Question

Edward (Ted) Williams is an 82year old male who is day 4 post-operative following a bowel resection and formation of a temporary colostomy. Ted had previously had a coloscopy and biopsy that confirmed a malignant mass. He has a past medical history of; heart failure, type II diabetes melilites, obesity and gout. (BMI 37.6m2; Height 175cm; weight 115kgs) • Ted is a widower and lives alone. His wife died 3 years ago following a bout of pneumonia. One year ago, Ted moved into a retirement village located in a regional area two and a half hours from the city. The retirement village is near where he lived with his wife and children until they left home. Ted has 2 grown up children, a son Christopher who lives overseas with his wife and son, and a daughter Janice who lives with her husband and 3 children in the city. While Ted lives alone, he has a partner Gwen 78, who also lives in the same retirement village as Ted. • Current medication: Metformin 500mg Mane Captopril 12.5mg mane Frusemide 40mg mane Allopurinol 100mg Daily Paracetamol 1g QID • Ted is now day 4 post op. He was Nil By Mouth (NBM) for the first 48 hours after surgery. Yesterday he commenced on a full fluid diet and has upgraded to a light diet yesterday evening. Today, Ted was given his regular metformin and ate breakfast. Since then Ted has vomited twice and feels nauseous. He has been given ondansetron 4mg for nausea. • Teds vital signs at 10am are as follows: T 38.1; HR 98 reg; BP 135/85; RR 26; SpO2 94% on 3L NP. He has right sided inspiratory coarse crackles and he has a moist productive cough. He has PCA morphine in situ for effective pain regulation. Ted has some abdominal pain that he says is at a scale of 4-5/10, he says the pain worsens on palpation to 7/10 and you note that his abdomen is distended. The colostomy bag is intact and the stoma can be sighted through the bag. The stoma is warm, pink, moist and slightly raised above the skin. There has been no output since his surgery. He has sluggish bowel sounds and has not passed flatus. The abdominal laparotomy has a clear occlusive dressing (opsite) and there is minimal ooze present. He has a redivac drain with 30mls of haemoserous fluid, and a urinary catheter in situ and is passing approx. 60-70mls of urine/hr.

• Question 4: Select two classes of drugs that would be used to manage Ted’s post operative condition. Please provide a rationale for why that drug class would be suitable for Ted. Provide a detailed description of the pharmaco-dynamics of each of the selected class of drug as well as the potential side effects and the nursing implications for administration

Answer 1

Two classes of drugs that would be used to manage Ted’s postoperative condition are proton pump inhibitors (PPI) and analgesics.

a) Pharmacodynamics of PPI: PPIs are given to reduce the gastric acid secretion, which usually increases after bowel resection. Activated PPI inhibits the gastric hydrogen-potassium adenosinetriphosphatase enzyme at the secretory surface of gastric parietal cells to block gastric acid secretion. The PPI forms a covalent bond with the H⁺, K⁺-ATPase through a disulfide bond. The PPIs bind to Cys813, the primary site of inhibition.

Side effects of PPIs: Nausea, vomiting, diarrhea, abdominal pain, flatulence, upper respiratory infection, dizziness, etc are the side effects.

b) Pharmacodynamics of analgesics: Analgesics are a necessity for this postop patient to reduce the pain. Patient-controlled analgesia (PCA) is a delivery system to administer analgesics that can be used by patients to control postop pain. Opioid analgesics act on the central nervous system with the help of opioid receptors for pain relief. These receptors have two functions; recognition and biological action. The binding affinity correlates with analgesic potency. The equilibrium inhibition constant (Ki) is used to measure the binding affinity.

Side effects: Morphine use has a risk for abuse/addiction. Nausea, vomiting, constipation, dizziness, drowsiness, etc are other side effects.