European Journal of Cardiovascular Medicine

Long-term cognitive effects of anaesthetics on psychiatric patients are very important to know, but not many studies have been done on them. Psychiatric patients are more likely to have problems during surgery because their bodies don't react  well to stress [1]. Because psychiatric patients are weak and easily hurt, it is very important to look into the long-term effects of anesthetics on their brains. Psychiatric patients are more likely to be affected by anesthetics side effects because they have more than one medical condition. It is hard to judge changes in thinking that are caused by anesthesia, and mental diseases make it even harder [2]. Even with these problems, it is very important to know what the long-term cognitive effects of anesthesia are on psychiatric patients in order to improve patient outcomes and professional care. Therapeutic decision-making and informed consent are affected when people don't know how anaesthetic drugs affect the cognitive abilities of psychiatric patients. Clinicians have to weigh the benefits of anaesthesia against the chance that psychiatric patients will lose more of their cognitive abilities. The results of this study can also be used to make customized anesthetic protocols and treatments that will help psychiatric patients think more clearly during medical procedures.

Objectives of the Study

• Determine if frequent anaesthetics have enduring cognitive effects on psychiatric
• Evaluate the frequency and severity of cognitive impairment in this sample after anaesthesia exposure.
• Anaesthesia increases the likelihood of cognitive impairment in psychiatric patients; hence risk factors must be identified.

Background Information on Anaesthetic Agents

This study used intravenous and inhalational anaesthetics, which are clinically used. Intravenous anaesthetics like propofol and benzodiazepines help mental illness patients undergoing elective surgeries and induce anaesthesia [3]. These medications boost central nervous system inhibitory neurotransmission via GABA receptors, causing sedation and hypnosis. Inhaled anaesthetics like desflurane and sevoflurane are used to maintain general anaesthesia during surgery of a psychiatric patient . These gaseous chemicals affect glutamate and GABA receptors to create reversible forgetfulness and drowsiness [4]. Inhalational anaesthetics don't influence cognitive function in most people, but further research is needed, especially in vulnerable groups such as those with mental illness [5]. Prior research suggests that intravenous and inhalational anaesthetics may affect cognitive impairment in the initial postoperative period, although the exact type and duration are unknown [6]. Additionally, long-term mental illness patients' cognitive impacts of anaesthesia are seldom studied. By reviewing the cognitive consequences of these medicines, this study hopes to fill this information gap and improve clinical treatment for Psychiatric patients who need anaesthesia.

Compared to patients experiencing neurotic depression or anxiety, dissociative disorder sufferers need less anesthetic drugs. Just as acute functional psychosis takes less time than chronic psychosis, organic psychosis also requires less time than acute functional psychosis. [7]. These medications are vital for patient comfort and safety during these surgical procedures, but increasingly, there is evidence of cognitive consequences in psychiatric patients [8]. This literature review synthesises research on the cognitive effects of anaesthetic drugs on psychiatric patients, identifies gaps in knowledge, and discusses theoretical frameworks or mechanisms.

Cognitive Effects of Anaesthetic Agents in Psychiatric Patients

Multiple studies have examined how anaesthetic medications affect psychiatric patients' cognition, each with its own technique and results. [9,10] observed no statistically significant differences in cognitive outcomes between psychiatric patients who underwent local anaesthesia for modest surgical procedures and those who did not. Patient-specific variables affect cognitive results, however the study found a subgroup of people with pre-existing cognitive deficits whose symptoms exacerbated after anaesthesia. A comprehensive investigation [11] examined the cognitive effects of common anaesthetics used in psychiatric patients . The review found mixed results, but it stressed the need for more research in psychiatric patients to understand anaesthetics' cognitive impacts and mechanisms.

Gaps in Knowledge

The cognitive effects of anaesthetics on psychiatric patient have been extensively studied, although many questions remain. Few research has examined the long-term cognitive effects of frequent or prolonged anaesthesia. To determine if psychiatric patients’ cognitive abnormalities remain and identify risk factors for persistent cognitive impairment, longitudinal studies with prolonged follow-ups are needed. Some researchers disagree on which cognitive domains anaesthesic drugs impact most. Anaesthesia affects memory, focus, and executive function in certain trials but not others. Standardised neuropsychological tests and cognitive batteries are needed to measure cognition . Few studies support neuroinflammation, neurotransmitter dysregulation, and neuronal death ideas. Anaesthetics' effects on psychiatric patients’ cognition should be studied using neuroimaging, biomarker analysis, and animal models.

Theoretical Frameworks or Mechanisms Underlying Cognitive Effects

Psychiatric patients’ cognitive consequences after anaesthetics are explained by numerous perspectives. The cholinergic theory states that anaesthetics impair cognition by disrupting brain cholinergic neurotransmission. The glutamatergic hypothesis posits that anaesthetics interact with glutamatergic neurotransmission to impact synaptic plasticity and cognition. Glutamate, the brain's excitatory neurotransmitter, regulates synaptic transmission and plasticity. The cognitive effects of anaesthetics in psychiatric patients are linked to glutamatergic dysfunction, which is linked to many mental diseases for instance, schizophrenia and severe depression. Anaesthetic medications’ cognitive effects in psychiatric populations are linked to neuroinflammation and neurotransmitter imbalance. CNS microglia are immunological cells. They can cause inflammation under anaesthesia. It releases reactive oxygen species and pro-inflammatory cytokines. Chronic neuroinflammation is linked to Alzheimer's and Parkinson's, therefore anaesthetic exposure, neuroinflammation, and cognitive impairment in psychiatric patients may be linked. These theoretical frameworks help explain the cognitive effects of anaesthetic drugs in psychiatric populations, but further research is needed to confirm these assumptions and identify the neurobiological processes involved. Future research on anaesthetic medications’ cognitive consequences in psychiatric patients can help amend clinical practice guidelines for this sensitive population.

Figure 1 Psychiatric disorders and mechanisms (Source: [12])

Study Design

Anaesthetic medications’ long-term cognitive effects in psychiatric patients were examined in this retrospective cohort study. Due to their use of medical records, retrospective cohort studies can help determine a link between anaesthetic medications and long-term cognitive impairment. Long-term examination of cognitive outcomes enables scientists to comprehend the duration and variability of anaesthetic effects.

Participants and Setting

The study included psychiatric  patients of MGMMC & LSK Hospital, Kishanganj, Bihar ; undergoing anaesthetic  procedures. A past medical or surgical procedure involving anaesthetic medications and a mental illness history were required. Patients with substance abuse, serious neurological comorbidities, or inadequate medical records for cognitive examination were ineligible. The participating hospital collected data from inpatient and outpatient psychiatric units. Eligible patients were identified and clinical data was gathered from computerised and paper medical records.

Data Collection Methods

Psychiatric patients who met inclusion criteria had their medical records thoroughly reviewed for this study.  Researchers examined medical records to establish the patient's demographics (gender, age, etc.), mental health diagnosis, anaesthetic exposure (kind, dose, duration), and cognitive effects. Cognitive findings were tested using traditional neuropsychological measures of processing speed, executive function, memory, and attention. The MMSE, MoCA, TMT, and RAVLT were popular neuropsychological tests. Tests were chosen for reliability, validity, and cognitive domain relevance. This research met all ethical criteria laid down by MGMMC and LSK Hospital's Institutional Review Board approval. Informed consent was waived or not sought per institutional policy. Storing anonymized data protected patient data. Cognitive outcome analysis used multivariate regression to account for confounding variables to reduce bias. The study followed strict methodological requirements to improve patient care by revealing the cognitive consequences of anaesthesia on psychiatric patients.

Description of the Sample

The study included 100 anaesthetized mental illness patients from MGM Medical College and LSK Hospital, Kishanganj, Bihar, India. The sample included schizophrenia, major depressive disorder, bipolar affective disorder, and anxiety disorders. With a mean of forty-two (SD= twelve), the sample's ages ranged from twenty to sixty-five. This study's 60% female participants were typical of psychiatric populations. 70% of patients had undergone spinal anaesthesia & general anaesthesia, whereas 30% had minor surgical procedures or diagnostics.

Table 1 Demographic table

Analysis of Cognitive Effects

 Patients exposed to anaesthesia , performed significantly lower on cognitive tests. Anaesthetic-exposed psychiatric patients fared worse on memory, attention, and executive function tests. Patients exposed to spinal  anaesthesia & general anaesthesia, scored lower on the RAVLT and TMT, demonstrating substantial verbal memory and processing speed impairments. A high Trail Making Test Part B (TMT-B) score and an inaccurate Stroop Color-Word test result revealed that minor procedure patients who underwent local anaesthesia had attention and executive function issues.

Statistical Findings

Table 2: Cognitive Performance of Anaesthesia-Exposed and Non-Exposed Patients

Anaesthesia-exposed patients performed worse in several cognitive domains, according to independent samples t-tests. Anaesthesia exposure was associated with poorer verbal memory, slower processing speed, impaired attention, and compromised executive function compared to non-exposed patients (RAVLT: t(50) = -4.67, p < 0.001, TMT: t(50) = 3.12, p = 0.003, TMT-B: t(50) = 2.46, p = 0.012, and Stroop Test: t(50) = 2.14, p = 0.028. Psychiatric patients are more susceptible to the cognitive effects of anaesthesia, therefore our results demonstrate the importance of closely monitoring and providing individualised treatments to decrease cognitive impairment.

Anaesthetic exposure in psychiatric patients is linked to adverse cognitive outcomes, says this study. Anaesthetic-exposed individuals had significantly lower memory, attention, processing speed, and executive function than non-exposed patients. Because cognitive deficits are so widespread in psychiatric patients, these findings suggest that anaesthesia may have cognitive effects. Given that cognitive impairments can significantly impact treatment outcomes and quality of life, psychiatric patients need specialised interventions to lower cognitive risks and improve care.

Table 3 Comparison table

The comparative table provides insightful summaries of four studies on anaesthetic medications’ cognitive effects on psychiatric patients. The present retrospective cohort study included 100 participants .The present study and Study 1, both demonstrated significant cognitive deficits connected to anaesthetic exposure in a larger group. Study 2, a prospective longitudinal investigation, found no cognitive changes between anaesthetized and non-anesthetized individuals. This shows how complex these effects are and how research design and patient characteristics may have contributed. Study 3, a systematic review, noted the conflicting outcomes between studies and the need for more research on cognitive consequences and causes. These investigations show that rigorous approaches and interdisciplinary collaboration are needed to completely understand the cognitive risks of anaesthetic medicines in psychiatric patients.

Limitations of the Study

This study's findings should be interpreted with certain cautions. First, selection bias and the study's retroactive approach may limit its applicability. Due to medical record data collection, the results may have been based on inaccurate or insufficient reporting of critical clinical variables. The study size of 100 individuals disallowed subgroup analysis by psychiatric diagnosis or anaesthetic type, which may have reduced statistical power to detect modest or moderate effects. Finally, because there was no control group of psychiatric patients without surgeries, future research needs stronger methodological designs to clarify cognitive outcomes.

Future Research

Future research should address the limitations of this study and clarify the complex relationship between anaesthetic exposure and cognitive function in psychiatric illness. Larger, longer-term prospective longitudinal investigations are needed to discover whether cognitive deficits persist and how they develop following anaesthesia as well as risk factors for chronic cognitive impairment exist. Mechanistic studies combining biomarker analysis and cutting-edge neuroimaging can also help explain anaesthetics' cognitive effects. Evidence-based anaesthetic management guidelines for psychiatric patient can be guided by comparative effectiveness research on anaesthetic medicines and administration techniques to improve patient outcomes and treatment quality.  

A retrospective cohort study assessed the long-term cognitive effects of anaesthetic medicines on psychiatric  patients of MGMMC & LSK Hospital, Kishanganj , Bihar; undergoing surgeries. Memory, attention, processing speed, and executive function were impaired in anaesthetized patients. Anaesthesia hazards in psychiatric patients are highlighted by these cognitive deficits. These patients need close monitoring and targeted therapies to limit cognitive hazards and give the best care. This study is significant because it improves our understanding of anaesthetic drugs' cognitive impact on psychiatric patients . By showing the long-term effects of anaesthesia on this vulnerable population, the study will improve clinical practice and raise awareness of its cognitive hazards. Personalised anaesthesia management regimens for psychiatric patients are needed to avoid adverse effects and maximise cognition preservation. The study also stresses the need of psychiatry, neuropsychology, and anesthesiology working together to test and manage cognitive functions in mentally ill anaesthetized patients. Using scientifically recognised anaesthetic  management to minimise cognitive risks and routine cognitive evaluations can improve success rates in psychiatric patients undergoing anaesthesia . Anaesthetic medicines are crucial for mental health  and cognitive outcomes in psychiatric patients undergoing surgery, according to this study. More studies are needed to understand cognitive impairment after anaesthesia and find effective treatments to lessen cognitive dangers and improve long-term results for this vulnerable group.

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