Tonsillectomy is one of the most common surgeries in children which is associated with many morbidities such as postoperative pain, nausea, vomiting, bleeding and laryngospasm .

Laryngospasm is a dangerous complication of tonsillectomy that occurs following tracheal extubation It is characterized by a strong, involuntary contraction of the laryngeal muscles, it's frequency in children is higher than adults due to their narrow upper airways that can be blocked following edema and inflammation The incidence of laryngospasm is 17 per 1000 children younger than nine years old, which increases to 96 per 1000 children with upper respiratory tract infections There are several ways to prevent this complication, including complete haemostasis during surgery, gentle suctioning of the oropharynx before extubation and the use of drugs as intravenous or topical lidocaine, propofol and etc .

Postoperative pain control after the tonsillectomy has a very important role in recovery time, hospitalization duration, bleeding, nausea and vomiting.

Lidocaine is an antiarrhythmic drug and its main mechanism of action is blocking voltage-gated Na+ channels that inhibit the activity of the upper laryngeal nerve and reduces the long-term blockage of the glottis .

Magnesium sulphate has a calcium antagonist property, which provides muscle relaxation and increases flaccidity. It also has an antagonistic action on sodium channels and N-methyl-D-aspartate receptors and reduces the release of substance P, which decreases the airway reactivity and stress responses .

Therefore we decided to compare the effect of intravenous injection of magnesium sulfate and lidocaine on the prevention of laryngospasm occurrence, and analgesic requirement in tonsillectomy the goal of the study Comparing the effectiveness of magnesium sulfate and lidocaine in prevention of post tonsillectomy complication .

Tonsillectomy is one of the most common surgeries in children which is associated with many morbidities such as postoperative pain, nausea, vomiting, bleeding and laryngospasm .

Laryngospasm is a dangerous complication of tonsillectomy that occurs following tracheal extubation It is characterized by a strong, involuntary contraction of the laryngeal muscles, it's frequency in children is higher than adults due to their narrow upper airways that can be blocked following edema and inflammation The incidence of laryngospasm is 17 per 1000 children younger than nine years old, which increases to 96 per 1000 children with upper respiratory tract infections There are several ways to prevent this complication, including complete haemostasis during surgery, gentle suctioning of the oropharynx before extubation and the use of drugs as intravenous or topical lidocaine, propofol and etc .

Postoperative pain control after the tonsillectomy has a very important role in recovery time, hospitalization duration, bleeding, nausea and vomiting.

Lidocaine is an antiarrhythmic drug and its main mechanism of action is blocking voltage-gated Na+ channels that inhibit the activity of the upper laryngeal nerve and reduces the long-term blockage of the glottis .

Magnesium sulphate has a calcium antagonist property, which provides muscle relaxation and increases flaccidity. It also has an antagonistic action on sodium channels and N-methyl-D-aspartate receptors and reduces the release of substance P, which decreases the airway reactivity and stress responses .

Therefore we decided to compare the effect of intravenous injection of magnesium sulfate and lidocaine on the prevention of laryngospasm occurrence, and analgesic requirement in tonsillectomy

Inclusion Criteria:

• -ASA physical status I-II.
• Both sexes.
• Age: children 3-14years old.
• patients subjected for tonsillectomy or adeno-tonsillectomy surgery with parental consent for participation in the study.

Exclusion Criteria:

• - patients who refused to participate in this study.
• History of allergic response to magnesium sulfate and liodcaine .
• the Prescence of cardiovascular, respiratory and kidney diseases.
• A recent history of upper respiratory tract infection and febrile illness.
• History of mythenia gravis.
• patients subjected for adeno-tonsillectomy with myringotomy