How well does serum bicarbonate concentration predict the venous pH in children being evaluated for diabetic ketoacidosis?

Utilizing serum bicarbonate instead of venous pH to transition from intravenous to subcutaneous insulin shortens the duration of insulin infusion in pediatric diabetic ketoacidosis

Background Standard therapy of diabetic ketoacidosis (DKA) in pediatrics involves intravenous (IV) infusion of regular insulin until correction of acidosis, followed by transition to subcutaneous (SC) insulin. It is unclear what laboratory marker best indicates correction of acidosis. We hypothesized that an institutional protocol change to determine correction of acidosis based on serum bicarbonate level instead of venous pH would shorten the duration of insulin infusion and decrease the number of pediatric intensive care unit (PICU) therapies without an increase in adverse events. Methods We conducted a retrospective (pre/post) analysis of records for patients admitted with DKA to the PICU of a large tertiary care children's hospital before and after a transition-criteria protocol change. Outcomes were compared between patients in the pH transition group (transition when venous pH≥7.3) and the bicarbonate transition group (transition when serum bicarbonate ≥15 mmol/L). Results We evaluated 274 patient records (n=142 pH transition group, n=132 bicarbonate transition group). Duration of insulin infusion was shorter in the bicarbonate transition group (18.5 vs. 15.4 h, p=0.008). PICU length of stay was 3.2 h shorter in the bicarbonate transition group (26.0 vs. 22.8 h, p=0.04). There was no difference in the number of adverse events between the groups. Conclusions Transitioning patients from IV to SC insulin based on serum bicarbonate instead of venous pH led to a shorter duration of insulin infusion with a reduction in the number of PICU therapies without an increase in the number of adverse events.

Resolution of ketoacidosis in children with new onset diabetes: Evaluation of various definitions

AIMS

Data are sparse concerning use of serum electrolyte parameters as compared to venous blood gas (VBG) measurements to monitor acid-base status during treatment of diabetic ketoacidosis (DKA). We explored the utility of various parameters to define DKA resolution by investigating the relationship of venous pH (vpH), anion gap (AG), serum bicarbonate (HCO₃), and glucose concentration during management of DKA in children with new onset diabetes mellitus (NODM).

METHODS

We included all patients with NODM presenting with DKA to Boston Children's Hospital from 10/1/07-7/1/13. DKA was defined as serum glucose ≥ 200 mg/dL (11.1 mmol/L) and vpH<7.30; severity as mild <7.30, moderate<7.20, severe<7.10; resolution of DKA as vpH≥7.30 and AG≤18 mmol/L. We used Cox regression to determine time to DKA resolution, and logistic regression to evaluate different serum HCO₃ cut-off values as predictors of DKA resolution.

RESULTS

263 patients (133F, mean age 9.9±4.4 years, 74% White) were included. DKA was mild in 134 (51%), moderate in 75 (28%) and severe in 54 (20%). In mild DKA, AG closed after normalization of vpH; in moderate and severe DKA, AG closed before normalization of vpH. HCO₃>15mmol/L correlated with vpH≥7.30, and had 76% sensitivity and 85% specificity to predict DKA resolution. Median times to DKA resolution were similar using two different definitions: vpH and AG (8.4h [IQR 6.3-11.9]) vs. HCO₃>15 mmol/L (7.9 h [IQR 5.0-11.8]), p=.42.

CONCLUSIONS

During management of pediatric DKA, HCO₃ > 15 mmol/L reliably predicts resolution of DKA. In low-resource settings where VBG is unavailable, electrolyte parameters alone may be used to determine DKA resolution.

Is Serum Bicarbonate Level Associated With Negative Outcomes in Pediatric Patients?: A Retrospective Cohort Study

OBJECTIVES

Early identification of children at risk for adverse outcomes is important. Serum bicarbonate is easily collected and widely available. We described the relationship between bicarbonate and adverse outcomes in children presenting to the emergency department (ED).

METHODS

We conducted a retrospective cohort study of children aged 0 to 17 years from January 1, 2007, to December 31, 2011, who had a serum bicarbonate measured in the ED. Primary outcome was the predictive ability of bicarbonate for the individual components of the composite outcome that included at least one of the following: intensive care unit admission, assisted ventilation, inotropic support, cardiopulmonary resuscitation, or death. Secondary outcome was the relationship between bicarbonate level of greater and less than 13 mEq/L and the composite outcome.

RESULTS

We reviewed 16,989 charts, of which 432 had an adverse outcome. Receiver operating characteristic curve analysis showed that a bicarbonate level of less than 18.5 mEq/L predicted inotropic support with an area under the curve of 0.69 (95% confidence interval [CI], 0.60-0.77; P < 0.001) and death with an area under the curve of 0.75 (CI, 0.66-0.85; P < 0.001). Significantly more patients with bicarbonate level of less than 13 mEq/L had at least 1 adverse outcome compared with those with bicarbonate level of greater than 13 mEq/L (4.4% vs 2.5%, P = 0.001), odds ratio 1.96 (95% CI, 1.3-2.97).

CONCLUSIONS

Among children presenting to the ED, bicarbonate level of 18.5 mEq/L had fair specificity in predicting inotropic support and death. Negative outcomes are significantly associated with bicarbonate level of less than 13 mEq/L. Bicarbonate should routinely be measured in children at risk of clinical deterioration.

Venous serum bicarbonate concentration predicts arterial pH in adults with diabetic ketoacidosis

OBJECTIVE

The initial assessment of metabolic acidosis in subjects with diabetic ketoacidosis (DKA) is arterial blood gas analysis. This process is expensive, painful, and technically difficult. Furthermore, blood gas analysis may not be available in some facilities, especially in developing countries where DKA-associated morbidity and mortality remain high. Therefore, we investigated the utility of venous bicarbonate concentration obtained from a basic metabolic panel in predicting arterial pH in adults with DKA.

METHODS

We performed a retrospective analysis of clinical and biochemical data of 396 adults admitted to 2 community teaching hospitals with DKA. We determined the correlation between arterial pH and venous serum parameters. Using multiple logistic regression, we obtained a predictive formula for arterial pH from serum venous bicarbonate level.

RESULTS

The patient population was 59.0% male and had a mean age of 36.7 ± 13.3 years. We derived that arterial pH = 6.97 + (0.0163 x bicarbonate), and by applying this equation, we determined that serum venous bicarbonate concentration of ≤20.6 mEq/L predicted arterial pH ≤7.3 with over 95% sensitivity and 92% accuracy.

CONCLUSION

Venous serum bicarbonate obtained from the basic metabolic panel is an affordable and reliable way of estimating arterial pH in adults with DKA. Validation of this formula in a prospective study would offer a more accessible means of estimating metabolic acidosis in adults with DKA, especially in developing countries where DKA incidence and mortality remain high.

The evolution of diabetic ketoacidosis: An update of its etiology, pathogenesis and management

The prognosis of diabetic ketoacidosis has undergone incredibly remarkable evolution since the discovery of insulin nearly a century ago. The incidence and economic burden of diabetic ketoacidosis have continued to rise but its mortality has decreased to less than 1% in good centers. Improved outcome is attributable to a better understanding of the pathophysiology of the disease and widespread application of treatment guidelines. In this review, we present the changes that have occurred over the years, highlighting the evidence behind the recommendations that have improved outcome. We begin with a discussion of the precipitants and pathogenesis of DKA as a prelude to understanding the rationale for the recommendations. A brief review of ketosis-prone type 2 diabetes, an update relating to the diagnosis of DKA and a future perspective are also provided.

Use of Serum Bicarbonate to Substitute for Venous pH in New-Onset Diabetes

OBJECTIVE

To investigate whether serum bicarbonate (HCO3) levels can be used to accurately diagnose diabetic ketoacidosis (DKA) and classify its severity in children with new-onset diabetes mellitus (NODM).

METHODS

Retrospective study of all patients with NODM presenting to Boston Children's Hospital from October 1, 2007, to July 1, 2013. DKA was defined as blood glucose ≥200 mg/dL, venous pH (vpH) <7.3, and urine ketones ≥2+, and severe DKA as vpH <7.1. Linear regression was used to assess serum HCO3 as a predictor of vpH, and logistic regression to evaluate serum HCO3 as a predictor of DKA and severe DKA.

RESULTS

Of 690 study cohort subjects (47% girls, age 10.8 ± 4.3 years, 76.7% white), 19.4% presented with DKA. The relationship between serum HCO3 and vpH was log-linear (r = 0.87, 95% CI 0.85-0.89, P < .001). HCO3 predicted vpH (R(2) 0.75, P < .001) using the formula vpH = 6.81301 + (0.17823*ln[HCO3]) and DKA and severe DKA (c-statistic 0.97 [95% CI 0.96-0.99, P < .001] and 0.99 [95% CI 0.991-0.999, P < .001], respectively). HCO3 cutoffs of <18 and <8 mmol/L had sensitivities of 91.8% and 95.2%, and specificities of 91.7% and 96.7%, respectively, to diagnose DKA and severe DKA. Findings were similar in a validation cohort of 197 subjects.

CONCLUSIONS

Serum HCO3 concentration alone can substitute for vpH to diagnose DKA and classify severity in children with NODM. It is suggested as an alternative to reliance on vpH, especially in settings in which access to vpH measurement is limited.

Euthyroid sick syndrome in children with diabetic ketoacidosis

OBJECTIVES

To investigate characteristics of euthyroid sick syndrome (ESS) in children with diabetic ketoacidosis (DKA).

METHODS

This retrospective study was carried out between May 2010 and April 2013 at the Pediatric Department of Shandong Provincial Hospital, Shandong University, Shandong, China. Diabetic ketoacidosis children were divided into 2 groups: euthyroidism (group one, n=30) and ESS (group 2, n=40). C-peptide, glycosylated hemoglobin (HbA1c), bicarbonate, anion gap (AG), free triiodothyronine (FT3), free thyroxine (FT4), and thyrotropin (TSH) levels were measured before and after 7 days of insulin treatment. Daily blood glucose (BG) profiles were recorded.

RESULTS

Glycosylated hemoglobin, AG, the mean daily BG, and fasting blood glucose levels were higher, and bicarbonate, FT3, FT4, and TSH levels were lower in group 2 than in group one (all p&lt;0.05). Free triiodothyronine (r=-0.593, p&lt;0.001) and FT4 (r=-0.402, p=0.001) were negatively correlated with HbA1c. Free triiodothyronine (r=-0.438, p&lt;0.001) and FT4 (r=-0.505, p&lt;0.001) were negatively correlated with AG, and FT3 (r=0.503, p&lt;0.001) and FT4 (r=0.448, p&lt;0.001) were positively correlated with bicarbonate.

CONCLUSION

Diabetic ketoacidosis children with ESS have poor diabetic control. Free thyroid hormones are associated with the severity of DKA.

Diabetic ketoacidosis in the pediatric emergency department

Despite many advances, the incidence of pediatric-onset diabetes and diabetic ketoacidosis (DKA) is increasing. Diabetes mellitus is 1 of the most common chronic pediatric illnesses and, along with DKA, is associated with significant cost and morbidity. DKA is a complicated metabolic state hallmarked by dehydration and electrolyte disturbances. Treatment involves fluid resuscitation with insulin and electrolyte replacement under constant monitoring for cerebral edema. When DKA is recognized and treated immediately, the prognosis is excellent. However, when a patient has prolonged or multiple courses of DKA or if DKA is complicated by cerebral edema, the results can be devastating.

Diabetic ketoacidosis at diabetes onset: still an all too common threat in youth

OBJECTIVE

To define the demographic and clinical characteristics of children at the onset of type 1 diabetes (T1D), with particular attention to the frequency of diabetic ketoacidosis (DKA).

STUDY DESIGN

The Pediatric Diabetes Consortium enrolled children with new-onset T1D into a common database. For this report, eligible subjects were aged <19 years, had a pH or HCO(3) value recorded at diagnosis, and were positive for at least one diabetes-associated autoantibody. Of the 1054 children enrolled, 805 met the inclusion criteria. A pH of <7.3 and/or HCO(3) value of <15 mEq/L defined DKA. Data collected included height, weight, hemoglobin A1c, and demographic information (eg, race/ethnicity, health insurance status, parental education, family income).

RESULTS

The 805 children had a mean age of 9.2 years, 50% were female; 63% were non-Hispanic Caucasian. Overall, 34% of the children presented in DKA, half with moderate or severe DKA (pH <7.2). The risk for DKA was estimated as 54% in children aged <3 years and 33% in those aged ≥ 3 years (P = .006). In multivariate analysis, younger age (P = .002), lack of private health insurance (P < .001), African-American race (P = .01), and no family history of T1D (P = .001) were independently predictive of DKA. The mean initial hemoglobin A1c was higher in the children with DKA compared with those without DKA (12.5% ± 1.9% vs 11.1% ± 2.4%; P < .001).

CONCLUSION

The incidence of DKA in children at the onset of T1D remains high, with approximately one-third presenting with DKA and one-sixth with moderate or severe DKA. Increased awareness of T1D in the medical and lay communities is needed to decrease the incidence of this life-threatening complication.

Current concepts and controversies in prevention and treatment of diabetic ketoacidosis in children

Diabetic ketoacidosis (DKA) is caused by absolute or relative lack of insulin. Lack of insulin leads to hyperglycemia, ketonemia, and acidosis. Prevalence of DKA at diagnosis of type 1 diabetes (T1D) varies around the world from 18 % to 84 %. Incidence of recurrent DKA is higher among females, insulin pump users, those with a history of psychiatric or eating disorder, and suboptimal socioeconomic circumstances. DKA is the most common cause of death in children with T1D. Children with DKA should be treated in experienced centers. Initial bolus of 10-20 mL/kg 0.9 % saline is followed by 0.45 %-0.9 % saline infusion. Fluid infusion should precede insulin administration (0.1 U/kg/h) by 1-2 hours. The prevention of DKA at diagnosis of diabetes can be achieved by an intensive community intervention and education of health care providers to raise awareness. Prevention of recurrent DKA requires continuous patient education and access to diabetes programs and telephone services.