Comparison of Arterial and Venous Blood Gas Values in the Initial Emergency Department Evaluation of Patients With Diabetic Ketoacidosis

doi:10.1016/S0196-0644(98)70254-9

Annals of Emergency Medicine

Volume 31, Issue 4, April 1998, Pages 459-465

Presented in part at the Society for Academic Emergency Medicine Annual Meeting, Denver, CO, May 1996.

https://doi.org/10.1016/S0196-0644(98)70254-9 Get rights and content

Abstract

Study objective: To determine whether venous blood gas values can replace arterial gas values in the initial emergency department evaluation of patients with suspected diabetic ketoacidosis. Methods: This prospective comparison was performed in an adult university teaching hospital ED. Samples for arterial and venous blood gas analysis were obtained during initial ED evaluations. The venous gas samples were collected with samples for other blood tests at the time of intravenous line insertion. Both arterial and venous samples were obtained before the initiation of treatment. Result: Data from 44 episodes of diabetic ketoacidosis in 38 patients were analyzed. Laboratory findings of those patients with diabetic ketoacidosis were as follows (mean±SD): arterial pH, 7.20±.14; venous pH, 7.17±.13; serum glucose, 33.8±16 mmol/L (609±288 mg/dL); arterial HCO ₃^–, 11.0±6.0 mmol; venous HCO ₃^–, 12.8±5.5 mmol/L; serum CO ₂, 11.8±5.0 mmol/L; and anion gap, 26.7±7.6 mmol/L. The mean difference between arterial and venous pH values was 0.03 (range 0.0 to 0.11). Arterial and venous pH results (r=.9689) and arterial and venous HCO ₃^– results (r=.9543) were highly correlated and showed a high measure of agreement. Conclusion: Venous blood gas measurements accurately demonstrate the degree of acidosis of adult ED patients presenting with diabetic ketoacidosis. [Brandenburg MA, Dire DH: Comparison of arterial and venous blood gas values in the initial emergency department evaluation of patients with diabetic ketoacidosis. Ann Emerg Med April 1998; 31:459-465.]

Section snippets

INTRODUCTION

Diabetic ketoacidosis (DKA) is a metabolic derangement consisting of high blood glucose concentration, measurable ketone bodies, and metabolic acidosis, and is an endocrinologic emergency responsible for approximately 110,000 hospital admissions in the United States annually.¹ DKA is the most common serious and life-threatening acute complication of diabetes. The mortality rate is currently estimated at 2% to 10% for patients hospitalized with DKA.1, 2, 3

Determination of arterial blood gas

METHODS

Patients presenting to the ED at University Hospital in Oklahoma City, the adult teaching hospital for the University of Oklahoma, College of Medicine, were eligible for this study if they had a fingerstick bedside blood glucose measurement in excess of 13.9 mmol/L (>250 mg/dL), urine dipstick result positive for ketones, and the emergency physician clinically suspected DKA before the results of further laboratory tests were known. This protocol was reviewed by the Office of Research

RESULTS

A convenience sample of 61 patients with 68 suspected episodes of DKA was enrolled into this study during a 14-month period (no patient was enrolled more than twice). Data on 23 patients with 24 episodes were omitted from anal-ysis for the following reasons: patient did not have acidosis, 14; serum ketone results were negative, 5; no venous blood gas analysis was done, 2; no arterial blood gas analysis was done, 1; no serum ketone analyses were done, 1; and patient was not hyperglycemic, 1.

DISCUSSION

At present, there is no consensus definition in the medical literature regarding the diagnostic criteria for DKA.² Our study criteria are most similar to the diagnostic guidelines used by Fleckman.17, 18

In DKA, mortality is related to the age and state of consciousness of the patient, and the degree of acidosis, hyperglycemia, and azotemia.¹⁹ Determination of acid-base status, therefore, has prognostic as well as diagnostic value. To clearly characterize the acidosis, a measurement of the

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Cited by (137)

A comparison of venous blood gas analysis with paired specimens collected in syringes and evacuated blood collection tubes
2020, Clinica Chimica Acta
Venous blood samples collected in evacuated blood collection tubes are generally not considered suitable for measurement of oxygenation status. However, whether pH, pCO₂ and HCO₃^– results from venous blood samples collected in evacuated tubes are reliable remains unclear.
Paired samples were collected from 38 healthy volunteers using two collection methods: (1) collection of blood directly into a blood gas syringe and (2) collection of blood into an evacuated tube with subsequent anaerobic transfer into a blood gas syringe. Samples were analyzed for pH, pCO₂, HCO₃^–, and pO₂.
Samples collected in evacuated tubes showed significant positive mean biases of 0.03 and 7.5 mmHg for pH and pO₂, respectively, and significant negative mean biases of 5.0 mmHg and 1.2 mmol/l for pCO₂ and HCO₃^–, respectively. Collection in evacuated tubes resulted in biases exceeding the total allowable errors in 16%, 40%, 21% of samples for pH, pCO₂, HCO₃^–, respectively, when compared to samples collected in syringes directly.
Samples for venous blood gas analysis should be collected directly into blood gas syringes for accurate assessment of ventilation and/or acid-base status. Biases observed for samples collected in evacuated tubes are consistent with air contamination and/or vacuum effects.
New Test, Old Disease: A Case Series of Diabetic Ketoalkalosis
2020, Journal of Emergency Medicine
Citation Excerpt :
In our case series, we noted a discrepancy between our AGs calculated from VBG and BMP and took a closer look at the electrolytes, specifically HCO3, Na, K, and Cl. Most studies compared reliability of electrolytes between arterial blood gas and venous blood gas samples as opposed to basic metabolic panel (16,17). However, there are a few studies that have evaluated certain electrolyte values obtained from VBG to BMP (18–22).
Diabetic ketoalkalosis (DKAlk) was first described in 1967 as a rare complication of diabetic ketoacidosis with normal or elevated pH/bicarbonate and elevated anion gap (AG) from high β-hydroxybutyrate (BHB).
We report a case series of patients with DKAlk to show how venous blood gas (VBG) electrolytes alone may misdiagnose these patients.
This was a case series of DKAlk patients with concomitant VBG and basic metabolic panel (BMP) electrolytes who met the following criteria for DKAlk: BMP hyperglycemia (glucose >250 mg/dL), elevated AG (>15 mEq/L), elevated BHB (>1.2 mmol/L), and high Delta (Δ) gap (>6 mEq/L [bicarbonate gap (BG): measured bicarbonate – 24] – [AG – 12]). Data are reported as median with interquartile range (IQR) (25%, 75%) and group comparisons utilized Mann-Whitney U test (two-tailed, α = 0.05).
We found 10 patients with DKAlk in 2 months. Patients ranged in age from 13 to 77 years, 50% were male, and all were African American. Most patients (8 of 10) were vomiting with hyperglycemia (350 to >600 mg/dL). DKAlk BMP AG ranged from 18 to 34 mmol/L and BHB from 1.74 to 9.09 mmol/L. For bicarbonate, we found no significant difference between VBG (24 mmol/L) and BMP (22 mmol/L) (p = 0.796). VBG chloride (98 mmol/L) was significantly higher than BMP chloride (88 mmol/L) (p < 0.005). This falsely elevated VBG chloride resulted in undervaluing of all VBG AGs, missing almost all of the patients with DKAlk.
We found that DKAlk is more common than previously reported. We recommend screening with BMP electrolytes and BHB levels for hyperglycemic ED patients who are vomiting or suspected of hypovolemia.
Acute Management of Diabetic Ketoacidosis in Adults at 3 Teaching Hospitals in Canada: A Multicentre, Retrospective Cohort Study
2019, Canadian Journal of Diabetes
Diabetic ketoacidosis (DKA) is a common acute complication of diabetes mellitus and is associated with significant morbidity and mortality. There is currently a paucity of data concerning the Canadian experience with DKA. We aimed to characterize the acute management and course of DKA at several Canadian hospitals.
We performed a retrospective cohort study of patients admitted to 3 teaching hospitals in Edmonton, Canada. We extracted clinical and laboratory data from the medical charts of patients admitted to general internal medicine wards or intensive care units with moderate or severe DKA.
We included 103 admissions (84 patients) in our study. The majority (68.9%) had type 1 diabetes and presented with severe DKA (60.2%). In the first 24 h, the median (interquartile range) intravenous fluid received was 7.0 (5.5 to 8.8) litres; 23.3% received a priming insulin bolus, 24.3% received bicarbonate and 91.3% received potassium. Hypoglycemia was relatively rare (5.8%), but hypokalemia was common (41.7%). The median time to anion gap ≤12 mmol/L was 8.8 (6.0 to 12.3) h. In 27.1% of cases, intravenous insulin was stopped prior to subcutaneous insulin administration, with a median of 95 (30 to 310) min elapsing before subcutaneous insulin was given. DKA-related mortality was 2.9%.
The acute management of DKA was generally aligned with clinical guidelines. Areas for improvement include preventing hypokalemia by proactively increasing potassium repletion, reducing initial insulin boluses, administering subcutaneous insulin before stopping intravenous insulin and administering sodium bicarbonate judiciously. Protocols and preprinted order sets may be helpful, especially in smaller centres.
L'acidocétose diabétique (ACD) est une complication à court terme fréquente du diabète sucré et est associée à des taux significatifs de morbidité et de mortalité. Il existe actuellement peu de données sur l'expérience canadienne en ce qui concerne l'ACD. Nous avions pour objectif de caractériser la prise en charge à court terme et l'évolution de l'ACD dans plusieurs hôpitaux du Canada.
Nous avons réalisé une étude de cohorte prospective auprès de patients admis dans 3 hôpitaux d'enseignement d'Edmonton, au Canada. Nous avons extrait les données cliniques et de laboratoire des dossiers médicaux des patients admis dans les salles de médecine interne générale ou dans les unités de soins intensifs en raison d'une ACD modérée ou grave.
Nous avons tenu compte de 103 admissions (84 patients) pour notre étude. La majorité (68,9 %) des patients avaient le diabète de type 1 et présentaient une ACD grave (60,2 %). Dans les 24 premières heures, le volume médian de fluide reçu par voie intraveineuse (intervalle interquartile) était de 7,0 (5,5 à 8,8) litres; 23,3 % ont reçu un bolus d'amorçage d'insuline, 24,3 % ont reçu du bicarbonate et 91,3 % ont reçu du potassium. L'hypoglycémie était relativement rare (5,8 %), mais l'hypokaliémie était fréquente (41,7 %). Le temps médian au trou anionique ≤12 mmol/L était de 8,8 (6,0 à 12,3) h. Dans 27,1 % des cas, l'administration de l'insuline par voie intraveineuse était interrompue avant l'administration sous-cutanée d'insuline; un temps médian de 95 (30 à 310) min s'écoulait avant l'administration sous-cutanée d'insuline. La mortalité liée à l'ACD était de 2,9 %.
La prise en charge à court terme de l'ACD était généralement conforme aux lignes directrices de la pratique clinique. Les points à améliorer étaient les suivants: la prévention de l'hypokaliémie par l'augmentation proactive de la réplétion en potassium, la réduction des bolus initiaux d'insuline, l'administration sous-cutanée d'insuline avant l'interruption de l'insuline intraveineuse et l'administration judicieuse de bicarbonate de sodium. Les protocoles et les modèles d'ordonnances préimprimées peuvent être utiles, particulièrement dans les plus petits centres.
Hyperglycemic Emergencies in Adults
2018, Canadian Journal of Diabetes
Pseudohypobicarbonatemia in a Patient Presenting with Suspected Diabetic Ketoacidosis
2018, AACE Clinical Case Reports
Citation Excerpt :
In the ICU, blood chemistries were repeated and a venous blood gas collected. The TCO2 concentration remained low at 12 mmol/L, but on blood gas, the level was 23 mmol/L. His venous pH was 7.37, which is expected to only be 0.03 (range, 0.0 to 0.11) units lower than the arterial pH (2). After initial presentation, blood glucose rapidly decreased and remained manageable throughout the remainder of the time in the ICU (160 to 290 mg/dL).
Objective: In the diagnosis of acid-base disturbances, an accurate assessment of bicarbonate is essential. It can be determined by measurement of a urea and electrolyte panel or calculated on a blood gas analysis. Discrepancies in these two values can be due to endogenous interferents. We report a case of pseudohypobicarbonatemia suspected due to hypertriglyceridemia, despite lipidemia being within the reported acceptable range for the analyzer.
Methods: We detail the hospital course of a 33-year-old man who presented with presumed diabetic ketoacidosis based on new-onset hyperglycemia, positive ketones, and measured bicarbonate in the range 9 to 16 mmol/L. The latter caused the calculation of anion gap metabolic acidosis. We review bicarbonate metabolism and technical aspects of its measurement. Further, we review additional reports and research pertinent to our patient's diagnostic dilemma.
Results: Based on our patient's initial presentation, he was placed on an insulin drip for approximately 30 hours. During the hospital course, his calculated bicarbonate levels from blood gases ranged from 20 to 26 mmol/L, significantly higher than the measured bicarbonates. On the insulin drip, his triglyceride levels fell slightly and his measured bicarbonate levels increased to more closely mirror the values obtained on blood gas analysis but still varied by greater than expected. Posthospitalization, when his triglycerides were near normal, his measured bicarbonate was normal.
Conclusion: The current case highlights the importance of recognizing discordant measured and calculated bicarbonate and that endogenous interferents can lead to falsely low or high carbon dioxide values.
Abbreviations: DKA diabetic ketoacidosis DM diabetes mellitus ED emergency department ICU intensive care unit TCO₂ total carbon dioxide U&E urea and electrolyte
Controversies in the management of hyperglycaemic emergencies in adults with diabetes
2017, Metabolism: Clinical and Experimental
Citation Excerpt :
Initial laboratory evaluation includes arterial blood gas sampling for measurement of pH and bicarbonate, and then pH rechecking every 2–4 h until stabilization (Fig. 2) [14]. There is growing evidence that arterial and venous samples may have sufficient agreement to be clinical interchangeable in DKA patients without respiratory failure or haemodynamic instability [15,16]. Brandenburg and Dire reported a mean difference between arterial and venous pH values of 0.03 and a high correlation between venous and arterial samples for pH (r = 0.97) and bicarbonate (r = 0.95) [15].
Hyperglycaemic emergencies are associated with significant morbi-mortality and healthcare costs. Management consists on fluid replacement, insulin therapy, and electrolyte correction. However, some areas of patient management remain debatable. In patients without respiratory failure or haemodynamic instability, arterial and venous pH and bicarbonate measurements are comparable. Fluid choice varies upon replenishment phase and patient's condition. If patient is severely hypovolaemic, normal saline solution should be the first option. However, if patient has mild/moderate dehydration, fluid choice must take in consideration sodium concentration. Insulin therapy should be guided by β-hydroxybutyrate normalization and not by blood glucose. Variations of conventional insulin infusion protocols emerged recently. Priming dose of insulin may not be required, and fixed rate insulin infusion represents the best option to suppress hepatic glucose production, ketogenesis, and lipolysis. Concomitant administration of basal insulin analogues with regular insulin infusion accelerates ketoacidosis resolution and prevents rebound hyperglycaemia. Simpler protocols using subcutaneous rapid-acting insulin analogues for mild/moderate diabetic ketoacidosis treatment have proven to be safe and effective, but further studies are required to confirm these results. Treatment with bicarbonate, phosphate, and low-molecular-weight heparin is still disputable, and randomized controlled trials are urgently needed to optimize patient management and decrease the morbi-mortality of hyperglycaemic emergencies.

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^☆: From the Section of Emergency Medicine & Trauma, University of Oklahoma Health Sciences Center, Oklahoma City, OK.

^☆☆: Address for reprints: Daniel J Dire, MD, Section of Emergency Medicine & Trauma, PO Box 26307, Room EB319, Oklahoma City, OK 73126-0307, 405-271-5135

^★: 47/1/88630

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Comparison of Arterial and Venous Blood Gas Values in the Initial Emergency Department Evaluation of Patients With Diabetic Ketoacidosis☆,☆☆,★

Abstract

Section snippets

INTRODUCTION

METHODS

RESULTS

DISCUSSION

Lancet

Med Clin North Am

Med Clin North Am

Med Clin North Am

Lancet

Ann Emerg Med

Lancet

Endocrinol Metab Clin North Am

Lancet

Lancet

Clin Chim Acta

Clin Chim Acta

Ann Emerg Med

Am J Med Sci

Trends in diabetes and diabetic complications, 1980–1987

Diabetes Care

Diabetic ketoacidosis

Diabetic ketoacidosis

Estimation of arterial Po 2, Pco 2, pH, and lactate from arterialized venous blood.

J Appl Physiol

Comparison of pH in human arterial, venous, and capillary blood

Am J Clin Pathol

Estimation of arterial Po ₂, Pco ₂, pH, and lactate from arterialized venous blood.