Hypotensive anaesthesia and blood loss in orthognathic surgery: a clinical study

Efficacy and safety of intraoperative controlled hypotension: a systematic review and meta-analysis of randomised trials

BACKGROUND

Intraoperative controlled hypotension improves surgical field visibility by reducing blood loss (efficacy) but poses potential risks linked to organ hypoperfusion (safety). The use of controlled hypotension persists despite increasing evidence of associations between intraoperative inadvertent hypotension and adverse outcomes. Therefore, we tested the hypothesis that the focus and results of intraoperative controlled hypertension research differ across anaesthesia and surgery investigators because of differing priorities.

METHODS

We systematically reviewed randomised trials comparing controlled hypotension with usual care with trials categorised by investigators' affiliation.

RESULTS

We identified 48 eligible trials, of which 37 were conducted by anaesthesia investigators and 11 by surgery investigators. For the primary outcome, 54% of the anaesthesia-led trials focused on safety, whereas all (100%) surgery-led trials focused on efficacy (P=0.004). Compared with usual care, mean arterial pressure in controlled hypotension was 23% (95% confidence interval [CI] 17-29%) lower in anaesthesia trials and 30% (95% CI 14-37%) lower in surgery trials; estimated blood loss was 44% (95% CI 30-55%) less in anaesthesia trials and 38% (95% CI 30-49%) less in surgery trials. Overall, blood loss was reduced by 43% (95% CI 32-53%), and trial sequential analysis supported an efficacy conclusion. Mean arterial pressure and estimated blood loss reductions were associated (R2=0.41, P=0.002). All trials were underpowered for safety outcomes, and none adequately evaluated myocardial or renal injury.

CONCLUSIONS

Anaesthesia researchers prioritised safety outcomes, whereas surgery researchers emphasised efficacy in controlled hypotension trials. Controlled hypotension significantly reduces blood loss. In contrast, safety outcomes were poorly studied. Given increasing observational evidence linking inadvertent hypotension to myocardial and renal injury, the safety of controlled hypotension remains to be addressed.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023450397).

Effectiveness of prophylactic tranexamic acid versus placebo or no intervention for reducing blood loss in healthy patients undergoing orthognathic surgery: a systematic review protocol

OBJECTIVE

The objective of this review is to evaluate the effectiveness of perioperative prophylactic tranexamic acid for reducing blood loss in orthognathic surgery in healthy patients.

INTRODUCTION

Orthognathic surgery can cause significant hemorrhage, which requires postoperative blood transfusions. The most widely studied pharmaceutical adjunct for reducing blood loss is tranexamic acid, a synthetic amino acid that reversibly inhibits plasminogen activation. It is widely used and validated in other surgical procedures to limit blood loss; however, it is not a gold standard in orthognathic surgery.

INCLUSION CRITERIA

We will include clinical trials comparing tranexamic acid to appropriate controls. The primary outcomes are intraoperative blood loss, change in hematocrit/hemoglobin level, and need for blood transfusion. Secondary outcomes include operating time, length of hospital stay, and adverse reactions. Studies of patients with pre-existing coagulopathies and those undergoing only minor orthognathic surgery (eg, genioplasty) will be excluded.

METHODS

We will search 3 electronic databases (PubMed, Embase, and Cochrane Library) from database inception. Titles, abstracts, and full-text papers will be assessed against the inclusion criteria by 2 independent reviewers. Risk of bias will be assessed using the Cochrane Risk of Bias 2.0 tool. Data will be extracted by 2 independent reviewers. Meta-analysis will be conducted for all outcomes where appropriate, with weighted mean differences used for intraoperative blood loss, changes in hematocrit/hemoglobin levels, operation time, and length of stay; and risk ratio for transfusion rates and adverse outcomes. Certainty of the evidence will be presented using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42022314403.

Systematic mapping review of orthognathic surgery

STUDY DESIGN

Systematic mapping review AIM AND SCOPE: The objective of this mapping review was to identify, describe, and organize clinical research currently available from systematic reviews and primary studies regarding co-interventions and different surgical modalities used in orthognathic surgery (OS) and their outcomes.

METHODS

Systematic reviews (SRs), randomized controlled trials, and observational studies that evaluated perioperative OS co-interventions and surgical modalities were identified in an exhaustive search of MEDLINE, EMBASE, Epistemonikos, Lilacs, Web of Science, and CENTRAL. Grey literature was also screened.

RESULTS

Included were 35 SRs and 253 primary studies, 103 from SRs, and another 150 identified in our search. Overall, SR quality was rated as critically low, with only two SRs rated as of high quality. 19 questions on population, interventions, comparisons, and outcomes (PICO) extracted from the SRs focused on osteosynthesis methods, surgical cutting devices, and use of antibiotics, corticosteroids, and induced hypotension. Also identified were 15 research gaps. Evidence bubble maps were created to graphically depict the available evidence.

CONCLUSION

Future high-quality research, both primary and secondary, is needed to address the knowledge gaps identified in this systematic mapping review.

Development and Validation of a Nomogram to Predict the Risk of Blood Transfusion in Orthognathic Patients

OBJECTIVE

This study aims to establish a nomogram to predict the probability of blood transfusion in patients with preoperative autologous blood donation before orthognathic surgery.

METHODS

The authors conducted a retrospective case-control study on consecutive orthognathic patients with preoperative autologous blood donation from January 2014 to December 2020. The outcome variable was the actual transfusion of autologous blood (ATAB). Predictors included patients' demographics, preoperative blood cell test, vital signs, American Society of Anesthesiologists classification, surgical procedure, operation duration, and blood loss. Univariable and multivariable logistic regressions were performed to identify independent risk factors associated with ATAB. A nomogram was constructed to predict the risk for ATAB. The performance of the nomogram was evaluated using the area under the receiver operating characteristic curve, calibration curve and the consistency index.

RESULTS

A total of 142 patients (75 males and 67 females) with an average age of 22.72 ± 5.34 years donated autologous blood before their orthognathic surgery. Patients in the transfusion group (n = 56) had significantly lower preoperative red blood cell counts (4.74 ± 0.55 × 109/L versus 4.98 ± 0.45 × 109/L, P = 0.0063), hemoglobin (141.48 ± 15.18 g/dL versus 150.33 ± 14.73 g/dL, P = 0.0008), and hematocrit (41.05% ± 4.03% versus 43.32% ± 3.42%, P = 0.0006), more bimaxillary osteotomies (92.86% versus 56.98%, P < 0.001), longer operation duration (348.4 ± 111.10 minutes versus 261.6 ± 115.44 minutes, P < 0.001), and more intraoperative blood loss (629.23 ± 273.06 ml versus 359.53 ± 222.84 ml, P < 0.001) than their counterparts (n = 86) in the non-transfusion group. Univariable and multivariable logistic regression demonstrated that only hemoglobin (adjusted odds ratio [OR] 0.864, 95% confidence interval [CI]:0.76-0.98, P = 0.026), operation procedures (adjusted OR 8.14, 95% CI:1.69-39.16, P = 0.009), and blood loss (adjusted OR 1.006, 95% CI:1.002-1.009, P < 0.001) were independent risk factors for ATAB. The area under the receiver operating characteristic curve of the nomogram was 0.823. The consistency index of the nomogram was 0.823. The calibration curve illustrated that the nomogram was highly consistent with the actual observation.

CONCLUSIONS

The nomogram is a simple and useful tool with good accuracy and performance in predicting the risk for blood transfusion.

Predictors of Blood Loss During Orthognathic Surgery and the Need for Pre-Deposit Autologous Blood Donation

ABSTRACT

The aim of this study was to identify the clinico-laboratory predictors of relative blood loss (RBL) during orthognathic surgery and determine the need for predeposit autologous blood donation (PABD) for the surgery. Using a retrospective study design, 297 patients who underwent bimaxillary orthognathic surgery between 2016 and 2020 were enrolled. To investigate patient-specific risk factors, we calculated the allowable blood loss (ABL) for each patient and RBL as the ratio of estimated intraoperative blood loss (EIBL) to ABL. The correlations between the clinico-laboratory variables and EIBL and RBL were analyzed using stepwise multivariate regression analysis, and independent t test and one-way ANOVA were performed.There was no significant difference in transfusion rate between the PABD group (N = 202/279) and non-PABD group (N = 77/279) (P = 0.052). Sex (P < 0.001), body mass index class (P = 0.001), operative time (P < 0.001), and baseline hematocrit (P < 0.001) were significant predictors of EIBL and RBL. EIBL exceeded ABL in only 2 patients. The significant factors of RBL in orthognathic surgery were hematocrit, body mass index, and operative time. Clinicians should be more careful about bleeding in patients with low baseline hematocrit level or high body mass index, or those expected to undergo prolonged surgeries owing to a complicated surgical plan. The need for PABD before orthognathic surgery is low.

Dynamic thiol/disulphide balance in patients undergoing hypotensive anesthesia in elective septoplasties

OBJECTIVE

We aimed to investigate the effects of hypotensive anaesthesia on oxidative stress with serum thiol/disulphide balance in patients undergoing elective septoplasty procedures under general anaesthesia.

METHODS

Seventy-two patients between the ages of 18-60, with a physical condition I -II, according to the American Society of Anesthesiologists, were included in this prospective observational study. Septoplasty was chosen for standard surgical stress. According to the maintenance of anaesthesia, patients were divided into the groups as Hypotensive Anaesthesia (n = 40) and Normotensive Anaesthesia (n = 32). Serum thiol/disulphide levels were measured by the method developed by Erel & Neşelioğlu.

RESULTS

The native thiol and total thiol values of both groups measured at the 60th min intraoperatively were significantly lower than the preoperative values (both P < .01). Intraoperatively, at the 60th min, there was no significant difference in terms of post-native thiol and post-total thiol levels between hypotensive and normotensive anaesthesia groups (P = .68 and .81, respectively). Age >40 years and female gender were found to have a significant effect on dynamic oxidative stress (P = .002 and .001, respectively).

CONCLUSION

This pilot study has found that hypotensive anaesthesia had no adverse effect on dynamic thiol/disulphide balance in elective surgeries.

Intraoperative Blood Loss and Postoperative Pain in the Sagittal Split Ramus Osteotomy and Intraoral Vertical Ramus Osteotomy: A Literature Review

Purpose

The purpose of the present study was to review the literature regarding the blood loss and postoperative pain in the isolated sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO).

Materials and Methods

Investigating the intraoperative blood loss and postoperative pain, articles were selected from 1970 to 2021 in the English published databases (PubMed, Web of Science, and Cochrane Library). Article retrieval and selection were performed by two authors, and they independently evaluated them based on the eligibility criteria. The articles meeting the search criteria had especially at least 30 patients.

Results

In the review of intraoperative blood loss, a total of 139 articles were retrieved and restricted to 6 articles (SSRO: 4; IVRO: 2). In the review of postoperative pain, a total of 174 articles were retrieved and restricted to 4 articles (SSRO: 3; IVRO: 1). The mean blood loss of SSRO and IVRO was ranged from 55 to 167 mL and 82 to 104 mL, respectively. The mean visual analog scale (VAS) scores of the first postoperative day were 2 to 5.3 in SSRO and 2.93 to 3.13 in IVRO. The mean VAS scores of the second postoperative day were 1 to 3 in SSRO and 1.1 to 1.8 in IVRO.

Conclusion

Compared to traditional SSRO, IVRO had a significantly lower amount of blood loss. However, the blood transfusion is not necessary in a single-jaw operation (SSRO or IVRO). Postoperative pain was similar between SSRO and IVRO.

Predictors of Red Blood Cell Transfusion in Bimaxillary Orthognathic Surgery: A Retrospective Study

Background: Orthognathic surgery requires red blood cell (RBC) transfusions more frequently than other oral and maxillofacial surgeries. The purpose of this study was to identify reliable predictors for RBC transfusion during bimaxillary orthognathic surgery (BOS). Methods: This retrospective study reviewed 1,616 electronic medical records of patients who underwent BOS during a 5-year period at Seoul National University Dental Hospital. The perioperative variable data were collected from electronic medical records and analyzed by dividing patients into the two groups (non-transfusion and transfusion group). Results: Of the 1,616 patients, 1,311 patients were excluded. The remaining 305 patients were divided into non-transfusion (NTF, n = 256) and transfusion (TF, n = 49) groups. Univariate logistic regression analysis revealed that age, body mass index, the presence of several adjunctive surgeries (including genioplasty, extraction, and mandibular angle reduction), preoperative hemoglobin (Hb) and prothrombin time, surgical time, amount of fluid infusion and blood loss, and mean pulse rate during surgery were significant factors predicting RBC transfusion. Multivariate logistic regression analysis revealed that preoperative Hb and blood loss amount during surgery were significantly related to RBC transfusion in BOS patients. Conclusion: Since blood loss amounts could not be measured preoperatively, we found that the independent predictor associated with RBC transfusion during BOS was a low preoperative Hb level.

Usefulness of Tranexamic Acid Administration During Sagittal Split Ramus Osteotomy

ABSTRACT

Tranexamic acid has been used to reduce intraoperative bleeding; however, its effect on anti-inflammation and the amount of drainage after orthognathic surgery is yet to be determined. Therefore, we aimed to examine the effect of tranexamic acid on intraoperative bleeding volume and operation time, amount of drainage, and anti-inflammation after orthognathic surgery. Forty healthy women who underwent bilateral sagittal split ramus osteotomy under general anesthesia participated in this study. The amount of intraoperative bleeding, the operation time, the amount of drainage, and the C-reactive protein level were compared between patients intravenously administered with tranexamic acid before surgery (before-surgery group) and those administered with the drug after surgery (after-surgery group). All data were analyzed using the Student t-test. Results were considered to be statistically significant when P < 0.05. Although no significant difference was found in the amount of drainage between the groups (P > 0.05), significant variations were detected in the amount of bleeding during surgery (before-surgery group: 161.7 ± 45.3 mL versus after-surgery group: 270.2 ± 24.0 mL; P = 0.0009), operation time (before-surgery group: 141.3 ± 16.8 min versus after-surgery group: 166.8 ± 24.9 min; P = 0.03), and postoperative C-reactive protein level (before-surgery group: 3.77 ± 0.40 mg/dL versus after-surgery group: 5.02 ± 0.75 mg/dL; P = 0.012) between the groups. In conclusion, administering tranexamic acid before surgery was found to significantly decrease bleeding, reduce operation time, and suppress postoperative inflammation.

Tranexamic Acid Is Associated With Improved Operative Field in Orthognathic Surgery

PURPOSE

In the past, both tranexamic acid and dexmedetomidine have been used separately to decrease intraoperative blood loss during orthognathic surgery. However, their combined use in the same setting has never been prospectively evaluated. The present study was conducted to evaluate the effect of tranexamic acid on operative field visibility and blood loss during orthognathic surgery after dexmedetomidine-induced hypotensive anesthesia.

PATIENTS AND METHODS

The present prospective, randomized clinical trial included patients who had undergone orthognathic surgery under general anesthesia. The patients were divided into 2 groups. The dexmedetomidine and tranexamic (DT) group received an intravenous bolus of tranexamic acid (15 mg/kg) and intravenous dexmedetomidine (0.25 to 0.7 μg/kg/hr) as maintenance infusion. The dexmedetomidine (DS) group received only intravenous dexmedetomidine at the same dosage. All the patients received a bolus dose of intravenous dexmedetomidine (1 μg/kg) before the start of anesthesia induction. The operating surgeon rated the quality of the surgical visual field every 15 minutes using the Fromme ordinal scale. Intraoperative blood loss was estimated using the modified gross formula. The operating surgeon's satisfaction was assessed using a Likert scale. Data were analyzed using SPSS, version 22.0 (IBM Corp, Armonk, NY). Kolmogorov-Smirnov tests were used to assess the normality of the measured data, and categorical variables were analyzed using the χ² or Fischer exact test.

RESULTS

The study sample included 36 patients, with a mean age of 23.67 ± 11.298 years in the DS group and 20.28 ± 3.286 years in the DT group. Of the patients in the DS and DT groups, 66.66 and 61.11% were male, respectively. No statistically significant differences were found in the baseline characteristics between the 2 treatment groups. The surgeon reported a significantly better surgical visual field in the DT group compared with that in the DS group (P = .001). Also, the intraoperative blood loss significantly less in the DT group (231.11 ± 137.64 mL vs 360.17 ± 187.86 mL; P = .025).

CONCLUSIONS

Tranexamic acid improved surgical field visibility and reduced intraoperative blood loss when administered in conjunction with dexmedetomidine during orthognathic surgery under controlled hypotensive anesthesia.

Effectiveness Comparison of Dexmedetomidine and Remifentanil for Perioperative Management in Patients Undergoing Endoscopic Sinus Surgery

BACKGROUND

For patients undergoing endoscopic sinus surgery, intranasal injection of epinephrine can cause acute increases in heart rate and blood pressure.

OBJECTIVE

Among the drugs for reducing hyperdynamic effects, dexmedetomidine and remifentanil are expected to blunt the acute hemodynamic responses after intranasal injection of epinephrine. Our study compared a difference in the 2 drugs in their abilities to blunt the hemodynamic responses in intraoperative period and postoperative profile.

METHODS

In this study, the patients were randomly divided into the dexmedetomidine and remifentanil groups. During the intraoperative period, the hemodynamic values were recorded. The surgical condition was assessed by a single surgeon. During the postoperative period, hemodynamic values, sedation scale score, and pain score were recorded.

RESULT

No significant differences in hemodynamic variables were found between the groups before and after intranasal injection of epinephrine. Comparison of the group mean values before endotracheal intubation revealed that the blood pressure values in the remifentanil group were significantly lower than those in the dexmedetomidine group. At 2 minutes after endotracheal intubation, blood pressure and heart rate values in the remifentanil group were significantly lower than those in the dexmedetomidine group. The sedation score was significantly lower in the dexmedetomidine group on arrival and at 30 minutes after arrival at the postanesthetic care unit (P < .001 and P = .001, respectively). At 30 and 60 minutes after the operation, the pain scores were significantly lower in the dexmedetomidine group (P = .015 and P = .001, respectively).

CONCLUSION

Dexmedetomidine had better postoperative sedative and analgesic effects than remifentanil for patients undergoing endoscopic sinus surgery in this study. Remifentanil and dexmedetomidine attenuated acute hemodynamic responses to be within normal ranges after intranasal injection of epinephrine, and no significant differences in terms of hemodynamic variables. Remifentanil was superior to dexmedetomidine in inducing hypotension during endotracheal intubation.

Comparison of effects and safety in providing controlled hypotension during surgery between dexmedetomidine and magnesium sulphate: A meta-analysis of randomized controlled trials

Background

Effectiveness of controlled hypotension has been proven in alleviating intraoperative bleeding. Many recent studies emphasized the efficacy of dexmedetomidine and magnesium in providing controlled hypotension during various surgeries. The present meta-analysis of randomized controlled trials (RCTs) was performed to evaluate comprehensively the effects and safety of these two medications.

Methods

Literature search was performed in four databases from inception to April 2019. All RCTs that used dexmedetomidine and magnesium as hypotensive agents were enrolled. The outcomes contained bleeding condition of surgical site, hemodynamic parameters, duration of surgeries, number of patients requiring opioid/analgesia administration, recovery period, and adverse events emerged during surgeries.

Results

Ten studies with 663 patients met with our inclusion criteria. The results indicated that both bleeding score and values of mean arterial pressure (MAP) and heart rate (HR) were significantly lower in patients receiving dexmedetomidine (SMD 1.65 with 95% CI [0.90,2.41], P<0.00001) compared to the patients receiving magnesium. The effect in decreasing the necessity of using opioid/analgesia was affirmative in dexmedetomidine group (29.13% with magnesium vs 10.78% with dexmedetomidine), and the condition was more favorable in magnesium group in reducing recovery period (SMD -1.98 with 95% CI [-4.27,0.30], P = 0.09). Compared with magnesium, using of dexmedetomidine was associated with higher incidence of bradycardia but lower incidence of nausea and vomiting.

Conclusion

Compared with magnesium, dexmedetomidine is more effective to provide promising surgical field condition, favorable controlled hypotension, and less necessity of opioid or analgesia administration. But long recovery period and high-probability bradycardia should be deliberated.

Decreases in Oral Tissue Blood Flow Induced by Remifentanil Are Not Accompanied by Deterioration of Oral Tissue Oxygen Tension in Rabbits

PURPOSE

The purpose of this study was to investigate the effects of remifentanil infusion on tissue blood flow and tissue oxygen tension in the mandibular bone marrow and masseter muscle in rabbits. In addition, changes in tissue oxygen consumption in those tissues during remifentanil infusion were investigated.

MATERIALS AND METHODS

Sixteen male tracheotomized Japanese White rabbits were anesthetized with sevoflurane under mechanical ventilation. Under oxygen and air inhalation, fraction of inspiratory oxygen was set at 0.4 and remifentanil was infused at a rate of 0.4 μg ∙ kg^-1 ∙ min^-1. Measurements were performed before remifentanil infusion, 20 minutes after the start of remifentanil infusion, and 20 and 60 minutes after the completion of remifentanil infusion (n = 8). The observed variables included heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), mandibular bone marrow tissue blood flow (BBF), masseter muscle tissue blood flow (MBF), mandibular bone marrow tissue oxygen tension (PbO₂), and masseter muscle tissue oxygen tension (PmO₂). Another 8 rabbits were observed for arterial pH, lactate, base excess (BE), and tissue oxygen consumption in the region from which the retromandibular vein received venous blood. Measurements were performed before remifentanil infusion and 20 minutes after the start of remifentanil infusion.

RESULTS

HR, SBP, DBP, MAP, BBF, and MBF decreased during remifentanil infusion. PbO₂ increased 20 minutes after remifentanil infusion and returned to almost the baseline value 60 minutes after remifentanil infusion. PmO₂ did not change throughout the experiment. The difference between the arterial oxygen content of the femoral artery and the venous oxygen content of the retromandibular vein decreased during remifentanil infusion. Arterial pH, lactate, and BE did not change during remifentanil infusion.

CONCLUSIONS

Remifentanil decreased BBF and MBF but did not decrease PbO₂ and PmO₂. It is suggested that tissue oxygen consumption decreased during remifentanil infusion.

Blood loss mitigation and replacement in facial surgery: a review

PURPOSE OF REVIEW

To provide a comprehensive overview of the predisposing factors that contribute to a risk of excess bleeding for surgical therapy in the head and neck regions, provide a thorough overview of techniques and tools for managing blood loss complications, and provide intervention algorithms to help guide clinical decision making.

RECENT FINDINGS

With the current landscape of medications and reversal agents, protocols for intervention in a variety of situations, and new tools for blood loss management all rapidly changing and being developed it is critical to stay up to date to provide patients the best care in the most critical of situations.

SUMMARY

With the risk of blood loss complications in head and neck surgery ranging from minimal to extreme surgeons require a comprehensive understanding risk factors, patient evaluation tools, and proper management algorithms. The first opportunity to prevent unnecessary blood loss and blood loss complications is the health history and physical appointment where a clinician can identify any medications, conditions, or other predisposing factors that would elevate a patient's risk of excess bleeding and the necessity for treatment augmentation. Although not all complications can be prevented because of the natural physiological variation that occurs from patient to patient, despite proper and proper diagnostics, a full working knowledge of most likely complications, hemostatic tools, and concise communication with team members can prevent a lot of blood loss and the complications associated.

Minimally invasive orthognathic surgery: a systematic review

Minimally invasive techniques are currently applied in many oral and maxillofacial surgical procedures, including orthognathic surgery. A systematic review on the application of potentially minimally invasive procedures in orthognathic surgery was performed to provide a clear overview of the relevant published data. Articles in English on minimally invasive orthognathic procedures, published in the scientific literature, were obtained from the PubMed, Embase, and Cochrane Library databases, and an additional manual search (revised 31 December 2016). After screening the abstracts and applying the eligibility criteria, 403 articles were identified. All articles reporting the potential for minimally invasive orthognathic surgery were included (n=44). The full papers were evaluated in detail and categorized as articles on a minimally invasive surgical approach (n=4), endoscopically assisted orthognathic procedures (n=17), or the use of a piezoelectric device in orthognathic surgery (n=25); two articles were each included in two categories. Although a small incision and minimal dissection is the basic principle of a minimally invasive technique, most articles (90.9%) reported the endoscope and piezoelectric instrument as important tools in minimally invasive orthognathic surgery. Evidence from available studies suggests that patients undergoing minimally invasive orthognathic surgery have less morbidity and make a faster recovery. Further research should aim to obtain higher levels of evidence.

Controlled Hypotension During Rhinoplasty: A Comparison of Dexmedetomidine with Magnesium Sulfate

Objective

The current study aimed at comparing the efficacy of dexmedetomidine and magnesium sulfate to control blood pressure (BP) during rhinoplasty and the resultant effects on the quality of surgical field in terms of bleeding and visibility.

Methods

The current randomized, prospective, double-blind study was conducted on 60 patients aged 18 to 50 years classified as ASA (American Society of Anesthesiologists) physical status I who were candidates for rhinoplasty. Patients were randomly divided into 2 groups: (1) group Dex, received 1 µg/kg dexmedetomidine in 10 minutes before induction of anesthesia, followed by 0.4 - 0.6 µg/kg/hour during the maintenance of anesthesia, and (2) group Mg, received 40 mg/kg in 10 minutes before anesthesia induction followed by 10 - 15 mg/kg/hour during anesthesia maintenance. In both groups, the goal was to achieve a mean arterial pressure (MAP) of 60 - 70 mmHg. Hemodynamic variables, anesthetic, opioid, muscle relaxant requirements, and surgical field condition were recorded. Sedation score, time to reach modified Aldrete score ≥ 9, and adverse effects including nausea and vomiting (N&V) and shivering were recorded.

Results

Controlled hypotension was achieved in both groups. There was no significant difference in MAP between the groups, but heart rate (HR) was significantly lower in the Dex group (P < 0.001), compared with that of the Mg group. Bleeding score was lower (P < 0.001) and surgeon's satisfaction score was higher (P < 0.001) in the Dex group. More patients required fentanyl (P < 0.001) or nitroglycerin (P < 0.001) and the mean fentanyl (P = 0.005) or nitroglycerin (P < 0.001) required doses were higher in the Mg group. Patients in the Dex group required more frequent administration of cisatracurium (P = 0.004). Five patients in the Dex group versus no patients in the Mg group received atropine (P = 0.023). Ramsay sedation score and time to reach modified Aldrete score ≥ 9 were significantly higher in the Dex group (P < 0.001 and P < 0.001, respectively). The incidence rate of N&V and shivering were similar in both groups.

Conclusion

Dexmedetomidine was more effective than magnesium to achieve controlled hypotension, and provide a favorable surgical field condition. However, dexmedetomidine also heightened the risk of induced bradycardia and prolonged sedation. These are 2 important points to consider when applying this drug as a hypotensive agent during operation.

Risk factors for intraoperative bradycardia during ear, nose, throat and maxillofacial surgery

Intraoperative bradycardia (IOB) is one of the most common cardiac arrhythmias observed in clinical anaesthetic practice. Controlled hypotension, as a strategy of lowering patient's blood pressure during anesthesia has been practiced for decades in head and neck surgery. The aim of our study was to determine the incidence and the risk factors for intraoperative bradycardia in maxillofacial, ear, nose and throat surgery, as well as to determine whether controlled hypotension affects the occurrence of IOB. The retrospective study included 2304 patients who underwent maxillofacial, ear, nose or throat surgery. We studied the influence of: sex, age, comorbidity, type of surgery, duration of anesthesia and controlled hypotension on the occurrence of IOB. IOB was registered in 473 patients (20.5%). Patients with controlled hypotension had IOB significantly more often than patients without controlled hypotension (33.9 vs 15.1%) (p = 0.000). The significant predictors of IOB were: age (OR = 1.158; 95% CI = 1.068-1.256; p = 0.000), sex (OR = 0.786; 95% CI = 0.623-0.993; p = 0.043), ischemic heart disease (OR = 2.016; 95% CI = 1.182-3.441; p = 0.010); ear surgery (OR = 1.593; 95% CI = 1.232-2.060; p = 0.000), anesthesia duration, (OR = 1.006; 95% CI = 1.004-1.007; p = 0.000) and controlled hypotension (OR = 2.204; 95% CI = 1.761-2.758; p = 0.000). IOB is common in maxillofacial, ear, nose and throat surgery, particularly in male, older age and patients with ishemic heart disease. The ear surgery, longer anesthesia duration and controlled hypotension raise the risk for occurrence of IOB.

The effect of different dosage regimens of tranexamic acid on blood loss in bimaxillary osteotomy: a randomized, double-blind, placebo-controlled study

The purpose of this study was to compare the effects of three dosage regimens of intravenous tranexamic acid and normal saline placebo on blood loss and the requirement for transfusion during bimaxillary osteotomy. A prospective, randomized, double-blind, placebo-controlled study was performed. Eighty patients scheduled for elective bimaxillary osteotomy were divided into four groups: a placebo group and three groups receiving a single dose of tranexamic acid 10, 15, or 20mg/kg body weight after the induction of anaesthesia. Demographic data, the anaesthetic time, the operative time, and the experience of the surgical team were similar in the four groups. Patients receiving placebo had increased blood loss compared to those receiving tranexamic acid. No significant difference in blood loss was found among those who received 10, 15, or 20mg/kg body weight of tranexamic acid. There was no significant difference in transfusion requirement, amount of 24-h postoperative vacuum drainage, length of hospital stay, or complications among the four groups. Prophylactic tranexamic acid decreased bleeding during bimaxillary osteotomy. Of the three dosages of tranexamic acid studied, the most efficacious and cost-effective dose to reduce bleeding was 10mg/kg body weight.

Quantitative analysis of facial soft tissue perfusion during hypotensive anesthesia using laser-assisted indocyanine green fluorescence angiography

The aim of this study was to quantitatively evaluate the efficacy of induced hypotensive anesthesia in decreasing facial soft tissue perfusion during orthognathic surgery using laser-assisted indocyanine green fluorescence angiography. This retrospective study involved the evaluation of 16 patients who underwent orthognathic surgery. Data collection included facial tissue perfusion of the bilateral cheeks and chin at normotension and with pharmacologically induced hypotensive anesthesia. There were statistically significant differences in the facial tissue perfusion at normal and depressed levels of blood pressure (P<0.001). This study used an objective measure to demonstrate the long-standing belief that hypotensive anesthesia is efficacious in reducing tissue perfusion in the surgical field. The data suggest that pharmacologically depressing the level of mean arterial pressure by 18% may result in a 41-52% decrease in facial soft tissue perfusion. This study reports a novel method of quantitative analysis.

Epinephrine Injection in Greater Palatine Canal: An Alternative Technique for Reducing Hemorrhage During Septoplasty

OBJECTIVE

Obtaining adequate hemostasis during otolaryngology operations is necessary because a small amount of blood can be problematic and obscure the visual field. The authors aimed to compare the efficacy of combined greater palatine canal (GPC) and transnasal injection of lidocaine + epinephrine to transnasal injection alone in patients who underwent septoplasty.

METHODS

Patients with nasal septum deviation who were eligible for surgical correction of deviations were enrolled. Transnasal injections of 2 mL of 1% lidocaine + epinephrine 1:100,000 were performed in both groups and for patients in the combination group the same solution was also injected in the GPC. Objective (amount of suctioned blood) and subjective (intraoperative bleeding score) assessments were done during operation. Close hemodynamic monitoring was performed for all patients.

RESULTS

A total of 50 patients were enrolled and randomly allocated to study groups. No significant differences were observed in systolic and diastolic blood pressure, heart rate, and mean arterial pressure of study subjects between 2 groups. The amount of bleeding in patients who received GPC injection and their counterparts in the other arm of the trial were 34.64 ± 26.66 and 100.48 ± 20.90 mL, respectively (P < 0.001). The mean intraoperative bleeding score in combination group was 0.79 ± 0.42 and significantly lower than the corresponding figure in monotherapy group, which was 1.75 ± 0.41 (P < 0.001).

CONCLUSIONS

Based on the findings of the current study, the authors suggest that combined GPC and transnasal injection of lidocaine and epinephrine is a safe and effective method for reducing bleeding during septoplasty.

Operative time, blood loss, hemoglobin drop, blood transfusion, and hospital stay in orthognathic surgery

PURPOSE

This study was conducted to evaluate the operative time, blood loss, hemoglobin drop, blood transfusion, and length of hospital stay in orthognathic surgery.

METHODS

A 10-year retrospective analysis was performed on patients who underwent bilateral sagittal split osteotomy (with or without genioplasty), Le Fort I osteotomy (with or without genioplasty), or any combination of these procedures. A total of 271 patients were included.

RESULTS

The age range was 17 to 49 years, with a mean age of 24.13 ± 4.51 years. Approximately 62% of patients underwent double-jaw surgery. The most common procedure was bilateral sagittal split with Le Fort I (37%). The average operative time was 3.96 ± 1.25 h. The mean estimated blood loss was 345.2 ± 149.74 mL. Approximately 9% of patients received intraoperative blood transfusion. The mean hemoglobin drop in the non-transfusion cases was 2.38 ± 0.89 g/dL. The mean postoperative hospital stay was 1.85 ± 0.83 days. Only one patient was admitted to the ICU for one night.

CONCLUSIONS

In orthognathic surgery, blood loss is relatively minor, blood transfusion is frequent, and ICU admission is unlikely. Operative time, blood loss, blood transfusion, and the complexity of the surgical procedure can significantly increase the length of hospital stay. Males may bleed more than females in orthognathic surgery. Hemoglobin drop can be overestimated due to hemodilution in orthognathic surgery, which may influence the decision to use blood transfusion.

Comparison of different hypotensive anaesthesia techniques in orthognathic surgery with regard to intraoperative blood loss, quality of the surgical field, and postoperative nausea and vomiting

Sixty-three consecutive patients undergoing bimaxillary surgery between June and August 2015 were included in this study. Twenty-one patients were included in each of three study groups. In group 1, sevoflurane was the sole maintenance anaesthesia agent used; in group 2, propofol was the predominant agent, in addition to a reduced amount of sevoflurane; in group 3, patients received sevoflurane until fixation was completed, at which point it was switched to propofol. The mean intraoperative blood loss (ml) was 707.14±290.74 in group 1, 917.62±380.30 in group 2, and 750.00±331.84 in group 3; the difference between groups 1 and 2 was significant (P=0.047). The mean score for the quality of surgical field assessment was 1.32±0.44 in group 1, 2.04±0.49 in group 2, and 1.45±0.53 in group 3 (P=0.003). The postoperative nausea and vomiting (PONV) rate was 28.6% in group 1, 9.5% in group 2, and 14.3% in group 3 (P=0.343). The quality of the surgical field was significantly better in groups 1 and 3 than in group 2. The average blood loss in group 1 was also significantly less than in group 2. The PONV rates were lower than those reported in other studies.

Comparison of intraoperative blood loss between four different surgical procedures in the treatment of bimaxillary protrusion

OBJECTIVE

This study was aimed at investigating the correlation between intraoperative blood loss and operation-related factors in the treatment of bimaxillary protrusion with four different procedures.

STUDY DESIGN

Ninety-four patients were separated into the following four surgical groups: group 1: anterior subapical osteotomy of the maxilla (ASO Mx) + bilateral parasymphyseal osteotomy of the mandible (BPsO Md) + genioplasty (GeP); group 2: ASO Mx + BPsO Md; group 3: ASO Mx + ASO Md + GeP; and group 4: ASO Mx + ASO Md. Patient- and operation-related factors (age, intraoperative blood loss, operation time, and preoperative and postoperative blood parameters) were compared among the four groups.

RESULTS

The mean operation time and intraoperative blood loss were 438.7 minutes and 369.9 mL in group 1; 432.5 minutes and 356.5 mL in group 2; 393.3 minutes and 387.3 mL in group 3; and 353.5 minutes and 289.5 mL in group 4. Intergroup differences in intraoperative blood loss were not significant. A significant correlation between intraoperative blood loss and operation time was found in group 4 but not in the other groups.

CONCLUSIONS

No significant differences in blood loss were found among the four different surgical procedures in the treatment of bimaxillary protrusion.

The effect of blood pressure and cardiac output on the quality of the surgical field and middle cerebral artery blood flow during endoscopic sinus surgery

BACKGROUND

A clear surgical field is critical during endoscopic sinus surgery (ESS). Hypotensive anesthesia and cardiac output (CO) may optimize the surgical field; however, evidence of their effect on bleeding and cerebral blood flow is conflicting. The aim of this study was to evaluate the effect of blood pressure (BP) and CO on intraoperative bleeding and middle cerebral artery blood flow velocity (Vmca ) during ESS.

METHODS

This was a prospective randomized controlled trial. Patients undergoing ESS for chronic rhinosinusitis at a tertiary institution in 2013 were randomized to receive BP manipulation using target-controlled noradrenaline infusion during surgery to either their left or right sinuses. The contralateral side in each patient served as control. Bleeding was scored using a 0 to 10 point bleeding assessment scale (BAS, 0-10) and Vmca was measured using transcranial Doppler ultrasonography every 10 minutes or when surgically opportune, and time-matched with BP and CO. Data was analyzed using Bland-Altman methods.

RESULTS

A total of 105 time points were collected across a mean arterial pressure (MAP) range of 32 to 118 mmHg. Significant correlations were demonstrated between MAP and Vmca (r = 0.7, p < 0.0001), MAP and BAS (r = 0.50, p < 0.0001), CO and Vmca (r = 0.57, p < 0.0001), and CO and BAS (r = 0.42, p < 0.0001). The best surgical fields were seen at 40 to 59 mmHg MAP. However, MAP below 60 mmHg produced >50% reduction in Vmca in more than 10% of time points.

CONCLUSION

Balancing surgical visibility with organ perfusion remains a challenge. The results of this study show that moderate hypotension significantly improves the surgical field; however reducing BP below 60 mmHg may risk cerebral hypoperfusion.

Predictors of blood loss during orthognathic surgery: outcomes from a teaching institution

PURPOSE

The objective of the study was to correlate different orthognathic surgical procedures with operating time and blood loss, reported from an accredited resident training institution.

METHODS

Ninety-five patient records were evaluated retrospectively. Individual blood volume, percent blood volume lost (BVL), and estimated blood loss (EBL) for each patient were recorded and correlated with operating time (OT). Statistics included independent t tests, one-way analysis of variance, and linear regression.

RESULTS

The mean OT for all procedures was 203 min with mean blood loss 556 ml. Mean EBL for males was 676 ml versus 468 ml for females. Overall BVL was 12.4 %, while for males, BVL was 13.3 % compared to 11.8 % for females. For a single orthognathic procedure (n = 45), mean OT 145 min., EBL 414 ml, and BVL 9.0 %; two procedures (n = 41), mean OT was 239 min., EBL 659 ml, and BVL 15 %; three procedures (n = 9), mean OT 328 min, EBL 793 ml, and BVL was 17 %.

CONCLUSION

Examination of individual procedures suggests a shorter OT for Le Fort I procedures with slightly greater EBL. Concomitant orthognathic procedures are associated with greater OT and EBL. Blood volume should be calculated for male and female patients separately. Percent BVL can be predicted based on OT using a basic equation.

Intraoperative Hemorrhage and Postoperative Sequelae after Intraoral Vertical Ramus Osteotomy to Treat Mandibular Prognathism

Objective. To investigate the factors affecting intraoperative hemorrhage and postoperative sequelae after orthognathic surgery. Materials and Methods. Eighty patients with mandibular prognathism underwent surgical mandibular setback with intraoral vertical ramus osteotomy (IVRO). The correlation between the blood loss volume and postoperative VAS with the gender, age, and operating time was assessed using the t-test and Spearman rank correlation coefficient. The correlation between the magnitude of mandibular setback with the presence of TMJ clicking symptoms and lip sensation was also assessed. Results. The mean operating time and blood loss volume for men and women were 249.52 min and 229.39 min, and 104.03 mL and 86.12 mL, respectively. The mean VAS in men and women was 3.21 and 2.93, and 1.79 and 1.32 on the first and second postoperative days. There is no gender difference in the operating time, blood loss, VAS, TMJ symptoms, and lip numbness. The magnitude of mandibular setback was not correlated with immediate and long-term postoperative lip numbness. Conclusion. There are no gender differences in the intraoperative hemorrhage and postoperative sequelae (pain, lip numbness, and TMJ symptoms). In addition, neither symptom was significantly correlated with the amount of mandibular setback.

The Effects of Oral Atenolol or Enalapril Premedication on Blood Loss and Hypotensive Anesthesia in Orthognathic Surgery

PURPOSE

The aim of this study was to evaluate the effects of premedication with oral atenolol or enalapril, in combination with remifentanil under sevoflurane anesthesia, on intraoperative blood loss by achieving adequate deliberate hypotension (DH) during orthognathic surgery. Furthermore, we investigated the impact thereof on the amount of nitroglycerin (NTG) administered as an adjuvant agent.

MATERIALS AND METHODS

Seventy-three patients undergoing orthognathic surgery were randomly allocated into one of three groups: an angiotensin converting enzyme inhibitor group (Group A, n=24) with enalapril 10 mg, a β blocker group (Group B, n=24) with atenolol 25 mg, or a control group (Group C, n=25) with placebo. All patients were premedicated orally 1 h before the induction of anesthesia. NTG was the only adjuvant agent used to achieve DH when mean arterial blood pressure (MAP) was not controlled, despite the administration of the maximum remifentanil dose (0.3 μg kg⁻¹ min⁻¹) with sevoflurane.

RESULTS

Seventy-two patients completed the study. Blood loss was significantly reduced in Group A, compared to Group C (adjusted p=0.045). Over the target range of MAP percentage during DH was significantly higher in Group C than in Groups A and B (adjusted p-values=0.007 and 0.006, respectively). The total amount of NTG administered was significantly less in Group A than Group C (adjusted p=0.015).

CONCLUSION

Premedication with enalapril (10 mg) combined with remifentanil under sevoflurane anesthesia attenuated blood loss and achieved satisfactory DH during orthognathic surgery. Furthermore, the amount of NTG was reduced during the surgery.

Prevention of Bleeding in Orthognathic Surgery--A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

The objective of the present study was to evaluate the efficacy of hemostatic adjuncts on intraoperative blood loss (IOB) in orthognathic surgery (OS) detected by randomized controlled trials (RCTs) of the highest quality.

MATERIALS AND METHODS

A search of the Medline, Cochrane, Embase, and Web of Science databases was performed in January 2015, and the risk of bias was assessed using the Jadad and Delphi scales. The predictor variable was the hemostatic measures, and the main outcome variable was the total IOB volume. The secondary outcome variables were the hemoglobin and hematocrit and operating time. This review is registered at PROSPERO (CRD42014014840).

RESULTS

Eleven trials were included for review. The individual trials demonstrated the effects on IOB from hypotensive anesthetic regimens, the use of aprotinin, and the herbal medicine Yunnan Baiyao. Six studies of tranexamic acid (TXA), with 288 patients, were suitable for a meta-analysis of continuous data. TXA reduced IOB by an average of 171 mL (95% confidence interval [CI] -230 to -112; P < .00001). Its topical use yielded similarly significant results (mean difference -197, 95% CI -319 to -76; P < .001). A subgroup analysis showed a decreased operating time in the TXA groups by an average of 15 minutes (mean difference -14.78, 95% CI -22.21 to -7.35; P < .0001).

CONCLUSIONS

Efficient hemostatic adjuncts exist for OS. Our meta-analysis showed that TXA significantly reduces IOB by an average of one third, regardless of whether it was given intravenously (IV) or applied topically. Additional RCTs are needed to confirm the effect of topical TXA in OS, and larger studies of intravenous administration are needed before any routine recommendations. No hemostatic effect of hypotensive anesthesia was found, mainly owing to imprecise descriptions of the blinding procedures. Transparent and uniform trial reporting is thus encouraged in future studies.

Hypotensive Anesthesia Is Associated With Shortened Length of Hospital Stay Following Orthognathic Surgery

PURPOSE

To evaluate the impact of induced hypotensive anesthesia on length of hospital stay (LOS) for patients undergoing maxillary Le Fort I osteotomy in isolation or in combination with mandibular orthognathic surgery.

MATERIALS AND METHODS

A retrospective cohort study design was implemented and patients undergoing a Le Fort I osteotomy as a component of orthognathic surgery at the Mayo Clinic from 2010 through 2014 were identified. The primary predictor variable was the presence of induced hypotensive anesthesia during orthognathic surgery. Hypotensive anesthesia was defined as at least 10 consecutive minutes of a mean arterial pressure no higher than 60 mmHg documented within the anesthetic record. The primary outcome variable was LOS in hours after completion of orthognathic surgery. The secondary outcome variable was the duration of surgery in hours. Multiple covariates also abstracted included patient age, patient gender, American Society of Anesthesiologists score, complexity of surgical procedure, and volume of intraoperative fluids administered during surgery. Univariable and multivariable models were developed to evaluate associations between the primary predictor variable and covariates relative to the primary and secondary outcome variables.

RESULTS

A total of 117 patients were identified undergoing Le Fort I orthognathic surgery in isolation or in combination with mandibular surgery. Induced hypotensive anesthesia was significantly associated with shortened LOS (odds ratio [OR] = 0.33; 95% confidence interval [CI], 0.12-0.88; P = .026) relative to patients with normotensive regimens. This association between hypotensive anesthesia and LOS remained statistically significant in a subgroup analysis of 47 patients in whom isolated Le Fort I surgery was performed (OR = 0.13; 95% CI, 0.03-0.62; P = .010). Induced hypotensive anesthesia was not statistically associated with shorter duration of surgery.

CONCLUSION

Induced hypotensive anesthesia represents a potential factor that minimizes postoperative LOS for patients undergoing routine maxillary orthognathic surgery alone or in combination with mandibular procedures. Hypotensive anesthesia does not appear to be effective in minimizing the duration of surgery within this same patient population.

Hypotensive anesthesia versus normotensive anesthesia during major maxillofacial surgery: a review of the literature

Steady blood pressure within normal limits during surgery is one of the markers of the ideal and skillful anesthesia. Yet, reduced blood pressure is advantageous in some settings because it can contribute to a reduction in overall blood loss and improve the surgical field conditions. Controlled hypotension during anesthesia or hypotensive anesthesia is often used in major maxillofacial operations. Since hypotensive anesthesia carries the risk of hypoperfusion to important organs and tissues, mainly the brain, heart, and kidneys, it cannot be applied safely in all patients. In this paper we review the medical literature regarding hypotensive anesthesia during major maxillofacial surgery, the means to achieve it, and the risks and benefits of this technique, in comparison to normotensive anesthesia.

Effect of changes in end-tidal carbon dioxide tension on oral tissue blood flow during dexmedetomidine infusion in rabbits

A decrease in arterial carbon dioxide tension induces an increase in masseter muscle blood flow and a decrease in mandibular bone marrow blood flow during general anesthesia. In addition, dexmedetomidine infusion reduces oral tissue blood flow. In this study we investigated how end-tidal carbon dioxide tension (ET-CO2 ) changes influence on oral tissue blood flow during continuous dexmedetomidine infusion in rabbits. Eleven male Japan White rabbits were anesthetized with sevoflurane. Then, ET-CO2 was set at 30 mmHg and adjusted to 40 and 60 mmHg, and heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, common carotid artery blood flow, mandibular bone marrow blood flow, masseter muscle blood flow, and blood flow in other oral tissues were measured. Following this, the ET-CO2 was returned to 30 mmHg and dexmedetomidine was infused over 60 min. The measurements were repeated. Most parameters increased, regardless of whether or not dexmedetomidine was present, and heart rate and masseter muscle blood flow decreased in an ET-CO2 -dependent manner. Dexmedetomidine infusion suppressed ET-CO2 -dependent masseter muscle blood flow change. Masseter muscle blood flow during ET-CO2 at 30 mmHg with dexmedetomidine was the same as that during ET-CO2 at 40 mmHg without dexmedetomidine. Our findings suggest that dexmedetomidine infusion and slight hypocapnia under general anesthesia suppress an increase in masseter muscle blood flow as well as reducing mandibular bone marrow blood flow. These results may be of significance for decreasing bleeding during oral and maxillofacial surgery.

Intraoperative blood loss and blood transfusion requirements in patients undergoing orthognathic surgery

Procedures for the surgical correction of dentofacial deformities may produce important complications, whether due to the potential for vascular injury or to prolonged surgery, both of which may lead to severe blood loss. Fluid replacement with crystalloid, colloid, or even blood products may be required. The aim of this study was to assess blood loss and transfusion requirements in 45 patients (18 males and 27 females; mean age 29.29 years, range 16-52 years) undergoing orthognathic surgery, assigned to one of two groups according to procedure type-rapid maxillary expansion or double-jaw orthognathic surgery. Preoperative hemoglobin and hematocrit levels and intraoperative blood loss were measured. There was a substantial individual variation in pre- and postoperative hemoglobin values (10.3-17 and 8.8-15.4 g/dL, respectively; p < 0.05). Mean hematocrit values were 41.53 % preoperatively (range 31.3-50.0 %) and 36.56 % postoperatively (range 25-43.8 %) (p < 0.05). Mean blood loss was 274.60 mL (range 45-855 mL). Only two patients required blood transfusion. Although blood loss and transfusion requirements were minimal in the present study, surgical teams should monitor the duration of surgery and follow meticulous protocols to minimize the risks.

Assessment of the related factors of blood loss and blood ingredients among patients under hypotensive anesthesia in orthognathic surgery

OBJECTIVE

The objective of the study was to understand the factors associated with presurgical and postsurgical blood loss and blood ingredients among patients in the treatment of mandibular prognathism by intraoral vertical ramus osteotomy combined genioplasty.

METHODS

Preoperative and postoperative values of blood loss and blood ingredients were collected from 30 mandibular prognathic patients who underwent orthognathic surgery. The linear regression models and correlation coefficients were used to identify factors with respect to patients' blood loss level and 3 types of blood ingredients (ie, red blood cells, hemoglobin, and hematocrit).

RESULTS

The mean blood loss and operation time were 179.2 mL and 311.7 minutes, respectively. No blood transfusion was received by our patients. After adjusting for potential factors, the regression models showed that no significant factor was found to be associated with blood loss and reduce blood ingredients. Moreover, female patients were found to be more likely to have a low level of presurgical blood ingredients (β = -0.293 to -3.551; P < 0.05), whereas female sex (β = -1.606 to -4.008; P < 0.001), a high blood loss level (β = -0.003 to -0.009; P < 0.05), and long operation time (β = -0.005 to -0.018; P < 0.05) were associated with a low level of postsurgical blood ingredients (ie, hemoglobin and hematocrit).

CONCLUSIONS

No significant factor was associated with blood loss and reduced blood ingredients among patients in orthognathic surgery with hypotenstive anesthesia. Improvements in anesthesia provided surgeons with more time to promote hemostasis during surgery. Hypotensive anesthesia was a well-accepted method to reduce blood loss during orthognathic surgery.

Factors that determine intraoperative blood loss in bimaxillary osteotomies and the need for preoperative blood preparation

PURPOSE

To define factors that influence blood loss in bimaxillary osteotomies and the need for blood preparation at the Faculty of Dentistry, Mahidol University, Bangkok, Thailand.

PATIENTS AND METHODS

We retrospectively studied 208 patients who underwent bimaxillary osteotomies during 2005 to 2009. Possible factors for intraoperative blood loss such as age, body weight, gender, operative time, experience of the surgeons, and different operative procedures were statistically analyzed.

RESULTS

Female patients had a significantly higher percentage of blood loss from allowable blood loss than male patients (P = .006). Experience of the surgeons had a significant influence on blood loss (P = .02) and operative time (P < .001). No significant difference in blood loss was found among the 4 groups classified by operation (P = .852). Simple regression analysis showed a significantly positive correlation between blood loss and duration of operation (R(2) = 0.15, P < .001). There was no correlation between blood loss and patient age (P = .35).

CONCLUSION

The factors that influence blood loss include patient gender, experience of the surgeon, and operative time. Blood preparation should be considered in women, especially small individuals in whom a long operative time is expected and who are being operated on by an inexperienced surgeon. Because of the low rate of transfusion, a group-and-save policy is appropriate.

Comparison of local anaesthesia with dexmedetomidine sedation and general anaesthesia during septoplasty

BACKGROUND AND OBJECTIVE

To compare general anaesthesia and local anaesthesia with dexmedetomidine on the basis of postoperative pain and surgical bleeding after septoplasties.

METHOD

Sixty patients with ASA 1 or 2 were divided into the local anaesthesia with dexmedetomidine (LAD) group (n = 30) and the general anaesthesia group (n = 30). Heart rate (HR), SBP and DBP were monitored. The amount of surgical bleeding, duration of surgery and recovery, postoperative pain evaluations [by visual analogue scale (VAS)] and nausea-vomiting were also recorded. Patients' satisfaction with anaesthesia and quality of breathing was questioned 1 week after discharge.

RESULTS

HR values were significantly higher in the general anaesthesia group than in the LAD group at the 15th min and at the end of surgery. The SBP value at the 30th min was significantly higher in the LAD group than in the general anaesthesia group. No difference was observed between the groups with respect to the DBP value. Surgical bleeding and the duration of recovery were significantly less in the LAD group. The postoperative VAS scores were significantly higher in the general anaesthesia group than in the LAD group. Postoperative nausea-vomiting was also significantly greater in the general anaesthesia group. Although more patients in the LAD group preferred this anaesthetic procedure to general anaesthesia, the quality of breathing was better in both groups after surgery.

CONCLUSION

Septoplasty performed under local anaesthesia with dexmedetomidine sedation resulted in less surgical bleeding, less postoperative pain, a more stable haemodynamic state, less nausea-vomiting, a shorter recovery period and a higher level of anaesthesia satisfaction.

Effect of induced hypotensive anaesthesia vs isovolaemic haemodilution on blood loss and transfusion requirements in orthognathic surgery: a prospective, single-blinded, randomized, controlled clinical study

Induced hypotensive anaesthesia and isovolaemic haemodilution are well-established blood-sparing techniques in major surgery. This prospective study compared them for blood loss, transfusion requirements, and surgical field quality during standardized orthognathic operations. In a surgeon-blinded trial, 60 healthy patients requiring either Le Fort I osteotomy or bimaxillary surgery were randomly allocated to receive normotensive anaesthesia, induced hypotensive anaesthesia, or induced hypotensive anaesthesia combined with isovolaemic haemodilution. Blood loss and haemoglobin level were measured intraoperatively and calculated on postoperative day 3. The surgeons rated surgical field quality. Mean blood loss was 1021.63, 392.38 (p<0.05) and 1191.65ml in the normotensive, hypotensive and haemodilution groups, respectively. Mean haemoglobin level immediately after surgery was 9.3, 10.3, and 7.4g/dl (p<0.05), respectively. No hypotensive group patients received transfusions; four normotensive group patients required allogenic transfusions; seven haemodilution group patients needed autogenous retransfusions (p<0.05). Surgical field quality was significantly better in the hypotensive than in the normotensive (p<0.05) or haemodilution (p<0.05) groups. In orthognathic surgery, hypotensive anaesthesia significantly reduces blood loss and transfusion requirements and minimizes allogenic transfusions risks. Induced hypotensive anaesthesia combined with isovolaemic haemodilution has no additional blood-sparing effects but impairs surgical field quality.