Examining the advantages associated with the utilization of noradrenaline in preventing spinal hypotension during cesarean births. This involves assessing the positive outcomes and potential benefits derived from incorporating noradrenaline into the medical approach.

Spinal anesthesia is used during cesarean section to provide rapid onset and dense block of motor and sensory nerves, intraoperative analgesia, and help patients remain conscious (1,2).Hypotension is common during induction of spinal anesthesia for cesarean delivery (CD) (3).If not promptly treated, a decrease in blood pressure (BP) can have deleterious effects, which include maternal nausea, vomiting, dizziness, and cardiovascular instability as well as decreased uteroplacental blood flow with resultant fetal acidosis, hypoxia, and bradycardia.In the last decade, the α-agonist phenylephrine (PE) has been the vasopressor of choice for the prevention and treatment of spinal induced hypotension (4).To prevent and treat postspinal anesthesia hypotension during cesarean section, vasopressors are recommended. Vasopressors (especially potent α-adrenergic receptor agonists) help offset the decrease in arteriolar dilation and peripheral vascular resistance caused by sympathetic nerve blockade after spinal anesthesia and may be associated with decreased incidence of neonatal acidosis.(5,6). Norepinephrine is another vasopressor that was recently introduced in obstetric anesthesia (7). Norepinephrine is characterized by α-adrenergic agonistic activity in addition to a weak β-adrenergic agonistic activity; thus, norepinephrine is considered a vasopressor with minimal cardiac depressant effect(7).; these pharmacologic properties would make norepinephrine an attractive alternative to phenylephrine and ephedrine in obstetric anesthesia. Although the use of norepinephrine for prophylaxis against postspinal hypotension has shown promising results,(7,8) evidence is lacking on the optimum dose for norepinephrine infusion during cesarean delivery.

Inclusion Criteria:

• The subject is scheduled for elective cesarean section .
• No obvious abnormalities in preoperative ECG, blood routine, electrolytes, and other tests.
• ASA class 1-3.

Exclusion Criteria:

• Patients have body mass index (BMI) >35 kg/m2. -Patients are known hypersensitivity to any of the drugs that would be used in the study. -
• Severe cardiac, renal, lung, or liver diseases.
• Eclampsia or preexisting hypertension (baseline systolic blood pressure ≥160 mmHg)
• hemoglobin <7 g/dL, or fetal distress.
• Patients that are immunologically compromised.
• Sleep apnea syndrome or difficult airway. 8.preexisting hypoxemia (Spo2< 90 %).
• Patient refusal.

Sample size was calculated using Epi- Info7. Based on Frequency of spinal hypotension decrease to 20% in patients received0.5_.10mg epinephrine ( put ref . ). With a confidence limits 5% and a confidence level of 90% the minimum patients required for this study is 173cases