Table 3.

Summary of results: systemic corticosteroids perioperatively.

Name	Author and publication date	Type of study	Number of patients	Investigated drug	Side effects	Conclusions	Quality of evidence
Impact of Preoperative Systemic Corticosteroids on the Histology and Diagnosis of Eosinophilic Chronic Rhinosinusitis [25]	Akiyama 2019	Case series	44	Preoperative oral prednisolone (0.3 mg/kg as a guide).	Not mentioned.	Oral prednisolone did not appear to markedly affect the tissue eosinophil count.	Low
Prospective evaluation of oral corticosteroid as a predictor of postoperative olfactory recovery after functional endoscopic surgery for nasal polyposis [26]	Rives 2019	Prospective	119	Oral prednisolone 1 mg/kg/day for 5 days preoperatively.	Not mentioned.	Olfactory recovery greater than 50% after a course of OCS therapy may be a predictor of better subjective postoperative recovery.	Low
Differential effects of postoperative oral corticosteroid on eosinophilic vs. non-eosinophilic CRSwNP subtypes [27]	Shen 2019	Randomized controlled trial	100	Oral prednisolone (30 mg/day) for 2 weeks after surgery.	No severe side effects.	The subjective parameters, including self-rated nasal health, decreased in both groups over time, but demonstrated no statistically significant differences between the corticosteroid and placebo groups.	Moderate
Effect of steroids for nasal polyposis surgery: A placebo-controlled, randomized, double-blind study [28]	Ecevit 2015	Randomized controlled trial	22	Six pills of 10 mg prednisolone and 90 mg lactose for 7 days, reduced to one pill taken every other day preoperatively.	Not mentioned.	Preoperative administration of systemic corticosteroids improves the perioperative visibility by reducing blood loss and shortens the operation time.	Moderate
Impact of perioperative systemic steroids on surgical outcomes in patients with chronic rhinosinusitis with polyposis: evaluation with the novel Perioperative Sinus Endoscopy (POSE) scoring system [29]	Wright 2007	Randomized controlled trial	26	30 mg of prednisone for 5 days preoperatively and 9 days postoperatively.	Not mentioned.	Pretreatment with systemic corticosteroids appears to confer the advantages of facilitating surgery and results in endoscopically healthier sinus cavities in the short term.	Moderate
Oral Corticosteroids Following Endoscopic Sinus Surgery for Chronic Rhinosinusitis Without Nasal Polyposis: A Randomized Clinical Trial [30]	Chang 2021	Randomized controlled trial	72	12-day postoperative taper of oral prednisone: 30 mg, 4 days; 20 mg, 4 days; and 10 mg 4 days.	Not mentioned.	Oral prednisone following endoscopic sinus surgery conferred no additional benefit over placebo. These results suggest that the risks of oral corticosteroids may outweigh the benefits.	Moderate
Lack of additive benefit of oral steroids on short-term postoperative outcomes in nasal polyposis [31]	Arancibia 2020	Randomized controlled trial	70	Postoperative 30 mg of oral prednisone for 1 week, 20 mg for 1 week, 10 mg for 1 week, and finally 5 mg for 1 week.	Not mentioned.	Postoperative OCS as an add-on treatment for CRSwNP patients does not improve sinonasal and QoL outcomes; thus, they should not be routinely recommended.	Moderate