Title : Predictors of post-operative complications in patients following cardiac surgery: A prospective observational study
Abstract:
Introduction: Cardiac surgery remains a vital intervention for severe cardiovascular conditions. Despite advancements in surgical expertise and technology, postoperative complications—ranging from metabolic and hematologic disturbances to cardiovascular dysregulation—are common. Integrating clinical pharmacists into postoperative care offers a proactive strategy to identify, manage, and prevent medication-related complications, supporting enhanced clinical outcomes.
Aim: To evaluate the role of clinical pharmacists in identifying and managing postoperative complications—including adverse drug reactions (ADRs), drug–drug interactions, and untreated indications—in patients undergoing cardiac surgery, and to assess the impact of pharmacist-led interventions on postoperative care.
Methodology: In this prospective observational study, 103 patients undergoing various cardiac procedures (including coronary angiography, angioplasty, CABG, temporary pacemaker implantation, ASD closure, and valve replacement) were enrolled. Clinical pharmacists systematically collected patient demographics, comorbidities, medication histories, nursing notes, and laboratory data from patient records. They monitored the postoperative period to detect drug-related problems, assessed ADR causality using Naranjo’s Algorithm and WHO UMC criteria, evaluated severity, predictability, and preventability, and documented interventions in patients’ medication records.
Results: Postoperative complications were observed in 91 (88.3%) of patients, with common issues including hyponatremia (36.6%), anemia (32.2%), hypertension (32.2%), tachycardia (14.4%), hypokalemia (14.4%), and hypophosphatemia (11.1%). Drug-related problems occurred in 39 patients (35%), notably ADRs, drug–drug interactions, and untreated indications.
Clinically-reviewed ADRs included drug-induced hypoglycemia, heparin-induced thrombocytopenia, metoprolol-induced bradycardia, hydrochlorothiazide-induced hyponatremia, and amlodipine-induced edema—predominantly classified as ‘probable’ or ‘possible,’ mild in severity, predictable, and preventable. Significant drug–drug interactions (e.g., aspirin–metformin hypoglycemia, furosemide–telmisartan hypotension, aspirin–sacubitril/valsartan hypokalemia) were identified. Additionally, untreated indications such as respiratory acidosis and anemia were detected.
Clinical pharmacists documented and intervened in critical postoperative complications
• Anemia: Reported cases led to blood transfusions or investigations for infections/inflammation.
• Electrolyte imbalances: Interventions with IV sodium, potassium, or calcium supplementation were recommended and implemented.
• Blood pressure disturbances: Both hypertension and hypotension were managed through pharmacist-guided
medication adjustments (e.g., beta-blockers, ARBs, CCBs, diuretics) and IV fluids as needed.
• Heart rate irregularities: Tachycardia and bradycardia were managed via medication changes, fluid management, ECG monitoring, and pacemaker guidance.
• Surgical wound infections: Early infections were flagged, prompting initiation of IV vancomycin.
Discussion: The high prevalence of postoperative complications underscores the complex healthcare needs of cardiac surgery patients. Clinical pharmacist interventions were pivotal in detecting drug-related problems and postoperative complications early, guiding physician-led management, and preventing escalation. Their documentation and communication enhanced coordination and patient safety. Integrating clinical pharmacists into cardiac surgery teams may significantly improve recovery trajectories and reduce preventable drug-related harm.
