Spinal anesthesia in elderly patients

What the randomized trials actually showed, why moderate dose reduction does not prevent hypotension, and how hip fracture and TURP pull the decision in different directions.

Published August 13, 2026 · Last reviewed September 27, 2026 · Written by Anastasia Jackson, DNAP, CRNA

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Spinal versus general anesthesia: what the trials found

Observational data suggested for years that regional anesthesia lowered mortality, delirium, and major complications after hip fracture. Two large randomized trials tested that directly, and neither confirmed it.

REGAIN

A pragmatic, randomized superiority trial at 46 US and Canadian hospitals enrolling 1,600 previously ambulatory patients aged 50 or older undergoing hip fracture surgery. Mean age 78, 67% women. The primary outcome was a composite of death or inability to walk approximately 10 feet independently or with a walker at 60 days.¹

Hospital length of stay, return to prefracture residence, overall health and disability, chronic pain, and satisfaction with anesthesia care were all similar.^1,2

The finding most summaries leave out

Both differences were small in magnitude. But the direction is the opposite of what most clinicians would predict, and it is worth knowing before telling a patient that a spinal will hurt less afterward.

RAGA

A separate randomized trial of 950 patients aged 65 and older, focused specifically on postoperative delirium within seven days. It compared three neuraxial techniques — spinal, epidural, or combined spinal-epidural — against general anesthesia, and again found no superiority for neuraxial.⁴ RAGA should be read with its power limitation in mind: the observed delirium rate of about 5% was less than half the anticipated value, leaving the trial underpowered to exclude a clinically meaningful difference.²⁹

Even in cognitive impairment, where the benefit was most expected

A post hoc secondary analysis of REGAIN stratified by preoperative cognitive status. Among patients with cognitive impairment including dementia, new or worsened delirium occurred in 33.9% of the spinal group versus 37.8% of the general anesthesia group (OR 0.85, CI 0.60–1.19). Among those without cognitive impairment, 16.2% versus 16.0%. There was no interaction, and delirium severity, in-hospital complications, and 60-day functional recovery did not differ.⁵

Honest caveats in the other direction

Crossover was asymmetric. 15% of patients randomized to spinal received general anesthesia, while only 3.5% randomized to general received spinal.¹ Crossover of that magnitude, in that direction, biases an intention-to-treat analysis toward the null.

Some in-hospital secondary outcomes numerically favored spinal. Death during hospitalization occurred in 0.6% versus 1.6%, acute kidney injury in 4.5% versus 7.6%, and critical care admission in 2.3% versus 3.7%.² These were secondary, unpowered, and should not be read as established benefits — but they are in the data, and the trials did not show spinal to be worse.

Sedation may explain the conflicting literature. RAGA delivered neuraxial anesthesia without sedation, whereas in REGAIN nearly all spinal patients were sedated (about 44% received midazolam and 23% ketamine, both deliriogenic).⁴ Large registry and instrumental-variable analyses suggest spinal anesthesia without sedation may modestly reduce delirium — roughly a 5% absolute reduction in the National Hip Fracture Database cohort.^32,33 This does not overturn the randomized null, but it is a plausible reason the observational and randomized signals diverge, and an argument for minimizing sedation when a spinal is used.

Why the physiology is different after 75

Hypotension after spinal block is the hazard that defines this population. It has been reported in a wide range of elderly hip surgery populations, with the figure depending heavily on how hypotension is defined. Note that the trials of prophylaxis on this page were designed around it being common enough to be worth preventing rather than around any single incidence estimate.⁷

The mechanism is contested, and that matters for treatment

Two lines of evidence disagree. One study of elderly patients found that spinal-induced hypotension is driven primarily by a fall in stroke volume, with mean cardiac output dropping about 11% forty minutes after onset.⁸ Another, in patients over 80, concluded that a decrease in systemic vascular resistance rather than cardiac output is the main mechanism.⁹

Additional mechanistic work reinforces that no single mechanism dominates: postspinal hypotension has been linked to impaired cardiac performance in the elderly,³⁵ to venodilation with reduced venous return in frail hip fracture patients,³⁶ and echocardiographic data show that advancing age amplifies falls in both cardiac output and systemic vascular resistance.³⁷

The practical implication is that neither fluid alone nor vasoconstriction alone reliably fixes the problem, because the dominant mechanism varies between patients. Elderly patients frequently cannot increase stroke volume in response to increased preload, and therefore often require a vasopressor rather than more fluid.¹⁰

Why volume overload is a real cost

Empiric fluid loading carries the potential for volume overload with particular risk in cardiac disease, and excessive fluid can cause urinary retention, pulmonary edema, and increased length of stay.^8,11 In a frail patient, the fluid given to prevent hypotension can itself be the complication.

Dose in the elderly — and why “reduce it” is not enough

There is no percentage to subtract for age. Age changes the pharmacodynamics — reduced CSF volume and altered spread mean a given dose produces a higher block and lasts longer — but no validated age-adjustment formula exists.

Genuinely low doses are a different matter. A meta-analysis of six randomized trials in elderly hip surgery found that a low spinal dose, mean 6.5 mg, was associated with a markedly lower incidence of hypotension than a high dose, mean 10.5 mg — odds ratio 0.09 (95% CI 0.04 to 0.21).²⁵ The classic minidose regimen (4 mg bupivacaine with 20 mcg fentanyl) produced far less hypotension than 10 mg in the Ben-David trial — 1 of 10 versus 9 of 10 patients requiring vasopressor support.³⁰ A 2026 randomized trial found 5 mg produced better hemodynamic stability and faster discharge than 7.5 mg in elderly hip fracture patients.³¹ These low-dose regimens typically depend on a peripheral nerve block to preserve block adequacy. The practical message is that moderate dose trimming is not a hypotension strategy — treating it as one leads to an inadequate block and a hypotensive patient — but a genuinely low minidose paired with regional analgesia does reduce hypotension, and lower doses also shorten motor block and speed recovery.²⁵

Intrathecal opioid as an adjuvant

Adding fentanyl or sufentanil allows a lower local anesthetic dose while maintaining adequate surgical anesthesia. The synergy is real; the hypotension benefit from moderate dose reduction, per the trial above, is not established, whereas true minidose regimens do reduce it.

Peripheral nerve blocks: often the higher-yield decision

Since spinal and general anesthesia are a wash on the outcomes patients care most about, regional analgesia is arguably the higher-yield intervention. Fascia iliaca and PENG (pericapsular nerve group) blocks are now central to hip-fracture pathways, both for preoperative analgesia and for their opioid-sparing effect.

In a 2025 stepped-wedge randomized trial, ultrasound-guided fascia iliaca blocks delivered by emergency physicians reduced 7-day delirium (OR 0.72, 95% CI 0.57–0.93).³⁴ These blocks also underpin the low-dose spinal regimens above: a PENG or fascia iliaca block maintains analgesia while the intrathecal dose is minimized, which is how the hemodynamic advantage of a minidose spinal is achieved without an inadequate block.³¹

Preventing hypotension: what actually works

Prophylactic vasopressor infusion

This has the strongest supporting data. In a randomized trial of patients aged 70 and older undergoing hip surgery under spinal with propofol sedation, a continuous norepinephrine infusion started after the block significantly reduced the number of hypotensive episodes compared with saline.¹³ A 2026 randomized non-inferiority trial in elderly patients undergoing hip surgery under spinal anesthesia found a norepinephrine infusion of 0.07 mcg/kg/min non-inferior to 0.1 mcg/kg/min for maintaining mean arterial pressure, with lower total norepinephrine consumption and fewer heart-rate disturbances.¹⁴

Choosing the agent

Fluid: co-load rather than preload, and consider imaging it

Co-loading — infusing fluid immediately after the block rather than before it — is at least as effective as preloading provided the bolus is given quickly.¹¹ Pre-emptive fluid therapy guided by inferior vena cava ultrasound lowered the incidence of post-spinal hypotension — 27.5% versus 42.5% with empiric loading, a relative risk reduction of 35% — and reduced the need for vasoactive drugs. It did so by giving more fluid, not less: the total volume given was significantly higher in the ultrasound-guided group.¹⁶ Imaging tells you which patients will respond to volume. It does not spare them the volume, and where overload is the greater risk that is the trade-off to weigh rather than a way around it.

Hip fracture: the question behind the question

A hip fracture in an older adult is frequently the presenting sign of something else — an arrhythmia, syncope, sepsis, dehydration, a new medication, or occult bleeding. The workup question is what broke the hip, not just which hip broke.

That reframing matters more to the anesthetic than the choice of technique does, because the answer changes the resuscitation, the monitoring, and sometimes the timing. A patient who fell because of a GI bleed and a patient who tripped on a rug need different anesthetics regardless of whether either gets a spinal.

The standing trio to quantify before choosing anything

• Volume status — the hypotension hazard is worst in the volume-depleted, and these patients are frequently dry from reduced intake, occult blood loss into the thigh, and time on the floor before being found.
• Anemia — a hemoglobin that would be tolerable in a well-perfused patient is not tolerable during a sympathectomy.
• Anticoagulation — see below. In practice this often chooses the anesthetic.

Anticoagulation frequently decides it

Neuraxial timing is gated by the specific agent, the last dose, and renal function. A patient on a direct oral anticoagulant whose last dose was yesterday evening is not a spinal candidate this morning, and the choice is made before any discussion of delirium or ambulation. Given that the randomized evidence shows no superiority for either technique, there is no strong reason to delay surgery in order to make a spinal possible — and delay itself carries risk in hip fracture. Hold intervals by agent are set out at clopidogrel hold time before neuraxial and pain procedures.

What spinal still offers

Avoiding airway instrumentation, avoiding a volatile agent in a brain that tolerates it poorly, and a smoother early course in some patients. These are reasonable preferences. They are not outcome benefits, and the distinction is worth being honest about with patients and families.

TURP: where awake is the monitor

This is the one setting on this page where the technique has a specific mechanistic argument behind it rather than a habit.

Why awake matters

Signs of TURP syndrome are detected earlier in an awake patient under spinal anesthesia. In an anesthetized patient, tachycardia and hypertension may be the only indicators — the neurologic manifestations are masked and the cardiovascular signs predominate.^17,18

The second argument is more specific and less often taught: an awake patient gives early warning of bladder or capsular perforation, because they will complain of new shoulder pain or periumbilical pain from irrigation fluid tracking into the peritoneum.¹⁹ No monitor shows that.

What has changed — and what has replaced it

TURP syndrome results from absorption of electrolyte-free irrigation fluid through open prostatic venous sinuses, at a rate of roughly 20 mL per minute.¹⁹ Historically the irrigant was 1.5% glycine. Reported incidence varies widely because definitions and populations differ: 0.78% to 1.4% with glycine irrigation,¹⁸ up to 2.1% in one report,²¹ a pooled 2% across 103 randomized trials of TURP published 2000 to 2022,²⁷ up to 8% in a mild form with 1–2% severe,²⁰ and 10–15% of procedures in one educational review.¹⁷ The outlier is 23.5% in 98 patients aged 70 and older having monopolar resection under regional anesthesia, where the syndrome was defined by symptoms alone — a central nervous system disturbance with a circulatory abnormality — rather than by a sodium threshold.²⁶ The meta-analysis authors attribute a declining incidence mainly to bipolar resection with saline irrigation, although their own comparison across time periods found no statistically significant difference.²⁷

Bipolar resectoscopes allow the use of electrolyte-containing irrigation.¹⁷ With bipolar resection in saline, dilutional hyponatremia has been described as a historical event in the 21st century,²¹ and one series concluded that repeated postoperative electrolyte analysis can be omitted.²²

Recognizing and managing it

The conventional teaching is that onset may be as early as 15 minutes into the procedure, or as late as 24 hours after surgery.^17,24 Sodium below 120 mmol/L is invariably symptomatic, and the rate of fall matters more than the absolute number.²⁰

Management principles: stop the resection, tell the surgeon immediately, and correct deliberately. Hypertonic saline is reserved for neurologic manifestations, and correction is indicated only where measured serum osmolality is below 260 mOsmol/kg, which is the check that separates true dilutional hypo-osmolality from other causes of a low measured sodium. Correction should not exceed roughly 10–12 mmol per 24 hours because of the risk of osmotic demyelination.²⁴ Diuretic therapy is not appropriate in a hemodynamically unstable patient.¹⁸

Practical prevention

• Keep the irrigation bag no more than about 60 cm above the patient^20,24 and drain frequently — absorption is pressure-driven.
• Minimize resection time.
• Avoid hypotonic IV fluids.
• Check the sodium if the case runs long, if the gland is large, or if anything changes.

The trade-off, stated plainly

Spinal for TURP requires a cooperative patient in lithotomy with head-down tilt, and anticoagulation timing that permits the block. Where general anesthesia is used instead, the early warning is lost, and the fluid deficit, sodium trend, and hemodynamics carry the entire surveillance burden. That is a manageable situation — it just has to be a decision rather than an accident.

A practical checklist

Frequently asked questions

Is spinal or general anesthesia better for hip fracture surgery in the elderly?

Neither is superior on the outcomes that matter most. The REGAIN trial randomized 1,600 patients and found death or new inability to walk at 60 days in 18.5% of the spinal group versus 18.0% of the general anesthesia group.¹ The choice is individualized, and in practice it is usually decided by anticoagulation timing and how much hypotension the patient can tolerate.

Does spinal anesthesia reduce postoperative delirium?

No. Delirium occurred in 20.5% of the spinal group and 19.7% of the general anesthesia group in REGAIN.¹ The RAGA trial, which studied delirium specifically in 950 patients aged 65 and over, also found no superiority for neuraxial anesthesia.⁴ A secondary analysis found no benefit even among patients with pre-existing cognitive impairment,⁵ and the 2025 ASA Practice Advisory reached the same conclusion.²⁸

How much should you reduce the spinal dose for an elderly patient?

There is no validated percentage. Age reduces CSF volume and increases spread, so a given dose produces a higher and longer block — but no age-adjustment formula has been established. Moderate dose reduction alone does not reliably prevent hypotension: one randomized comparison of 7.5 mg bupivacaine with fentanyl against 12.5 mg plain found hypotension in 59.5% overall with no difference between groups.¹² A genuinely low minidose does reduce it — 4 mg with fentanyl produced far less hypotension than 10 mg in the Ben-David trial³⁰ — but these regimens typically depend on a peripheral nerve block to preserve block adequacy. Choose the dose for the dermatomal level actually required, add a regional block, and manage hypotension separately.

Do peripheral nerve blocks help in hip fracture surgery?

Yes. Fascia iliaca and PENG blocks are opioid-sparing and, in a 2025 randomized trial of emergency-physician-delivered fascia iliaca blocks, reduced 7-day delirium (OR 0.72, 95% CI 0.57–0.93).³⁴ Because spinal and general anesthesia are equivalent on the major outcomes, adding a regional block is often the higher-yield decision — and it enables the low-dose spinal regimens that improve hemodynamic stability.³¹

What is the best way to prevent hypotension after spinal anesthesia in older patients?

A prophylactic vasopressor infusion started after the block has the strongest supporting evidence — continuous norepinephrine significantly reduced hypotensive episodes in patients aged 70 and older undergoing hip surgery,¹³ and a 2026 trial found 0.07 mcg/kg/min non-inferior to 0.1 mcg/kg/min with lower total consumption.¹⁴ Fluid co-loading helps, and inferior vena cava ultrasound to guide fluid therapy reduced both hypotension and vasopressor requirements compared with empiric loading — though the guided patients received more total fluid, not less.¹⁶

Why is spinal anesthesia preferred for TURP?

Because an awake patient is a monitor. Signs of TURP syndrome are detected earlier in an awake patient; under general anesthesia the neurologic signs are masked and tachycardia and hypertension may be the only indicators.^17,18 An awake patient also reports the new shoulder or periumbilical pain that signals bladder or capsular perforation, which no monitor detects.¹⁹

Is TURP syndrome still a concern with modern equipment?

Much less so where bipolar resection in saline is used — dilutional hyponatremia has been described as largely a historical event with that technique.^21,22 But bipolar technology does not prevent fluid absorption, and symptomatic saline absorption causing hyperchloremic metabolic acidosis has been reported, including a case where bicarbonate rather than vasopressors restored blood pressure.²³ Know which system and irrigant your surgeon is using, because it changes what you are watching for.

Does spinal anesthesia reduce pain after hip fracture surgery?

No — in REGAIN it was associated with slightly more. Worst pain in the first 24 hours was greater with spinal (mean difference 0.40 on a 0–10 scale), and 25% of the spinal group versus 18.8% of the general anesthesia group were still using prescription analgesics at 60 days.³ Both differences were small, but the direction is the opposite of common assumption.

References

1. Neuman MD, Feng R, Carson JL, et al; REGAIN Investigators. Spinal anesthesia or general anesthesia for hip surgery in older adults. N Engl J Med. 2021;385(22):2025–2035. doi:10.1056/NEJMoa2113514. PMID 34623788
2. Neuman MD, Ellenberg SS, Sieber FE, et al. Comparing two types of anesthesia for hip fracture surgery — the REGAIN trial. Patient-Centered Outcomes Research Institute; July 2023. Bookshelf ID NBK618691. doi:10.25302/07.2023.pcs.140618876. PMID 41118476. Reports in-hospital secondary outcomes including death, acute kidney injury, and critical care admission.
3. Neuman MD, Feng R, Ellenberg SS, et al. Pain, analgesic use, and patient satisfaction with spinal versus general anesthesia for hip fracture surgery: a randomized clinical trial. Ann Intern Med. 2022;175(7):952–960. PMID 35696684
4. Li T, Li J, Yuan L, et al. Effect of regional vs general anesthesia on incidence of postoperative delirium in older patients undergoing hip fracture surgery: the RAGA randomized trial. JAMA. 2022;327(1):50–58. doi:10.1001/jama.2021.22647
5. Outcomes with spinal versus general anesthesia for patients with and without preoperative cognitive impairment: secondary analysis of a randomized clinical trial. PMID 37170754
6. White SM, Tedore T, Shelton CL. There is (probably) no (meaningful) difference in (most) outcomes between spinal and general anaesthesia for hip fracture surgery: time to move forward. Br J Anaesth. 2023;130(4):385–389. doi:10.1016/j.bja.2023.01.013. PMID 36801101.
7. Comparing two different norepinephrine infusion rates for prophylaxis against spinal-induced hypotension in the elderly. ClinicalTrials.gov NCT07077265. A non-inferiority comparison of norepinephrine 0.07 against 0.1 mcg/kg/min; now published (see ref 14). The registry record carries no incidence figure and none is attributed to it here.
8. Hofhuizen C, Lemson J, Snoeck M, Scheffer GJ. Spinal anesthesia-induced hypotension is caused by a decrease in stroke volume in elderly patients. Local Reg Anesth. 2019;12:19–26. doi:10.2147/LRA.S193925. PMID 30881108. PMC6404676.
9. Hypotension from spinal anesthesia in patients aged greater than 80 years is due to a decrease in systemic vascular resistance. PMID 22537572
10. Neal JM. Hypotension and bradycardia during spinal anesthesia: significance, prevention, and treatment. Tech Reg Anesth Pain Manag. 2000;4(4):148–154. doi:10.1053/trap.2000.20600.
11. Ferré F, Martin C, Bosch L, Kurrek M, Lairez O, Minville V. Control of spinal anesthesia-induced hypotension in adults. Local Reg Anesth. 2020;13:39–46. doi:10.2147/LRA.S240753. PMID 32581577. PMC7276328.
12. Martyr JW, Clark MX. Hypotension in elderly patients undergoing spinal anaesthesia for repair of fractured neck of femur: a comparison of two different spinal solutions. Anaesth Intensive Care. 2001;29(5):501–505. doi:10.1177/0310057X0102900509. PMID 11669431.
13. Norepinephrine prevents hypotension in older patients under spinal anesthesia with intravenous propofol sedation: a randomized controlled trial. Sci Rep. 2023;13:20977. doi:10.1038/s41598-023-48178-2
14. Wahib M, Mostafa M, Hasanin A, et al. Norepinephrine infusion for prophylaxis against spinal-induced hypotension in elderly patients undergoing hip surgery: a randomized controlled comparison of two doses. BMC Anesthesiol. 2026. ClinicalTrials.gov NCT07077265. A norepinephrine infusion of 0.07 mcg/kg/min was non-inferior to 0.1 mcg/kg/min for maintaining mean arterial pressure, with lower total norepinephrine consumption and fewer heart-rate disturbances.
15. Hemodynamic effects of norepinephrine versus phenylephrine infusion for prophylaxis against spinal anesthesia-induced hypotension in the elderly population undergoing hip fracture surgery: a randomized controlled trial. Korean J Anesthesiol. doi:10.4097/kja.20519
16. Ceruti S, Anselmi L, Minotti B, et al. Prevention of arterial hypotension after spinal anaesthesia using vena cava ultrasound to guide fluid management. Br J Anaesth. 2018;120(1):101–108. doi:10.1016/j.bja.2017.08.001. PMID 29397116.
17. Hyponatremia and transurethral resection of prostate syndrome. OpenAnesthesia. openanesthesia.org/keywords/hyponatermia-and-transurethral-resection-of-prostate-syndrome. Accessed August 2026.
18. TUR syndrome — a report. Urol Case Rep. 2019;26:100982. PMID 31388497, PMC6677916. Reports onset five minutes after the end of the procedure. And: Boukatta B, Sbai H, Messaoudi F, et al. Transurethral resection of prostate syndrome: report of a case. Pan Afr Med J. 2013;14:14. doi:10.11604/pamj.2013.14.14.1906
19. TURP syndrome. Anaesthesia educational review. Anaestheasier, last updated 13 August 2025. anaestheasier.com/turp-syndrome. Describes absorption rate, and shoulder or periumbilical pain as the awake sign of perforation.
20. Porter M, McCormick B. Anaesthesia for transurethral resection of the prostate (TURP). World Federation of Societies of Anaesthesiologists, Update in Anaesthesia. 2003;(16):21–26. resources.wfsahq.org/wp-content/uploads/uia-16-ANAESTHESIA-FOR-TRANSURETHRAL-RESECTION-OF-THE-PROSTATE-TURP.pdf.
21. Transurethral resection of the prostate in saline versus nonconductive solution to treat benign prostatic hyperplasia: a randomized controlled study. UroToday Int J. 2010 Feb;3(1). doi:10.3834/uij.1944-5784.2010.02.05
22. Bipolar transurethral resection in saline: the solution to avoid hyponatraemia and transurethral resection syndrome. PMID 20345336
23. Okuma N, Hino H, Kuroki M, Matsuura T, Mori T. Symptomatic absorption of normal saline during transurethral resection of the prostate: a case report. JA Clin Rep. 2022;8:44. doi:10.1186/s40981-022-00532-5
24. TURP syndrome. Life in the Fast Lane, Critical Care Compendium. litfl.com/turp-syndrome. Summarizing Gravenstein D. Anesth Analg. 1997;84(2):438–446.
25. Spinal anesthesia and hypotensive events in hip fracture surgical repair in elderly patients: a systematic review and meta-analysis. J Anesth Analg Crit Care. 2022;2(1):19. doi:10.1186/s44158-022-00047-6. PMID 37386657. Six randomized trials, 344 patients, median age 82. A low spinal dose, mean 6.5 mg, was associated with a lower incidence of hypotension than a high dose, mean 10.5 mg — odds ratio 0.09 (95% CI 0.04 to 0.21).
26. Nakahira J, Sawai T, Fujiwara A, Minami T. Transurethral resection syndrome in elderly patients: a retrospective observational study. BMC Anesthesiol. 2014;14:30. doi:10.1186/1471-2253-14-30. PMID 24782656. PMC4004457. Men aged 70 and older, monopolar resection with 3% D-sorbitol irrigation under regional anesthesia; 23 of 98 (23.5%, 95% CI 14.9 to 32.0%) met a symptom-based definition.
27. Porto JG, Bhatia AM, Bhat A, et al. Evaluating transurethral resection of the prostate over twenty years: a systematic review and meta-analysis of randomized clinical trials. World J Urol. 2024;42(1):639. doi:10.1007/s00345-024-05332-3. PMID 39547977. PMC11568034. 103 randomized trials, 8,521 patients; pooled TURP syndrome rate 2%.
28. Sieber F, McIsaac DI, Deiner S, et al. 2025 American Society of Anesthesiologists Practice Advisory for Perioperative Care of Older Adults Scheduled for Inpatient Surgery. Anesthesiology. 2025. Found neither neuraxial nor general anesthesia associated with lower delirium risk, including in the hip-fracture subgroup (RR 1.05, 95% CI 0.76–1.43; moderate strength of evidence).
29. Nobuhara C, Devinney M, Berger M. Regional vs general anesthesia and incidence of postoperative delirium in older patients undergoing hip fracture surgery. JAMA. 2022. Notes RAGA was underpowered — the observed delirium rate was less than half the anticipated value.
30. Ben-David B, Frankel R, Arzumonov T, Marchevsky Y, Volpin G. Minidose bupivacaine-fentanyl spinal anesthesia for surgical repair of hip fracture in the aged. Anesthesiology. 2000. 4 mg bupivacaine with 20 mcg fentanyl caused markedly less hypotension than 10 mg (1 of 10 versus 9 of 10 requiring vasopressor).
31. Mafizer M, Kavak Akelma F, Nalbant B. Impact of bupivacaine dose on haemodynamics in elderly hip surgery: a randomized controlled trial. BMC Geriatr. 2026. 5 mg produced better hemodynamic stability and faster discharge than 7.5 mg.
32. Matharu GS, Shah A, Hawley S, et al. The influence of mode of anaesthesia on perioperative outcomes in people with hip fracture: a prospective cohort study from the National Hip Fracture Database for England, Wales and Northern Ireland. BMC Med. 2022. Spinal anesthesia without sedation associated with roughly a 5% absolute reduction in delirium.
33. Tanios AG, Gallagher EL, McManus MS, et al. The effect of type of anaesthetic on delirium after surgery for acute hip fracture: an instrumental variable analysis to assess causation. Anaesth Intensive Care. 2025. Instrumental-variable analysis supporting a delirium reduction with spinal anesthesia when sedation is minimized.
34. Lee JS, Chenkin J, Simard R, et al. Ultrasound-guided regional anesthesia by emergency physicians for hip fractures and delirium: a randomized clinical trial. JAMA Netw Open. 2025. Stepped-wedge trial; ED-delivered ultrasound-guided fascia iliaca blocks reduced 7-day delirium (OR 0.72, 95% CI 0.57–0.93).
35. Jakobsson J, Kalman SH, Lindeberg-Lindvet M, Bartha E. Is postspinal hypotension a sign of impaired cardiac performance in the elderly? An observational mechanistic study. Br J Anaesth. 2017;119(6):1178–1185. doi:10.1093/bja/aex274. PMID 29040402.
36. Olsen F, Hård af Segerstad M, Dalla K, Ricksten SE, Nellgård B. Fractional spinal anesthesia and systemic hemodynamics in frail elderly hip fracture patients. F1000Res. 2023. Attributes the cardiac output fall to venodilation and reduced venous return.
37. Lairez O, Ferré F, Portet N, et al. Cardiovascular effects of low-dose spinal anaesthesia as a function of age: an observational study using echocardiography. Anaesth Crit Care Pain Med. 2015. Advancing age amplifies falls in both cardiac output and systemic vascular resistance.