Previously, we reviewed biological evidence that mercury could induce autoimmunity and coronary arterial wall relaxation as observed in Kawasaki syndrome (KS) through its effects on calcium signaling, and that inositol 1,4,5-triphosphate 3-kinase C (ITPKC) susceptibility in KS would predispose patients to mercury by increasing Ca2+ release. Hg2+ sensitizes inositol 1,4,5-triphosphate (IP3) receptors at low doses, which release Ca2+ from intracellular stores in the sarcoplasmic reticulum, resulting in delayed, repetitive calcium influx. ITPKC prevents IP3 from triggering IP3 receptors to release calcium by converting IP3 to inositol 1,3,4,5-tetrakisphosphate. Defective IP3 phosphorylation resulting from reduced genetic expressions of ITPKC in KS would promote IP3, which increases Ca2+ release. Hg2+ increases catecholamine levels through the inhibition of S-adenosylmethionine and subsequently catechol-O-methyltransferase (COMT), while a single nucleotide polymorphism of the COMT gene (rs769224) was recently found to be significantly associated with the development of coronary artery lesions in KS. Accumulation of norepinephrine or epinephrine would potentiate Hg2+-induced calcium influx by increasing IP3 production and increasing the permeability of cardiac sarcolemma to Ca2+. Norepinephrine and epinephrine also promote the secretion of atrial natriuretic peptide, a potent vasodilator that suppresses the release of vasoconstrictors. Elevated catecholamine levels can induce hypertension and tachycardia, while increased arterial pressure and a rapid heart rate would promote arterial vasodilation and subsequent fatal thromboses, particularly in tandem. Genetic risk factors may explain why only a susceptible subset of children develops KS although mercury exposure from methylmercury in fish or thimerosal in pediatric vaccines is nearly ubiquitous. During the infantile acrodynia epidemic, only 1 in 500 children developed acrodynia whereas mercury exposure was very common due to the use of teething powders. This hypothesis mirrors the leading theory for KS in which a widespread infection only induces KS in susceptible children. Acrodynia can mimic the clinical picture of KS, leading to its inclusion in the differential diagnosis for KS. Catecholamine levels are often elevated in acrodynia and may also play a role in KS. We conclude that KS may be the acute febrile form of acrodynia.
Acrodynia ; Arterial Pressure ; Autoimmunity ; Calcium ; Calcium Signaling ; Catechol O-Methyltransferase ; Catecholamines ; Child ; Coronary Vessels ; Diagnosis, Differential ; Epinephrine ; Heart Rate ; Humans ; Hydrazines ; Hypertension ; Inositol ; Inositol 1,4,5-Trisphosphate ; Inositol 1,4,5-Trisphosphate Receptors ; Inositol Phosphates ; Mucocutaneous Lymph Node Syndrome ; Norepinephrine ; Permeability ; Phosphorylation ; Polymorphism, Single Nucleotide ; Powders ; Relaxation ; Risk Factors ; S-Adenosylmethionine ; Sarcolemma ; Sarcoplasmic Reticulum ; Tachycardia ; Thimerosal ; Thrombosis ; Tooth ; Tooth Eruption ; Vaccines ; Vasoconstrictor Agents ; Vasodilation

INTRODUCTIONCardiopulmonary resuscitation (CPR) guidelines were revised in 2005 based on new evidence and expert consensus. However, the benefits of the new guidelines remain undetermined and their influence has not been published in Asia. This study aimed to evaluate the impact of implementing the new resuscitation guidelines and identify factors that influence the discharge survival of out-of-hospital cardiac arrest (OHCA) patients in an Asian metropolitan city.

MATERIALS AND METHODSThis was an observational cohort study of all OHCA patients seen by the emergency medical service during the period before (Nov 2003 to Oct 2005) and after (May 2006 to Oct 2008) implementing the new resuscitation guidelines. Detailed clinical information was recorded using the Ustein style template. Statistical analysis was done using X2 test or t-test for univariate analysis and the logistic regression model for multivariate analysis.

RESULTSThere were 463 patients before and 430 patients after the new guidelines who received resuscitation. The rate of recovery of spontaneous circulation (ROSC), survival-to-intensive care unit (ICU) admission, and survival-to-hospital discharge all showed no benefits regarding the new resuscitation guidelines (ROSC: 42% vs 39%, P = 0.32; Survival-to-ICU admission: 33% vs 30%, P = 0.27; survival-to-hospital discharge: 10% vs 7%, P = 0.09). The rate of ventricular fibrillation/pulseless ventricular tachycardia (VF/pulseless VT), rate of witnessed arrest, and rate of bystander CPR were much lower than in Western studies. After multivariate logistic regression, factors related to discharge survival were witnessed arrest and initial rhythm with VF/pulseless VT. The new resuscitation guidelines did not significantly influence the discharge survival.

CONCLUSIONSWe did not observe any improvement in survival after implementing the new guidelines. Independent factors of survival-to-hospital discharge are witnessed arrest and initial rhythm with VF/pulseless VT. Because the rates of VF/pulseless VT and bystander CPR in Asia are low, popularising CPR training programmes and increasing the rate of bystander CPR may be more important for improving OHCA survival rates than frequent guideline changes.

Aged ; Aged, 80 and over ; Cardiopulmonary Resuscitation ; methods ; standards ; Emergency Service, Hospital ; statistics & numerical data ; Female ; Hospitals, University ; statistics & numerical data ; Humans ; Male ; Middle Aged ; Out-of-Hospital Cardiac Arrest ; mortality ; therapy ; Patient Discharge ; statistics & numerical data ; Practice Guidelines as Topic ; Survival Analysis ; Taiwan ; epidemiology