Neuroanesthesia

Workforce Challenges for the Neurosurgical Care of Brain Tumors in Low- and Middle-Income Countries: A Scoping Review

Limited neurosurgical workforces remain one of the critical problems experienced in low resource settings. Therefore, our study aims to explore and summarize the key challenges to neurosurgical care of brain tumors in terms of workforce in LMICs. A comprehensive literature search was conducted using Scopus, PubMed, CINAHL, and Google Scholar from inception to October 20, 2022. All extracted data were screened independently by 2 reviewers and thematically analyzed. We found and screened 3764 articles, of which 33 studies were included in our final analysis as per our inclusion criteria. Among the studies included, 33% highlighted the limited number of neurosurgeons, 39% emphasized the absence of specialized surgical teams, 7% pointed out a shortage of nursing staff, and 4% noted suboptimal anesthesia teams. The study uncovered the need for improved training programs in neuro-oncology (32%) and neuro-anesthesia (3%), as well as improved collaboration (32%), and multidisciplinary team structures (15%), are essential for tackling these workforce challenges and improving patient outcomes. It is crucial to implement targeted interventions and policy changes to address the barriers to the workforce in providing effective neurosurgical care to patients with brain tumors in developing countries. This might entail capacity building and training programs for healthcare professionals. Policymakers should consider allocating resources and funding for workforce development and making neurosurgical care a priority in healthcare plans.

The relationship between anti-seizures medications and metabolic acidosis in craniotomy operations: is topiramate or zonisamide the cause of metabolic acidosis?

BACKGROUND/AIM

The most commonly prescribed anti-seizures medications (ASMs) for the treatment of epilepsy are currently topiramate, zonisamide, lacosamide, carbamazepine and levetiracetam. The objective of this study was to examine the correlation between preoperative, intraoperative, and postoperative metabolic acidosis and the use of ASMs prior to craniotomy operations.

MATERIALS AND METHODS

This retrospective cross-sectional study evaluated patients who underwent intracranial surgery with craniotomy under general anaesthesia between May 2020 and April 2023 and used ASMs. The patients were classified into four groups based on the pharmacological mechanisms of action of the ASMs administered before intracranial surgery (Group-I, zonisamide or topiramate; Group-II, lacosamide; Group-III, carbamazepine; Group-IV, levetiracetam). Metabolic acidosis severity was defined based on base excess (BE) levels: mild (-3 to -5), moderate (-5 to -10), and severe (below - 10). The study investigated the correlation between ASMs and the severity of metabolic acidosis in preoperative, intraoperative, and postoperative blood gas measurements.

RESULTS

Out of 35 patients, 24 patients underwent intracranial surgery and 11 patients underwent epilepsy surgery. There were statistically significant differences in the severity of metabolic acidosis between preoperative (p < 0.001), intraoperative (p < 0.001) and postoperative (p = 0.01) groups. The preoperative mean BE of group-I was - 4.7, which was statistically lower than that of group-III (p = 0.01) and group-IV (p < 0.001). Intraoperatively and postoperatively, group-I had a mean BE of -7.5 and - 3.2, respectively, which was statistically lower than that of groups II (p = 0.007; p = 0.04), III (p = 0.002; p = 0.03), and IV (p < 0.001; p = 0.009). There was no statistically significant difference in BE between groups II, III and IV at all three time points. Group I had the lowest BE at all three time points. Intraoperative bicarbonate was administered to all patients in group I, whereas no intraoperative bicarbonate was required in the other groups. In group I, 50% of patients required postoperative intensive care.

CONCLUSION

The use of ASMs in patients undergoing surgery is important in terms of mortality and morbidity. Topirimat and zonisamide are ASMs that can cause preoperative, intraoperative and postoperative metabolic acidosis. Patients receiving topirimat or zonisamide are particularly susceptible to metabolic acidosis. Special care should be taken in the management of anaesthesia in patients receiving these drugs, and monitoring of the perioperative metabolic status is essential.

Review, analysis, and education of antiseptic related ocular injury in the surgical settings

Preoperative skin antiseptic preparation is the gold standard for prevention of surgical infection. However, improper use of antiseptics may lead to severe ocular damage. Currently, the most common surgical antiseptics can be divided into aqueous-based and alcohol-based disinfectants, with chlorhexidine and iodine/iodophors being the two major components. Chlorhexidine has a persistent antimicrobial effect and is resistant to neutralization by blood or organic products in surgical wounds. Nevertheless, due to its toxicity to the ears, meninges, and eyes, application of chlorhexidine should be prohibited in these surgical fields. Iodine/iodophor is better tolerated by the ocular surface and is the recommended antiseptic for ophthalmic or head and neck surgeries close to the periocular area. Alcohol is less pricey and has a rapid antiseptic effect, though its desiccating effect and flammability restrict the use in mucosal or laser surgeries. The single or combined use of these antiseptics may inadvertently induce severe ocular damage, especially during time-consuming head and neck surgeries with prone, hyperextension, or lateral tilt positions, or surgeries under general anesthesia. Apart from the choice of antiseptics, appropriate selection and attachment of bio-occlusive dressings are key to avoiding antiseptic-related ocular injuries. In this review, we provided a comprehensive summary of the characteristics of antiseptics used in surgical settings and the possible mechanisms and outcomes of antiseptic-related ocular injuries. The prevention, diagnosis, and acute management of these complications were also discussed.

The role of "Integrated Pulmonary Index" monitoring during morphine-based intravenous patient-controlled analgesia administration following supratentorial craniotomies: a prospective, randomized, double-blind controlled study

OBJECTIVE

Morphine is commonly used in post-operative analgesia, but opioid-related respiratory depression causes a general reluctance for its use. The "Integrated Pulmonary Index" is a tool calculated from non-invasively obtained respiratory and hemodynamic parameters. The aim of this prospective, randomized, double blind, and placebo-controlled study is to determine a more safe and effective dose for morphine in patient-controlled analgesia following supratentorial craniotomy using the "Integrated Pulmonary Index".

METHODS

This study included 60 patients (ASA I, II, and III). All patients used iv PCA for 24 h following supratentorial craniotomy. The PCA was set to administer a bolus dose of 1 mg morphine in Group 1 and 0.5 mg morphine in Group 2. The PCA contained placebo in Group 3 and patients received dexketoprofen 50 mg iv after awakening, repeated every 8 h. The IPI and NRS scores, total morphine consumption, and morphine related side-effects were recorded at 10 min, 1, 2, 6, 12, and 24 h post-operatively. The lowest IPI score, count of apnea, and desaturation events were recorded during the study period.

RESULTS

The IPI scores were similar among the groups. Although a statistically significant difference was not observed among the groups the lowest IPI scores were observed in Group 1; apnea and desaturation counts were also higher in Group 1. Statistically significant differences were not observed among the groups in terms of pain scores, but were lower in Groups 1 and 2 compared to Group 3.

CONCLUSION

Patient controlled analgesia with 0.5 mg morphine may be safe and effective for pain management following supratentorial craniotomies. Integrated pulmonary index can be used for detecting opioid-induced respiratory depression. Clinical Trials registration number: NCT02929147.