The Efficacy of L-Carnitine in the Management of Acute Carbon Monoxide Poisoning

Carbon monoxide (CO) poisoning results in high morbidity and mortality worldwide. CO is described as a "silent killer" because CO is colorless, odorless, and tasteless but highly toxic. The diagnosis of acute CO poisoning depends on the history of exposure to a source of fire in a closed space along with the clinical and laboratory findings. The pathophysiology of CO poisoning is not fully understood; however, it is proved that CO induces hypoxia by forming carboxyhemoglobin (COHb) and shifting the oxygen dissociation curve to the left. The molecular mechanisms of CO poisoning include oxidative injury through the generation of free radicals. In addition, oxygen therapy might enhance the reactive oxygen species (ROS) production and result in reperfusion injury. Free radicals could induce a serious impact on vital organs, including the heart, and brain. L-Carnitine is an endogenous mitochondrial constituent that contributes to normal mitochondrial activities. L-Carnitine is an antioxidant with potent ROS scavenging ability. ROS-mediated pathology of CO suggests that antioxidants are potentially useful agents in the alleviation of CO toxicity. Thus, the current study will investigate the therapeutic efficacy of L-Carnitine in improving the prognosis of acute CO poisoning. The current clinical trial will include patients with moderate and severe acute carbon monoxide poisoning according to Poisoning Severity Score.

A randomized clinical trial (phase II) will be conducted at Alexandria Main University Hospital. The total required sample size is 72. The sample size was calculated by G power 3.1.9.4 software program depending on the primary outcome. According to these assumptions: Effect size, defined as the difference between group 1 and group 2 in the mean troponin levels at 24 hr, was calculated according to Sun et al. (2011) and was 0.657, alpha error =0.05, power of 80%, allocation ratio 1:1. A 20% expected attrition was added to the sample size to account for loss to follow-up. So, the final sample size was 72; 36 patients per group. All patients will be subject to the following: 1. History taking: * Personal data: age, and sex. * Exposure-related data: circumstances of exposure, and time till hospitalization. * Past medical history. 2. Clinical assessment: * Glasgow coma scale, vital signs, and general examination. * Laboratory investigations: arterial blood gases (ABG), Carboxy hemoglobin level (COHb), and cardiac enzymes (CPK, CK-MB, Troponin). * Electrocardiogram (ECG).