Detection of Hypocalcemia in Susceptible Neonates

Colletti, Richard B.; Pan, Mary; Smith, E. L.; Genel, Myron

doi:10.1056/nejm197404252901703

Cited by 40 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2~^ Bunker et al' attempted to quantitate the hemodynamic effects of intravenously administered sodium citrate in man, but Ca 2+ could only be calculated from the formulas of Hastings et al 16 Recently, Colletti et al 18 have reported the first correlation of measurement of Ca 2+ with cardiac parameters, the ECG intervals Q O T C and Q 0 T.…”

Section: Discussionmentioning

confidence: 99%

Ionized calcium and the heart. Elucidation of in vivo concentration-response relationships in the open-chest dog.

Bristow¹,

Schwartz²,

Binetti³

et al. 1977

Circulation Research

View full text Add to dashboard Cite

SUMMARY Pharmacological relationships between ionized calcium and cardiac electric and mechanical parameters were explored in the open-chest dog. A technique that allows the determination of reliable, repeatable concentration-response relationships in vivo was developed. This method consists of alternating infusions of sodium citrate and calcium gluconate and direct measurement of serum ionized calcium by an ion-specific electrode. With this technique, four consecutive curves for ionized calcium vs. the first derivative of the left ventricular pressure (dP/dt) were essentially superimposable within the limits of 2-10 mg/100 ml. Relationships between ionized calcium and the electrocardiograph (ECG) interval measured from the end of the S wave to the peak of the T wave (S a T c ) proved to be superior to other ECG measurements as a correlate of ionized calcium. Ionized calcium correlated better than total calcium with physiological function in several situations. Postsurgical ionized calcium levels (4.92 ± 0.10 mg/100 ml) were consistently higher than preanesthetic values (4.57 ± 0.07 mg/100 ml, P < 0.025), whereas total calcium measurements were not significantly different (X = 5.3 ± 0.10 mEq/liter, X = 5.1 ± 0.10 mEq/liter, P < 0.1). This difference in ionized calcium was shown to be able to account for significant alterations in dP/dt, suggesting that fluctuations in ionized calcium may be involved in the regulation of the contractile state of the heart. VARIATIONS in the extracellular concentration of ionized calcium (Ca 2+ ) have important effects on the electrical and mechanical function of the intact mammalian heart. In man, hypocalcemia associated with rapid transfusion of citrated blood has been implicated as a cause of decreased contractility, cardiovascular collapse, and cardiac arrest.1 " 4 Hypercalcemia has been associated with an increase in contractility in animals, 5 " 7 and conduction disturbances, ventricular irritability, and cardiac arrest have been.described in man. 8 " 10 Recent studies have shown that the fraction of myocardial calcium that is correlated with contractility is readily exchangeable and in rapid equilibrium with plasma Ca 2 " 1 ". 11- 12 Since it has been suggested that alterations in cellular calcium levels are a common mediator of a variety of pharmacological influences on the contractile state of the heart, 13 it is possible that minor as well as major changes in the extracellular Ca 2+ can have important effects on cardiac function.Because to determine quantitative relationships in vivo between Ca 2+ and myocardial response throughout a wide range of serum Ca 2+ . MethodsTwenty-two mongrel dogs weighing 14-30 kg were sedated with morphine sulfate (2 mg/kg) intramuscularly, then anesthetized with intravenous chloralose and urethane at doses of 85 mg/kg and 625 mg/kg, respectively. Ventilation was provided by a Harvard pump delivering room air through a cuffed endotracheal tube. Arterial blood gases were monitored frequently with a Corning model 165 gas analyzer and pH w...

show abstract

Section: Discussionmentioning

confidence: 99%

Ionized calcium and the heart. Elucidation of in vivo concentration-response relationships in the open-chest dog.

Bristow¹,

Schwartz²,

Binetti³

et al. 1977

Circulation Research

View full text Add to dashboard Cite

show abstract

“…The better correlation of Ca, with Q-oTc than with Q-Tc in acute hypocalcemia in adults is in agreement with the results of Colletti et a1. 5 in chronic hypocalcemia in neonates and those of Surawicz et aLZ4 in hypocalcemia induced by EDTA infusion. Correction of the Q-oT for the heart rate (Q-oTc) did not greatly influence the correlation with free calcium due to the small changes in heart rate observed in our subjects.…”

Section: Relationship Of Calcium and Ecgmentioning

confidence: 91%

Relationship of Physical Symptoms, ECG, Free Calcium, and Other Blood Chemistries in Reinfusion with Citrated Blood

Ladenson¹,

Miller²,

Sherman³

1978

Transfusion

View full text Add to dashboard Cite

Changes in ECG, free calcium (CaF), and other biochemical parameters were measured during reinfusion of citrate anticoagulated blood in 12 subjects undergoing plateletpheresis. Physical symptoms during the procedure were also monitored. The CaF was found to correlate best with the Q-oTc interval as compared to the Q-oT, Q-Tc, or Q-T interval. While the correlation was significant (r = 0.592, p less than .001), the Q-oTc could not predict the CaF. A number of other blood constituents were found to change during plateletpheresis, with most directly related to either citrate administration or hemodilution. Severe physical symptoms were found in one subject and no symptoms in three. In the subjects without symptoms the changes in Q-oTc, Pi, alkaline phosphatase, and glucose through the plateletpheresis procedure were different from changes in all subjects. The decrease in glucose level was the most striking single factor correlating with the lack of physical symptoms during the citrate-induced hypocalcemia associated with plateletpheresis. It is concluded that monitoring of the ECG cannot substitute for direct measurement of free calcium in citrate-induced hypocalcemia, that the physical symptoms associated with similar levels of hypocalcemia are variable, that glucose level may be a marker for the effects of citrate-induced hypocalcemia, and that lowered citrate loads during plateletpheresis appear warranted.

show abstract

“…Patients were withdrawn from the study if the QeTc was greater than 0 55 s.05 After the 120 min sample and rhythm strip had been taken the citrate infusion was stopped and a further blood sample and strip were taken 15 min later to confirm restoration of the serum ionised calcium concentration and QTc intervals toward normal. As QaTc is known to correlate better with the simultaneous ionised calcium concentration than QeTc'4 and as errors in the determination of QoTc can reflect accurate identification of the apex of the T wave, 12 QaTc was the standardised interval used in analysis. Changes in the whole blood ionised calcium concentration and QaTc from baseline (0 min) were calculated for each time point and expressed as a ratio.…”

Section: Methodsmentioning

confidence: 99%

Dynamic assessment of the electrocardiographic QT interval during citrate infusion in healthy volunteers.

Davis

Singh

Choo

et al. 1995

Heart

View full text Add to dashboard Cite

show abstract

Detection of Hypocalcemia in Susceptible Neonates

Cited by 40 publications

References 18 publications

Ionized calcium and the heart. Elucidation of in vivo concentration-response relationships in the open-chest dog.

Ionized calcium and the heart. Elucidation of in vivo concentration-response relationships in the open-chest dog.

Relationship of Physical Symptoms, ECG, Free Calcium, and Other Blood Chemistries in Reinfusion with Citrated Blood

Dynamic assessment of the electrocardiographic QT interval during citrate infusion in healthy volunteers.

Contact Info

Product

Resources

About