Hyperkalemia is caused by:
(Refer: Miller’s, Clinical Anaesthesia, 7th edition, pg no: 2373-2383)
Systemic effects of Succinyl choline

Cardiovascular system - Profound bradycardia
Hyperkalemia - Due to excessive muscle fasciculations.
CNS - Increases intracranial tension.
Eye - Increases intraocular tension.
GIT - Increases intragastric pressure, increases salivation,gastric secretions and peristalsis.
Muscle pains - Due to excessive muscle contractions.
Malignant hyperthermia-SCh is the most common drugcausing this.
Anaphylaxis.
Masseter spasm.
N2O
Atracurium
Succinyl choline
Pancuronium