Anaesthesia During Labour By Adnan Akram Pdf

Anaesthesia during Labour

Adnan Akram 03.11.2009

Riga. Latvia

Types of Anaesthesia used

1. Spinal Anaesthesia 2. Epidural Anaesthesia 3. General Anaesthesia 4. Pudendal block 5. Paracervical block 6. IV meperidine 7. IM morphine

1. Spinal Anaesthesia

Spinal anaesthesia also known as subarachnoid anaesthesia is a form of local or regional anaesthesia, which involves injection of an anaesthetic drug into the subarachnoid cerebrospinal fluid space (CFS).

Positions (a). sitting position

Positions (b) lateral

It is given generally through a fine needle, usually 3.5 inches (9 cm) long. For extremely obese patients, some anaesthesiologists are known to prefer spinal needles which are seven inches (18 cm) long

A 25G choice needle is inserted into the introducer, passing through the epidural space, dura, and arachnoid to the sub arachnoid space stopping when the presence of CSF is determined. CSF is aspirated and mixing lines are identified as a change in baricity and temperature as the local anesthetic and CSF mix in the syringe. The dose is slowly injected.

Agents used in Spinal Anaesthesia

Local Anaesthetics Bupvicaine HCl Ropavacaine HCl Lignocaine HCl

Bupivacaine hydrochloride Bupivacaine is a local anaesthetic that stabilises the neuronal membrane and prevents the initiation and transmission of nerve impulses. This drug is very potent, four times that of lignocaine , and has a rapid onset of anaesthesia with prolonged duration of action. Bupivacaine is suitable for continuous epidural blockade. 12-18mg, 90-120min (with epinephrine 150 mins)

Ropivacaine Hydrochloride Ropivacaine has both anaesthetic and analgesic effects . At higher doses it produces surgical anaesthesia with motor block, while at lower doses it produces a sensory block, including analgesia, with little motor block. 16-18mg, 90-120min

Lignocaine Lignocaine has the same mechanism of anaesthetic action to that of bupivacaine and ropivacaine. 75-100mg, 60-75min

Complications of Spinal Anaesthesia 1. Total Spinal Anaesthesia: hypotension, rapidly increasing motor block, temporarily loss of breathing, loss of consciousness, dilated pupils, and is preceded by respiratory distress due to the blockade of some nerve cells. 2. High Block: nasal stiffness and difficulty breathing.

2. Epidural Anaesthesia

Epidural anaesthesia is a local anaesthetic infused into the epidural (extradural) space. The injection is usually made in the lumber region at the L2/3 or L3/4 space.

Needle An 18G Touhy needle is advanced through the ligamentum flavum until a loss of resistance is felt on attempted injection of air or saline.

Indications for Epidural Anaesthesia Labour Thoracic Surgery Abdominal Surgery Orthopaedic surgery

Agents Used in Epidural Anaesthesia The patient is injected a combination of local anesthetics and opioids . This combination works better than either type of drug used alone. Common local anesthetics include lidocaine, bupivacaine, and some derivates of lopivacaine, chloroprocaine. Common opioids include morphine, fentanyl, sufentanil, and pathedine

Spinal & Epidural Combination

3. General Anaesthesia

Indications - emergency cesarean sections - some types of forceps and other assisted deliveries.

Side effects of GA during labour The new born is more effected, major sideeffects that can be seen are - breathing difficulties in newborn

4. Pudendal Block

Indications for Pudendal Block Pudendal block is used primarily to relieve pain in the second and third stages of labor for both normal and instrumental (outlet) delivery.

Agents Used Generally, a short-acting agent, such as lidocaine 1% or prilocaine 1%, produces very satisfactory analgesia for 1.5-2.5 h. When analgesia of very rapid onset is required, 2-chloroprocaine 2% can be used. The duration of this agent will, however, be no more than 1.5 h. A volume of 20 ml should not be exceeded for a block of both nerves

Complications 1. maternal hematoma 2. systemic toxic reaction 3. trauma to the sciatic nerve 4. puncture of the rectum

5. Paracervical Block

Usage Paracervical blockade may be used as a means of reducing pain during the first stage of labour. Pain associated with uterine contraction and cervical stretching and dilatation is transmitted from these structures on visceral afferents which accompany sympathetic fibres

5 cm, 22-gauge or 25-gauge needle to inject the lignocaine solution. First 1 mL of 0.5% lignocaine solution is injected into the anterior or posterior lip of the cervix which has been exposed by the speculum.

Complications

The proximity of uterine blood vessels in the vaginal fornices creates maternal and fetal risks. Fetal bradycardia occurs in 10-50% of cases. Failure rate is 24 percent

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