Hyperbaric Bupivacaine Versus Hyperbaric Prilocaine 2% for Cesarean Section Under Spinal Anesthesia

Time to regression of motor block is the time between maximal blockade (score 1, as evaluated by the Modified Bromage scale), and no blockade (score 6). Degree of motor blockade is assessed before and 10, 15, 20 minutes after spinal anesthesia, then every 15 minutes until the end of surgery, and thereafter, every 30 minutes until complete regression of motor block

Time between spinal injection and reached bilateral T4 sensory level.

Level of Sensory block is assessed as loss of sensation to cold, and represents the dermatomal level under which anesthesia is effective. It is measured every 2 minutes after spinal anesthesia during 15 minutes, then every 5 minutes until the end of surgery, thereafter, once 30 minutes until total regression of sensory block (T12-S1). A dermatome is the area of skin that is supplied by a single spinal nerve - Dermatome levels : C5-C8 for Cervical levels and T1-T4 for Thoracic levels.

To perform cesarean section loss of cold sensation at a dermatome of at least T4 has to be obtained.

The results are expressed as the number of patients reaching each dermatomal level from T4 and above (see below) as maximal sensory level, this is a usual outcome used to evaluate the quality of anesthesia.

Evaluation at every 2 minutes after spinal anesthesia during 15 minutes, then every 5 minutes until the end of surgery, and thereafter, every 30 minutes until total regression of sensory block (T12-S1).

Time of installation of the motor block (time between spinal injection and maximum motor block of 1, as evaluated by the Modified Bromage scale). Degree of motor blockade is assessed before and 10, 15, 20 minutes after spinal anesthesia

Arterial blood pressure will be measured at every 1 minute during the first 15 minutes, then at every 2.5 minutes until the end of surgery, and at every 20 minutes in the Post Anesthesia Care Unit (PACU). A low blood pressure (hypotension) is defined as a systolic blood pressure lower than 20% or more than the basal blood pressure (Systolic blood pressure before spinal anesthesia)

All parturients will be questioned and examined for urinary retention (yes or no)

Time for the patients to be able to walk in their room then in the hallway without any assistance for the first time.

All patients will be asked to rate their satisfaction about anesthetic technique during surgery and in the arrival in the Post Anesthesia Care Unit (PACU). Satisfaction evaluated by Visual analog scale (0 cm= very unsatisfied and 10cm = very satisfied)

Maternal rehabilitation is evaluated at postoperative Day1, postoperative Day 2 and postoperative Day 3. Evaluation by Visual analog scale (0 cm= very poor and 10cm = excellent)

Evaluation from 15 minutes after spinal injection to the end of surgery, then every 4 hours for 24 hours, then once a day for 3 days (score 0=no symptom; 1=symptom with no necessary treatment; 2=symptom present and treated)

Evaluation of apparition of TNS at postoperative Day 1, postoperative Day 2, postoperative Day 3 and postoperative Day 15. TNS are defined as pain and/or dysesthesia occurred after complete release of sensory block at the gluteal level, at the thighs and at the legs.

Pain levels will be determined at incision, baby delivery, peritoneal and skin closure, every 5 minutes during surgery, and thereafter every 4 hours for 24 hours. Visual analog pain score (scale = 0 no pain; 10 = worst pain imaginable). Patient will receive additional analgesic treatment above VAS>3.

Newborn Apgar score assessed at 1, 5, 10 minutes after baby extraction. The Apgar score is determined by evaluating the newborn baby on five simple criteria on a scale from 0 to 2, then summing up the five values thus obtained. The overall resulting score ranges from 0 to 10 ( 0-3 : severely depressed, 4-6 : Moderately depressed and 7-10 : Excellent condition).

The five criteria are summarized using words chosen to form an abbreviation (Appearance, Pulse, Grimace, Activity, Respiration).

Newborn Methemoglobinemia (MetHb) will be assessed at delivery by cordal blood sample, as a routine control in obstetrics, and expressed as a percentage of total hemoglobinemia.

Methemoglobinemia (MetHb) is a blood disorder in which an abnormal amount of methemoglobin (hemoglobin in the form metalloprotein) is produced. This specific type of of Hemoglobin carries oxygen through your blood but doesn't release it to the cells.

Newborn umbilical pH will be assessed at delivery by cordal blood sample, as a routine control, and expressed as standard value

Time between incision and end of surgery

Time between spinal injection and baby delivery

Time between baby delivery, and the end of surgery

Total blood loss (milliliters) during surgery

Satisfaction ranged between 1 (totally unsatisfied) to 4 (totally satisfied) assessed at the end of surgery

Satisfaction ranged between 1 (totally unsatisfied) to 4 (totally satisfied) assessed at postoperative Day 3