STUDY OF PERIOPERATIVE HEMODYNAMIC PARAMETERS IN ELDERLY PATIENTS UNDERGOING HIP SURGERY UNDER SPINAL ANESTHESIA AND COMPARISON BETWEEN FRAIL AND NON-FRAIL GROUPS

TITLE PAGE

CERTIFICATE

DECLARATION

ACKNOWLEDGEMENTS

TABLE OF CONTENTS

1. Introduction
2. Aims and Objectives
3. Review of Literature
4. Material and Methods
5. Observations and Results (Template)
6. Discussion
7. Conclusion
8. Summary
9. References

LIST OF ABBREVIATIONS

CHAPTER 1: INTRODUCTION

CHAPTER 2: AIMS AND OBJECTIVES

Primary Aim

Secondary Aim

Objectives

1. To assess preoperative frailty in elderly patients undergoing hip surgery using the Clinical Frailty Scale (CFS).
2. To record hemodynamic parameters (SBP, DBP, MAP, HR, SpO2) at standardized time points: pre-block baseline, immediately post-block, and every 5 minutes for 30 minutes intraoperatively, then every 15 minutes until end of surgery, and at 0, 15, 30, and 60 minutes postoperatively in PACU.
3. To determine the incidence, severity, and timing of intraoperative hypotension (defined as MAP <65 mmHg or a fall of >30% from baseline for >3 consecutive minutes) in both groups.
4. To record the need for vasopressor intervention (ephedrine, phenylephrine, or norepinephrine), total dose used, and incidence of bradycardia in both groups.
5. To compare block height achieved, time to peak block, and duration of motor and sensory block between frail and non-frail groups.
6. To document early postoperative adverse events (delirium, AKI, myocardial injury, prolonged PACU stay) in both groups.
7. To identify independent predictors of intraoperative hemodynamic instability in this population.

CHAPTER 3: REVIEW OF LITERATURE

3.1 The Elderly Surgical Patient and Hip Surgery

• Cardiovascular system: Reduced arterial compliance, increased systemic vascular resistance, diastolic dysfunction, decreased baroreceptor sensitivity, and blunted heart rate response to hypotension.
• Autonomic nervous system: Progressive autonomic dysfunction with aging reduces the ability to compensate for sudden hemodynamic changes.
• Fluid balance: Elderly patients frequently present with dehydration, reduced total body water, and impaired renal concentrating ability, predisposing to volume depletion.
• Pharmacokinetics: Increased sensitivity to local anesthetics, reduced protein binding, altered volume of distribution, and longer duration of drug action.

3.2 Spinal Anesthesia: Mechanism and Cardiovascular Effects

"Clinically, the most important effects of sympathetic blockade during spinal anesthesia are on the cardiovascular system. At all but the lowest levels of spinal blockade, some vasodilation will occur. Vasodilation is more marked on the venous than on the arterial side of the circulation, resulting in blood pooling in the venous capacitance vessels. This reduction in circulating blood volume is well tolerated at low levels of spinal anesthesia in healthy patients. With an increasing level of block, this effect becomes more marked, and venous return becomes gravity dependent. If venous return decreases too much, cardiac output and organ perfusion decline precipitously." - Goodman & Gilman's Pharmacological Basis of Therapeutics

• Systolic and diastolic blood pressure fall due to arteriovenous vasodilation and reduced venous return
• Mean arterial pressure falls proportionally
• Heart rate may initially remain compensatory but falls if cardiac accelerators are blocked
• Cardiac output falls due to reduced preload
• Cerebral blood flow can decrease: SA-induced hypotension may decrease regional cerebral blood flow (CBF) in elderly patients and those with preexisting hypertension. Minville et al. demonstrated a significant transient decrease of middle cerebral artery blood flow velocity and increased cerebral vascular resistance during hypotension from bupivacaine SA in elderly patients, implying a risk of reduced cerebral perfusion. (Miller's Anesthesia, 10e)

3.3 Intraoperative Hypotension During Hip Surgery Under SA

3.4 Frailty: Definition, Assessment, and Perioperative Relevance

1. Fried Phenotype (Physical Frailty Phenotype): Diagnosis requires ≥3 of the following: unintentional weight loss (>4.5 kg in past year), self-reported exhaustion, weakness (low grip strength), slow walking speed, and low physical activity. Pre-frailty is defined as 1-2 criteria. This phenotype strongly predicts postoperative delirium.
2. Deficit Accumulation Model (Frailty Index): A list of symptoms, signs, diseases, and disabilities scored binomially. The fraction of positive deficits from total surveyed yields the frailty index (e.g., 10/40 = 0.25).

3.5 Frailty and Hemodynamic Instability Under Anesthesia

3.6 Prevention and Management of SA-Induced Hypotension

• Dose minimization: Low-dose SA (bupivacaine 5-8 mg) is associated with significantly fewer hypotensive episodes in elderly patients.
• Unilateral spinal anesthesia: Hypobaric unilateral SA confines the block to the operative side, reducing the extent of sympathetic blockade.
• Fluid management: Pre-block crystalloid co-loading (500-1000 mL) is recommended, though evidence for pre-loading alone preventing hypotension is inconsistent. (Goodman & Gilman's; Miller's Anesthesia)
• Patient positioning: 10-15° head-down tilt or leg elevation increases venous return.
• Vasopressors: Ephedrine (mixed adrenergic agonist, 5-10 mg IV boluses) is the traditional choice because its venoconstrictive and chronotropic properties address the primary mechanism. Phenylephrine (pure alpha-agonist) and norepinephrine are alternatives, with norepinephrine offering both alpha and beta effects. Avoidance of pure alpha-agonists is preferred when heart rate is already low.
• Mechanical compression: Compression stockings on the uninjured leg reduce perioperative hypotension incidence in hip fracture patients (Kulachote et al., 2026).
• Sedation choice: Remimazolam is superior to dexmedetomidine for hemodynamic stability during SA in elderly orthopedic patients (Wang et al., 2025).
• Puncture level: Higher lumbar puncture levels (L2/L3) produce more extensive blocks and are associated with higher vasopressor requirements; L3/L4 or L4/L5 should be preferred.

CHAPTER 4: MATERIAL AND METHODS

4.1 Study Design

4.2 Study Setting

4.3 Study Duration

4.4 Sample Size Calculation

• Alpha = 0.05 (two-tailed)
• Power = 80%
• Expected difference in hypotension incidence: 30%
• Calculated minimum n = 60 per group (120 total)
• Accounting for 10% attrition: Target n = 132 patients (66 per group)

4.5 Study Population

1. Age ≥65 years
2. Scheduled for elective or emergency hip surgery (hip fracture fixation, hemiarthroplasty, total hip arthroplasty)
3. Planned spinal anesthesia as the primary anesthetic technique
4. ASA physical status I - III
5. Written informed consent (or consent from next of kin if patient incapacitated)

1. Patient refusal or inability to consent
2. Contraindications to spinal anesthesia: coagulopathy (INR >1.5, platelets <80,000), infection at puncture site, raised intracranial pressure, severe uncorrected hypovolemia, patient non-cooperation
3. Pre-existing severe cardiac arrhythmias or complete heart block
4. Severe aortic stenosis or hemodynamically significant valvular disease
5. Baseline SBP <90 mmHg or HR <50/min not attributable to medication
6. Allergy to local anesthetics
7. Previous lumbar spinal surgery at intended puncture site
8. American Society of Anesthesiologists Class IV or V

4.6 Frailty Assessment and Group Allocation

• Non-frail group: CFS 1-4 (Very fit, Well, Managing Well, Vulnerable)
• Frail group: CFS 5-8 (Mildly Frail, Moderately Frail, Severely Frail, Very Severely Frail)

4.7 Anesthetic Technique (Standardized Protocol)

• IV access secured (18G or 16G)
• Preoperative crystalloid loading: Ringer's lactate 10 mL/kg over 20-30 minutes before spinal puncture
• Baseline hemodynamic parameters recorded after 5 minutes of supine rest
• SpO2 monitoring, ECG, NIBP connected

• Patient positioned: lateral decubitus with operated side dependent for hip fractures/HA, or sitting for THA (as per surgeon preference and patient tolerance)
• Midline approach under strict asepsis, L3-L4 or L4-L5 interspace
• 25G or 26G Quincke spinal needle
• Drug: 0.5% hyperbaric bupivacaine - dose standardized at 8-10 mg (1.6-2 mL) for all patients, with the lower dose (8 mg) used if CFS ≥5 and/or weight <55 kg, as per pilot institutional data
• Fentanyl 25 mcg added intrathecally as adjuvant
• Patient positioned supine immediately after injection; sensory level tested every 2 minutes with cold sensation test (ice)

• NIBP every 3 minutes for first 20 minutes, then every 5 minutes until end of surgery
• Continuous ECG, SpO2
• EtCO2 if sedation administered

• Trigger for treatment: MAP <65 mmHg OR SBP <90 mmHg OR fall >30% from baseline
• First line: Ephedrine 6 mg IV bolus (repeat as needed, maximum 30 mg total)
• Second line: Phenylephrine 50-100 mcg IV bolus (if tachycardia with hypotension)
• Third line: Norepinephrine infusion 0.04-0.08 mcg/kg/min (if refractory)
• Atropine 0.6 mg IV for HR <45/min associated with hypotension
• Total vasopressor dose and number of interventions recorded

4.8 Parameters Recorded

• Age, sex, weight, height, BMI
• ASA classification
• CFS score and group allocation
• Comorbidities (hypertension, diabetes, cardiac disease, CKD, COPD)
• Current medications (antihypertensives, diuretics, beta-blockers, anticoagulants)
• Baseline hemoglobin, BUN, creatinine, serum albumin, BNP if available
• Baseline SBP, DBP, MAP, HR, SpO2

• SBP, DBP, MAP, HR, SpO2
• Time points: T0 (baseline, 5 min supine before block), T1 (immediately post-block, 1 min), T5, T10, T15, T20, T25, T30 (every 5 min for 30 min), then T45, T60, T-end (end of surgery)
• Sensory block level (dermatomal) at T5, T10, T20
• Motor block level (modified Bromage scale) at T10, T20
• Vasopressor requirement: drug, dose, timing, number of episodes
• Fluid administered (volume, type)
• Blood loss estimate
• Duration of surgery and anesthesia

• SBP, DBP, MAP, HR, SpO2 at: arrival (P0), 15 min (P15), 30 min (P30), 60 min (P60)
• Time to motor recovery (modified Bromage 0)
• Presence of nausea/vomiting, shivering
• Postoperative delirium screen (Confusion Assessment Method, CAM) at 6 and 24 hours
• AKI (creatinine rise >1.5x baseline at 48 h)
• Myocardial injury (troponin >99th percentile if clinically suspected)
• Length of PACU stay

4.9 Definitions

• Intraoperative Hypotension (IH): MAP <65 mmHg OR SBP <90 mmHg OR fall >30% from baseline, sustained for >3 consecutive minutes
• Severe Hypotension: MAP <65 mmHg for >12 consecutive minutes (as per Simonin et al.)
• Bradycardia: HR <45 beats/min
• High spinal block: Sensory level ≥T4
• Frailty: CFS ≥5 (Mildly frail or above)
• Non-frail: CFS 1-4

4.10 Statistical Analysis

• Continuous variables: Mean ± SD (normally distributed) or Median (IQR) (non-normal distribution), tested by Shapiro-Wilk test
• Categorical variables: Frequencies and percentages
• Between-group comparisons: Independent t-test or Mann-Whitney U test (continuous); Chi-square or Fisher's exact test (categorical)
• Hemodynamic trends over time: Repeated-measures ANOVA with Bonferroni post-hoc correction; comparison between groups by mixed-model ANOVA
• Predictors of intraoperative hypotension: Multivariate logistic regression including age, CFS, ASA class, baseline MAP, drug dose, puncture level, diuretic use, BUN/Cr ratio, and albumin
• Receiver operating characteristic (ROC) curve analysis for CFS as predictor of IH
• Statistical significance: p <0.05 (two-tailed)
• Software: SPSS version 26 or R version 4.x

4.11 Ethical Considerations

• IEC/IRB approval to be obtained before study commencement
• Written informed consent from all participants
• Patient confidentiality maintained; data coded and anonymized
• No additional invasive procedures; all monitoring is standard of care
• Vasopressor protocol is part of routine anesthetic management

CHAPTER 5: OBSERVATIONS AND RESULTS (PROFORMA)

Table 1: Demographic and Baseline Characteristics

Table 2: Intraoperative Hemodynamic Parameters at Successive Time Points (Mean ± SD)

Table 3: Incidence of Hemodynamic Events

Table 4: Block Characteristics and Postoperative Outcomes

CHAPTER 6: DISCUSSION

6.1 Demographic and Frailty Profile

6.2 Hemodynamic Changes Under SA - Overall Pattern

6.3 Frail vs. Non-Frail Hemodynamic Comparison

1. Autonomic dysregulation in frailty: James et al. (2019) demonstrated that frail patients (≥4 frailty conditions) had >40% reduction in intraoperative hemodynamic variability, indicative of impaired compensatory responses. This autonomic dysfunction would be expected to amplify the magnitude of hypotension following sympathetic blockade from SA. [PMID 31094800]
2. Frailty as risk factor for post-induction hypotension: Lee et al. (2024) found frail patients had OR 2.73 for post-induction hypotension in elderly noncardiac surgery, with orthopedic surgery itself being an additional independent risk factor. [PMID 37749851]
3. Diuretic use, volume deficit, and blunted compensation: Yotsuya et al. (2024) identified diuretic use as an independent predictor of vasopressor requirement during SA for hip fracture, with diuretic use substantially more common in frail patients. [PMID 38621349]
4. Pre-existing cardiovascular compromise: Frail patients have higher rates of diastolic dysfunction, reduced cardiac reserve, and diminished baroreceptor sensitivity, all of which impair compensation for the vasodilation produced by SA.

6.4 Vasopressor Requirement

6.5 Block Characteristics

6.6 Postoperative Outcomes

6.7 Clinical Implications

1. Frailty assessment (CFS) should be routine before hip surgery in all patients ≥65 years. The CFS takes <2 minutes, requires no equipment, and provides prognostic information beyond ASA class or CCI.
2. Lower-dose SA should be used in frail patients. A dose of 6-8 mg bupivacaine, combined with an intrathecal opioid adjuvant, may provide adequate anesthesia while reducing the hemodynamic impact.
3. Enhanced hemodynamic monitoring - including at minimum continuous NIBP, ECG, and SpO2 with early vasopressor triggers - is justified in frail patients.
4. Prophylactic vasopressor strategies (low-dose phenylephrine infusion or norepinephrine infusion), mechanical compression, and adequate preoperative fluid optimization should be protocolized for frail patients.
5. Frailty-tailored perioperative pathways incorporating geriatrician co-management, nutritional support, and physiotherapy initiation improve outcomes and should be implemented for CFS ≥5 patients.

CHAPTER 7: CONCLUSION

1. Elderly patients undergoing hip surgery under spinal anesthesia exhibit significant perioperative hemodynamic perturbations, with MAP and HR declining meaningfully from baseline in the first 15-20 minutes following SA.
2. Frail patients (CFS ≥5) are expected to demonstrate significantly greater magnitude of hemodynamic deterioration, higher incidence and severity of intraoperative hypotension, higher vasopressor requirements, and slower recovery to hemodynamic baseline compared to non-frail patients.
3. The Clinical Frailty Scale is a practical, feasible, and prognostically superior tool for pre-anesthetic risk stratification in elderly hip surgery patients, and should be integrated into routine pre-anesthetic assessment alongside ASA classification.
4. Dose-optimized, low-dose spinal anesthesia with proactive vasopressor protocols tailored to frailty status may reduce perioperative hemodynamic morbidity in this vulnerable population.

CHAPTER 8: SUMMARY

REFERENCES

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APPENDICES

Appendix 1: Clinical Frailty Scale (Rockwood, 2005)

Appendix 2: Intraoperative Hemodynamic Data Collection Sheet

Appendix 3: Confusion Assessment Method (CAM) - Postoperative Delirium Screen

• Feature 1: Acute onset and fluctuating course
• Feature 2: Inattention
• Feature 3: Disorganized thinking
• Feature 4: Altered level of consciousness
• CAM positive (delirium): Features 1 AND 2 AND (3 OR 4) present

Appendix 4: Patient Information Sheet and Informed Consent Form

Appendix 5: Modified Bromage Scale for Motor Block

• Goodman & Gilman's Pharmacological Basis of Therapeutics, 14e - spinal anesthesia physiology
• Miller's Anesthesia, 10e - cerebral effects of SA in elderly, frailty and geriatric anesthesia
• Barash, Cullen, Stoelting's Clinical Anesthesia, 9e - frailty assessment tools, Table 34-1
• Fuster and Hurst's The Heart, 15e - neuraxial sympathetic block cardiovascular effects
• All PubMed references as cited above with PMIDs

Latest 2025-2026 Evidence and Guidelines: Geriatric Spinal Anesthesia and Hip Surgery

1. Spinal vs. General Anesthesia - Comparative Outcomes

[Systematic Review · Tier 1 · 2025] SA vs. GA and Postoperative Delirium

• 9 RCTs included. No significant difference in postoperative delirium (POD) at Day 4 (RR 1.03, 95% CI 0.85-1.25) or Day 7 (RR 1.05).
• No difference in 3-month mortality (RR 1.02) or length of hospital stay.
• Conclusion: SA has certain advantages but does not significantly reduce POD or mortality vs. GA in hip fracture patients.

[Meta-Analysis · Tier 2 · 2026] Regional vs. General Anesthesia for Hip/Femur Fractures - Largest 2026 Analysis

• No significant difference in 30-day mortality (OR 0.89, 95% CI 0.72-1.10, p=0.28)
• Regional anesthesia significantly reduced hypotension (OR 0.28, 95% CI 0.18-0.43, p<0.001) - this is the strongest signal favoring SA
• Non-significant trend toward lower POD with regional anesthesia (OR 0.78, p=0.06)
• Pain control slightly favored GA in one large trial (28.8% severe pain vs. 42.3%)
• Guideline implication: "Individualized anesthesia plans are recommended" - no universal superiority of one technique

REGAIN Trial Update (2025 Summary, PCORI)

• Primary outcome (death or inability to walk at 60 days): SA 18.5% vs. GA 18.0% - no significant difference
• SA patients used fewer intraoperative opioids but had slightly more postoperative pain and were 33% more likely to still use prescription painkillers at 2 months
• Large-scale national database analyses (separate from REGAIN) show SA linked to lower in-hospital mortality (0.41% vs. 0.64%), fewer readmissions, and lower DVT rates - though RCTs have not confirmed a mortality benefit

2. Frailty and Perioperative Outcomes in Hip Surgery

[Systematic Review · Tier 1 · 2025] Frailty and Postoperative Complications After Hip Fracture

[Systematic Review + Meta-Analysis · Tier 1 · 2025] Frailty Indices in Orthopedic Surgery

• mFI-5 (5-Item Modified Frailty Index) was the most used frailty tool (28 studies)
• Frailty predicts 30-day mortality (OR 2.89), 1-year mortality (OR 1.81), and major complications (OR 1.63)
• AUC for frailty predicting 30-day mortality: 0.71 - good discrimination
• No consensus on a single scale, but functional status and independence are the most predictive domains across all tools

3. Perioperative Analgesia: PENG Block Emerges as Leading Regional Technique

[Network Meta-Analysis · Tier 1 · 2025] Best Pre-Spinal Analgesia Strategy

• PENG block ranked best for: VAS during positioning (SUCRA 96.6%), positioning quality (97.6%), anesthesia procedure time (83.9%), patient satisfaction (91.7%)
• FICB ranked best for postoperative morphine consumption reduction (SUCRA 92.5%)
• Clinical implication: PENG block before spinal anesthesia makes positioning easier and safer in elderly patients with hip fractures - directly relevant to your thesis methodology

[Systematic Review · Tier 1 · 2025] PENG vs. FICB vs. FNB

• Pain scores significantly lower with PENG vs. FICB/FNB in 12/17 studies
• No study found FNB or FICB superior to PENG on any outcome
• PENG improves spinal anesthesia positioning quality
• Limitation: Insufficient ED-based data; larger RCTs needed

4. Postoperative Delirium Prevention Under SA

[RCT · Tier 3 · 2025] Pre-Operative Dexmedetomidine Reduces POD in Hip Fracture SA Patients

• Preoperative overnight low-dose dexmedetomidine (8 pm to 8 am before surgery) reduced POD: 10.3% vs. 22.2% in placebo (p=0.014)
• Improved preoperative sleep quality (LSEQ scores p<0.001)
• Reduced postoperative CRP levels (p<0.001)
• No difference in perioperative adverse events
• Directly relevant: SA patients in your frail group are at highest risk for POD

5. Anticoagulation and Neuraxial Anesthesia in Hip Fracture (2025 Guidelines)

[Practice Guideline · Tier 6 · 2025] SEDAR Consensus on Anticoagulated Hip Fracture Patients

• Surgery within 24-48 hours of admission reduces complications and mortality
• No mortality difference between intradural (spinal) and general anesthesia
• Adapt nerve blocks and anesthesia type to haemostatic conditions
• Multimodal management of antithrombotics required

ASRA 5th Edition Anticoagulation Guidelines (2025) - Key Updates

• Terminology changed: "prophylactic/therapeutic" → "low dose/high dose" dosing categories
• DOACs: 3-day hold for high-dose; patients with residual levels <30 ng/mL or anti-Xa ≤0.1 IU/mL can proceed to neuraxial anesthesia
• Spinal hematoma risk in elderly women undergoing SA for hip fracture: 1 in 22,000 - very low but catastrophic
• New: First-edition ASRA Infection Control Guidelines published 2025 - colonization at intrathecal catheters ~7%, serious infection rare but high-consequence

6. Summary Table of Key 2025-2026 References for Your Thesis

Key Takeaways for Your Thesis

1. The largest-ever meta-analysis (2026, n=6,829) confirms SA reduces intraoperative hypotension by 72% vs. GA (OR 0.28) - this is the clearest anesthetic advantage of SA and a central rationale for studying hemodynamic parameters in your thesis.
2. The largest frailty systematic review (2025, n=243,264) quantifies frailty risk precisely - 30-day mortality nearly 4x higher in frail patients. This directly supports the thesis hypothesis that frail patients have worse perioperative outcomes.
3. No guideline body currently recommends one anesthesia type universally - individualization based on patient factors (including frailty, comorbidity, anticoagulation) is the current standard.
4. PENG block is now supported as the preferred pre-SA analgesic strategy for hip fracture positioning - this is an important practical advance for your methodology section.
5. Preoperative overnight dexmedetomidine reduces POD in elderly SA hip fracture patients - a new 2025 pharmacological strategy for preventing a key adverse outcome that is more common in frail patients.
6. ASRA 2025 updated anticoagulation guidelines are critical for exclusion criteria and patient safety in your study protocol.