Background: This study assessed perioperative factors associated with planned and unplanned postoperative ICU admission and evaluated the outcome of the two groups. There are limited researches evaluating these factors. Hence, it is important to do an audit that assesses the perioperative factors to help creating a criteria for postoperative ICU admissions.

Materials and methods: This retrospective study evaluated medical records of 68 patients above 18 years between January'2016- December'2018 that were admitted to ICU postoperatively in Sultan Qaboos University hospital in Oman. Both planned and unplanned admissions were assessed who underwent elective as well as emergency surgeries. Neurologic and cardiothoracic surgeries were excluded. Data collected included patient's demographics, social status like smoking, ASA physical status (American Society of Anesthesiologists), associated comorbidities, other perioperative factors and investigations, surgical and anesthesia details were recorded. The primary outcome studied was reasons of admission for planned versus unplanned postoperative ICU admissions. The secondary outcomes included mortality outcome and length of stay in ICU.

There are 2 Levels of care available for patients who require high level of organ support and monitoring. First of them is the high dependency unit (HDU) where higher level organ support and monitoring is given (exception for mechanical ventilation) such as invasive blood pressure monitoring. Second one is the intensive care unit (ICU), which provides support for patients with multiple organ dysfunction that needs higher level of care which cannot be provided in the ward or the high dependency unit (HDU) and without this care the patient may not survive.

ICU admission post-operatively can be either in a planned or unplanned way. The complex interaction between associated comorbidities, anticipated complications intra-operatively and high American Society of Anesthesiologists (ASA) Physical Status are major factors in planning for ICU admission post-operatively. ASA physical status indicates patient's health status and has been accepted as a determinant of comorbidity and mortality. Unplanned ICU admissions can be due to unpredicted surgical or anesthetic intra-operative complications or poor assessment of perioperative factors. After surgery, some patients are admitted to ICU for further management and monitoring based on their underlying low functional status and co-morbidities. Out of these some patients may actually need ICU interventions and others may not. If an ICU bed is booked for unworthy patient, this may lead to unnecessary increased expenditure, wastage of valuable resources as well as deny the ICU services to potentially survivable and worthy critically ill patient.

This study aimed to assess perioperative factors associated with planned and unplanned admissions to find out the main reasons of admission to ICU at Sultan Qaboos University hospital (SQUH). This will help to lay guideline for guiding future admission to ICU for surgical patients in immediate postoperative period and help to reduce the unplanned admission.

Methods

This retrospective observational study traced all adult patients (above 18 years old) who underwent surgery and got admitted to ICU directly from operating theatre during the 3-year period: 2016-2018 at SQUH. These were segregated into planned and unplanned admissions. Required information was accessed using the hospital information system after receiving the ethical approval from Sultan Qaboos University Hospital Ethics and Research Committee (MREC#1937). Patients who were admitted to specialized ICU and those who underwent neurologic or cardiothoracic operations were excluded from this study since they are admitted postoperatively to ICU by default.

Patient's data that were collected included age, gender, social status like smoking, ASA physical status (American Society of Anesthesiologists), associated comorbidities such as diabetes, hypertension, ischemic heart disease, valvular heart disease, pulmonary diseases, chronic kidney disease and cirrhosis. Associated factors and investigations were collected like dehydration, hypoxia, hypercarbia, pH changes, pulmonary complications, fluid/electrolyte imbalance, temperature changes, random blood sugar, sepsis, coagulopathy, elevated WBC, low hemoglobin, hemodynamic instability, septic shock, hypovolemic shock, infection, blood loss more than 20%, hypotension and cardiac arrhythmia. Type, nature and duration of surgery, type of anesthesia and airway issues were recorded. Patients mortality outcome and length of stay in ICU were included as well.

Statistical methods: Statistical Package for the Social Sciences (SPSS) was used for patient's data analysis. Descriptive statistics were used to determine median, frequencies and percentages of the data and were presented in form of graphs and tables. For testing the significance between the way of ICU admission (planned/unplanned) and different variables, Chi-square and Fisher's exact test were used. To assess risk factors of mortality outcome and long ICU stay, odds ratio was used. P-value of 0.05 or less was considered to be significant.

Inclusion Criteria:

• Adult patients over the age of 18 who underwent surgery and got admitted directly to ICU postoperatively

Exclusion Criteria:

• Patients who were admitted to specialized ICU ( cardiothoracic and neurosurgery ) or to the ward and then ICU
• Pediatric patients

Adult patients (above 18 years old) who underwent surgery and got admitted to ICU directly from operating theatre