Clinical utility of standard base excess in the diagnosis and interpretation of metabolic acidosis in critically ill patients (original) (raw)
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Asian Journal of Medical Sciences
Abnormalities identified by various methods (strong ion gap (SIG), AG, lactic acidosis) appears to be more common in critically ill patients and are associated with increased mortality especially when it occurs early in the course of critical illness. 2 Certain types of metabolic acidosis are strong independent predictors of mortality in critically ill patients and should be monitored in intensive care units. 2 Lactic acidosis is commonly associated with mortality and hence Serum lactate is considered as an prognostic indicator of illness severity. 3-5
Journal of Critical Care, 2010
Purpose: Inorganic apparent strong ion difference (SIDai) improves chloride-associated acidosis recognition in dysnatremic patients. We investigated whether the difference between sodium and chloride (Na + -Cl − ) or the ratio between chloride and sodium (Cl − /Na + ) could be used as SIDai surrogates in mixed and dysnatremic patients. Patients and methods: Two arterial blood samples were collected from 128 patients. Physicochemical analytical approach was used. Correlation, agreement, accuracy, sensitivity, and specificity were measured to examine whether Na + -Cl − and Cl − /Na + could be used instead of SIDai in the diagnosis of acidosis. Results: Na + -Cl − and Cl − /Na + were well correlated with SIDai (R = 0.987, P b 0.001 and R = 0.959, P b 0.001, respectively). Bias between Na + -Cl − and SIDai was high (6.384 with a limit of agreement of 4.463-8.305 mEq/L). Accuracy values for the identification of SIDai acidosis (b38.9 mEq/L) were 0.989 (95% confidence interval [CI], 0.980-0.998) for Na + -Cl − and 0.974 (95% CI, 0.959-0.989) for Cl − /Na + . Receiver operator characteristic curve showed that values revealing SIDai acidosis were less than 32.5 mEq/L for Na + -Cl − and more than 0.764 for Cl − /Na + with sensitivities of 94.0% and 92.0% and specificities of 97.0% and 90.0%, respectively. Na + -Cl − was a reliable SIDai surrogate in dysnatremic patients. Conclusions: Na + -Cl − and Cl − /Na + are good tools to disclose SIDai acidosis. In patients with dysnatremia, Na + -Cl − is an accurate tool to diagnose SIDai acidosis.
INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY
Metabolic acidosis is prevalent among critically ill patients and the common cause of metabolic acidosis in ICU is lactic acidosis. However, not all ICUs can provide lactate measurement. The traditional method that uses Henderson-Hasselbach equation (completed with BE and AG) and alternative method consisting of Stewart and its modification (BDEgap and SIG), are acid-base balance parameters commonly used by clinicians to determine metabolic acidosis in critically ill patients. The objective of this study was to discover the association between acid-base parameters (BE, AGobserved, AGcalculated, SIG, BDEgap) with lactate level in critically ill patients with metabolic acidosis. This was an analytical study with a cross-sectional design. Eighty-four critically ill patients hospitalized in the ICU department Dr. M. Djamil Padang Hospital were recruited in this study from January to September 2016. Blood gas analysis and lactate measurement were performed by potentiometric and amperomet...
Critical care (London, England), 2005
Acid-base abnormalities are common in critically ill patients. Our ability to describe acid-base disorders must be precise. Small differences in corrections for anion gap, different types of analytical processes, and the basic approach used to diagnose acid-base aberrations can lead to markedly different interpretations and treatment strategies for the same disorder. By applying a quantitive acid-base approach, clinicians are able to account for small changes in ion distribution that may have gone unrecognized with traditional techniques of acid-base analysis. Outcome prediction based on the quantitative approach remains controversial. This is in part due to use of various technologies to measure acid-base variables, administration of fluid or medication that can alter acid-base results, and lack of standardized nomenclature. Without controlling for these factors it is difficult to appreciate the full effect that acid-base disorders have on patient outcomes, ultimately making result...
Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine, 2010
The correct renal response to metabolic acidosis should be a negative shift in the urinary strong ion difference ([SID](urinary) = [Na(+)](urinary) + [K(+)](urinary) - [Cl(-)](urinary)). Our hypothesis was that the failure to decrease the [SID](urinary) is frequently present and leads to a more severe metabolic acidosis. Prospective observational study conducted in the medical/surgical intensive care unit of a teaching hospital between 1 January 2006 and 30 April 2007. Participants were 98 patients with metabolic acidosis on ICU admission and 10 healthy volunteers. None. Severity of metabolic acidosis; behaviour of acid-base variables according to positive or negative [SID](urinary). Twelve patients (12%) had negative [SID](urinary) and 86 (88%) had positive [SID](urinary). Compared with patients with positive [SID](urinary), those with negative [SID](urinary) had higher [HCO(3) (-)] (20 ±2 v 18 ±3 mmol/L), base excess ([BE]) (-5 ±2 v -7 ±2 mmol/L), anion gap ([AG]) (21 ±5 v 17 ±4 m...
Defining metabolic acidosis in patients with septic shock using Stewart approach
The American Journal of Emergency Medicine, 2012
Purpose: The aim of this study was to define the nature of metabolic acidosis in patients with septic shock on admission to intensive care unit (ICU) using Stewart method. We also aimed to compare the ability of standard base excess (SBE), anion gap (AG), and corrected AG for albumin and lactate (AGcorr) to accurately predict the presence of unmeasured anions (UA). Patients and Methods: Thirty consecutive patients with septic shock were prospectively included on ICU admission. Stewart equations modified by Figge were used to calculate the strong ion difference and the strong ion gap (SIG). Results: Most patients had multiple underlying mechanisms explaining the metabolic acidosis. Unmeasured anions and hyperchloremia were present in 70% of the patients. Increased UA were present in 23% of patients with normal values of SBE and [HCO 3 − ]. In these patients, plasma [Cl − ] was significantly lower compared with patients with low SBE and increased UA (103 [102-106.6] vs 108 [106-111] mmol/L; P = .01, respectively). Corrected AG for albumin and lactate had the best correlation with SIG (r² = 0.94; P b .0001) with good agreement (bias, 0, and precision, 1.22) and highest area under the receiver operating characteristic curve (0.995; 95% confidence interval, 0.87-1) to discriminate SIG acidosis. Conclusions: Patients with septic shock exhibit a complex metabolic acidosis at ICU admission. High UA may be present with normal values of SBE and [HCO 3 − ] as a result of associated "relative" hypochloremic alkalosis. Corrected AG for albumin and lactate offers the most accurate bedside alternative to Stewart calculation of UA.
Assiut Scientific Nursing Journal, 2020
Background: Acid-base disturbances are common in critically ill patients and pose a great burden in the management of the underlying condition. Aim: To explore the common types of acid-base disturbances among the critically ill patients in ICU. Design: A descriptive study design was utilized. Setting: This study was carried out in the Trauma and general Intensive Care Units at Assiut university hospital. Sample: Eighty adult male and female patients admitted to trauma and general ICUs. Tools: Three tools were used in this study, patient assessment tool, APACHE II tool, and Acid-base parameters assessment tool. Result: Eighty patients suffered from acid-base disorders with mean age (41.88 ±13.39) years. The mean pH on admission was (7.34 ±0.13), the mean length of ICU stay was (10.90 ±7.86). Respiratory alkalosis was the most frequent of simple acid-base disturbance (73.8%) followed by metabolic alkalosis (33.8%), respiratory acidosis (32.5%). Mixed acid-base disorders were relatively less frequent, the common combination was metabolic acidosis with respiratory acidosis (15.0%). Conclusion: Acidbase disturbance are common among critically ill patients presenting at the ICU. Respiratory alkalosis was the most frequent simple acid-base disturbance was observed among such group of patients. Recommendation: Acid-base disturbance should be monitored closely, diagnosed early, and managed correctly during hospitalization.
Stweard analysis of apparently normal acid-base state in the critically ill
Purpose: This study aimed to describe Stewart parameters in critically ill patients with an apparently normal acid-base state and to determine the incidence of mixed metabolic acid-base disorders in these patients. Materials and Methods: We conducted a prospective, observational multicenter study of 312 consecutive Dutch intensive care unit patients with normal pH (7.35 ≤ pH ≤ 7.45) on days 3 to 5. Apparent (SIDa) and effective strong ion difference (SIDe) and strong ion gap (SIG) were calculated from 3 consecutive arterial blood samples. Multivariate linear regression analysis was performed to analyze factors potentially associated with levels of SIDa and SIG. Results: A total of 137 patients (44%) were identified with an apparently normal acid-base state (normal pH and −2 b base excess b 2 and 35 b PaCO2 b 45 mm Hg). In this group, SIDa values were 36.6 ± 3.6 mEq/L, resulting from hyperchloremia (109 ± 4.6 mEq/L, sodium-chloride difference 30.0 ± 3.6 mEq/L); SIDe values were 33.5 ± 2.3 mEq/L, resulting from hypoalbuminemia (24.0 ± 6.2 g/L); and SIG values were 3.1 ± 3.1 mEq/L. During admission, base excess increased secondary to a decrease in SIG levels and, subsequently, an increase in SIDa levels. Levels of SIDa were associated with positive cation load, chloride load, and admission SIDa (multivariate r2 = 0.40, P b .001). Levels of SIG were associated with kidney function, sepsis, and SIG levels at intensive care unit admission (multivariate r2 = 0.28, P b .001). Conclusions: Intensive care unit patients with an apparently normal acid-base state have an underlying mixed metabolic acid-base disorder characterized by acidifying effects of a low SIDa (caused by hyperchloremia) and high SIG combined with the alkalinizing effect of hypoalbuminemia.