Sigmoidoscopy and laparoscopy are distinct medical procedures that enable physicians to internally inspect different parts of the GI tract. Although they serve different purposes, each is essential for diagnosing and, in some cases, treating various medical conditions.
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...

Spinal anesthetics are given during lower abdomen and limb surgeries to block sensory and motor neurons. They are administered in the mid to low lumbar regions, primarily acting on the cauda equina's nerve roots. The blockade level depends on the local anesthetic (LA) concentration. Usually, low LA concentrations are sufficient to block sensory fibers, while only high LA concentrations block motor fibers. Other factors like injection volume and speed, the patient's posture, and the drug...

Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery.
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...

Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity.
One of the advantages of...

Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational.
General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain...

Local anesthetics (LAs) block the sodium channels of nerve trunks, sensory nerve endings, and neuromuscular junctions. Although LAs can block all kinds of nerves, the sensitivity of nerve fibers differs according to nerve types and structures. LAs are known to block myelinated fibers faster than unmyelinated ones. Also, they block pain or sensory neurons at low concentrations without affecting the motor neurons involved in muscle contractions. This helps relieve labor pain without affecting the...