Serum lactate and base deficit as predictors of mortality and morbidity

OBJECTIVES: To determine whether lactate levels and base deficits in critically ill surgical intensive care unit (SICU) patients correlate and whether either measure is a significant indicator of mortality and morbidity. METHODS: A review was made of 137 SICU patients who had serial lactate and blood gas measurements. Patients were stratified by absolute lactate and base deficit values as well as time to lactate clearance. RESULTS: Initial and 24-hour lactate level was significantly elevated in nonsurvivors versus survivors (P = 0.002). Initial base deficit was not significantly different; 24-hour base deficit did achieve statistical significance (P = 0.02). Subgroup analysis among trauma patients (n = 36) and major abdominal surgery (n = 101) confirmed the significant correlation between lactate levels and survival. There was poor correlation between initial and 24-hour lactate and base deficit among all patients (r = -0.3 and -0.5). Mortality if lactate normalized within 24 hours was 10%, compared with 24% for >48 hours and 67% if lactate failed to normalize. Physical status at discharge was related to initial lactate (P = 0.05), as well as to lactate clearance time (P = 0.01). CONCLUSIONS: Elevated initial and 24-hour lactate levels are significantly correlated with mortality and appear to be superior to corresponding base deficit levels. Lactate clearance time may be used to predict mortality and is associated with outcome at discharge. Initial base deficit is a poor predictor of mortality and did not correlate with lactate levels except in trauma nonsurvivors. In addition to being used as an endpoint for resuscitation, lactate may be predictive of certain morbidities and patient outcome at discharge.     

Lactate and base deficit in trauma: does alcohol or drug use impair their predictive accuracy?

BACKGROUND: Abnormal blood lactate and base deficit (BD) reflect hypoperfusion and have been documented to predict outcome in trauma. Alcohol and drug use may also induce metabolic acidosis in trauma victims, potentially diminishing the predictive accuracy of lactate and BD. We, therefore, sought to examine the effect of alcohol and drug use on the predictive accuracy of admission blood lactate and BD in trauma. METHODS: Prospective data were collected on 15,179 patients admitted to the R Adams Cowley Shock Trauma Center over a 3-year period from 1998 to 2000. Patients were stratified by age, gender, race, injury severity score (ISS), Glasgow coma score (GCS), alcohol concentration and illicit drug use. Multiple regression analyses were used to assess admission blood lactate and BD as independent risk factors for mortality, intensive care unit (ICU) admission, and ICU and hospital length of stay (LOS) controlling for alcohol and drug use [cocaine, phencyclidine and methamphetamines] by measured serum concentrations. RESULTS: The mean age of the study cohort was 37 +/- 19 years, mean ISS was 9 +/- 10, mean GCS 14.1 +/- 2.7, 71% were male and 77% sustained blunt trauma. Alcohol testing was completed in 13,102 of 15,179 (86.3%) of patients. Alcohol screen was positive in 27% (n = 3536) of the total cohort tested (n = 13,102) with a mean blood alcohol concentration of 141 +/- 95 mg/dL; 7% (n = 992) had positive drug screens. Increasing injury severity was associated with significantly increased admission blood lactate and BD (p < 0.001). Patients with positive alcohol and drug screens had significantly increased admission blood lactate, BD and injury severity compared with patients with negative alcohol and drug screens (p < 0.01). Patients with positive alcohol and drug screens had a significant increase in admission to the ICU (p < 0.05), but no significant increase in mortality, ICU or hospital LOS compared with patients with negative screens. Multiple logistic and linear regression analyses confirmed admission lactate and BD as significant independent predictors of mortality, ICU and hospital LOS (p < 0.01). These results were unchanged after controlling for alcohol and drug use as covariates in the logistic and linear regression analyses. CONCLUSION: Alcohol and drug use are common in trauma, but do not impair the predictive accuracy of admission lactate and BD in trauma outcome. Admission lactate and BD are therefore confirmed as significant independent predictors of trauma outcome in patients with acute alcohol and drug use in this largest clinical study to date.     

APACHEⅡ与TRISS评分系统对急诊重症创伤患者预后预测的比较

目的比较急性生理和慢性健康状况评价系统(APACHE)Ⅱ与创伤严重程度评分(TRISS)对急诊重症创伤患者死亡率的预测能力。方法将2010年4月至2011年5月在本院急诊抢救室治疗的重症创伤患者纳入本研究。统计患者的一般资料、受伤机制、手术、APACHEⅡ和TRISS评分等,并预测死亡率,预测结果与实际死亡率比较,通过受试者操作工作特征曲线下面积(ROC曲线)和诊断结果判断两种评分模型对死亡率的预测能力。结果 282例患者中,33例死亡(11.7%),249例存活(88.3%)。死亡患者和存活患者两组比较,APACHEⅡ、RTS、ISS和年龄均有显著差异。通过ROC曲线下面积分析,急诊APACHEⅡ和TRISS的ROC曲线面积为0.90±0.03和0.76±0.05。APACHEII的预测能力更好,P<0.05。以0.5为判断死亡标准,经Kappa检验,APACHEⅡ、TRISS与实际死亡率的一致性为0.64(P<0.05)和0.43(P<0.05)。结论急诊APACHEⅡ和TRISS都能准确预测急诊重症创伤患者的死亡率,APAHCEⅡ的预测价值更高。     

Sublingual capnometry for rapid determination of the severity of hemorrhagic shock

BACKGROUND: Sublingual capnometry (SLCO2) is a rapid, minimally invasive bedside test of focal tissue perfusion. We hypothesized that SLCO2 could diagnose hemorrhagic shock and monitor adequacy of resuscitation. We compared the ability of SLCO2, serum lactate (LAC), and base deficit (BD) to predict outcome in hypotensive trauma patients. METHODS: Prospective, observational trial at two Level I trauma centers was performed. Inclusion criteria were blunt or penetrating trauma patients, age > or =16 years, with hypotension (systolic blood pressure < or =90 mm Hg). SLCO2, LAC, and BD were measured in each patient at admission, at the end of active hemorrhage, and at 6, 24, and 48 hours. Data are reported as means (+/-SD). RESULTS: A total of 86 patients were enrolled: mean age 35 (+/-17) years, 80% male, 51% blunt trauma, Injury Severity Score score 20 (+/-14). Twenty patients died. SLCO2 at admission was 52.4 (+/-13.3) in survivors versus 87.9 (+/-35.6) in nonsurvivors (p < 0.001). Receiver operating characteristic (ROC) curves showed that SLCO2, LAC, and BD were all good predictors of mortality. The area under each ROC curve was as follows: SLCO2 (0.82; 95% CI 0.70-0.96; p < 0.001), LAC (0.80; 95% CI 0.69-0.91; p < 0.001), BD (0.87; 95% CI 0.77-0.98; p < 0.001). There was no significant difference (p > 0.05) in the areas under the three curves. CONCLUSIONS: SLCO2 predicted survival in hypotensive trauma patients. It had equivalent diagnostic ability to LAC and BD. This rapid test may supplement standard, more invasive measures of hemorrhagic shock.     

Discordance between lactate and base deficit in the surgical intensive care unit: which one do you trust?

PURPOSE: Both lactate and base deficit (BD) are used as predictors of injury severity and mortality. We examined the significance of these measures when used in combination, and particularly when they provide conflicting data. METHODS: We reviewed all intensive care unit patients with simultaneously obtained lactate and BD measurements. The ability to predict mortality and hospital stay was compared alone, in combination, and when there was disagreement between the measures. Receiver operating characteristic curves were generated to compare predictive abilities. RESULTS: There were 1,298 patients with 12,197 sets of paired laboratory data; 1,026 trauma patients and 272 surgical patients. Lactic acidosis was present in 41% and a significant BD level (> 2) was found in 52%. Nonsurvivors had higher admission lactate (6.2 vs. 3.3) and base deficit (6.1 vs. 3.2) levels than survivors (both P < .01), with a modest correlation (r = .52) between the measures. The admission lactate and BD levels had similar predictive ability for mortality, with areas under the receiver operating characteristic curve of .7 and .66, respectively (both P < .01). However, the predictive ability of the BD level decreased significantly during the intensive care unit stay (area, .5) compared with lactate level (area, .68). Lactate and BD levels disagreed in 44% of all laboratory sets. In patients with a normal lactate level (< 2.2), the BD level had no predictive ability for mortality (area, .48; P = .26). However, in patients with a normal BD level (< 2.0), the lactate level retained its predictive ability for mortality (area, .67; P < .01). Lengths of stay were longer among patients with an increased lactate level, even when the BD level was normal. There was no improvement in predictive ability using a combination of the 2 measures. CONCLUSIONS: Both lactate and BD levels may be used to identify lactic acidosis and predict mortality at admission. Increased lactate levels predict mortality and a prolonged course regardless of the associated BD level, whereas an increased BD level has no predictive value if the lactate level is normal.     

Postoperative lactate concentrations predict the outcome of infants aged 6 weeks or less after intracardiac surgery: a cohort follow-up to 18 months

OBJECTIVES: An observational cohort study was conducted in infants less than 6 weeks of age undergoing intracardiac surgery to examine the predictive value of serial postoperative lactate determination on survival and early childhood neurodevelopment. METHODS: A total of 85 infants with congenital heart disease underwent intracardiac surgery between 1996 and 1999. Differences in serial lactate concentrations after surgery among 3 outcome groups were compared. The predictive value of plasma lactate concentration on outcome (1) at discharge from initial hospitalization and (2) 18 to 24 months postnatal age was examined. RESULTS: Compared with survivors, the nonsurvivors had higher lactate concentrations on admission to the pediatric intensive care unit at day 1 peak and area under the curve of the lactate profile than those of adverse and intact survivors (all P < .001, analysis of variance). Significant differences in the time for lactate concentrations to return to 2 mmol/L or less during the first postoperative day were observed among the groups: nonsurvivors > adverse survivors > intact survivors. Lactate concentrations of less than 7 mmol/L on admission or less than 8 mmol/L at day 1 peak predicted survival with 82% sensitivity and 83% specificity, and positive and negative predictive values of 97% and 43%, respectively (P < .001, chi2). Plasma lactate concentrations were associated with adverse outcome but had lower predictive values compared with that for nonsurvival. CONCLUSIONS: Serial lactate determination accurately predicts survival and may help differentiate survivors with adverse outcome from those with intact neurodevelopment in early childhood.     

Serial Measurement of Arterial Lactate Concentrations as a Prognostic Indicator in Relation to the Incidence of Disseminated Intravascular Coagulation in Patients with Systemic Inflammatory Response Syndrome

To demonstrate the prognostic value of measuring blood lactate concentrations and to investigate the mechanisms of lactate production in patients with systemic inflammatory response syndrome (SIRS), we conducted a prospective cohort study. Among 22 patients with SIRS, there were 9 survivors and 13 nonsurvivors. Serial arterial lactate concentrations were measured on the day of admission to the intensive care unit (day 0), then on days 1–4. The subjects of this study consisted of 14 patients with SIRS, 6 with severe sepsis, and 2 with septic shock. On admission, the lactate concentrations did not differ between the two groups, but remained high in the nonsurvivors throughout the study period, while they progressively decreased in the survivors. The incidence of disseminated intravas-cular coagulation (DIC) was significantly higher in the nonsurvivors than in the survivors. The nonsurvivors had persistently higher DIC scores and lower platelet counts than the survivors. The changes in lactate concentration over time were statistically different between the patients with DIC and those without DIC. The findings of this study clearly demonstrated that serial arterial lactate measurements can predict a poor outcome in patients with SIRS, severe sepsis, or septic shock. DIC might play an important role in the pathogenesis of lactate production in these newly defined critically ill patients. Received: March 1, 2000 / Accepted March 6, 2001     

Association of serum albumin concentration and mortality risk in critically ill patients

In this study we aimed to examine the association between serum albumin concentration and mortality risk in critically ill patients. We retrospectively studied 1003 patients admitted to ourIntensive Care Unit (ICU) over an 18-month period. Serial albumin measurements over 72 hours were compared between survivors and non-survivors, and medical and surgical patients were also compared. Our results showed that serum albumin decreased after ICU admission, most rapidly in the first 24 hours, in both survivors and non-survivors. Serum albumin was lower in non-survivors than in survivors, but albumin concentrations poorly differentiated the two groups. Medical patients had higher admission albumin levels than surgical patients, but both subgroups showed a similar albumin profile over 72 hours. We evaluated the prognostic value of serum albumin using receiver operator characteristic (ROC) curves. We constructed ROC curves for APACHE II score, admission albumin, albumin at 24 and 48 hours. We also combined APACHE II with albumin values and constructed the corresponding ROC curves. Our data showed that serum albumin had low sensitivity and specificity for predicting hospital mortality. Combining APACHE II score with serum albumin concentrations did not improve the accuracy of outcome prediction over that of APACHE II alone.     

Serial estimations of blood lactate predict postoperative outcome in cancer patients undergoing head and neck surgeries

To determine predictability of serial estimations of blood lactate levels for postoperative outcome of head and neck cancer patients and determine validity of single versus serial estimations for accurate prediction of outcome.The study included 322 cancer patients assigned for major head and neck surgeries and admitted to ICU. Data collection included age, sex, and associated comorbidities, and clinical status was determined using APACHE II score. Arterial lactate was measured at time of admission (T0), and 8-hourly (T8, T16, T24), and percentage of change of blood lactate level was calculated versus T0 level. Patients were categorized as survivor and non-survivors, and among each group, patients were categorized according to estimated level of blood lactate into four categories.The mean of APACHE score at ICU admission was 16.6 ± 3.1, and mean duration of ICU and hospital stay was 3.2 ± 1.2 and 19.3 ± 5.5 days, respectively. Fifty-two patients died for postoperative mortality rate 16.1%. Non-survivors were significantly older and had significantly higher APACHE score and significantly longer ICU and hospital stay. At admission blood lactate level was significantly higher in non-survivors compared to survivors. All patients showed progressive increase of blood lactate level, but non-survivors showed significantly higher frequency of elevated blood lactate strata compared to survivors with significantly higher difference between both groups at T8, T16, and T24. There was positive significant correlation between high at admission blood lactate level and APACHE score. Regression analysis defined % of change of blood lactate at T16, high APACHE score, high at admission blood lactate and old age as specific predictors for postoperative mortality in descending order of specificity. Serial estimations of blood lactate are conclusive test for follow-up of patients undergoing major surgical procedures requiring ICU admission. Combined high APACHE score and percentage of change of blood lactate could discriminate survivors from non-survivors especially 16-h after ICU admission.     

APACHE-II scoring system in perforative peritonitis

BACKGROUND: Prospective assessment of the Acute Physiology and Chronic Health Evaluation-II (APACHE-II) scoring system of stratification of disease severity has been shown to provide objective discrimination between low-risk and high-risk groups of patients with intra-abdominal sepsis. The current study was undertaken to evaluate the performance of APACHE-II score in prediction of mortality risk in patients with peritonitis due to hollow viscus perforation. STUDY DESIGN: Fifty patients admitted to a teaching hospital with peritonitis due to hollow viscus perforation were prospectively studied over a 2-year period. APACHE-II points were assigned to all patients in order to calculate their individual risk of mortality before undergoing emergency surgery. The accuracy in outcome prediction of the APACHE-II system was assessed by means of receiver operating characteristic (ROC) curve and the Pearson correlation coefficient and its significance test. RESULTS: Of the 50 patients admitted during the study period, there were 42 (84%) survivors and 8 (16%) nonsurvivors. Mean APACHE-II score of the study population was 11.38 with a range of 1 to 23. The predicted death rate was 23% and the observed death rate was 16%. Mean APACHE-II score in survivors was 9.88, whereas in nonsurvivors it was 19.25. Using ROC analysis, the area under the curve was found to be .984. Correlation of APACHE-II score and predicted death rate showed perfect correlation, with r = .99 and P <.001 [R2 = .9993]. APACHE-II score between 11 and 15 showed a sensitivity and specificity of 100% and 73.8%, respectively, and APACHE-II score of 16 to 20 had a sensitivity and specificity of 87.5% and 100%, respectively. CONCLUSION: APACHE-II score between 11 and 20 was shown to be a better predictor of risk of mortality in patients with peritonitis due to hollow viscus perforation. Predicted mortality did not correlate with observed mortality in patients with APACHE-II scores of 1 to 10 and greater than 20. The APACHE-II scoring system can be used to assess group outcomes in patients with peritonitis due to hollow viscus perforation. However, it does not provide sufficient confidence for outcome prediction in individual patients.     

Serial lactate and admission SOFA scores in trauma: an analysis of predictive value in 724 patients with and without traumatic brain injury

Objective

Arterial lactate, base excess (BE), lactate clearance, and Sequential Organ Failure Assessment (SOFA) score have been shown to correlate with outcome in severely injured patients. The goal of the present study was to separately assess their predictive value in patients suffering from traumatic brain injury (TBI) as opposed to patients suffering from injuries not related to the brain.

Materials and methods

A total of 724 adult trauma patients with an Injury Severity Score (ISS) ≥ 16 were grouped into patients without TBI (non-TBI), patients with isolated TBI (isolated TBI), and patients with a combination of TBI and non-TBI injuries (combined injuries). The predictive value of the above parameters was then analyzed using both uni- and multivariate analyses.

Results

The mean age of the patients was 39 years (77 % males), with a mean ISS of 32 (range 16–75). Mortality ranged from 14 % (non-TBI) to 24 % (combined injuries). Admission and serial lactate/BE values were higher in non-survivors of all groups (all p < 0.01), but not in patients with isolated TBI. Admission SOFA scores were highest in non-survivors of all groups (p = 0.023); subsequently septic patients also showed elevated SOFA scores (p < 0.01), except those with isolated TBI. In this group, SOFA score was the only parameter which showed significant differences between survivors and non-survivors. Receiver operating characteristic (ROC) analysis revealed lactate to be the best overall predictor for increased mortality and further septic complications, irrespective of the leading injury.

Conclusion

Lactate showed the best performance in predicting sepsis or death in all trauma patients except those with isolated TBI, and the differences were greatest in patients with substantial bleeding. Following isolated TBI, SOFA score was the only parameter which could differentiate survivors from non-survivors on admission, although the SOFA score, too, was not an independent predictor of death following multivariate analysis.     

The prognostic value of the delayed cutaneous immune reaction following multiple trauma in comparison with other clinical parameters

Infection is a frequent cause of morbidity and mortality after multiple trauma. Although impaired immune function has been assumed to be associated with the development of infection and sepsis in trauma victims, its predictive role is still controversial. In a prospective study, the predictive value of the immunological in vivo response to intradermally applied recall antigens was compared with serial determinations of routine parameters. PATIENTS AND METHODS. Using the commercially available Multitest device, the cutaneous delayed-type hypersensitivity (DTH) response to seven standardized recall antigens was sequentially tested at defined time intervals in 35 mechanically ventilated multiple-trauma patients (4 females, 31 males). Routine clinical and laboratory parameters (FiO2, lactate, creatinine, platelet count, absolute and differential white blood cell (WBC) count) were determined every day. Injury severity scores (ISS), infections, and intensive care unit (ICU) mortality were prospectively documented by the same investigator. RESULTS AND DISCUSSION. The overall ICU mortality was 23%. In survivors, the mean ISS was 29.5, in nonsurvivors 38.9 (P less than 0.05). Mortality significantly increased in association with sepsis. Interestingly, the DTH response and severity of the trauma did not show any interdependence. Immediately after ICU admission, DTH testing failed to correlate with either infection or mortality: most of the multiply traumatized patients were anergic on initial skin testing. In the early posttraumatic stage, the serum levels of creatinine or lactate, lymphocyte and promyelocyte counts, and FiO2 proved to be more reliable predictors. In the later course, however, a good correlation was found between sequential skin test results and the development of infection. Beginning on the 4th day after trauma, DTH scores below 5 mm defined a population with a high incidence of developing a clinically important septic episode. In conclusion, lactate, FiO2, and WBC counts are early indicators of an impending poor outcome, whereas the skin test response is not. In the later course, however, the sequentially determined DTH response may substantially contribute to the identification of multiple-trauma patients at increased risk of infection.     

Diagnosis of acid-base derangements and mortality prediction in the trauma intensive care unit: the physiochemical approach

BACKGROUND: Conventional measures such as anion gap and base deficit can be inadequate for defining and managing complex acid-base derangements. Physiochemical analysis is an alternative approach based on the principles of electroneutrality and conservation of mass, and may be more accurate for defining the presence and type of acidosis and unmeasured anions. METHODS: We retrospectively analyzed 2,152 sets of laboratory data from 427 trauma patients admitted to the intensive care unit. All data sets included simultaneous measurements of an arterial blood gas with base deficit (BD), serum electrolytes, albumin, lactate, and a calculated anion gap (AG). Physiochemical analysis was used to calculate the corrected anion gap (AGcorr), the apparent strong ion difference, the effective strong ion difference, the strong ion gap (SIG), and the base deficit corrected for unmeasured anions (BDua). Statistical analysis comparing AG and BD to the physiochemical measures was performed on all data and the subset of admission laboratory data only (n = 427). RESULTS: Unmeasured anions as defined by an elevated SIG were present in 92% of patients (mean SIG, 5.9 +/- 3.3), whereas hyperlactatemia and hyperchloremia were present in only 18% and 21%, respectively. The physiochemical approach yielded a different clinical interpretation of the acid-base status than the conventional approach in 597 (28%) of the data sets. Lactate level was more strongly correlated with the physiochemical measures of SIG (r = 0.48) and AGcorr (r = 0.47) than with the conventional measures of AG (r = 0.24) and BD (r = 0.36, p < 0.01 for all). Both admission BD and BDua were significantly elevated in nonsurvivors, and logistic regression analysis for prediction of mortality revealed an area under the curve of 0.70 for BDua (p < 0.01) versus 0.65 for BD (p < 0.01). AGcorr and SIG did not differentiate survivors from nonsurvivors in the group as a whole. However, analysis of patients with a normal admission lactate level (n = 322) demonstrated a significant difference between survivors and nonsurvivors in SIG (7 vs. 5, p = 0.009), BDua (-4.2 vs. -2.0, p = 0.004), and AGcorr (21 vs. 19, p = 0.04), whereas the conventional measures of BD and AG showed no significant discriminatory ability. CONCLUSION: Unmeasured anions are the most common component of metabolic acidosis in trauma intensive care unit patients. The physiochemical approach can significantly alter the acid-base diagnosis compared with conventional measures. The SIG, AGcorr, and BDua may be particularly helpful in predicting acid-base derangements and mortality in patients with normal serum lactate levels.     

Systemic inflammatory response syndrome and nosocomial infection in trauma

BACKGROUND: Admission systemic inflammatory response syndrome (SIRS) score has been previously reported to be an accurate predictor of infection and outcome in trauma. However, the data were limited to the first 7 days of admission. Our objective in this follow-up study was to prospectively evaluate the utility of daily SIRS scores in the second and third week of admission as compared with the first week in prediction of nosocomial infection and outcome in high-risk trauma patients. METHODS: Prospective data were collected on 1,277 consecutive trauma patients admitted during a 28-month period to the intensive care unit. SIRS scores were calculated daily for the first week and every other day for the following 2 weeks. Patients were categorized into SIRS occurring "early" (week 1), "middle" (week 2), and "late" (week 3). Centers for Disease Control and Prevention guidelines were used for the diagnosis of infection. Multivariate linear and logistic regression analyses were utilized for statistical analyses, controlling for the covariates of age, Injury Severity Score, and admission Glasgow Coma Scale score. RESULTS: The trauma cohort included patients with blunt injuries (84%) and penetrating injuries (16%). The mean age was 43 +/- 21 years with an overall mortality of 14.7%. Nosocomial infection developed in 580 (45.4%) of the study patients (respiratory site most common) with a total of 1,001 infections (some patients with multiple infections). SIRS (defined as SIRS score >/=2) was common, with 92.4% of patients manifesting SIRS at admission. SIRS was most prevalent during the first week postinjury (91% of patients manifesting SIRS), decreasing to 69% and 50% during postinjury weeks 2 and 3. SIRS was more common in patients who acquired nosocomial infections compared with noninfected patients. Logistic regression analysis confirmed that patients with "middle" SIRS during week 2 (odds ratio [OR] 17.62, confidence interval [CI] 12.95-23.97, p < 0.0001, receiver operating characteristic [ROC] 0.83) and "late" SIRS during week 3 (OR18.12, CI 12.71-25.84, p < 0.0001, ROC 0.81) had significantly greater risk for nosocomial infection compared with patients with "early" SIRS during week 1 (OR 4.55, CI 2.57-8.06, p < 0.0001, ROC 0.65) postinjury. CONCLUSION: SIRS is predictive of nosocomial infection in trauma through postinjury day 21. Nosocomial infection should be considered as a treatable cause of SIRS in trauma patients, and early diagnostic interventions should be initiated to evaluate for potential causes.     

Lactate and lactate clearance in critically burned patients: usefulness and limitations as a resuscitation guide and as a prognostic factor

ObjectiveLactate levels to guide resuscitation in critically burned patients are controversial. The purpose of our study was to determine whether absolute lactate values or lower lactate clearance predict mortality, and whether these are useful tools in the resuscitation phase.MethodsWe conducted a prospective, unicentric, observational study of a cohort of 214 burn patients admitted in the Burn Intensive Care Unit. We collected demographic and laboratory data, complications, absolute lactate levels and lactate clearance every 8 h since admission to 72 h. In critical patients we monitored hemodynamic parameters with transpulmonary thermodilution. We used Student’s t-test or nonparametric tests, mixed models and Pearson and Spearman methods, Fisher’s exact and chi-squared test.ResultsOf the 214 patients, 76.6% were male, mean age were 46 ± 15 years and 23.0 ± 19.5% of Total Basal Surface Area (TBSA) burned. Initial mean absolute levels of lactate were 2.02 ± 1.62 mmol/L in survivors vs. 4.05 ± 3.90 mmol/L in nonsurvivors. Initial elevated lactate levels increased mortality (p < .001), length of ICU stay, mechanical ventilation and shock. In the subgroup of burned TBSA < 20%, lowering the lactate cut-off point from 2.0 to 1.8 mmol/L improved the mortality prediction (OR:9.3). We found no relationship between lactate clearance in the first 24 h and mortality. In more severe patients (> 20% TBSA burned and initial lactate levels > 2), a good correlation was found between lactate and cardiac index; but not with intrathoracic blood volume index (ITBVI). Patients with low ITBVI preload (< 600 mL/m²) did not show significant differences in lactate clearance compared with those with ITBVI > 600.ConclusionsInitial elevated lactate levels are a factor of poor prognosis and the cut-off point that best predicts mortality should be adjusted in the patients with TBSA burned < 20%.The global clearance of lactate in the first 24 h, unlike what occurs in other injuries, does not correlate with mortality.Monitoring lactate can ensure adequate peripheral perfusion during resuscitation with lower than normal fluid preload values.     

Neutrophil-derived circulating free DNA (cf-DNA/NETs), a potential prognostic marker for mortality in patients with severe burn injury

The predictive value of circulating free DNA/neutrophil extracellular traps (cf-DNA/NETs) has recently been shown in patients with major trauma for sepsis, multiple organ failure, and mortality. Here we report on the predictive potential of cf-DNA/NETs for mortality in patients with severe burn injury. In a prospective study 32 patients with severe burn injury were included. Blood samples were sequentially obtained on day 1, 3, 5, and 7 after admission. cf-DNA/NETs was directly quantified from plasma by means of rapid fluorescence assay. Time kinetics of cf-DNA/NETs were correlated with clinical data, C-reactive protein (CRP), procalcitonin (PCT), and interleukin (IL)-6. Furthermore sensitivity, specificity, and positive and negative predictive value, as well as receiver operation characteristic (ROC) curves were calculated. Seven patients died within the first month after burn injury. cf-DNA/NETs values from these patients were significantly increased already on day 1 and 3 after admission compared with patients who survived (p < 0.01). In contrast, PCT levels of nonsurvivors were significantly elevated on day 3 and 5 (p < 0.01), while CRP and IL-6 did not show any significant difference between survivors and nonsurvivors. At a cutoff of 255 ng/ml, cf-DNA/NETs had sensitivity of 0.8 and specificity of 0.74. ROC revealed largest areas under the curve (AUC) for cf-DNA/NETs on day 1 (0.851) and 3 (0.883) after admission. For all values between day 1 and 7, AUC was 0.815. cf-DNA/NETs seems to be a rapid, valuable marker for prediction of mortality in burn patients. A larger confirmation trial ought to be carried out.     

Role of admission gas exchange measurement in predicting congenital diaphragmatic hernia survival in the era of gentle ventilation

Background/Purpose

Neonates with significant congenital diaphragmatic hernia (CDH) require cardiopulmonary support. Management has been characterized by progressive abandonment of hyperventilation. Ability to prognosticate outcomes using measures of ventilation and oxygenation with gentle ventilation remains unclear. We sought to determine whether assessment of gas exchange at the time of NICU admission is predictive of survival in this current era.

Methods

Neonates with CDH admitted to a Children’s Hospital from 1995 to 2006 were evaluated for demographics, blood gas (ABG) measurements and ventilator settings for the first 48 hours, and discharge outcome.

Results

One-hundred-and-nineteen CDH patients were admitted, 88 (74%) survived. Mean admission ABG pCO₂ was higher in infants who died compared to survivors (86 ± 48 versus 49 ± 20, p ≤ 0.001); positive predictive value (PPV) for mortality of pCO₂ ≥ 80 mmHg was 0.71. Mean first hour preductal oxygen saturation (preductalO₂Sat) was lower in infants who died compared to survivors (81 ± 17 versus 97 ± 5, p < 0.001); PPV for mortality of preductalO₂Sat < 85% was 0.82. Eleven patients met both pCO₂ and preductalO₂Sat criteria, and 10 (91%) died, PPV of 0.92. Within hours of admission, pCO₂ and preductalO₂Sat differences between survivors and nonsurvivors lost significance.

Conclusion

Admission pCO₂ and preductalO₂Sat may be useful in predicting survival in neonatal CDH. The differential in gas exchange between survivors and nonsurvivors loses significance with contemporary neonatal care.     

Improved prediction of outcome in patients with severe acute pancreatitis by the APACHE II score at 48 hours after hospital admission compared with the APACHE II score at admission. Acute Physiology and Chronic Health Evaluation

HYPOTHESIS: The 48-hour APACHE (Acute Physiology and Chronic Health Evaluation) II score is a better predictor of pancreatic necrosis, organ failure, and mortality in patients with severe acute pancreatitis than the score at hospital admission. DESIGN: A retrospective analysis of 125 patients with acute pancreatitis. SETTING: A tertiary public teaching hospital. PATIENTS: Patients with severe acute pancreatitis as defined by 3 or more Ranson criteria or a hospital stay of longer than 6 days. MAIN OUTCOME MEASURES: Pancreatic necrosis, organ failure, and mortality. RESULTS: A significant association was found between the 48-hour score and the presence of pancreatic necrosis (P<.001), organ failure (P =.001), and death (P<.001). By contrast, the APACHE II score at admission was significantly associated only with the presence of organ failure (P =.007). Deteriorating APACHE II scores over 48 hours were significantly associated with a fatal outcome (P =.03). The combined APACHE II score (defined as the sum of the admission and 48-hour scores) was significantly higher among nonsurvivors than survivors (P<.001), and was strongly associated with the presence of pancreatic necrosis (P =.001) and organ failure (P<.001). The 48-hour and combined scores accurately predicted outcome in 93% of the patients compared with 75% by the admission score. CONCLUSIONS: The 48-hour APACHE II score has improved predictive value compared with the admission score for identifying patients with severe acute pancreatitis who have a poor outcome. A deteriorating APACHE II score at 48 hours after admission may identify patients at risk for an adverse outcome.     

Massive transfusion exceeding 50 units of blood products in trauma patients

BACKGROUND: Massive transfusion of blood products in trauma patients can acutely deplete the blood bank. It was hypothesized that, despite a large allocation of resources to trauma patients receiving more than 50 units of blood products in the first 24 hours, outcome data would support the continued practice of massive transfusion. METHODS: A retrospective review of charts and registry data of trauma patients who received over 50 units of blood products in the first day was conducted for a 5-year period at a Level I trauma center. Patients were stratified into groups on the basis of the number of transfusions received. Results are expressed as mean +/- SD. Univariate analysis and multivariate logistic regression were used to identify those risk factors determined in the first 24 hours after admission that were predictive of mortality. Physiologic differences between survivors and nonsurvivors were also examined. RESULTS: Of 7,734 trauma patients admitted between July 1, 1995, and June 30, 2000, 44 (0.6%) received > 50 units of blood products in the first day. Overall mortality in these patients was 57%. There was no significant difference (p = 0.565, chi2) in mortality rate between patients who received > 75 units of blood products in the first day versus those who received 51 to 75 units. Multiple logistic regression analysis identified only one independent risk factor, base deficit > 12 mmol/L, associated with mortality. Base deficit > 12 mmol/L increases the risk of death by 5.5 times (p = 0.013; 95% confidence interval, 1.44-20.95). Neither the total blood product transfusion requirement in the first day nor the packed red blood cell transfusion amount in the first day were significant independent risk factors. Causes of the 25 deaths in this series included exsanguination in the operating room (n = 1) or in the surgical intensive care unit (n = 12), multiple organ failure/sepsis (n = 3), head injury (n = 3), respiratory failure (n = 2), cerebrovascular accident (n = 1), and other (n = 3). Of the survivors, 63% were discharged to home, 21% to rehabilitation, 11% to nursing home, and 5% to another acute care facility. Of the nonsurvivors, the mean Injury Severity Score was 43, 88% had a base deficit > 12 mmol/L, 68% had a Glasgow Coma Scale score < 8, and 64% had a Sequential Organ Failure Assessment score > 10. CONCLUSION: The 43% survival rate in trauma patients receiving > 50 units of blood products warrants continued aggressive transfusion therapy in the first 24 hours after admission.     

The effect of anemia and blood transfusions on mortality in closed head injury patients

BACKGROUND: The purpose of this study was to determine if anemia in isolated head trauma patients results in a higher mortality rate that would justify a more liberal use of blood transfusions. METHODS: A retrospective review of isolated blunt head trauma patients was performed between January 2001 and December 2006. Comparisons were made between survivors and nonsurvivors regarding demographics, laboratory values, transfusions received, and lengths of stay. RESULTS: There were 788 patients with 735 survivors who were significantly younger (46.3 y +/- 21.5 survivors versus 68.9 y +/- 18.8 nonsurvivors, P < 0.0001) and less injured [(ISS: 14.7 +/- 5.2 survivors versus 23.2 +/- 4.7 nonsurvivors, P < 0.0001), (head abbreviated injury severity: 3.7 +/- 0.7 survivors versus 4.7 +/- 0.5 nonsurvivors, P < 0.0001)] than those who died (n = 53). The survivors also had shorter lengths of stay (days) [(ICU: 2.4 +/- 4.2 versus 5.6 +/- 11.7, P = 0.03), (hospital: 6.3 +/- 9.8 versus 7.8 +/- 14.8, P = 0.02)]. Multivariate logistic regression showed age (OR 1.063, CI 1.042-1.084), ISS (OR 1.376, CI 1.270-1.491), minimum hemoglobin (OR 0.855, CI 0.732-1.000), and total blood products transfused (OR 1.073, CI 1.008-1.142) to be independent predictors of mortality with an ROC of 0.942. Outcome was independent of the operative procedures, hematocrit and packed red blood cells transfused at 24, 48, and 72 h. Hemoglobin levels of <8 mg/dL were more predictive of death than >8 mg/dL (P = 0.01). CONCLUSIONS: This study supports the need to balance mild anemia with judicious blood product use in the head trauma patient. Given the risk with blood product use, each transfusion should be carefully considered and the patient re-evaluated regularly to determine the need for further intervention.