Effects of posture, hypotension and locally applied vasoconstriction on the middle ear microcirculation in anaesthetized humans

Efficacy of perioperative lidocaine infusion on surgical field quality during functional endoscopic sinus surgery: a systematic review and meta-analysis with trial sequential analysis

PURPOSE

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) that assessed the efficacy of perioperative intravenous lidocaine versus placebo in improving the quality of surgical field during functional endoscopic sinus surgery (FESS).

METHODS

PubMed, Scopus, Web of Science, and CENTRAL were thoroughly searched from inception until June 2023. The included RCTs were evaluated via RoB-2 tool. Our primary endpoint included intraoperative surgical field quality, and secondary endpoints involved operative duration, estimated blood loss, time for post-anesthesia care unit (PACU) discharge, postoperative pain, mean difference in heart rate (HR), and mean difference in mean arterial pressure (MAP). Continuous data were pooled as mean difference (MD) or standardized mean difference (SMD) via RevMan software. Also, the certainty of evidence for each outcome were assessed according to the GRADE system.

RESULTS

Four RCTs with total of 267 patients were included. Regarding the intraoperative quality of surgical field, the results indicated a significant difference in favor of the lidocaine group compared to the placebo group (n = 3 RCTs, MD - 0.80, 95% CI [- 0.98, - 0.61], p < 0.001, moderate certainty of evidence). The trial sequential analysis showed there is a substantial and conclusive evidence. Regarding time for PACU discharge, there was a significant difference that favor lidocaine group (p < 0.05). On the contrary, there was no significant difference between lidocaine and placebo groups in terms of operative duration, estimated blood loss, postoperative pain, mean change in MAP and HR, (p > 0.05).

CONCLUSION

Our review revealed that lidocaine infusion, compared with a placebo, significantly improved the surgical field and shortened the time required for PACU discharge. However, lidocaine did not reduce surgery time, estimated blood loss, postoperative pain, MAP, or HR.

Tranexamic acid in endoscopic sinus and skull base surgery: A systematic review and meta-analysis

OBJECTIVE

Endoscopic sinus surgery (ESS) and endoscopic skull base surgery (ESBS) approaches have revolutionized the management of sinonasal and intracranial pathology. Maintaining surgical hemostasis is essential as bleeding can obscure the visibility of the surgical field, thus increasing surgical duration, risk of complications, and procedural failure. Tranexamic acid (TXA) acts to reduce bleeding by inhibiting fibrin degradation. This review aims to assess whether TXA improves surgical field quality and reduces intraoperative blood loss compared with control.

METHODS

We searched PubMed, MEDLINE, Embase, Web of Science, and Cochrane Library from inception until September 1, 2022. Two reviewers independently screened citations, extracted data, and assessed methodological quality using the Cochrane risk-of-bias tool for randomized trials. Data were pooled using a random-effect model, with continuous data presented as mean differences and dichotomous data presented as odds ratios.

RESULTS

Seventeen ESS randomized controlled trials (n = 1377) and one ESBS randomized controlled trial (n = 50) were reviewed. Significant improvement in surgical field quality was achieved with both systemic TXA (six studies, p < 0.00001) and topical TXA (six studies, p = 0.01) compared with the control. Systemic TXA (eight studies) and topical TXA (three studies) both achieved a significant reduction in intraoperative blood loss compared with the control (p < 0.00001). There were significant differences in operative times (p < 0.001) but no significant difference in perioperative outcomes (p = 0.30).

CONCLUSION

This meta-analysis demonstrated that the administration of TXA in ESS can improve surgical field quality and reduce intraoperative blood loss. TXA use did not result in increased perioperative complications including thrombotic events.

Evaluation of the perioperative effects of dexmedetomidine on tympanoplasty operations

PURPOSE

This randomized double-blind study aimed to evaluate the effects of dexmedetomidine on hemodynamic parameters and the quality of surgery and recovery criteria in tympanoplasty operations.

MATERIALS AND METHODS

A total of 75 patients 18-55 years undergoing tympanoplasty, who were graded as American Society of Anesthesiologists physical status I-II, were randomly divided into three groups. Group 1 included patients receiving remifentanil alone, Group 2 included patients receiving dexmedetomidine + remifentanil and Group 3 included patients receiving dexmedetomidine + ½ remifentanil. Anesthesia was induced with propofol and cisatracurium. For maintenance of anesthesia, a mixture of 2-2.5% sevoflurane, 40-60% oxygen/air was used. The groups were compared in terms of hemodynamic parameters, surgical area, recovery criteria, modified Aldrete, pain scores, additional analgesic requirements and adverse effects.

RESULTS

Mean arterial pressure and heart rate values of Group 1 were higher at the time of intubation, incision, spontaneous breathing and extubation compared to Group 2 and Group 3. Surgical field satisfaction was higher in Group 2 and Group 3 than Group 1. Spontaneous breathing, eye opening and verbal cooperation times were shorter in Group 3 compared to Group 2. Eye opening and verbal cooperation times were longer in Group 2 compared to Group 1. The 30-minute modified Aldrete scores was higher in Group 3 compared to Group 1. There was no difference between the groups in terms of postoperative pain and adverse effects.

CONCLUSION

The use of dexmedetomidine during tympanoplasty operations may provide better hemodynamic control and surgical view, may provide faster recovery and may reduce remifentanil consumption.

Metoprolol Significantly Improves Visual Clarity and Hemodynamic Parameters during Functional Endoscopic Sinus Surgery

Background and Objectives

The success of functional endoscopic sinus surgery (FESS) depends on the visual clarity of the surgical field, which is understudied. Controlled hypotension has many advantages for FESS including reduction in blood loss and improved quality of the surgical field. This study determined whether the use of β-blockers as a premedication could improve the operative field in FESS. Methods : Sixty patients aged from 18 to 50 years, undergoing septoplasty and FESS were included in this prospective, randomized, double-blind, placebo-controlled study. Patients were randomly assigned to receive either metoprolol (100 mg, group 1) or a placebo (a vitamin tablet, group 2) 60 min before surgery.

Results

The average blood loss and surgery duration were not significantly higher in the placebo group. The surgical field was graded using the Fromme-Boezaart scale, and it was significantly clearer (p < 0.001) in metoprolol group. The mean arterial blood pressure was significantly lower in the metoprolol group after 30 min of induction until the end of surgery (p < 0.001). The heart rate was also significantly lower (p < 0.001) in those who received metoprolol from before induction of anesthesia up to the end of surgery. Conclusion : Metoprolol significantly improves visual clarity and hemodynamics during FESS. We would recommend the use of metoprolol in FESS and septoplasty.

Comparison of surgical field visibility during propofol or desflurane anesthesia for middle ear microsurgery

Background

To compare surgical field visibility between patients given propofol/remifentanil (PR) or desflurane/remifentanil (DR) anesthesia.

Methods

A total of 80 adult patients undergoing middle ear microsurgery due to cholesteatoma otitis media with American Society of Anesthesiologists physical status I and II were randomly assigned to the PR or DR groups. The depth of anesthesia was titrated to maintain a Bispectral index (BIS) between 40 and 50. Remifentanil was titrated to maintain the mean blood pressure within ±30% change of the pre-induction value. Surgical field visibility was rated at several timepoints by the surgeons using the Boezaart scores.

Results

Average Boezaart scores for surgical field visibility at different time points were < 2 in both PR and DR groups. Surgical field visibility score was lower in the PR group than in the DR group. Requirement for remifentanil was higher in the PR group (850 (488/1330) μg) than in the DR group (258 (143/399) μg, P < 0.0001). The site effect concentration of remifentanil was higher in the PR group (3.6(2.8/5.0)ng/ml) than in the DR group (1.7 (1.0/1.6) ng/ml, P < 0.0001). Hemodynamic profile (i.e., heart rate and mean blood pressure) was similar between groups (P > 0.05). Extubation time (PR group, 21 min vs. DR group, 19 min; P = 0.199) and post-anesthesia care unit time (PR group, 37 min vs. DR group, 34 min; P = 0.324) were comparable between groups.

Conclusion

Although PR anesthesia resulted in lower surgical field visibility scores than DR anesthesia, both groups had scores < 2, meaning no clinical differences between the two groups. DR provided acceptable operative conditions as well, albeit more remifentanil consumption was noted in the DR group.

Trial registration

China Clinical Research Information Service, ChiCTR-1,800,015,537. Registered 5 April 2018. Date of enrolment of the first participant to the trial: 2 May 2018.

Dexmedetomidine improves the quality of the operative field for functional endoscopic sinus surgery: systematic review

BACKGROUND

Intra-operative bleeding diminishes visualisation during functional endoscopic sinus surgery and can cause unfavourable outcomes. Dexmedetomidine is a potent alpha-2 agonist, with sympatholytic effects. This systematic review aimed to assess whether dexmedetomidine decreases intra-operative bleeding and improves operative field quality.

METHODS

All randomised, controlled trials that assessed the ability of dexmedetomidine to provide good operative fields for functional endoscopic sinus surgery were identified from Medline and Embase. The outcomes of interest were: operative field quality, intra-operative bleeding, operative time and adverse events.

RESULTS

Five studies (254 patients) met the inclusion criteria. When compared to saline, dexmedetomidine improved the quality of the operative field. The operative time was similar between groups. When compared to other drugs, dexmedetomidine was as effective as esmolol and remifentanil. There were no adverse incidents.

CONCLUSION

Dexmedetomidine is beneficial in providing good visibility during functional endoscopic sinus surgery. Controlled hypotensive anaesthesia with this medicine decreases intra-operative bleeding and enhances surgical field quality.

Controlled hypotension with desflurane combined with esmolol or dexmedetomidine during tympanoplasty in adults: A double-blind, randomized, controlled trial

BACKGROUND

Controlled hypotension is a technique that is used to limit intraoperative blood loss to provide the best possible surgical field during surgery.

OBJECTIVE

The aim of this double-blind, randomized, controlled study was to compare the effects of desflurane combined with esmolol or dexmedetomidine on the amount of blood in the surgical field, recovery time, and tolerability in adult patients undergoing tympanoplasty.

METHODS

Turkish patients aged 18 to 60 years, classified as American Society of Anesthesiologists physical status I or II, who were scheduled for tympanoplasty were randomly divided into 2 groups: the esmolol group or the dexmedetomidine group. After the anesthesia induction in the esmolol group, a loading dose of esmolol was infused intravenously over 1 minute at 1 mg/kg, followed by a maintenance rate of 0.4 to 0.8 mg/ kg/h. In the dexmedetomidine group, a loading dose of dexmedetomidine was infused intravenously over 10 minutes at a rate of 1 μg/kg, followed by a maintenance rate of 0.4 to 0.8 μg/kg/h. The infusion rates were then titrated to maintain mean arterial pressure (MAP) of 65 to 75 mm Hg. General anesthesia was maintained with desflurane 4% to 6%. Heart rate (HR) and MAP were recorded during anesthesia. The following 6-point scale was used to assess the amount of bleeding in the operative field: 0 = no bleeding, a virtually bloodless field; 1 = bleeding that was so mild that it was not a surgical nuisance; 2 = moderate bleeding that was a nuisance but did not interfere with accurate dissection; 3 = moderate bleeding that moderately compromised surgical dissection; 4 = bleeding that was heavy but controllable and that significantly interfered with surgical dissection; and 5 = massive bleeding that was uncontrollable and made dissection impossible. Scores ≤2 were considered to be optimal surgical conditions. The sedation score was determined at 15, 30, and 60 minutes after tracheal extubation using the following scale: 1 = anxious, agitated, or restless; 2 = cooperative, oriented, and tranquil; 3 = responsive to commands; 4 = asleep, but with brisk response to light, glabellar tap, or loud auditory stimulus; 5 = asleep, sluggish response to glabellar tap or auditory stimulus; and 6 = asleep, no response. Time to extubation and to total recovery from anesthesia (Aldrete score ≥9 on a scale of 0-10), adverse effects (eg, intraoperative hypotension [blood pressure <65 mm Hg], bradycardia [HR <50 beats/min]), intraoperative fentanyl consumption, and postoperative nausea and vomiting were recorded. Arterial blood gas analysis and kidney and liver function tests were conducted. All patients were evaluated by the same attending surgeon and anesthesiologist, both of whom were blinded to the administered study drugs.

RESULTS

Fifty-two consecutive white patients undergoing tympanoplasty were identified. Two patients had to be excluded because of hypertension and 2 refused to participate. Forty-eight patients were equally randomized to either the esmolol group (n = 24 [16 women, 8 men]; mean [SD] age, 38.4 [10.5] years) or the dexmedetomi-dine group (n = 24 [17 women, 7 men]; mean age, 35.5 [14.7] years). Sedation scores were not collected for 1 patient in the esmolol group; therefore, analysis was conducted for 23 patients. The median (range) of the scores for the amount of blood in the surgical field in the esmolol and dexmedetomidine groups was 1 (0-3) and 1 (0-2), respectively (P = NS). Mean intraoperative fentanyl consumption in the esmolol group was significantly higher than in the dexmedetomidine group (50.0 [3.0] vs 25.0 [2.5] μg/min; P = 0.002). In the esmolol group, the mean times to extubation and to recovery from anesthesia were significantly shorter than those of the dexmedetomidine group (7.0 [1.4] vs 9.1 [1.9] minutes, respectively; 5.9 [2.1] vs 7.9 [2.3] minutes; both, P = 0.001). The mean sedation scores were significantly lower in the esmolol group (n = 23, because of intent-to-treat analysis) compared with the dexmedetomidine group at 15 minutes (2.5 [0.6] vs 3.6 [0.5]; P = 0.001) and 30 minutes (2.6 [0.6] vs 3.3 [0.6]; P = 0.001) postoperatively. No significant differences were found between the study groups in regard to blood urea nitrogen or creatinine concentration, aspartate aminotransferase or alanine aminotransferase activities, pH, partial pressure of carbon dioxide, or bicarbonate, before or after the operation.

CONCLUSIONS

Both esmolol and dexmedetomidine, combined with desflurane, provided an effective and well-tolerated method of achieving controlled hypotension to limit the amount of blood in the surgical field in these adult patients undergoing tympanoplasty. Esmolol was associated with significantly shorter extubation and recovery times and significantly less postoperative sedation compared with dexmedetomidine.

The effects of nitrous oxide on controlled hypotension during low flow anesthesia

BACKGROUND AND OBJECTIVES

We investigated the effect of Nitrous Oxide (N2O) on controlled hypotension in low-flow isoflurane-dexmedetomidine anesthesia in terms of hemodynamics, anesthetic consumption, and costs.

METHODS

We allocated forty patients randomly into two equal groups. We then maintained dexmedetomidine infusion (0.1 μg.kg-1.min-1) for 10 minutes. Next, we continued it until the last 30 minutes of the operation at a dose of 0.7 μg.kg(-1).hour(-1). We administered thiopental (4-6 mg. kg(-1)) and 0.08-0.12 mg.kg(-1) vecuronium bromide at induction for both groups. We used isoflurane (2%) for anesthesia maintenance. Group N received a 50% O2-N2O mixture and Group A received 50% O -air mixture as carrier gas. We started low-flow anesthesia (1 L.min(-1)) after a 10-minute period of initial high flow (4.4 L.min(-1)). We recorded values for blood pressure, heart rate, peripheral O2 saturation, inspiratory isoflurane, expiratory isoflurane, inspiratory O2, expiratory O2, inspiratory N2O, expiratory N2O, inspiratory CO2, CO2 concentration after expiration, Minimum Alveolar Concentration. In addition, we determined the total consumption rate of fentanyl, dexmedetomidine and isoflurane as well as bleeding.

RESULTS

In each group the heart rate decreased after dexmedetomidine loading. After intubation, values were higher for Group A at one, three, five, 10, and 15 minutes. After intubation, the patients reached desired hypotension values at minute five for Group N and at minute 20 for group A. MAC values were higher for Group N at minute one, three, five, 10, and 15 (p < 0.05). FiO2 values were high between minute five and 60 for Group A, while at minute 90 Group N values were higher (p < 0.05). Fi Iso (inspiratuvar isofluran) values were lower in Group N at minute 15 and 30 (p < 0.05).

CONCLUSION

By using dexmedetomidine instead of nitrous oxide in low flow isoflurane anesthesia, we attained desired MAP levels, sufficient anesthesia depth, hemodynamic stability and safe inspiration parameters. Dexmedetomidine infusion with medical air-oxygen as a carrier gas represents an alternative anesthetic technique.

Induced hypotension for functional endoscopic sinus surgery: A comparative study of dexmedetomidine versus esmolol

OBJECTIVE

A comparative study to evaluate the efficacy of dexmedetomidine as a hypotensive agent in comparison to esmolol in Functional Endoscopic Sinus Surgery (FESS).

METHODS

Forty patients ASA I or II scheduled for FESS were equally randomly assigned to receive either dexmedetomidine 1 μg/Kg over 10 min before induction of anesthesia followed by 0.4-0.8 μg/Kg/h infusion during maintenance (DEX group), or esmolol, loading dose 1mg/kg was infused over one min followed by 0.4-0.8 mg/kg/h infusion during maintenance (E group) to maintain mean arterial blood pressure (MAP) between (55-65 mmHg). General anesthesia was maintained with sevoflurane 2%-4%. The surgical field was assessed using Average Category Scale and average blood loss was calculated. Hemodynamic variables (MAP and HR); arterial blood gas analysis; plasma cortisol level; intraoperative fentanyl consumption; Emergence time and total recovery from anesthesia (Aldrete score ≥9) were recorded. Sedation score was determined at 15, 30, 60 min after tracheal extubation and time to first analgesic request was recorded.

RESULT

Both DEX group and E group reached the desired MAP (55-65 mmHg) with no intergroup differences in MAP or HR. The for the quality of the surgical filed in the range of MAP (55-65 mmHg) were <=2 with no significant differences between group scores during hypotensive period. Mean intraoperative fentanyl consumption was significantly lower in DEX group than E group. Cortisol level showed no significant changes between or within groups. No significant changes were observed in arterial blood gases. Emergence time and time to achieve Aldrete score ≥9 were significantly lower in E group compared with DEX group. The sedation score were significantly lower in E group compared with DEX group at 15 and 30 minutes postoperatively. Time to first analgesic request was significantly longer in DEX group.

CONCLUSION

Both dexmedetomidine or esmolol with sevoflurane are safe agents for controlled hypotension and are effective in providing ideal surgical field during FESS. Compared with esmolol, dexmedetomidine offers the advantage of inherent analgesic, sedative and anesthetic sparing effect.

The effects of nitrous oxide on controlled hypotension during low flow anesthesia

BACKGROUND AND OBJECTIVES

We investigated the effect of Nitrous Oxide (N2O) on controlled hypotension in low-flow isoflurane-dexmedetomidine anesthesia in terms of hemodynamics, anesthetic consumption, and costs.

METHODS

We allocated forty patients randomly into two equal groups. We then maintained dexmedetomidine infusion (0.1 μg.kg(-1).min(-1)) for 10 minutes. Next, we continued it until the last 30 minutes of the operation at a dose of 0.7 μg.kg(-1).hour(-1). We administered thiopental (4-6 mg. kg(-1)) and 0.08-0.12 mg.kg(-1) vecuronium bromide at induction for both groups. We used isoflurane (2%) for anesthesia maintenance. Group N received a 50% O2-N2O mixture and Group A received 50% O2-air mixture as carrier gas. We started low-flow anesthesia (1L.min(-1)) after a 10-minute period of initial high flow (4.4L.min(-1)). We recorded values for blood pressure, heart rate, peripheral O2 saturation, inspiratory isoflurane, expiratory isoflurane, inspiratory O2, expiratory O2, inspiratory N2O, expiratory N2O, inspiratory CO2, CO2 concentration after expiration, Minimum Alveolar Concentration. In addition, we determined the total consumption rate of fentanyl, dexmedetomidine and isoflurane as well as bleeding.

RESULTS

In each group the heart rate decreased after dexmedetomidine loading. After intubation, values were higher for Group A at one, three, five, 10, and 15 minutes. After intubation, the patients reached desired hypotension values at minute five for Group N and at minute 20 for group A. MAC values were higher for Group N at minute one, three, five, 10, and 15 (p<0.05). FiO2 values were high between minute five and 60 for Group A, while at minute 90 Group N values were higher (p<0.05). FiIso (inspiratuvar isofluran) values were lower in Group N at minute 15 and 30 (p<0.05).

CONCLUSION

By using dexmedetomidine instead of nitrous oxide in low flow isoflurane anesthesia, we attained desired MAP levels, sufficient anesthesia depth, hemodynamic stability and safe inspiration parameters. Dexmedetomidine infusion with medical air-oxygen as a carrier gas represents an alternative anesthetic technique.

Effect of premedication with systemic steroids on surgical field bleeding and visibility during nasosinusal endoscopic surgery

INTRODUCTION

Chronic rhinosinusitis (CRS) is the inflammation of the nasal and paranasal sinus mucosa persisting for at least 12 weeks. The success of endoscopic sinus surgery (ESS) depends on minimising oedema and intraoperative bleeding. For this purpose, some surgeons advocate the use of preoperative systemic steroids (SS). Our aim was to assess if the administration of preoperative SS in patients with CRS with or without nasal polyps (NP) facilitates the surgical procedure.

METHODS

Non-randomized clinical trial in CRS patients with or without NP. Patients in the ESS group received oral meprednisone preoperatively, whereas the control group did not. The visibility of the surgical field, intraoperative bleeding and surgery duration were recorded.

RESULTS

Each group (SS group and control group) included 27 patients. The administration of SS reduced the values of all the parameters in patients without NP, with no significant differences. In patients with NP, only operative bleeding was reduced significantly.

CONCLUSIONS

Even though all the parameters decreased with the preoperative administration of SS, only operative bleeding was significantly reduced in patients with CRS with NP.

Effects of premedication with metoprolol on bleeding and induced hypotension in nasal surgery

BACKGROUND

One of the major problems in surgery is intraoperative bleeding which reduces visibility in the operative field. An important task for an anesthetist during head and neck surgery is to improve intraoperative visibility.

OBJECTIVES

The purpose of this study was to compare the amount of bleeding using different doses of oral metoprolol during three common types of nasal operation; rhinoplasty, septoplasty and functional endoscopic sinus surgery, as this is one of the complications during head and neck surgery.

PATIENTS AND METHODS

In a randomized, controlled, open clinical trial, 88 patients who were candidates for nasal operations were studied. Patients entering the study were divided into four groups and randomly assigned to receive 50 mg metoprolol a night before the operation, 50 mg metoprolol on the day of operation, 50 mg metoprolol on the night and on the day of operation, or a placebo. Following the patient's preparation on the operating table and after intubation, systolic and diastolic blood pressures were measured in a non-invasive oscillometric way, and their pulse rate was recorded simultaneously. All the data were recorded during the surgery as well. Bleeding was measured by the quality scale proposed by Formme and Boezaart.

RESULTS

There was a statistical significance between using metoprolol and the amount of intraoperative bleeding. All patients who received metoprolol the night before surgery and on the day of surgery had slight bleeding during the surgery. In addition, there was a statistical significance between patients' agitation levels and the time they received metoprolol.

CONCLUSIONS

Decreases in both systolic blood pressure and heart rate to less than 60 beats per minute reduces intraoperative bleeding. These rates can be achieved by using beta-blocker drugs. In this study, using a double-dose of metoprolol significantly reduced intraoperative bleeding and improved the quality of the operative field. It also reduced patients' agitation in the recovery room.

Hypotensive anaesthesia with remifentanil combined with desflurane or isoflurane in tympanoplasty or endoscopic sinus surgery: a randomised, controlled trial

Objective:

To compare the effect of remifentanil combined with desflurane or isoflurane on the quality of the operative field and surgical conditions, blood loss, and recovery during tympanoplasty or endoscopic sinus surgery.

Design:

Randomised, double-blinded clinical study.

Subjects:

Sixty-four patients were scheduled for elective tympanoplasty or endoscopic sinus surgery. The patients were randomly divided into two groups: desflurane or isoflurane. After anaesthesia induction, all patients received a continuous remifentanil infusion of 0.2–0.5 µg/kg/min until a mean arterial pressure of 65–75 mmHg was achieved. Heart rate and mean arterial pressure were recorded throughout anaesthesia. Blood loss was measured at the end of surgery. Achievement of a bloodless operative field was rated on a 100 mm visual analogue scale. Following completion of surgery, the time to extubation and to achievement of an Aldrete score of nine or more was recorded.

Results:

Sixty-three patients were evaluated. The total dose of remifentanil and the total blood loss were similar in both groups (p > 0.05). Time to extubation and to an Aldrete score of nine or more for the desflurane group was significantly less than for the isoflurane group (p < 0.05). No differences were found in the extent of achievement of a bloodless operative field, as assessed via visual analogue scale, comparing the study groups (p > 0.05).

Conclusion:

Although desflurane and isoflurane both enabled good surgical conditions (in terms of quality of operative field) and convenient induction of hypotension for tympanoplasty and endoscopic sinus surgery, the recovery characteristics of desflurane were better than those of isoflurane. Therefore, desflurane may be preferable to isoflurane in such circumstances.

Preoperative corticosteroid oral therapy and intraoperative bleeding during functional endoscopic sinus surgery in patients with severe nasal polyposis: a preliminary investigation

OBJECTIVES

The aim of the study was to investigate whether orally administered steroids might improve surgical field conditions during functional endoscopic sinus surgery.

METHODS

Total blood loss and visualization of the surgical field during the surgical procedure were compared in 2 groups of 18 patients each with severe nasal polyposis. The groups were similar in respect to age, body mass index, general health status, incidence of allergy, bronchial asthma, aspirin triad, and stage of disease. One group received 30 mg of prednisone daily for 5 consecutive days before the operation. The second group served as a control.

RESULTS

Although the total blood loss was only slightly less in the steroid group, the visual conditions of the surgical field improved significantly.

CONCLUSIONS

Better surgical field conditions were the results of the powerful anti-inflammatory and antiedematous activity of the drug, which facilitated blood and secretion evacuation from the operated area and prevented the optic system from staining.

Intravenous anesthesia provides optimal surgical conditions during microscopic and endoscopic sinus surgery

OBJECTIVES/HYPOTHESIS

Controlled hypotension is used to improve surgical conditions during microscopic and endoscopic sinus surgery. New short-acting anesthetics such as propofol and remifentanil allow exact control of intraoperative blood pressure and thus might be valuable tools to improve intraoperative conditions for the otorhinolaryngological surgeon. Intravenous anesthesia was compared with traditional balanced anesthesia by subjective assessment of surgical conditions made by two experienced otorhinolaryngological surgeons.

STUDY DESIGN

Prospective, randomized, patient- and observer-blinded study.

METHODS

Ninety consecutive patients were randomly assigned to receive intravenous anesthesia with propofol 5 to 8 mg.kg-1.h-1 and remifentanil 10 to 30 microg.kg-1.h-1 or with isoflurane (0.4-1.0 vol%) and repetitive doses of 0.5 to 1 mg alfentanil. An injectable vasodilator was used in both groups to keep mean arterial pressure between 60 and 70 mm Hg (8-9.3 hecto-pascal). The attending otorhinolaryngological surgeon was unaware of the type of anesthesia administered. Immediately after the operation the surgeons rated surgical conditions (bleeding from the surgical field) on a visual analogue scale (0-10 cm) and on a verbal rating scale.

RESULTS

Blood pressure was not different between the two groups, but heart rate was lower in the intravenous anesthesia group (mean heart rate in the intravenous anesthesia group, 62 beats per min [95% confidence interval, 52-72]; mean heart rate in the balanced anesthesia group, 75 beats per min [95% confidence interval, 67-83]). Surgical conditions were rated to be significantly better (P <.0001) during anesthesia with propofol-remifentanil (median rating: 2.8; 25th/75th percentile: 2.0/3.4) compared with isoflurane-alfentanil (median rating: 4.9; 25th/75th percentile: 3.6/7.6).

CONCLUSIONS

Intravenous anesthesia using propofol-remifentanil provides better surgical conditions compared with a traditional balanced anesthesia technique using isoflurane-alfentanil. It is hypothesized that lower cardiac output caused by decreased heart rate during deep general anesthesia is responsible for this result.

Remifentanil induces consistent and sustained controlled hypotension in children during middle ear surgery

PURPOSE

To determine in children whether remifentanil combined with sevoflurane, could induce controlled hypotension, reduce middle ear blood flow (MEBF) measured by laser-Doppler, and provide a satisfactory operative field.

METHODS

Forty children undergoing middle ear surgery and anesthetized with sevoflurane were randomly assigned to receive either 1 micro g x kg(-1) remifentanil iv followed by a continuous infusion of 0.2 to 0.5 micro g x kg(-1) x min(-1) or 0.25 micro g x kg(-1) x min(-1) nitroprusside iv and alfentanil iv (n = 20 in each group).

RESULTS

Controlled hypotension was achieved at the target mean arterial pressure (MAP) of 50 mmHg (P < 0.01) within 121 +/- 21 and 62 +/- 9 sec for remifentanil and nitroprusside respectively. MEBF decreased by 22 +/- 4 and 20 +/- 6% and preceded the decrease in MAP within 20 +/- 7 and 10 +/- 3 sec for remifentanil and nitroprusside respectively. Remifentanil, and nitroprusside decreased MEBF autoregulation (0.41 +/- 0.2 and 0.37 +/- 0.3 respectively). Controlled hypotension was sustained in both groups throughout surgery, and the surgical field rating was good. Nitroprusside increased PaCO(2) slightly, and there were no postoperative circulatory, neurological or metabolic complications in any of the groups.

CONCLUSION

Remifentanil combined with sevoflurane in children enabled controlled hypotension, reduced MEBF and provided good surgical conditions for middle ear surgery with no need for additional use of a specific hypotensive agent.

Remifentanil and controlled hypotension; comparison with nitroprusside or esmolol during tympanoplasty

PURPOSE

To determine whether remifentanil, combined with propofol, could induce controlled hypotension, reduce middle ear blood flow (MEBF) measured by laser-Doppler flowmetry, provide a "dry" operative field, and could be compared with nitroprusside or esmolol combined with alfentanil and propofol.

METHODS

Thirty patients undergoing tympanoplasty and anesthetized with 2.5 mg x kg(-1) propofol iv followed by a constant infusion of 120 microg x kg(-1) x min(-1), were randomly assigned in three groups to receive either 1 microg x kg(-1) remifentanil iv followed by a continuous infusion of 0.25 to 0.50 microg x kg(-1) x min(-1), or nitroprusside iv, or esmolol iv combined for the latter two groups with alfentanil iv.

RESULTS

Controlled hypotension was achieved at the target pressure of 80 mmHg within 107 +/- 16, 69 +/- 4.4, 53.3 +/- 4.4 sec for remifentanil, nitroprusside and esmolol respectively. MEBF decreased by 24 +/- 0.3, 22 +/- 3.3, 37 +/- 3% and preceded the decrease in SABP, within 30 +/- 6.1, 11.2 +/- 3.1, 15 +/- 2.8 sec for remifentanil, nitroprusside and esmolol respectively. Remifentanil, and nitroprusside decreased MEBF autoregulation less than esmolol (0.36 +/- 0.1, 0.19 +/- 0.2, -0.5 +/- 0.2). Controlled hypotension was sustained in all three groups throughout surgery, and the surgical field rating decreased in a range of 80% in all three groups. Nitroprusside decreased pH and increased PaCO2. There were no postoperative complications in any of the groups.

CONCLUSIONS

Remifentanil combined with propofol enabled controlled hypotension, reduced middle ear blood flow and provided good surgical conditions for tympanoplasty with no need for additional use of a potent hypotensive agent.