Total spinal blockade during local anesthesia of the nasal passages

Bilateral Superficial Trigeminal Nerve Blocks are not More Effective than a Placebo in Abolishing Post-operative Headache Pain in Pituitary Transsphenoidal Neurosurgery: A Prospective, Randomized, Doubleblinded Clinical Trial

BACKGROUND

Pituitary neurosurgery executed via the transsphenoidal endonasal approach is commonly performed for pituitary adenomas. Reasons for prolonged hospital stay include postoperative headache and protracted nausea with or without vomiting. Bilateral superficial trigeminal nerve blocks of the supra-orbital V1 and infra-orbital V2 (SION) nerves performed intra-operatively as a regional anesthetic adjunct to general anesthesia were hypothesized to decrease 6 hours postoperative morphine PCA (patient-controlled analgesia) use by patients.

METHODS

Forty-nine patients, following induction of general anesthesia for their transsphenoidal surgery, were prospectively randomized in a double-blinded fashion to receive additional regional anesthesia as either a block (0.5% ropivacaine with epi 1:200,000) or placebo/sham (0.9% normal saline). The primary endpoint of the study was systemic morphine PCA opioid consumption by the two groups in the first 6-hours postoperatively. The secondary endpoints included (1) pain exposure experienced postoperatively, (2) incidence of postoperative nausea and vomiting, and (3) time to eligibility for PACU discharge.

RESULTS

Of the 49 patients that were enrolled, 3 patients were excluded due to protocol violations. Ultimately, there was no statistically significant difference between morphine PCA use in the 6 hours postoperatively between the block and placebo/sham groups. There was, however, a slight visual tendency in the block group for higher pain scores, morphine use p=0.046, and delayed PACU discharge. False discovery rate corrected comparisons at each time point and then revealed no statistically significant difference between the two groups. There were no differences between the two groups for secondary endpoints.

CONCLUSION

It was found that a 6-hour postoperative headache after endoscopic trans-sphenoidal pituitary surgery likely has a more complicated mechanism involving more than the superficial trigeminovascular system and perhaps is neuro-modulated by other brain nuclei.

Perioperative management of patients undergoing transsphenoidal pituitary surgery

Pituitary adenomas often present with the symptoms of hormonal hypersecretion, and although medical therapy is available for most hyperfunctioning states, it is not curative. As a result, transsphenoidal pituitary surgery has become a commonly performed neurosurgical procedure with unique challenges for the anesthesiologist due to the distinct medical comorbidities associated with various adenomas. Any type of pituitary tumor may also produce hypopituitarism and local mass effects secondary to the expanding intrasellar mass. Here we review the perioperative concerns surrounding surgery to remove adenomas and decompress the sellar space. Special attention is given to Cushing's disease (hypercortisolism secondary to an adrenocorticotropic hormone-secreting adenoma), acromegaly (secondary to a growth hormone-secreting adenoma), and hyperthyroidism in the setting of thyrotropic adenomas. Operative risks, including bleeding, diabetes insipidus, the syndrome of inappropriate antidiuretic hormone secretion, and hypopituitarism, are addressed in detail. Understanding preoperative assessment, intraoperative management, potential complications, their management, and strategies for avoidance are fundamental to successful perioperative patient care and avoidance of morbidity and mortality.

Prevention of hypertension during trans-sphenoidal surgery--the effect of bilateral maxillary nerve block with local anaesthetics

BACKGROUND

Severe cardiovascular responses are known to occur during trans-sphenoidal excision of the pituitary gland despite adequate depth of anaesthesia. This study was undertaken to evaluate the effects of bilateral maxillary nerve block with local anaesthetics on the cardiovascular responses to various stimuli during this procedure.

METHODS

In a group of 32 patients, 5-10 ml of a mixture of bupivacaine 0.5% and lignocaine 2% (1:1) was injected in the pterygopalatine fossa after induction of general anaesthesia. Seven control group patients did not receive any nerve block. In all the patients, general anaesthesia was induced with thiopentone and maintained with nitrous oxide-oxygen, pentazocine, boluses of thiopentone and halothane. Pancuronium was used for neuromuscular blockade.

RESULTS

In both the groups, maximum hypertension occurred on opening the blades of the bivalve nasal speculum. In the study group, hypertensive response was significantly less following nasal infiltration with adrenaline containing solution (10.26% increase vs. 23.08% in the control group, P < 0.05), nasal dissection (2.82% vs. 9.45%, P < 0.01) and on application of the nasal speculum (14.93% vs. 35.16%, P < 0.01). The effect on heart rate response was not significant.

CONCLUSION

The described technique is a useful adjunct to general anaesthesia for suppressing the haemodynamic responses during trans-sphenoidal surgery.

Current concepts in retrobulbar anesthesia

Recently there have been major advances in the field of retrobulbar anesthesia. New agents which allow prolonged anesthesia and akinesia have been introduced. Several new techniques to administer retrobulbar anesthesia have been developed. The toxicity of local anesthetics and the complications arising from such injections have been studied, and ways to avoid and manage them have been expanded.