Nervous system toxicity anoxia

Liver Although chloroform is no longer in use as a volatile anesthetic agent, cases of occupational exposure as well as intentional inhalation and ingestion still present to clinicians. Chloroform was withdrawn from clinical use because it can cause nervous system depression, anoxia secondary to respiratory depression and airway obstruction, cardiac dysrhythmias potentiated by circulating catecholamines, and hepato-toxicity, which is thought to be secondary to oxidative injury caused by free radicals. 

In fact, CO s affinity for Hb is even greater than that of oxygen, by several hundred times Because the body s supply of red blood cells and Hb is limited, the presence of CO in inhaled air can deprive the body of oxygen, a condition called anoxia. The nature, duration, and severity of the resulting toxicity depend upon the blood COHb level created which, of course, depends upon the concentration of the CO in the inhaled air and the length of time the air is inhaled. The presence of COHb in the capillary blood imparts an abnormal red color to skin and fingernails. The conditions creating toxicity arise in the blood the actual effects appear in the nervous system, in the heart, and elsewhere. 

The acute toxicity from overexposure to petroleum ether is manifested primarily in central nervous system (CNS) effects. The mechanism of toxicity is unknown however, the general anoxia observed is most likely due to oxygen deprivation. The mechanism of toxicity from long-term overexposure to petroleum ether is dependent on the chemical makeup of the distillate. For example, if peripheral neuropathy is observed, it is most likely due to a high concentration of -hexane in the petroleum ether. -Hexane is known to cause axonal damage in peripheral nerves. 

Pentaborane is considered to be the most toxic boron hydride in the case of inhalation. Inhalation exposures of small laboratory animals showed values of LDjq of 9 to 46 mg m. It exerts particularly a cumulative action on the central nervous system, accompanied by tremor and cramps. Chronic exposures (for 6 months) to vapours at a concentration of 2.5 mg m resulted in an insufficient oxygen supply to tissues (anoxia), decreases in the body weight, apathy and tremor. Dissection demonstrated no serious pathological changes [77]. The chronic exposures of animals can lea4 to damage to the liver and kidneys [80]. 

---