title: Hypotensive anesthesia: Comparing the effects of different drug combinations on mean arterial pressure, estimated blood loss, and surgery time in orthognathic surgery.
abstract: Sevoflurane, an inhalational hypotensive anesthetic agent with a vasodilatory property, has been commonly used as a single agent to induce hypotension and effectively decrease blood loss in orthognathic surgery. However, it is common for patients to receive other hypotensive anesthetic agents in combination with sevoflurane. The purpose of our retrospective cohort study is to investigate whether administering an additional hypotensive agent has greater effect at reducing mean arterial pressure (MAP), estimated blood loss (EBL) and surgery time during orthognathic surgery.
  
  
  METHODS
  57 subjects, aged 0-89 of both genders, who underwent orthognathic surgery were investigated in this study. Each patient's anesthesia records were reviewed to record the following variables of interest: EBL, duration of surgery, and MAP reduction in %. 41 subjects were placed in Group I and they received sevoflurane alone. 16 subjects were placed in Group II and they received sevoflurane plus a "supportive" agent. These "supportive" agents were esmolol, labetalol, metoprolol, nicardipine, and dexmedetomidine. The significant differences between two groups were assessed by using ANCOVA and p < 0.05 was regarded as significant. Wilcoxon signed-rank test was used to look for differences in surgery time.
  
  
  RESULTS
  Subjects in Group II experienced a greater reduction in MAP during surgery than subjects in Group I, 27.30% and 20.44%, respectively (p = 0.027). There was no significant difference for sex (p = 0.417) or age group (p = 0.113) in estimated blood loss, however. The mean surgery time in Group I was 1.93, 2.77, and 4.54 h with respect to LeFort, BSSO/IVRO, and double jaw surgery. Patients in Group II had a mean surgery time of 1.73, 2.07, and 5.64 h with respect to LeFort, BSSO/IVRO, and double jaw surgery. No statistically significant difference was demonstrated in surgery time between Group I vs. Group II (p > 0.05). Subjects in Group II experienced, on average, more blood loss than subjects in Group I, 355.50 ml and 238.90 ml, respectively.
  
  
  CONCLUSIONS
  The use of multi-drug combination may offer significant advantage of reducing patients' mean arterial pressure. However, this has no significant effect on reducing blood loss or surgery time in comparison to sevoflurane alone.
authors.affiliation: Nova Southeastern University, College of Dental Medicine, 3200 South University Drive, Fort Lauderdale, FL 33328-2018, USA. Electronic address: jamestjeong@gmail.com.
authors.forename: James
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Department of Oral & Maxillofacial Surgery, Nova Southeastern University, College of Dental Medicine, 3200 South University Drive, Fort Lauderdale, FL 33328-2018, USA.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Portnof
authors.affiliation: Department of Oral & Maxillofacial Surgery, Nova Southeastern University, College of Dental Medicine, 3200 South University Drive, Fort Lauderdale, FL 33328-2018, USA.
authors.forename: Mona
authors.initials: M
authors.lastname: Kalayeh
authors.affiliation: Nova Southeastern University, College of Dental Medicine, 3200 South University Drive, Fort Lauderdale, FL 33328-2018, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Hardigan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D062186:Arterial Pressure / Q000187:drug effects*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D008875:Middle Aged; D061646:Operative Time; D056948:Orthognathic Surgical Procedures; D000077149:Sevoflurane; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D000959:Antihypertensive Agents; D008738:Methyl Ethers; D000077149:Sevoflurane
keywords: Blood loss; Hypotensive anesthesia; Mean arterial pressure; Orthognathic surgery; Sevoflurane