Background & objective: Patients with chronic sinusitis, not responding to medical treatment are managed with functional endoscopic sinus surgery (FESS) by ENT specialists. The surgery demands a bloodless field for its success. Even minimal amount of blood can obscure the surgical field to the operating surgeon. We compared three drugs, propofol, dexmedetomidine, and nitroglycerin as hypotensive agents and their effect on blood loss in FESS. Methodology: Our study included sixty adult patients scheduled for FESS at Ain Shams University hospitals from September 2018 to September 2019. All patients were ASA I and II and they were distributed into three groups in a random manner, twenty patients in each group. Patients in Group D were administered dexmedetomidine 1 μg/kg as a loading dose over 10 min (in 100 ml normal saline) just after induction, then 0.5 μg/kg/h was infused. Group P patients were administered propofol infusion 8 mg/kg/h. Group N patients were administered nitroglycerin infusion of 2 μg/kg/min. Hemodynamic parameters were recorded every 15 min. We used bleeding score to examine the quality of operating field. We recorded the time to achieve target mean arterial blood pressure. Duration of operation was recorded. Results: In Groups D and P, our target of mean arterial pressure of 55-65 mmHg was achieved. The hypotensive drugs used in these groups offered good quality of surgical field and shorter duration of surgery. Group D also achieved target blood pressure faster than Group P with significantly lower heart rate in Group D. Conclusion: Dexmedetomidine and propofol had more favorable effects for attaining the desired blood pressure than nitroglycerin with lower heart rate in dexmedetomidine group. Dexmedetomidine and propofol were associated with less bleeding and shorter duration of surgery in patients undergoing FESS. Also dexmedetomidine was faster in achieving target blood pressure than propofol. Trial Registry: PACTR202202877370804 Abbreviations: FESS - Functional endoscopic sinus surgery; CSF - Cerebrospinal fluid; GABA - γ-aminobutyric acid’ MAP - Mean arterial blood pressure Key words: Anesthesia; Anesthesia, General; Endoscopy / methods; Humans; Propofol; Dexmedetomidine; Nitroglycerin; Controlled hypotension; FESS. Citation: Saleh SAEM, Awad HGS, Shonoda AMF, ElShorbagy MS, Doaa Mohammed Kamal ElDin DMK. A comparison between propofol, dexmedetomidine and nitroglycerin as hypotensive agents and their effect on blood loss in functional endoscopic sinus surgery (FESS). Anaesth. pain intensive care 2022;26(3):338-346. DOI: 10.35975/apic.v26i3.1908 Received: March 10, 2022; Reviewed: April 07, 2022; Accepted: May 05, 2022 Background & objective: Patients with chronic sinusitis, not responding to medical treatment are managed with functional endoscopic sinus surgery (FESS) by ENT specialists. The surgery demands a bloodless field for its success. Even minimal amount of blood can obscure the surgical field to the operating surgeon. We compared three drugs, propofol, dexmedetomidine, and nitroglycerin as hypotensive agents and their effect on blood loss in FESS. Methodology: Our study included sixty adult patients scheduled for FESS at Ain Shams University hospitals from September 2018 to September 2019. All patients were ASA I and II and they were distributed into three groups in a random manner, twenty patients in each group. Patients in Group D were administered dexmedetomidine 1 μg/kg as a loading dose over 10 min (in 100 ml normal saline) just after induction, then 0.5 μg/kg/h was infused. Group P patients were administered propofol infusion 8 mg/kg/h. Group N patients were administered nitroglycerin infusion of 2 μg/kg/min. Hemodynamic parameters were recorded every 15 min. We used bleeding score to examine the quality of operating field. We recorded the time to achieve target mean arterial blood pressure. Duration of operation was recorded. Results: In Groups D and P, our target of mean arterial pressure of 55-65 mmHg was achieved. The hypotensive drugs used in these groups offered good quality of surgical field and shorter duration of surgery. Group D also achieved target blood pressure faster than Group P with significantly lower heart rate in Group D. Conclusion: Dexmedetomidine and propofol had more favorable effects for attaining the desired blood pressure than nitroglycerin with lower heart rate in dexmedetomidine group. Dexmedetomidine and propofol were associated with less bleeding and shorter duration of surgery in patients undergoing FESS. Also dexmedetomidine was faster in achieving target blood pressure than propofol. Trial Registry: PACTR202202877370804 Abbreviations: FESS - Functional endoscopic sinus surgery; CSF - Cerebrospinal fluid; GABA - γ-aminobutyric acid’ MAP - Mean arterial blood pressure Key words: Anesthesia; Anesthesia, General; Endoscopy / methods; Humans; Propofol; Dexmedetomidine; Nitroglycerin; Controlled hypotension; FESS. Citation: Saleh SAEM, Awad HGS, Shonoda AMF, ElShorbagy MS, Doaa Mohammed Kamal ElDin DMK. A comparison between propofol, dexmedetomidine and nitroglycerin as hypotensive agents and their effect on blood loss in functional endoscopic sinus surgery (FESS). Anaesth. pain intensive care 2022;26(3):338-346. DOI: 10.35975/apic.v26i3.1908 Received: March 10, 2022; Reviewed: April 07, 2022; Accepted: May 05, 2022