Author: Javaria Salam, et al.
Cureus, June 26, 2026
Postoperative medical complications remain common after major abdominal surgery and can substantially prolong hospitalization and delay recovery. This prospective observational study evaluated patient and perioperative factors associated with complications during the first 30 postoperative days.
The investigators enrolled 284 adults undergoing elective or emergency major abdominal surgery at two tertiary hospitals in Pakistan. Ninety-six patients, or 33.8%, developed at least one postoperative medical complication.
Most common complications
Pulmonary complications were the most frequent, followed by:
• Acute kidney injury
• Systemic infection
• Delirium
• Cardiac complications
• Venous thromboembolism
Among patients who developed complications, 66.7% experienced a clinically significant event classified as Clavien-Dindo grade III or higher.
Patients with complications had a median hospital stay of 11 days compared with six days among those without complications.
Independent predictors
Six factors remained independently associated with postoperative medical complications after multivariable adjustment.
ASA physical status III or higher
Patients with ASA III or greater had approximately 2.4 times the odds of developing a complication.
This finding reflects the importance of reduced physiological reserve and greater systemic disease burden before surgery.
Hypoalbuminemia
A serum albumin level below 3.0 g/dL was associated with approximately 2.8 times the odds of postoperative complications.
Hypoalbuminemia may reflect malnutrition, inflammation, chronic illness, or a combination of these conditions. It was one of the strongest preoperative predictors in the study.
Emergency surgery
Emergency procedures were associated with approximately 1.9 times the odds of complications.
These patients often present with infection, obstruction, perforation, dehydration, or hemodynamic instability and have limited time for preoperative optimization.
Operative duration greater than 180 minutes
Operations lasting more than three hours were associated with approximately 2.2 times the odds of postoperative medical complications.
Longer procedures may reflect greater surgical complexity, tissue trauma, blood loss, fluid shifts, hypothermia, and prolonged anesthetic exposure.
Intraoperative hypotension
Mean arterial pressure below 65 mmHg was associated with approximately 2.4 times the odds of complications.
Inadequate organ perfusion during surgery may contribute to acute kidney injury, myocardial injury, cerebral dysfunction, and other postoperative organ complications.
Intraoperative blood transfusion
Patients receiving an intraoperative blood transfusion had approximately 2.9 times the odds of postoperative complications.
Transfusion may represent a marker of greater blood loss and surgical complexity, but it may also independently contribute to inflammatory, infectious, pulmonary, and immune-related complications.
Additional associations
Older age, diabetes, ischemic heart disease, open surgery, poor early postoperative pain control, and ICU admission were associated with complications during univariate analysis.
However, age and surgical approach did not remain independently significant after adjustment.
ICU admission and poor pain control were excluded from the final predictive model because they may represent consequences of early deterioration rather than true preoperative or intraoperative predictors.
Clinical implications
The findings support a structured perioperative approach focused on early identification of high-risk patients and optimization of potentially modifiable factors.
Important strategies include:
• Preoperative nutritional assessment
• Correction of anemia when possible
• Careful patient blood management
• Avoidance and prompt treatment of intraoperative hypotension
• Planning for prolonged or complex procedures
• Effective postoperative analgesia
• Early mobilization and respiratory therapy
• Increased surveillance for high-risk patients
Because pulmonary complications were the most frequent events, particular attention should be given to lung expansion, adequate pain control, early ambulation, respiratory monitoring, and appropriate postoperative oxygen or ventilatory support.
Important limitations
This was an observational study, so it demonstrates associations rather than causation.
The study involved only two tertiary hospitals in one geographic region, which may limit generalizability.
Some complications, particularly delirium and systemic infection, depended on clinical documentation rather than standardized screening tools.
Patients at higher risk may also have undergone more frequent testing and monitoring, potentially increasing the likelihood that complications were detected.
The study did not evaluate longer-term outcomes such as readmission, functional recovery, or mortality beyond 30 days.
Intraoperative hypotension and transfusion may partly reflect the severity and complexity of the operation rather than serving as entirely independent causes of complications.
Bottom line
Approximately one-third of patients undergoing major abdominal surgery developed a postoperative medical complication within 30 days.
ASA III or greater, marked hypoalbuminemia, emergency surgery, operations lasting more than three hours, intraoperative hypotension, and blood transfusion were independent predictors.
The findings reinforce the importance of nutritional optimization, hemodynamic stability, blood conservation, preoperative risk assessment, and targeted postoperative monitoring in reducing medical complications following major abdominal surgery.
Thank you to Cureus for allowing us to summarize this article.