Remifentanil Provides Hemodynamic Stability and Faster Awakening Time in Transsphenoidal Surgery

The effects of the administration sequence and the type of hypnotics on the development of remifentanil-induced chest wall rigidity: a randomized controlled trial

BACKGROUND

Research on remifentanil-induced chest wall rigidity is limited. Furthermore, its incidence is unknown, and the clinical factors influencing its development remain unclear. This prospective, double-blind, randomized controlled trial aimed to investigate the effects of the administration sequence of hypnotics and remifentanil as well as the type of hypnotic administered on the development of remifentanil-induced chest wall rigidity.

METHODS

A total of 125 older patients aged [Formula: see text] 65 years, who were scheduled to undergo elective surgery under general anesthesia, were enrolled in this study. Participants were randomly assigned to one of four groups; Thio-Remi, Pro-Remi, Remi-Thio, or Remi-Pro. After confirming the loss of consciousness and achieving a target effect-site concentration of 3 ng/mL remifentanil, the development of remifentanil-induced chest wall rigidity was evaluated.

RESULTS

The incidence of chest wall rigidity was significantly higher in the remifentanil-hypnotic group than in the hypnotic-remifentanil (opposite sequence) group (55.0% vs. 21.7%, P < 0.001). Logistic regression analysis revealed that remifentanil-hypnotic administration was a significant predictor of the development of chest wall rigidity (crude odds ratio 4.42, 95% confidence interval 1.99; 9.81, P < 0.001).

CONCLUSIONS

Pretreatment with hypnotics potentially reduces the development of chest wall rigidity during the induction of balanced anesthesia with remifentanil in older patients.

TRIAL REGISTRATION

This article was registered at WHO International Clinical Trials Registry Platform (Trial number: KCT0006542).

Anaesthetic challenges in a patient with acromegaly and multinodular goitre undergoing endoscopic pituitary surgery

Acromegaly is a progressive systemic disorder which is common among middle-aged women. A functioning growth hormone-secreting pituitary adenoma is the most common cause. Anaesthesia for pituitary surgery in patients with acromegaly is challenging. Rarely, these patients may develop thyroid lesions that may compromise the airway. We present the case of a young man with newly diagnosed acromegaly caused by a pituitary macroadenoma complicated by a large multinodular goitre. The aim of this report is to discuss the perianaesthetic approach in patients with acromegaly with a high risk of airway compromise undergoing pituitary surgery.

Long-Term Exposure to Morphine Induces Cross-Tolerance to Acute Antinociceptive Effect of Remifentanil on Somatic and Visceral Stimuli in Rats

Purpose

Remifentanil is one of the most commonly used opioids intraoperatively. Previous reports indicate that long-term use of opioids may lead to cross-tolerance to remifentanil, which poses a challenge in the control of acute pain intraoperatively. However, there is limited information regarding cross-tolerance to remifentanil, especially in visceral pain. Therefore, this study aimed to examine cross-tolerance to remifentanil in somatic and visceral tolerance using morphine-tolerant rats.

Methods

Six male Sprague-Dawley rats were allocated to the morphine and saline groups each. Tolerance to the antinociceptive effect of morphine was induced in rats in the morphine group. Remifentanil was continuously infused intravenously at 10 mcg/kg/min for 120 min to assess cross-tolerance from morphine to remifentanil. The antinociceptive effects on somatic and visceral nociceptive stimuli were measured using the tail-flick (TF) and colorectal distension (CD) tests, respectively. The antinociceptive efficacy was evaluated by converting the response threshold to the percentage maximal possible effect (%MPE).

Results

Remifentanil increased the %MPE in the morphine and saline groups in both the tests; however, the increase in %MPE was attenuated significantly in the morphine group compared with that in the saline group at 60, 90, and 120 min (all P < 0.01) in the TF test and at 90 and 120 min in the CD test (all P <0.05).

Conclusion

Our results indicate that morphine-tolerant rats exhibit cross-tolerance to remifentanil's acute antinociceptive effects on somatic and visceral stimuli. Cross-tolerance to remifentanil should be considered in the perioperative management of patients using morphine.

Control of Hemodynamic Responses and Perioperative Outcomes in Transsphenoidal Pituitary Surgery: A Qualitative Systematic Review of the Available Evidence

Transnasal transsphenoidal (TNTS) pituitary surgery is associated with short-lived but intense nociceptive stimuli which cause substantial hemodynamic perturbations that may increase blood loss and impair visualization of the surgical field. This systematic review aimed to critically appraise the clinical evidence for the efficacy and safety of various anesthetic techniques, other pharmacological modalities, and supplementary interventions by assessing intraoperative systemic hemodynamics, use of adjunct medications, quality of the surgical field, intraoperative blood loss, and recovery profiles in patients undergoing TNTS pituitary surgery. Relevant randomized clinical trials and observational studies were identified in a systematic literature search; 16 studies (13 randomized clinical trials, 3 observational studies) enrolling a total of 907 patients were identified for inclusion in this review. Propofol provided more potent hemodynamic control compared with volatile anesthetics with a sparing effect on the need for additional drugs to blunt hemodynamic responses. Recovery profiles between propofol and sevoflurane were either equivalent or favored sevoflurane, but both agents were superior to isoflurane. Regarding intraoperative analgesia, remifentanil was associated with superior hemodynamic control and recovery profiles than fentanyl. Dexmedetomidine had beneficial effects on hemodynamics, surgical field quality, recovery characteristics, and nociceptive properties compared with placebo. Although there was no clear-cut superiority of other adjunct pharmacological modalities on hemodynamic responses during surgery, regional blocks were associated with beneficial impacts on both primary and secondary outcomes. In summary, short-acting anesthetics, analgesics and dexmedetomidine seem to improve intraoperative hemodynamics, blood loss, and recovery qualities during TNTS pituitary surgery. However, definitive conclusions cannot be drawn because of methodological heterogeneity in the identified studies.

Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection

Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.

Safety of transsphenoidal microsurgical approach in patients with an ACTH-secreting pituitary adenoma

PURPOSE

Patients affected by Cushing's disease often have important comorbidities directly linked to hypercortisolism that might enhance the operative risk. We report the safety of transsphenoidal surgery in patients affected by Cushing's disease as compared with patients with nonfunctioning pituitary adenoma.

METHODS

We have retrospectively analyzed 142 patients with Cushing's disease and 299 patients with nonfunctioning pituitary adenoma who underwent transsphenoidal surgery performed by a single experienced neurosurgeon between September 2007 and December 2014. For all of them, an intraoperative computerized anesthetic record for the automatic storage of data was available.

RESULTS

The intraoperative vital parameters and the frequency of drugs administered during anesthesia were comparable between Cushing's disease and nonfunctioning pituitary adenoma groups. The duration of surgery was similar between the two groups (41.2 ± 11.8 vs. 42.9 ± 15.6 min), while the duration of anesthesia was slightly shorter in Cushing's disease patients (97.6 ± 18.1 min) than in nonfunctioning pituitary adenoma patients (101.6 ± 20.6 min, p = 0.04). The total perioperative mortality rate was 0.2% (0% in Cushing's disease vs. 0.3% in nonfunctioning pituitary adenoma). Cushing's disease patients had surgical and medical complication rates of 3.5% each, not different from those occurring in nonfunctioning pituitary adenoma. The postoperative incidence of diabetes insipidus (10.6%) and isolated hyponatremia (10.6%) in Cushing's disease patients was significantly higher than in nonfunctioning pituitary adenoma patients (4.4 and 4.1%; p = 0.02 and p = 0.01, respectively).

CONCLUSIONS

In a large series of unselected and consecutive patients with Cushing's disease, transsphenoidal surgery performed by one dedicated experienced neurosurgeon had a reasonably low risk of complications. In particular, despite the higher burden of comorbidities typically associated with hypercortisolism, medical complications are rare and no more frequent than in patients with nonfunctioning pituitary adenoma.

Safety of remifentanil in transsphenoidal surgery: A single-center analysis of 540 patients

Although some studies have examined the efficacy and safety of remifentanil in patients undergoing neurosurgical procedures, none has examined its safety in transsphenoidal operations specifically. In this study, all transsphenoidal operations performed by a single author from 2008 to 2015 were retrospectively reviewed to evaluate the safety of remifentanil in a consecutive series of patients. During the study period, 540 transsphenoidal operations were identified. Of these, 443 (82.0%) patients received remifentanil intra-operatively; 97 (18.0%) did not. The two groups were well-matched with regard to demographic categories, comorbidities, and pre-operative medications (p>0.05), except pre-operative tobacco use (p=0.021). Patients were also well-matched with regard to radiographic features and surgical techniques. Patients who received remifentanil were more likely to harbor a macroadenoma (78.1% vs. 67.0%, p=0.025), and had slightly longer anesthesia time on average (269.2minvs. 239.4min, p=0.024). All pathologic diagnoses were well-matched between the two groups, except that patients receiving remifentanil were more likely to harbor a non-functioning adenoma (46.5% vs. 26.8%, p<0.001). Analysis of post-operative complications showed no significant difference between patients who received remifentanil and those who did not, and length of stay and prevalence of ICU stay did not differ between the two groups. In a well-matched series of 540 patients undergoing transsphenoidal surgery, remifentanil was found to be a safe anesthetic adjunct. There were no significant differences in post-operative hospital course or complications in patients who did and did not receive intra-operative remifentanil.

Effects of remifentanil on convulsion duration and hemodynamic responses during electroconvulsive therapy: a double-blind, randomized clinical trial

BACKGROUND

Among the drugs used for the induction of anesthesia for electroconvulsive therapy (ECT), thiopental induces a greater degree of cardiovascular alteration than other agents. Remifentanil has been found to reduce blood pressure and heart rate when administered as an adjuvant during general anesthesia, with unknown effects on the duration of motor or electroencephalographic seizure activity during ECT. The purpose of this prospective, randomized, double-blind, placebo-controlled, crossover study was to evaluate the effects of supplementing thiopental anesthesia with remifentanil on convulsion duration and cardiovascular response during ECT.

METHODS

Twenty-four American Society of Anesthesiologists I and II patients receiving 6 sessions of ECT were randomly allocated to 2 groups. All patients were premedicated with atropine (0.4 mg, intravenously), then anesthesia was induced by thiopental (1.0 mg/kg), succinylcholine (0.5 mg/kg), and remifentanil (1.0 microg/kg) in the case group or normal saline (3 mL) in the control group in a crossover format. Stimulus amplitude for applying ECT was kept constant during the sessions of treatment in the course of study for each patient. Hemodynamic parameters, convulsion duration, and recovery parameters were recorded. Statistical analysis was done using paired t tests.

RESULTS

There was no statistically significant difference between the groups regarding convulsion duration, recovery times to eye opening, obeying specific commands, and walking without help. Remifentanil significantly attenuated the increase in heart rate and arterial blood pressure (P < 0.05).

CONCLUSIONS

Remifentanil (1 microg/kg) administered before thiopental (1 mg/kg) has no adverse effect on the duration of ECT-induced convulsion and recovery time, but it can attenuate the increase in heart rate and arterial blood pressure.