interhospital transfer on resource utilization and outcomes at a tertiary pediatric intensive care unit

Purpose

The study aimed to examine the effect of interhospital transfer on resource utilization and clinical outcomes at a tertiary pediatric intensive care unit (PICU) among patients with sepsis or respiratory failure.

Materials and methods

Data on 2146 consecutive admissions with respiratory failure or sepsis to the PICU were analyzed. Data included demographics, admission source, and outcomes. Admission source was classified as interhospital transfer from the emergency departments (ED), wards, or PICUs of referring hospitals; or from the study hospital ED (direct).

Results

Compared with direct admissions, inter-PICU transfers had higher crude mortality (odds ratio, 1.93; 95% confidence interval, 1.31-2.84) but not significant mortality difference (odds ratio, 1.16; 95% confidence interval, 0.71-1.86) after adjusting for illness severity, age, and sex. Conversely, ED transfers had lower PICU mortality than direct ED admissions. Children with transfer admissions stayed significantly longer and used more intensive care technology in the study PICU than children directly admitted (P < .01). In comparisons within quartiles of mortality risk, inter-PICU transfers had longer hospitalization and higher mortality in all but the highest quartile.

Conclusions

Interhospital transfer, particularly inter-PICU transfer, was associated with significant hospital resource consumption that often correlated with admission illness severity. Future prospective studies should identify determinants of pretransfer illness severity and investigate decision making underlying interhospital transfer.