Immediate Use of Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea Following Transsphenoidal Pituitary Surgery: A Case Series

American Rhinologic Society expert practice statement part 2: Postoperative precautions and management principles following endoscopic skull base surgery

The goal of this American Rhinologic Society expert practice statement (EPS) is to summarize the best available evidence regarding postoperative precautions for patients following endoscopic skull base surgery for intradural pathology. These topics include the administration of postoperative nasal hygiene; patient mobilization and activity level; the resumption of continuous positive airway pressure in patients with obstructive sleep apnea; and the timing and capacity with which a patient may be subjected to barotrauma, such as air travel postoperatively. This EPS was developed following the recommended methodology and approval process as previously outlined. Given the diverse practices and limited agreement on the accepted principles regarding postoperative precautions for patients following skull base surgery, this EPS seeks to summarize the existing literature and provide clinically relevant guidance to bring clarity to these differing practice patterns. Following a modified Delphi approach, four statements were developed, all of which reached consensus. Because of the paucity of literature on these topics, these statements represent a summation of the limited literature and the experts' opinions. These statements and the accompanying evidence are summarized below, along with an assessment of future needs.

Postoperative Obstructive Sleep Apnea Management Following Endoscopic Pituitary Surgery: A Systematic Review

OBJECTIVE

There is currently no consensus on the appropriate timing of noninvasive positive pressure ventilation (PPV) resumption in patients with obstructive sleep apnea (OSA) after endoscopic pituitary surgery. We performed a systematic review of the literature to better assess the safety of early PPV use in OSA patients following surgery.

METHODS

The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases in English were searched using the keywords: "sleep apnea," "CPAP," "endoscopic," "skull base," "transsphenoidal" and "pituitary surgery." Case reports, editorials, reviews, meta-analyses, unpublished and abstract-only articles were all excluded.

RESULTS

Five retrospective studies were identified, comprising 267 patients with OSA who underwent endoscopic endonasal pituitary surgery. The mean age of patients in four studies (n = 198) was 56.3 years (SD = 8.6) and the most common indication for surgery was pituitary adenoma resection. The timing of PPV resumption following surgery was reported in four studies (n = 130), with 29 patients receiving PPV therapy within two weeks. The pooled rate of postoperative cerebrospinal fluid leak associated with PPV resumption was 4.0% (95% CI: 1.3-6.7%) in three studies (n = 27) and there were no reports of pneumocephalus associated with PPV use in the early postoperative period (<2 weeks).

CONCLUSIONS

Early resumption of PPV in OSA patients after endoscopic endonasal pituitary surgery appears relatively safe. However, the current literature is limited. Additional studies with more rigorous outcome reporting are warranted to assess the true safety of re-initiating PPV postoperatively in this population.

The safety of respiratory positive pressure support immediately following pediatric tonsillectomy

INTRODUCTION

Adenotonsillectomy is the first-line treatment for pediatric obstructive sleep apnea (OSA). The postoperative course may be complicated by hypoxia, requiring intervention. Positive pressure respiratory support (PPS) could be used to bridge the postoperative period and avoid invasive mechanical ventilation; however, the safety of PPS following tonsillectomy has not been established. Objective To review the incidence of complications and risk factors associated with PPS use immediately after tonsillectomy.

METHODS

A retrospective cohort study between 2015 and 2020 of patients who underwent tonsillectomy and were admitted to the pediatric intensive care unit at a single healthcare system.

RESULTS

Seven hundred eighty patients met inclusion criteria, including 101 patients treated with PPS immediately following surgery. A similar number of patients were diagnosed with severe OSA in each group prior to surgery. One patient in the PPS cohort developed pneumomediastinum and pneumothorax. Eleven patients (12%) in the PPS group and 18 patients (2%) in the non-PPS group developed life-threatening complications, defined as pneumothorax/pneumomediastinum, re-intubation, post-tonsillectomy bleeding that required surgical intervention, pulmonary edema and death, and all occurred in patients who had not used PPS at baseline. Regression analysis identified body mass index, surgical technique, and PPS use to be associated with increased odds of life-threatening complications.

CONCLUSION

Our study suggests that PPS is generally safe to use. New-onset PPS is associated with increased odds of life-threatening complications, likely reflecting a severe post-surgical clinical course.

Optimizing Perioperative Care in Transsphenoidal Pituitary Surgery: Considerations for Enhanced Recovery After Surgery

OBJECTIVE

To identify key recommendations for maximizing the efficiency and efficacy of perioperative care in transsphenoidal pituitary surgery.

METHODS

The authors performed a comprehensive literature search of Enhanced Recovery After Surgery protocols implemented for patients undergoing transsphenoidal adenomectomy (TSA); individual recommendations were abstracted, and the evidence base thoroughly reviewed.

RESULTS

The authors identified 19 individual recommendations pertinent to the care of patients undergoing TSA, which were subdivided into preoperative (n=6), intraoperative (n=6), and postoperative (n=7) interventions. Key factors recommended for minimizing length of stay, preventing readmission, and improving patient outcomes included comprehensive patient education, multidisciplinary evaluation, avoidance of routine lumbar drain placement and nasal packing, and rigorous postoperative monitoring of pituitary function and salt-water imbalances. The overall level of evidence for 7/19 (37%) implemented recommendations was found to be low, suggesting a need for continued research in this patient population.

CONCLUSION

Several key interventions should be considered in the development of Enhanced Recovery After Surgery protocols for TSA, which may aid in further decreasing length of stay and promoting positive patient outcomes.

Postoperative protocols following endoscopic skull base surgery: An evidence-based review with recommendations

BACKGROUND

Postoperative management strategies for endoscopic skull base surgery (ESBS) vary widely because of limited evidence-based guidance.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from January 1990 through February 2022 to examine 18 postoperative considerations for ESBS. Nonhuman studies, articles written in a language other than English, and case reports were excluded. Studies were assessed for levels of evidence, and each topic's aggregate grade of evidence was evaluated.

RESULTS

A total of 74 studies reporting on 18 postoperative practices were reviewed. Postoperative pain management, prophylactic antibiotics, and lumbar drain use had the highest grades of evidence (B). The literature currently lacks high quality evidence for a majority of the reviewed ESBS precautions. There were no relevant studies to address postoperative urinary catheter use and medical intracranial pressure reduction.

CONCLUSION

The evidence for postoperative ESBS precautions is heterogeneous, scarce, and generally of low quality. Although this review identified the best evidence available in the literature, it suggests the urgent need for more robust evidence. Therefore, additional high-quality studies are needed in order to devise optimal postoperative ESBS protocols.

Anesthetic management during transsphenoidal pituitary surgery

PURPOSE OF REVIEW

Pituitary adenoma resections comprise a large proportion of intracranial tumor surgeries. This patient population is medically and physiologically complex and requires careful perioperative planning and management on the part of the anesthesiologist. This review will summarize anesthetic considerations for pre, intra, and postoperative management of patients undergoing transsphenoidal pituitary surgery.

RECENT FINDINGS

An endoscopic approach is favored for patients undergoing transsphenoidal pituitary surgery. Hemodynamic monitoring is important to maintain cerebral perfusion and avoid risk of bleeding; however, 'controlled' hypotension may have adverse effects. Multimodal analgesia is effective for the management of postoperative pain and may reduce the risk of postoperative complications, including respiratory depression and postoperative nausea and vomiting.

SUMMARY

Transsphenoidal pituitary surgery is a preferred approach for the surgical management of nonfunctioning pituitary macroadenomas with symptoms of mass effect and functioning adenomas that cannot be otherwise managed medically. Understanding tumor pathologies and systemic effects are essential for preoperative planning and providing safe anesthetic care during the perioperative period.

Safety of restarting continuous positive airway pressure (CPAP) therapy following endoscopic endonasal skull base surgery

Objectives

Patients with obstructive sleep apnea (OSA) are at increased risk of perioperative and postoperative morbidity. The use of continuous positive airway pressure (CPAP) in the perioperative period may be of potential benefit. However, among patients who have undergone endonasal skull base surgery, many surgeons avoid prompt re‐initiation of CPAP therapy due to the theoretical increased risk of epistaxis, excessive dryness, pneumocephalus, repair migration, intracranial introduction of bacteria, and cerebrospinal fluid (CSF) leak. The objective of this article is to review the most up‐to‐date literature regarding when it is safe to resume CPAP usage in the patient undergoing endonasal skull base surgery.

Data Sources and Methods

This review combines the most recent literature as queried through PubMed regarding the safety of CPAP resumption following endonasal skull base surgery.

Results

Recent surveys of skull base surgeons demonstrate little consensus regarding the post‐operative management of OSA. Recent cadaveric studies suggest that approximately 85% of delivered CPAP pressures are transmitted to the sphenoid sinus. Further, at frequently prescribed CPAP pressure settings, common sellar reconstruction techniques maintain their integrity while preventing very little transmission of pressure into the sella. In small retrospective case series, patients with OSA who received CPAP immediately following transsphenoidal pituitary surgery had similar rates of surgical complications as OSA patients who did not receive CPAP in the immediate post‐operative period. Concerns of re‐initiating CPAP too early, such as the development of pneumocephalus, rarely develop.

Conclusions

There remains a paucity of objective data regarding when it is safe to resume CPAP following endonasal skull base surgery. Recent cadaveric studies and small retrospective case series suggest that it may be safe to resume CPAP earlier than is often practiced following endonasal skull base surgery.

There is no consensus regarding the time course of when it is safe to resume CPAP therapy following endonasal skull base surgery.

Following endonasal skull base surgery there are potentially unique risks of initiation of CPAP including epistaxis, excessive nasal crusting/drying, graft migration, pneumocephalus, CSF leak, and intracranial introduction of bacteria.

Cadaveric modeling suggests that only a fraction of the delivered CPAP pressure is actually transmitted into the sella, and even the simplest sellar repair techniques can withstand low to moderate pressures.

Small case series' do not demonstrate increased rate of post‐operative complications in patients with OSA who received CPAP immediately after surgery.

The decision to start CPAP postoperatively must be tailored to each patient based on the severity of his/her OSA, intraoperative findings, and the type of skull base repair employed.

Cerebrospinal Fluid Leak after Transsphenoidal Surgery: A Systematic Review and Meta-analysis

Background Cerebrospinal fluid (CSF) leak is widely recognized as a challenging and commonly occurring postoperative complication of transsphenoidal surgery (TSS).

The primary objective of this study is to benchmark the current prevalence of CSF leak after TSS in the adult population.

Methods The authors followed the PRISMA guidelines. The PubMed, Embase, and Cochrane Library databases were searched for articles reporting CSF leak after TSS in the adult population. Meta-analysis was performed using the Untransformed Proportion metric in OpenMetaAnalyst. For two between-group comparisons a generalized linear mixed model was applied.

Results We identified 2,408 articles through the database search, of which 70, published since 2015, were included in this systematic review. These studies yielded 24,979 patients who underwent a total of 25,034 transsphenoidal surgeries. The overall prevalence of postoperative CSF leak was 3.4% (95% confidence interval or CI 2.8–4.0%). The prevalence of CSF leak found in patients undergoing pituitary adenoma resection was 3.2% (95% CI 2.5–4.2%), whereas patients who underwent TSS for another indication had a CSF leak prevalence rate of 7.1% (95% CI 3.0–15.7%) (odds ratio [OR] 2.3, 95% CI 0.9–5.7). Patients with cavernous sinus invasion (OR 3.0, 95% CI 1.1–8.7) and intraoperative CSF leak (OR 5.9, 95% CI 3.8–9.0) have increased risk of postoperative CSF leak. Previous TSS and microscopic surgery are not significantly associated with postoperative CSF leak.

Conclusion The overall recent prevalence of CSF leak after TSS in adults is 3.4%. Intraoperative CSF leak and cavernous sinus invasion appear to be significant risk factors for postoperative CSF leak.

Delayed CPAP-Induced Pneumocephalus and Meningitis Posttranssphenoidal Surgery

Transsphenoidal surgery (TSS) is a frequently used technique to remove pituitary adenomas. Rare complications of TSS include development of postoperative pneumocephalus. Many patients undergoing TSS also suffer from obstructive sleep apnea (OSA) and thus require positive pressure ventilation. The exact timing of when to safely reintroduce the CPAP machine in this subset of patients is presently not exactly known but is most often cited as being two to four weeks postoperatively. In this case, we describe the story of a 69-year-old female who underwent TSS for a nonsecreting pituitary adenoma in April 2012 and went on to develop pneumocephalus five weeks postoperatively after reintroduction of her CPAP machine. This is the latest presentation of pneumocephalus after reintroduction of CPAP documented in present literature. The case reopens the debate as to how many weeks postoperatively positive pressure ventilation should be withheld to prevent the development of pneumocephalus in patients having undergone TSS with simultaneous OSA.

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.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Perioperative management of endoscopic transsphenoidal pituitary surgery

The contemporary embrace of endoscopic technology in the approach to the anterior skull base has altered the perioperative landscape for patients requiring pituitary surgery. Utility of a multi-disciplinary unit in management decisions facilitates the delivery of optimal care. Evolution of technology and surgical expertise in pituitary surgery mandates ongoing review of all components of the care central to these patients. The many areas of potential variability in the pre, intra and post-operative timeline of pituitary surgery are readily identifiable. Core undertakings and contemporary controversies in the peri-operative management of patients undergoing endoscopic transsphenoidal pituitary surgery are assessed against the available literature with a view to providing guidance for the best evidence-based practice.

Clinical side effects of continuous positive airway pressure in patients with obstructive sleep apnoea

CPAP is considered the gold standard treatment in OSA and is highly efficacious in controlling OSA symptoms. However, treatment effectiveness is limited because of many factors including low adherence due to side effects. This review highlights the range of side effects associated with CPAP therapy in patients with OSA. This information is important for the initiation of patients onto CPAP as well as their continued care while on treatment, given the increase in non-medically supervised CPAP care models in use globally.