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

Systematic review with meta-analysis of relative risk of prolonged times to tracheal extubation with desflurane versus sevoflurane or isoflurane

The objective of this systematic review was to estimate the relative risk of prolonged times to tracheal extubation with desflurane versus sevoflurane or isoflurane. Prolonged times are defined as ≥15 min from end of surgery (or anesthetic discontinuation) to extubation in the operating room. They are associated with reintubations, naloxone and flumazenil administration, longer times from procedure end to operating room exit, greater differences between actual and scheduled operating room times, longer times from operating room exit to next case start, longer durations of the workday, and more operating room personnel idle while waiting for extubation. Published randomized clinical trials of humans were included. Generalized pivotal methods were used to estimate the relative risk of prolonged extubation for each study from reported means and standard deviations of extubation times. The relative risks were combined using DerSimonian-Laird random effects meta-analysis with Knapp-Hartung adjustment. From 67 papers, there were 78 two-drug comparisons, including 5167 patients. Studies were of high quality (23/78) or moderate quality (55/78), the latter due to lack of blinding of observers to group assignment and/or patient attrition because patients were extubated after operating room exit. Desflurane resulted in a 65% relative reduction in the incidence of prolonged extubation compared with sevoflurane (95% confidence interval 49% to 76%, P < .0001) and in a 78% relative reduction compared with isoflurane (58% to 89%, P = .0001). There were no significant associations between studies' relative risks and quality, industry funding, or year of publication (all six meta-regressions P ≥ .35). In conclusion, when emergence from general anesthesia with different drugs are compared with sevoflurane or isoflurane, suitable benchmarks quantifying rapidity of emergence are reductions in the incidence of prolonged extubation achieved by desflurane, approximately 65% and 78%, respectively. These estimates give realistic context for interpretation of results of future studies that compare new anesthetic agents to current anesthetics.

Changes of intraocular pressure and ocular perfusion pressure during controlled hypotension in patients undergoing arthroscopic shoulder surgery: A prospective, randomized, controlled study comparing propofol, and desflurane anesthesia

PURPOSE

The aim of the present study is to evaluate the effects of deliberate hypotensive anesthesia on intraocular pressure (IOP) and ocular perfusion pressure (OPP) and compare the effects of propofol total intravenous anesthesia (TIVA) and desflurane anesthesia on IOP and OPP.

METHODS

A total of 50 patients undergoing arthroscopic shoulder surgery in the lateral decubitus position were randomized to receive desflurane or propofol anesthesia. Mean arterial pressure (MAP) was maintained in the range of 60-75 mm Hg during hypotensive anesthesia. IOP was measured using a handheld tonometer at 7 time points: before induction (T1, baseline); immediately after endotracheal intubation (T2); 10 minutes after position change to lateral decubitus (T3); 10, 30, and 50 minutes after the start of hypotensive anesthesia (T4-T6); and at the end of surgery (T7).

RESULTS

MAP decreased about 35% to 38% during hypotensive anesthesia. Compared to baseline values, the IOP at T6 in dependent and non-dependent eyes decreased by 0.43 and 2.74 mm Hg, respectively in desflurane group; 3.61 and 6.05 mm Hg, respectively in the propofol group. IOP of both eyes in the propofol group was significantly lower than in the desflurane group from T2 to T7. OPP of both eyes in both groups was significantly lower than at baseline, except at T2 in the desflurane group. OPP of both eyes in the propofol group was significantly higher than that in the desflurane group at T5 and T6.

CONCLUSIONS

Hypotensive anesthesia reduced IOP and OPP, but propofol TIVA maintained higher OPP than desflurane anesthesia. These findings suggest that propofol TIVA can help mitigate the decrease of OPP during hypotensive anesthesia.

Effect of remifentanil on the recovery profile after head and neck surgeries: A prospective study

Background and Aims:

Development of opioid tolerance in the perioperative period due to remifentanil remains controversial. We evaluated occurrence of opioid tolerance and other adverse effects due to remifentanil in patients undergoing head and neck surgery.

Material and Methods:

We recruited adult participants with ASA status I to III who received general anesthesia for approximately 2 h for elective head and neck procedures. Remifentanil infusion was used in one group and intermittent boluses of morphine or fentanyl were administered in another group. Postoperative pain was treated with intermittent boluses of morphine and fentanyl in post-anaesthesia care unit (PACU) to achieve a numerical rating scale score of 3. Opioid requirement was assessed as an indicator of opioid tolerance. Patients were also evaluated for time to discharge from PACU.

Results:

We studied 222 adults aged between 21 and 80 years. One hundred and eleven patients received a combination of remifentanil infusion and morphine boluses, and another 111 patients received only fentanyl and/or morphine boluses intraoperatively. Fifty-one patients in the remifentanil group and 25 in the fentanyl/morphine group required opioids in the PACU. Opioid requirement were significantly more (mean ± SD, 44.98 ± 59.7 Vs 20.23 ± 46.66 mcg.kg⁻¹; P = 0.001) and required longer time to discharge from PACU in the remifentanil group compared to the fentanyl/morphine group (Mean ± SD, 88.6 ± 39.5 min Vs 73.1 ± 38.4 min; P < 0.001). No difference in the incidence of adverse effects in two groups was noted.

Conclusion:

At clinically relevant doses, intraoperative remifentanil infusion appears to increase opioid consumption in the immediate postoperative period. This can result in delayed discharge from PACU for patients undergoing elective head and neck procedures.

Evaluation of the efficacy of desflurane with or without labetalol for hypotensive anesthesia in middle ear microsurgery

Background and Aims:

Hypotensive anesthesia technique is used to reduce intraoperative bleeding and to improve the visibility of the operative field. The aim was to evaluate the efficacy of desflurane with and without labetalol for producing hypotensive anesthesia.

Material and Methods:

Sixty adult patients undergoing elective middle ear surgery were administered general anesthesia and randomly divided into two groups – Group D and Group L. The target mean arterial pressure (MAP) was 55–65 mmHg during hypotensive period. Group D patients received an increasing concentration of desflurane alone. Group L patients received 3% desflurane plus labetalol (loading dose 0.3 mg/kg intravenously, followed by 10 mg increments every 10 min). Student's t-test and paired t-test were used to compare the hemodynamic parameters. Visibility of the operative field, anesthetic and rescue drug requirement, partial pressure of oxygen in arterial blood, time taken for induction and reversal of hypotension and recovery characteristics were noted.

Results:

Target MAP was achieved in both the groups. Group D was associated with a higher mean heart rate compared with Group L (77.3 ± 11.0/min vs. 70.5 ± 2.5/min, respectively; P < 0.001) during the hypotensive period, along with a higher requirement for desflurane (P = 0.000) and metoprolol (P = 0.01). Time taken to achieve target MAP was lesser in Group L compared with Group D (33.7 ± 7.1 vs. 39.8 ± 6.2 min, respectively; P = 0.000). Time taken to return to baseline MAP was faster in Group D (P = 0.03). Emergence time was longer with desflurane alone (P = 0.000) resulting in greater sedation (P = 0.000) in the immediate postoperative period.

Conclusion:

Although desflurane is effective for inducing deliberate hypotension in middle ear microsurgery, the combination of desflurane with labetalol is associated with decreased requirement of desflurane, absence of reflex tachycardia, faster induction of hypotension, faster recovery from anesthesia, and less postoperative sedation.

Intraoperative Blood Loss During Orthognathic Surgery: A Comparison of Remifentanil-Based Anesthesia With Sevoflurane or Isoflurane

PURPOSE

The aim of the present study was to compare the blood loss with remifentanil-based anesthesia with sevoflurane or isoflurane during orthognathic surgery.

PATIENTS AND METHODS

In this randomized controlled clinical trial, the patients who were scheduled for orthognathic surgery were divided into 2 groups: the sevoflurane (Sevo) group and isoflurane (Iso) group. Anesthesia was maintained using end-tidal concentrations of 1.4% sevoflurane or 0.9% isoflurane. Remifentanil was continuously infused at 0.05 to 0.5 μg/kg/min to maintain the mean blood pressure (MBP) at 60 to 65 mm Hg. The intraoperative blood loss was compared between the 2 groups. The Student t test for unpaired samples was used for statistical analysis. P < .05 was considered statistically significant.

RESULTS

The study sample included 19 men and 45 women (n = 64). The mean age was 25 years (range 16 to 50). The intraoperative blood loss tended to be greater in the Iso group (n = 32; 4.79 ± 3.22 mL/kg) than in the Sevo group (n = 32; 4.00 ± 1.98 mL/kg). However, the difference between the 2 groups was not significant.

CONCLUSION

In a comparison of intraoperative blood loss during remifentanil-based anesthesia with sevoflurane or isoflurane during orthognathic surgery, no difference was observed between the 2 groups.

Comparison of esmolol to nitroglycerine in controlling hypotension during nasal surgery

OBJECTIVE

The aim of this study was to compare esmolol to nitroglycerine in terms of effectiveness in controlling hypotension during nasal surgery.

MATERIALS AND METHODS

After approval by our institutional Ethics Committee, 40 patients were recruited and randomized into two drug groups: esmolol (Group E) and nitroglycerine (Group N). In group E, a bolus dose of 500 μg/kg esmolol was administered over 30 sec followed by continuous administration at a dose of 25-300 μg/ kg/min to maintain systolic arterial pressure at 80 mmHg. In group N, nitroglycerine was administered at a dose of 0.5-2 μg/kg/min.

RESULTS

During the hypotensive period, systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, and heart rate were decreased 24%, 33%, 27% and 35%, respectively, in group E (p<0.001, p<0.001, p<0.001, p<0.001) and were decreased 30%, 33%, 34% and 23%, respectively, in group N (p<0.001, p<0.001, p<0.001, p<0.001). The decrease in heart rate was higher in group E during the hypotensive period (p=0.048). During the recovery period, diastolic arterial pressure and heart rate were decreased 9% and 18%, respectively, in group E (p=0.044, p<0.001). Systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure were decreased 7%, 3% and 7%, respectively, in group N (p=0.049, p=0.451, p=0.045).

CONCLUSION

Esmolol provides hemodynamic stability and good surgical field visibility and should be considered as an alternative to nitroglycerine.

[Specific anaesthetic procedures for nasal and sinus surgery]

In nasal and sinus surgery, the anaesthetist must share the operating field with the surgeon and take into account some patients' specific pathologies. Bleeding must be avoided by different means but the accurate gesture of the surgeon, added to the properties of the new anaesthetic drugs, may reduce the risk of this functional surgery.

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.

Perioperative and intraoperative maneuvers to optimize surgical outcomes in skull base surgery

There are many approaches to obtaining a workable endoscopic surgical field in sinus surgery. With extended sinus and transdural endoscopic surgery, a more rigid approach must be taken. There are 3 main factors that invariably lead to poor surgical outcomes in endoscopic sinus and skull base surgery: bleeding, inadequate access, and unidentified anatomic anomalies. Bleeding is arguably the most common reason for incomplete resection. An understanding of microvascular and macrovascular bleeding allows a more structured approach to improve the surgical field in extended endoscopic surgery. The endoscopic surgeon should always be comfortable in performing the same procedure as an open operation. However, converting or abandoning an endoscopic procedure should rarely occur because much of this decision making should take place preoperatively. Along with poor hemostasis, inadequate access is an important cause of poor outcome. Evaluation of the anatomy involved by pathology but also the anatomy that must be removed to allow adequate exposure is important. This article reviews the current techniques used to ensure optimal surgical conditions and outcomes.