Perioperative Complications in Elderly Patients Undergoing Intracranial Surgery—A Prospective Observational Study

Abstract

Background

Elderly patients undergoing intracranial surgery are at high risk of perioperative complications due to physiological changes, comorbidities, and surgical complexity. This study evaluates the incidence and nature of perioperative complications in this population.

Materials and Methods

A prospective observational study was conducted on 150 elderly patients (≥60 years) undergoing elective or emergency intracranial surgery. Preoperative variables, intraoperative events, and postoperative complications were recorded. Statistical tests, including chi-square and t-test, were applied, with a significance threshold of p < 0.05. Univariate and multivariate analyses were performed to identify predictors of poor outcomes.

Results

The median age was 65 years (range: 60–82), with 56.7% male patients. Hypertension (59.3%) was the most common comorbidity, and brain tumors (47.3%) were the most frequent diagnosis. Emergency surgeries comprised 30.7%, and 95.3% received general anesthesia. Intraoperative complications included hemodynamic fluctuations (32%), brain bulge (26.7%), and arrhythmias (10%). Blood loss >1,000 mL occurred in 16.7%, with 29.3% requiring transfusion. Postoperatively, electrolyte abnormalities (49.3%) were most common, followed by neurological (23.3%) and cardiovascular (18.7%) complications. The mean hospital stay was 8.1 ± 7.0 days. In-hospital mortality was 20%. Multivariate analysis identified vascular surgery, poor preoperative Glasgow coma scale (GCS), intraoperative hemodynamic instability, and postoperative cardiovascular and neurological complications as significant predictors of poor outcomes (p < 0.05).

Conclusion

Elderly patients undergoing intracranial surgery are at risk of major perioperative complications. Identifying high-risk factors such as vascular pathology, poor GCS, neurological or cardiovascular complications, and hemodynamic instability can aid in optimizing perioperative management and improving outcomes.

 

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Keywords

elderly - intracranial surgery - perioperative complications - neurosurgical outcomes

Introduction

With increasing life expectancy, more elderly patients are undergoing surgery, including neurosurgical procedures. Comorbidities such as diabetes mellitus, hypertension, ischemic heart disease, and chronic obstructive airway disease complicate perioperative management, increasing the risk of respiratory failure, ventilator-associated pneumonia, sepsis, renal failure, and metabolic disturbances.[1] Cardiovascular events, such as myocardial infarction and cardiac death, occur in 1 to 5% of elderly patients undergoing noncardiac surgery, worsening outcomes.[2]

Electrolyte imbalances are common in the elderly due to impaired renal function and conditions such as syndrome of inappropriate antidiuretic hormone secretion (SIADH) and diabetes insipidus.[3] [4] Diabetes mellitus exacerbates perioperative complications, including infections, renal failure, and cerebrovascular events, while hyperglycemia worsens brain trauma outcomes.[5] [6] Hypertension heightens the risk of intracranial hemorrhage and cerebral edema.[7] Venous thromboembolism is another concern, with an increased incidence of deep vein thrombosis and pulmonary embolism in the elderly, requiring careful anticoagulation management.[8]

Renal impairment due to aging predisposes patients to hyperkalemia, infections, and bleeding, especially in neurosurgical cases requiring mannitol and contrast agents.[9] Neurosurgical procedures may involve significant bleeding, necessitating transfusions that elevate infection risks.[10] [11] Gastroesophageal reflux disease increases aspiration risk, while decreased muscle mass and bone density heighten positioning-related complications.[12] [13]

Despite studies on specific neurosurgical conditions, data on perioperative complications in elderly craniotomy patients remain limited. This prospective observational study aims to assess the incidence, characteristics, and risk factors of intraoperative and postoperative complications in elderly patients undergoing intracranial surgery.

 

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Materials and Methods

Study Design and Population

This prospective observational study was conducted at a Neurosciences Centre, over a period of 1 year and 7 months. Patients aged ≥60 years scheduled for elective or emergency craniotomy procedures—including pituitary tumors, aneurysms, arteriovenous malformations (AVMs), supratentorial and infratentorial tumors, subdural and intracranial hematomas, decompressive craniectomy, and other neurosurgical interventions—were included. Patients aged <60 years were excluded.

 

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Preoperative and Intraoperative Variables

Preoperative assessments included demographic details, American Society of Anesthesiologists (ASA) physical status classification, medical history, airway evaluation, and relevant laboratory and radiological investigations. Intraoperative parameters recorded were induction technique, airway management, type of anesthesia (general or regional), patient positioning, estimated blood loss, volume of fluid and blood products administered, hemodynamic fluctuations (defined as a ≥20% increase or decrease in blood pressure [BP] or heart rate from baseline), and intraoperative complications such as brain bulge, sudden hemorrhage, or surgical difficulties noted by the operating team.

 

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Postoperative Monitoring and Complications

Postoperative care and decisions regarding intensive care unit (ICU) transfer were made at the discretion of the treating physician, based on individual patient needs. Patients were monitored for perioperative complications until discharge, including electrolyte disturbances such as hyponatremia (Na⁺ <135 mmol/L), hypernatremia (Na⁺ >145 mmol/L), hypokalemia (K⁺ <3.5 mmol/L), or hyperkalemia (K⁺ >5.5 mmol/L), which required medical management. Pulmonary complications included aspiration, atelectasis, pneumonia, pulmonary edema, or the need for reintubation or prolonged mechanical ventilation (more than 24 hours). Cardiovascular complications were defined as hypotension requiring inotropic support (mean arterial pressure <65 mm Hg or systolic BP <90 mm Hg with clinical symptoms), new-onset hypertension (systolic BP >180 mm Hg or diastolic BP >110 mm Hg), and arrhythmias. Neurological complications included hematoma, seizures, cerebrospinal fluid leak, hydrocephalus, meningitis, vasospasm, and venous infarcts. Metabolic complications included hyperglycemia requiring insulin therapy and hypothyroidism requiring thyroxine replacement.

 

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Outcome Assessment and Statistical Analysis

The Glasgow outcome scale (GOS) was documented at discharge. Patients were stratified into two age-based groups: Group A (<70 years) and Group B (≥70 years) for comparative analysis. Data were analyzed using Stata 11.2. Categorical variables were compared using the chi-square or Fisher's exact test, while continuous variables were analyzed using independent t-tests or Wilcoxon's rank-sum tests as appropriate. Univariate and multivariate logistic regression analyses identified risk factors associated with poor outcomes (GOS <3), with adjusted and unadjusted odds ratios (ORs) calculated. A p-value of <0.05 was considered statistically significant.

 

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Results

Preoperative Findings

A total of 150 patients aged ≥60 years underwent elective or emergency intracranial surgeries at AIIMS between December 2012 and June 2014. Eighteen patients were excluded due to a lack of consent or incomplete follow-up until hospital discharge. The median age of the cohort was 65 years (range: 60–82), with 85 (56.7%) males and 65 (43.3%) females. Hypertension (59.3%) was the most common comorbidity, followed by diabetes mellitus (19.3%), cardiovascular diseases (8%), and pulmonary diseases (6%). Brain tumors were the most common indication for surgery (47.3%), followed by vascular pathologies (20.7%), hematomas (15.3%), and other conditions (16.7%).

At presentation, 103 (68.7%) patients had a Glasgow coma scale (GCS) of 13 to 15, while 27 (18%) had a GCS ≤ 7. Signs of raised intracranial pressure (ICP) were noted in 66 (44%) patients. Elective surgeries were performed in 104 (69.3%) patients, while 46 (30.7%) underwent emergency procedures. Detailed demographic and preoperative characteristics are summarized in [Table 1].

Table 1 Demographic and preoperative characteristics

Patient profile	Frequency/amount (%) (n = 150
Mean age (y)a	65.4 ± 5.4 (60–82)
Age distribution (y)
≥70	41 (27.3%)
< 70	109 (72.7%)
Sex
Male	85 (58.5%)
Female	65 (41.5%)
Weight (kg)	61.1 ± 12.6 (30–110)
Body mass index (kg/m2)a	23.2 ± 4.1 (13.3–45.8)
ASA classification
ASA good (1 and 2)	107 (71.3%)
ASA poor (3 and 4)	43 (28.7%)
Comorbidities
Hypertension	89 (59.3%)
Diabetes mellitus	29 (19.3%)
Cardiovascular disease	12 (8.0%)
Pulmonary disease	9 (6.0%)
Others	12 (8.0%)
Hypothyroidism	8 (5.3%)
Chronic renal failure	4 (2.7%)
Diagnosis
Tumors	71 (47.3%)
Vascular lesions	31 (20.7%)
Hematoma	23 (15.3%)
Others	25 (16.7%)
Glasgow coma score
13–15	103 (68.7%)
8–12	20 (13.3%)
3–7	27 (18.0%)
Intracranial pressure
Raised	66 (44.0%)
Normal	84 (56.0%)

Abbreviation: ASA, American Society of Anesthesiologists.

Note: Age expressed in years (y); Body mass index calculated as weight in Kilograms divided bi height in meters squared (kg/m²).

 

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Intraoperative Findings

General anesthesia was administered in 143 (95.3%) patients, while local anesthesia was used in 7 (4.7%). The most common surgical position was supine (81.3%), followed by lateral (9.3%), prone (8%), and sitting (1.3%).

Significant intraoperative complications included brain bulge in 40 (26.7%) patients, hemodynamic fluctuations in 48 (32%), and arrhythmias in 15 (10%). Pulmonary complications, such as bronchospasm and increased airway pressure, occurred in 11 (7.3%) patients. Other issues, including hyperglycemia, hypothermia, and coagulopathy, were observed in 6 (4%) patients.

Extubation occurred in the operating room for 54 (36%) patients, while 96 (64%) were extubated in the ICU. The median duration of elective ventilation was 81 hours (range: 1–1,080). Detailed intraoperative parameters and complications are presented in [Table 2].

Table 2 Intraoperative parameters and complications

Intraoperative data	Frequency/amount (%) (n = 150)
Nature of surgery
Elective	104 (69.3%)
Emergency	46 (30.7%)
Mode of anesthesia
General	143 (95.3%)
Local	7 (4.7%)
Position
Supine	122 (81.4%)
Prone	12 (8.0%)
Lateral	14 (9.3%)
Sitting	2 (1.3%)
Fluid transfusion (mL)
< 2,000	35 (23.3%)
2,000–6,000	90 (60.0%)
> 6,000	25 (16.7%)
Blood loss (mL)
< 1,000	125 (83.3%)
1,000–2,000	18 (12.0%)
> 2,000	7 (4.7%)
Hemodynamic fluctuations	48 (32%)
Hypotension	27 (18.0%)
Hypertension	10 (6.7%)
Tachycardia	4 (2.7%)
Bradycardia	7 (4.6%)
Arrhythmias	15 (10.0%)
Pulmonary complications	11 (7.3%)
Other complications
Hyperglycemia, hypothermia, and coagulopathy	6 (4.0%)
Brain bulge	40 (26.7%)
Blood transfusion	44 (29.3%)
Duration of anesthesia (h)
< 3	15 (10.0%)
3–6	86 (57.3%)
> 6	49 (32.7%)

 

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Postoperative Findings

Electrolyte abnormalities were the most common postoperative complications (49.3%), followed by neurological (23.3%), cardiovascular (18.7%), pulmonary (15.3%), and metabolic (9.3%) complications. Neurological complications included diabetes insipidus (2.7%), meningitis (3.3%), hydrocephalus (3.3%), seizures (2.7%), vasospasm (3.3%), and postoperative hematoma (2%).

The mean hospital stay was 8 days (range: 1–45). A good outcome (GOS 4–5) was observed in 111 (74%) patients, while 39 (26%) had poor outcomes (GOS 1–3). Thirty patients (20%) died during hospitalization. Postoperative complications and clinical outcomes are summarized in [Table 3].

Table 3 Postoperative complications and outcomes

Parameters	Frequency/amount (%) (n = 150)
Postoperative ventilation	96 (64%)
Re-exploration	12 (8%)
Electrolyte abnormalities	74 (49.3%)
Hyponatremia	38 (25.3%)
Hypernatremia	12 (8%)
Hypokalemia	15 (10%)
Hyperkalemia	9 (6%)
Neurological complications	35 (23.3%)
Meningitis	5 (3.3%)
Hydrocephalus	5 (3.3%)
Vasospasm	5 (3.3%)
Diabetes insipidus	4 (2.7%)
Seizures	4 (2.7%)
Venous infarct	4 (2.7%)
Hematoma	3 (2%)
CSF rhinorrhea	2 (1.3%)
Cardiovascular complications	28 (18.7%)
Hypotension requiring inotropes	15 (10%)
New-onset hypertension	7 (4.7%)
Arrhythmias	6 (4%)
Pulmonary complications	23 (15.3%)
Metabolic complications	14 (9.3%)
Duration of ventilation (h)a	81.1 ± 160 (0–1,080)
Duration of hospital stay (d)a	8.1 ± 7.0 (1–45)
Glasgow outcome scale
Good	111 (74%)
Poor	39 (26%)
Death	30 (20%)

Abbreviation: CSF, cerebrospinal fluid.

Note: Duration of ventilation expressed in hours (h); Duration of hospital stay expressed in days (d).

 

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Risk Factor Analysis

Patients were stratified into two age groups: Group A (60–69 years, n = 109) and Group B (≥70 years, n = 41). Group B had a higher incidence of hypertension and poor ASA grade. However, the mortality rate was comparable (Group A: 19.2% vs. Group B: 21.9%).

Univariate analysis identified several factors significantly associated with poor GOS. Higher odds of poor outcomes were noted in patients with vascular pathologies (OR: 15.9, p = 0.001), lower preoperative GCS scores (GCS 3–7, OR: 19.9), emergency surgeries (OR: 5.5), raised ICP (OR: 6.94), excessive blood loss (>2,000 mL, OR: 8.27), failure of intraoperative extubation (OR: 34.7), and postoperative complications, particularly respiratory (OR: 63.6) and neurological (OR: 56.2) events.

Multivariate analysis identified independent predictors of poor GOS in elderly patients undergoing intracranial surgery. Low preoperative GCS scores (GCS 3–7, OR = 40.1; GCS 8–12, OR = 26.0) were the strongest predictors of poor outcomes. Neurological (OR = 40.85) and cardiovascular (OR = 13.3) complications significantly increased the risk of poor recovery. Patients with hemodynamic fluctuations (OR = 8.30) and vascular diagnoses (OR = 4.68) also exhibited higher odds of poor outcomes. The detailed findings are presented in [Table 4].

Table 4 Multivariate analysis of factors associated with poor Glasgow outcome scale

Parameter	Odds ratio	95% CI
Hemodynamic fluctuations	8.30	1.7–40.35
Vascular diagnosis	4.68	1.90–24.1
GCS 8–12	26	3.64–186.5
GCS 3–7	40.1	5.65–284.7
Neurological complications	40.85	7.8–214
Cardiovascular complications	13.3	2.68–16.1

Abbreviations: CI, confidence interval; GCS, Glasgow coma scale.

 

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Discussion

Our prospective observational study evaluated perioperative complications, surgical outcomes, and risk factors associated with poor prognosis in elderly patients undergoing intracranial surgery.

Preoperative Factors

Among preoperative factors, a low GCS score likely reflects severe baseline neurological compromise and impaired cerebral autoregulation, predisposing patients to secondary ischemic insults and poor recovery trajectories. Raised ICP can exacerbate perfusion deficits and increase the risk of intraoperative brain bulge and herniation. Vascular lesions—such as aneurysms, AVMs, or hematomas—pose technical challenges due to friable vessels and altered hemodynamics, especially in elderly brains with reduced compliance and impaired collateral circulation.[14] [15] [16] This explains the higher complication rates seen in vascular procedures in our cohort. Levy et al similarly noted poor outcomes in patients with low GCS at presentation despite aggressive intervention.[17] Age-related vascular fragility may help explain the higher mortality reported in elderly patients undergoing meningioma resection, as reported by Bateman et al[18] and Bartek et al,[19] and the poorer postoperative outcomes in patients >75 years noted by Proust et al.[20]

 

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Intraoperative Factors

Intraoperative hemodynamic fluctuations—particularly hypotension or hypertension beyond 20% of baseline—can critically affect cerebral perfusion in elderly patients, whose autoregulatory mechanisms are often compromised. Such instability may result in watershed infarcts or rebleeding in the postoperative period. Brain bulge, observed intraoperatively in over a quarter of patients, may reflect raised ICP or inadequate osmotic control, complicating surgical exposure and increasing the risk of parenchymal injury. Liberal fluid administration and transfusions can exacerbate cerebral edema and hemodilution, thereby worsening postoperative recovery. These findings are in line with prior studies by Abebe et al[21] and Mascha et al,[22] which underscored the prognostic significance of intraoperative instability.

 

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Postoperative Factors

The high rate of postoperative ventilation reflects both the severity of neurosurgical pathology and the physiological vulnerability of the elderly population. Prolonged mechanical ventilation may further predispose to pulmonary complications such as atelectasis or infection. Cardiovascular events—including hypotension necessitating inotropes and arrhythmias—likely represent dysautonomia, fluid shifts, and myocardial strain in this high-risk cohort, and were independently linked to poor outcomes.[23] [24] Electrolyte disturbances were also common, potentially driven by diuretic use, SIADH, or osmotic shifts postoperatively, and can significantly impact neurological recovery. Neurosurgical complications such as delayed hemorrhage or infarction further worsen prognosis, often necessitating re-exploration or prolonged ICU stay, as supported by Lee et al,[25] Lassen et al,[26] and Wang et al.[27]

Our study is one of the few to comprehensively evaluate perioperative complications in elderly patients undergoing intracranial surgery, including both elective and emergency cases, enhancing its real-world applicability. However, several limitations must be acknowledged: minor complications (e.g., postoperative nausea and vomiting) were not captured, and long-term outcomes beyond discharge were not assessed. The single-center design and limited sample size restrict generalizability, though the prospective nature offers valuable insights into this underrepresented group. Subgroup analyses (e.g., ≥70 years, supratentorial vs. infratentorial, elective vs. emergency) were exploratory and limited by smaller numbers, but still provide preliminary trends. Diagnosis-specific breakdowns within the vascular group were not captured in detail, which is a noted limitation.

 

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Conclusion

In elderly patients undergoing intracranial surgery, poor preoperative GCS, raised ICP, and vascular pathology were key predictors of poor outcomes. Intraoperative hemodynamic fluctuations and postoperative neurological and cardiovascular complications further increased the risk. Despite higher comorbidities in patients ≥70 years, mortality rates were similar across age groups. Early identification and management of high-risk factors can improve outcomes.

 

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Conflict of Interest

None declared.

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Publication History

Article published online:
15 September 2025