Spinal Anesthesia for Emergency Abdominal Surgery

Introduction:

An emergency laparotomy is a traditional surgical technique used to treat various intra-abdominal diseases with high morbidity and mortality. This general term encompasses multiple diseases and symptoms, frequently in individuals with considerable physiological derangement and comorbidities. Because of its well-known advantages, such as fast onset, functional sensory and motor block, and avoidance of problems of general anesthesia, spinal anesthesia is frequently used as a regional anesthetic treatment for lower limb and lower abdomen procedures. The most often used local anesthetic in spinal anesthesia is Bupivacaine 0.5 percent heavy, commercially available as a combination (50:50) of its two Levobupivacaine and Dextrobupivacaine.

The main reason for choosing spinal anesthesia over general anesthesia as the first choice for laparoscopic cases was its advantages, which included uniform total muscle relaxation, conscious patients, a relatively uneventful recovery, pain-free early postoperative period, and avoidance of the potential complications of general anesthesia.

What Is the Spinal Anesthesia Technique for Abdominal Surgery?

Spinal anesthesia is a type of regional anesthesia in which nerve roots are blocked by injecting a small volume of hyperbaric (heavy) local anesthetic solution into the subarachnoid fluid by lumbar puncture. It causes total analgesia, deep muscular relaxation, calm breathing, and a short, constricted bowel. The injection is given at a level lower than the second lumbar vertebra (the level at which the spinal cord ends), most commonly in the interspace between the third and fourth lumbar vertebrae.

A solution thicker than cerebrospinal fluid is typically employed, allowing the nature of the block to be adjusted by placing the patient such that the anesthetic drug flows "downhill" under gravity to the section that needs to be blocked. A 'medium' spinal block spans the area from T10 to L4 and is appropriate for herniorrhaphy, lower abdominal surgeries, and leg operations.

What Are the Advantages of Spinal Anesthesia?

• Anesthetic medicines and gasses are expensive and are sometimes difficult to transport. However, the expenditures on spinal anesthesia are negligible.

• If spinal anesthesia and associated surgeries are conducted effectively, most patients are pleased with the procedure and enjoy quick recovery and no side effects.

• As long as very high blocks are avoided, spinal anesthesia has few negative consequences on the respiratory system.

• As the airway is not impaired, there is very little chance of airway blockage or aspiration of contents from the stomach.

• In a conscious patient, the chance of unrecognized hypoglycemia is low. Diabetic individuals may typically resume their regular diet and insulin regimen quickly after surgery since they have less drowsiness, nausea, and vomiting.

• Spinal anesthesia gives great muscular relaxation to the lower abdomen and lowers limb surgery.

• Blood loss during surgery is significantly less than in procedures performed under general anesthesia. This is due to lower blood pressure and heart rate, as well as increased venous drainage, which results in minimal blood loss.

• Spinal anesthesia minimizes the occurrence of anastomotic dehiscence by increasing the blood supply to the intestines.

• Spinal anesthesia contracts the bowel and relaxes the sphincter muscles despite peristalsis persisting. Following surgery, normal gut function resumes quickly.

What Are the Disadvantages of Spinal Anesthesia?

• Sometimes, must abandon the approach since detecting the dural space and getting CSF is impossible.

• With higher blocks, hypotension may develop, and the anesthetist must be prepared to address this condition by having the proper resuscitative medicines and equipment on hand.

• Some patients are not mentally prepared to be awake throughout surgery; they should notice such patients during the preoperative evaluation.

• Even if a long-acting local anesthetic is administered, spinal anesthesia is not recommended for surgery extending more than two hours.

What Are the Indications for Emergency Abdominal Surgery?

The most common causes of non-obstetrical or gynecological surgical abdominal crises include urinary tract stones, intestinal obstruction (obstructed abdominal wall hernia is the most common), appendicitis, intra-abdominal abscess, diverticulitis, small bowel blockage, typhoid ileal perforation, perforated peptic ulcer.

Spinal anesthesia is especially appropriate for elderly patients suffering from systemic diseases such as chronic respiratory illness and hepatic, renal, and endocrine problems such as diabetes. In addition, many individuals with moderate heart problems benefit from the vasodilation caused by the spinal anesthetic.

What Are the Contraindications of Spinal Anesthesia?

The complications of spinal anesthesia can be broadly classified into absolute and relative contraindications.

• Absolute Contraindications - Patient refusal to undergo spinal anesthesia, any preexisting infection at the injection site, unattendedhypovolemia (decrease in the extracellular fluid volume), allergies, and increased intracranial pressure.

• Relative Contraindications - Any bleeding disorders, neurological disorders, blood poisoning (septicemia), or any additional burden to the heart.

What Are the Drugs Used in Spinal Anesthesia for Emergency Abdominal Surgery?

• Lidocaine - Five percent hyperbaric (heavy) Lidocaine lasts 45 to 90 minutes. The four percent hyperbaric (heavy) solution of Mepivacaine is equivalent to Lignocaine.

• 0.5 percent hyperbaric (heavy) Bupivacaine is the best agent to use. It has a longer duration of action than most other spinal anesthetics, often lasting two to three hours. It is identical to Cinchocaine - a 0.5 percent hyperbaric (heavy) solution.

• Pethidine or Meperidine - 0.5-1mg/kg is typically sufficient for spinal anesthesia.

• One percent of Tetracaine injectable solution can be made using dextrose, saline, or water. The option is determined by the length of the surgery and the quality of aftercare offered for patients whose surgeries terminate before their blocks wear off.

What Are the Complications of Spinal Anesthesia in Abdominal Surgery?

• Mild Complications - Nausea and vomiting from hypotension or bowel traction, urinary retention, feeling of chills and shivering, itching, and pain at the injection site.

• Moderate Complications - Failure of spinal anesthesia and headache caused primarily by cerebrospinal fluid leakage from the dural puncture site.

• Major Complications - Infection (abscess, meningitis) caused by contamination of cerebrospinal fluid with red cells, septic meningitis caused by non-sterile techniques, and 'total spinal' block with anesthesia, arachnoiditis, peripheral nerve injury, cardiovascular collapse, vertebral canal hematoma, and finally sometimes may cause death.

Conclusion:

In assessing and evaluating the risks and advantages, spinal anesthesia for emergency abdominal surgery can be considered safe. This is essential in our current economic conditions when patients are impoverished, hospital costs are expensive, and healthcare resources are few.