Crimson Publishers Publish With Us Reprints e-Books Video articles

Full Text

Developments in Anaesthetics and Pain Management

The Roles and Challenges of a Perioperative Geriatric Service

Zhaosheng Jin1,2*, Jack Roberts1,3 and Denish Sangtani1

1Havering and Redbridge University Hospitals NHS Trust, UK

2North Central School of Anaesthesia, UK

3Barts and The London School of Anaesthesia

*Corresponding author: Zhaosheng Jin, Queen’s hospital, Barking Havering and Redbridge University Hospitals NHS Trust, UK

Submission: February 19, 2018;Published: May 10, 2018

DOI: 10.31031/DAPM.2018.01.000511

ISSN 2640-9399
Volume1 Issue3


It is increasingly recognised that perioperative complications in the elderly population are associated with an increased length of hospital stay and an increased rate of morbidity and mortality. This has led to the development and implementation of proactive perioperative geriatric services aimed at preoperative optimisation, anticipation of possible complications and early perioperative intervention. In this review, we will discuss the impact of nonsurgical complications on perioperative outcome in the elderly population, as well as the evidence for perioperative geriatric services and its resource allocation.

Abbreviations: MI: Myocardial Infarction; SIRS: Systemic Inflammatory Response Syndrome; CNS: Central Nervous System; POD: Postoperative Cognitive Decline; AKI: Postoperative Acute Kidney Injury; CGA: Comprehensive Geriatric Assessment; NCEPOD: National Confidential Enquiry into Patient Outcome and Death; AAGBI: Association of Anaesthetists of Great Britain and Ireland; POPS: Proactive Care of Older People Undergoing Surgery; HDU: High Dependency Units


With the advancements in anaesthetic techniques and an ageing population, it is projected that patients will undergo surgery at increasingly advanced age. While most elderly patients will have an uneventful postoperative recovery, some can have a significantly protracted postoperative course. This is often associated with the development of postoperative complications with increased length of stay, functional deterioration and increased morbidity and mortality. Often such complications are not directly related to the surgical procedure but are results of the patients’ preoperative comorbidities, hospitalisation and the multisystem response to the surgical trauma. In order to minimise postoperative complications and improve outcomes, a number of surgical centres have developed a proactive multidisciplinary approach to the postoperative management of at-risk elderly patients. Here we will review the values and challenges of such services.

Postoperative complications and outcomes

The postoperative period is often characterised by an elevated stress and pro-inflammatory response; combined with immobility, malnutrition, dehydration and sleep disturbances. It is well recognised that these factors are associated with an increased risk of developing cardiovascular, respiratory, renal, immunological and cognitive dysfunctions. In an analysis of over one million surgical cases, Ferraris et al reported that non-surgical complications such as sepsis and myocardial infarction accounted for almost half of the total postoperative complications, and are associated with considerably higher mortality rates than the surgical complications [1]. This highlights the notion that the greatest threat to postoperative outcome is not the surgical trauma itself but the systemic pathophysiological changes associated with surgery and anaesthesia.

Cardiovascular complications

Postoperative myocardial infarction (MI) occurs as a result of the mismatch in myocardial oxygen demand and supply, whereby increased postoperative myocardial oxygen demand coupled with reduced coronary artery perfusion increases the risk of ischemia and infarction Contributory factors include the systemic inflammatory response syndrome (SIRS), the acute stress response due to surgical trauma and pain; hypovolemia due to blood loss and dehydration; as well as intraoperative hypotension. Postoperative MI has the highest mortality rate of all postoperative complications, with a 30 day mortality of 45% and a 5 year mortality of 66% [1,2].

Respiratory complications

Significant postoperative respiratory complications include atelectasis, lower respiratory tract infection, exacerbation of existing lung pathologies and acute lung injury/acute respiratory distress syndrome. These are thought to be partly a result of intraoperative invasive positive pressure ventilation, use of neuromuscular junction blockers, postoperative pain, immobility and opioid use. While the incidences of respiratory complications are heterogeneous in the literature [3,4], the reported mortality rate is consistently high [4-6]. Respiratory complications are associated with significantly longer hospital and intensive care unit stay [7-8].

Central Nervous System complications

Central nervous system (CNS) complications include postoperative delirium (POD), postoperative cognitive decline (POCD) and cerebral vascular events. The reported incidence is varied, but can be up to 60-70% [9,10]. While the exact pathophysiology is unclear, it is thought to be a result of the postoperative acute stress response, neuro inflammation, neurotransmitter imbalance and intraoperative hemodynamic instability [11-14] CNS complications can unmask or worsen pre-existing cognitive impairment [15,16]. Conversely, preoperative cognitive impairment also increases the risk of developing postoperative CNS complications [17]. In addition to increased length of hospital stay and mortality rate [18- 21], CNS complications are associated with significant functional decline [22,23] and subsequently increased requirement for care facilities[24,25].

Renal complications

Postoperative acute kidney injury (AKI) has been reported to occur in 1-10% of the surgical population, however in highrisk groups the incidence can be as high as 30% [1,26,27]. While postoperative AKI is traditionally attributed to renal hypo perfusion, more recent studies suggest that systemic inflammation may play a role in its pathogenesis [28-30]. Postoperative AKI may progress to chronic renal impairment needing renal replacement therapy [31,32] and is also associated with significantly higher short and long-term mortality [1,26,33,34].

It is worth noting that studies have demonstrated that patient age is predictive of the postoperative risk for all of the aforementioned complications [5,21,26,35] as well as postoperative sepsis [36], therefore it is not surprising that elderly patients are more likely to develop complications and have worse postoperative outcomes [37]. This forms the basis of the recommendation that a physician-led team should proactively manage postoperative elderly patients with multidisciplinary input aimed at optimising recovery, minimising complications and initiating early treatment.

Role and values of a perioperative geriatric service

In 2001, the National Service Framework for older people set out the recommendation that elderly patients in hospital should be managed under the supervision of a care of the elderly medicine consultant. A specialist old age multidisciplinary team in all hospitals was also advocated; a team consisting of a care of the elderly consultant, nurse specialist, physiotherapist, occupational therapist, speech and language therapist, dietician, social worker and pharmacist [38]. The importance of the specialist multidisciplinary team providing a ‘comprehensive geriatric assessment’ (CGA) service is again highlighted in the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) 2010 report and in a 2014 consensus document produced by the Association of Anaesthetists of Great Britain and Ireland (AAGBI), where the expanded role for senior geriatricians in coordinating peri-operative care for elderly patients is strongly supported [39,40].

The organisational structure of a CGA unit has been in existence since the 1980s. In a meta-analysis of 28 trials and over 9000 patients, Stuck et al reported significant reduction in mortality and functional independence in patients cared for under such arrangements [41]. In 2007, Harari et al. [42] first reported on their implementation of a CGA unit for elderly elective orthopaedic patients termed ‘proactive care of older people undergoing surgery’ (POPS) [42]. The scheme involved a comprehensive medical and functional preoperative assessment; as well as care of the elderly consultant led perioperative management. During the implementation stage, the wider team consisted of a full time nurse specialist and an occupational therapist, as well as the involvement of a physiotherapist and social worker that assessed and managed orthopaedic cases over a 6-month period. A significantly lower rate of postoperative non-surgical complications were reported, including delirium and pneumonia; earlier postoperative mobilisation; and a significantly shorter length of stay in hospital.

Subsequently, the POPS service has been adopted for most elective surgical specialties in the same centre including postoperative urology patients; again demonstrating a significant reduction in complication rate and a significant reduction in length of hospital stay [43]. Other centres that have adopted components of the POPS service in their perioperative management, have also reported promising results in terms of complication rate and length of stay [44-46].

Parallel to services such as POPS, surgical patients thought to be medically complex may often be referred to high dependency units (HDU) for postoperative management under the supervision of an intensive care physician, with higher nurse to patient ratios and access to continuous monitoring. The timely management of medical comorbidities and earlier identification and treatment of postoperative complications aims to prevent overt decomposition. Studies have demonstrated that surgical patients who are electively admitted to critical care units have significantly better outcomes than those admitted to the ward and subsequently require critical care. This demonstration of improved outcome is despite the fact that patients with elective admission to critical care sometimes having more medical comorbidities [47-49]. It has been shown that proactively admitting at-risk surgical patients to critical care may in fact reduce the mortality and length of stay without increasing the overall critical care unit bed burden [50].

Limitations with both the POPS and HDU model of postoperative care are that both have significant staffing and resources implications. In the next section we will discuss some of the rationing strategies which have been used to identify patients at highest risk of developing postoperative complications.

Resource limitation and rationing criteria

In the climate of limited resources, commissioners facing a number of challenges as increasing evidence support elderly medicine teams forming part of routine clinical care for at-risk older patients undergoing surgery. Workforce planning, resources and funding will be required to establish these services within existing pre-assessment and surgical pathways, and strategies developed to identify those patients at greatest risk of perioperative morbidity so resources can be best utilised. Efforts so far have largely focussed on specific patient populations, namely those with acute hip fracture. The successes of such initiatives are widely reported, often demonstrating significant reductions in length of stay [45,51,52] However, the rationing of resources in such a diagnosis-based manner may ultimately result in disparity and inequality amongst the elderly surgical patient population.

Work in 2007 by Harari et al was initially funded by charitable grant and substantively funded when financial viability, including a reduction in length of stay, was demonstrated [42]. Inclusion criteria for referral to their POPS service are reportedly broad, and referrals by surgeons, GPs, and nurse-led pre-operative triage are encouraged. Referral criteria include those patients aged over 65 with listed systemic comorbidity risk factors or daily living needs. Harari et al had initially used a pre-operative screening tool in an attempt to identify patients at greatest risk of post-operative problems but the sensitivity and specificity for a low vs. highrisk cut-off point was too low to limit the clinical intervention to patient’s with ≥2 risk factors.

Rationing strategies, like those above, use comorbidity risk stratifications a means to derive inclusion criteria. In 2000, Liu and Leung identified factors that were associated with postoperative morbidity in 367 patients over the age of 80 [53]. The most prevalent preoperative risk factors were a history of hypertension and coronary artery, pulmonary, and neurological diseases. A history of neurological disease (OR 4.0,95% confidence interval [CI] 2.3 - 6.9), congestive heart failure (OR 2.7, CI 1.4 - 5.3), and a history of arrhythmia (OR 2.3, CI 1.2 - 4.3) increased the odds of adverse postoperative events. Decreased functional status (OR 3.0, CI 1.4-6.4) and clinical signs of congestive heart failure (OR 2.1, CI 1.1-5.1) were the two most important predictors of postoperative adverse outcomes in a similar study of 544 patients aged 70 and older by Leung & Dzankic [54]. A number of global comorbidity indices have been successfully used to predict surgical outcomes [55] and may represent a more practical approach to developing referral criteria. One such tool is the Charlson Comorbidity Index (CCI); an index shown to stratify morbidity and mortality across a number of surgical specialities [56-58] and may have a role in the evaluation of perioperative risk in elderly patients [59]. However, its use as a tool in rationing access to perioperative elderly care services is not yet clearly established.

Other such predictors of surgical risk and outcomes include the concept of frailty. Frailty can be defined as a lack of physiological reserve seen across multiple organ systems and is an independent predictor of mortality, morbidity and institutionalisation after surgery [60]. Despite a growing body of evidence that frailty is associated with an increased risk of adverse health outcomes [61- 63] there is not yet a consensus on the definition of frailty or how best to assess and diagnose it. In 2010, Makary et al used a validated 5-point scale that included weakness, weight loss, exhaustion, low physical activity, and slowed walking speed to classify patients as frail, intermediately frail or non-frail. They concluded that the degree of frailty independently predicted postoperative complications, length of stay, and discharge to a skilled or assistedliving facility in older surgical patients [64]. The Edmonton Frail Scale is a further validated scoring assessment which is increasingly being utilised as a method of refining risk estimates of postoperative complications in older adults [65,66]. Results of a 2016 systemic review by Hui-Shan et al suggested that regardless of how frailty was measured -21 instruments in total - the strongest evidence was for associations between frailty and increased mortality, postoperative complications and length of stay [67].


While perioperative geriatric services are staff intensive and can require considerable set-up cost, the proactive multidisciplinary approach to managing postoperative complications will likely reduce complication rate and length of hospital stay. With appropriate rationing strategies, it could prove to be cost effective while also improving postoperative outcomes in elderly patients.


The authors would like to thank Dr. Maurice A Smith, M.B,Chb, MRCP(UK) FRCP(London), consultant geriatrician with special interests in perioperative medicine for his advice and amendments


  1. Ferraris VA, Bolanos M, Martin JT, Mahan A, Saha SP (2014) Identification of patients with postoperative complications who are at risk for failure to rescue. JAMA Surg 149(11): 1103-1108.
  2. Simons JP, Baril DT, Goodney PP, Bertges DJ, Robinson WP, et al. (2013) The effect of postoperative myocardial ischemia on long term survival after vascular surgery. J Vasc Surg 58(6): 1600-1608.
  3. Li C, Yang WH, Zhou J, Wu Y, Li YS, et al. (2013) Risk factors for predicting postoperative complications after open infrarenal abdominal aortic aneurysm repair: results from a single vascular center in China. J Clin Anesth 25(5): 371-378.
  4. Gupta H, Gupta PK, Schuller D, Fang X, Miller WJ, et al. (2013) Development and validation of a risk calculator for predicting postoperative pneumonia. Mayo Clin Proc 88(11): 1241-1249.
  5. Arozullah AM, Khuri SF, Henderson WG, Daley J (2001) Development and validation of a multifactorial risk index for predicting postoperative pneumonia after major noncardiac surgery. Ann Intern Med 135(10): 847-857.
  6. Khuri SF, Henderson WG, DePalma RG, Mosca C, Healey NA, et al. (2005) Determinants of long term survival after major surgery and the adverse effect of postoperative complications. Ann Surg 242(3): 326-341.
  7. Smith PR, Baig MA, Brito V, Bader F, Bergman MI, et al. (2010) Postoperative pulmonary complications after laparotomy. Respiration 80(4): 269-274.
  8. Nafiu OO, Ramachandran SK, Ackwerh R, Tremper KK, Campbell DA, et al. (2011) Factors associated with and consequences of unplanned post operative intubation in elderly vascular and general surgery patients. Eur J Anaesthesiol 28(3): 220-224.
  9. Watne LO, Idland AV, Fekkes D, Raeder J, Frihagen F, et al. (2016) Increased CSF levels of aromatic amino acids in hip fracture patients with delirium suggests higher monoaminergic activity. BMC Geriatr 16: 149.
  10. H OB, Mohan H, Hare CO, Reynolds JV, Kenny RA (2017) Mind over Matter? The Hidden Epidemic of Cognitive Dysfunction in the Older Surgical Patient. Ann Surg 265(4): 677-691.
  11. Cerejeira J, Batista P, Nogueira V, Vaz Serra A, Mukaetova Ladinska EB (2013) The stress response to surgery and postoperative delirium: evidence of hypothalamic pituitary adrenal axis hyper responsiveness and decreased suppression of the GH/IGF-1 Axis. J Geriatr Psychiatry Neurol 26(3): 185-194.
  12. Wan Y, Xu J, Ma D, Zeng Y, Cibelli M, et al. (2007) Postoperative impairment of cognitive function in rats: a possible role for cytokine mediated inflammation in the hippocampus. Anaesthesiology 106(3): 436-443.
  13. Ramirez Bermudez J, Ruiz Chow A, Perez Neri I, Soto Hernandez JL, Flores Hernandez R, et al.(2008) Cerebrospinal fluid homovanillic acid is correlated to psychotic features in neurological patients with delirium. Gen Hosp Psychiatry 30(4): 337-343.
  14. Egberts A, Fekkes D, Wijnbeld EH, van der Ploeg MA, van Saase JL, et al. (2015) Disturbed Serotonergic Neurotransmission and Oxidative Stress in Elderly Patients with Delirium. Dement Geriatr Cogn Dis Extra 5(3): 450-458.
  15. Khadka J, McAlinden C, Pesudovs K (2012) Cognitive trajectories after postoperative delirium. N Engl J Med 367(12): 1164.
  16. Inouye SK, Marcantonio ER, Kosar CM, Tommet D, Schmitt EM, et al. (2016) The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients. Alzheimer’s Dement 12(7): 766-775.
  17. Oh YS, Kim DW, Chun HJ, Yi HJ (2008) Incidence and risk factors of acute postoperative delirium in geriatric neurosurgical patients. J Korean Neurosurg Soc 43(3): 143-8.
  18. Maniar HS, Lindman BR, Escallier K, Avidan M, Novak E, et al. (2016) Delirium after surgical and transcatheter aortic valve replacement is associated with increased mortality. J Thorac Cardiovasc Surg 151(3): 815-823.
  19. Dubljanin Raspopovic E, Markovic Denic L, Marinkovic J, Radinovic K, Ilic N, (2014) et al. Early mortality after hip fracture: what matters? Psychogeriatrics 15(2): 95-101.
  20. Raats JW, van Eijsden WA, Crolla RM, Steyerberg EW, van der Laan L (2015) Risk Factors and Outcomes for Postoperative Delirium after Major Surgery in Elderly Patients. PLoS One 10(8): e0136071.
  21. Scholz AF, Oldroyd C, McCarthy K, Quinn TJ, Hewitt J (2016) Systematic review and meta analysis of risk factors for postoperative delirium among older patients undergoing gastrointestinal surgery. Br J Surg 103(2): e21-8.
  22. Lee KH, Ha YC, Lee YK, Kang H, Koo KH (2011) Frequency risk factors and prognosis of prolonged delirium in elderly patients after hip fracture surgery. Clin Orthop Relat Res 469(9): 2612-2620.
  23. Liang CK, Chu CL, Chou MY, Lin YT, Lu T, et al. (2014) Interrelationship of postoperative delirium and cognitive impairment and their impact on the functional status in older patients undergoing orthopaedic surgery: a prospective cohort study. PLoS One 9(11): e110339.
  24. Schroder Pedersen S, Kirkegaard T, Balslev Jorgensen M, Lind Jorgensen V (2014) Effects of a screening and treatment protocol with haloperidol on post cardiotomy delirium: a prospective cohort study. Interact Cardiovasc Thorac Surg 18(4): 438-445.
  25. Gleason LJ, Schmitt EM, Kosar CM, Tabloski P, Saczynski JS, et al. (2015) Effect of Delirium and Other Major Complications on Outcomes After Elective Surgery in Older Adults. JAMA Surg 150(12): 1134-1140.
  26. Bell S, Dekker FW, Vadiveloo T, Marwick C, Deshmukh H, et al. (2015) Risk of postoperative acute kidney injury in patients undergoing orthopaedic surgery development and validation of a risk score and effect of acute kidney injury on survival: observational cohort study. BMJ 351: h5639.
  27. Susantitaphong P, Cruz DN, Cerda J, Abulfaraj M, Alqahtani F, et al. (2013) World incidence of AKI: a meta-analysis. Clin J Am Soc Nephrol 8(9): 1482-1493.
  28. Goren O, Matot I (2015) Preoperative acute kidney injury. Br J Anaesth 115( Suppl 2): ii3-ii14.
  29. Kinsey GR, Okusa MD (2012) Role of leukocytes in the pathogenesis of acute kidney injury. Crit Care 16(2): 214.
  30. Prowle JR, Bellomo R (2015) Sepsis associated acute kidney injury: macro hemodynamic and micro hemodynamic alterations in the renal circulation. Semin Nephrol 35(1): 64-74.
  31. Ishani A, Nelson D, Clothier B, Schult T, Nugent S, et al. (2011) The magnitude of acute serum creatinine increase after cardiac surgery and the risk of chronic kidney disease progression of kidney disease and death. Arch Intern Med 171(3): 226-33.
  32. Chawla LS, Amdur RL, Shaw AD, Faselis C, Palant CE, et al. (2014) Association between AKI and long term renal and cardiovascular outcomes in United States veterans. Clin J Am Soc Nephrol 9(3): 448-456.
  33. Biteker M, Dayan A, Tekkesin AI, Can MM, Tayci I, et al. (2014) Incidence risk factors and outcomes of perioperative acute kidney injury in noncardiac and nonvascular surgery. Am J Surg 207(1): 53-59.
  34. Hobson C, Ozrazgat Baslanti T, Kuxhausen A, Thottakkara P, Efron PA, et al. (2015) Cost and Mortality Associated With Postoperative Acute Kidney Injury. Ann Surg 261(6): 1207-1214.
  35. Hansen PW, Gislason GH, Jorgensen ME, Kober L, Jensen PF, et al. (2016) Influence of age on perioperative major adverse cardiovascular events and mortality risks in elective non cardiac surgery. Eur J Intern Med 35: 55-59.
  36. Lakomkin N, Sathiyakumar V, Wick B, Shen MS, Jahangir AA, et al. (2017) Incidence and predictive risk factors of postoperative sepsis in orthopedic trauma patients. J Orthop Traumatol 18(2): 151-158.
  37. McVeigh TP, Al Azawi D, O’Donoghue GT, Kerin MJ (2013) Assessing the impact of an ageing population on complication rates and in patient length of stay. Int J Surg 11(9): 872-875.
  38. Care DoHaS (2001) National service framework: older people.
  39. Wilkinson K MI, Gough MJ, Stewart JAD (2010) NCEPOD- Elective & Emergency Surgery in the Elderly: An Age Old Problem Report (2010). National Confidential Enquiry into Patient Outcome and Death.
  40. Griffiths R, Beech F, Brown A, Dhesi J, Foo I, et al (2014) Peri-operative care of the elderly 2014: Association of Anaesthetists of Great Britain and Ireland. Anaesthesia 69( Suppl 1): 81-98.
  41. Stuck AE, Siu AL, Wieland GD, Adams J, Rubenstein LZ (1993) Comprehensive geriatric assessment: a meta-analysis of controlled trials. Lancet 342(8878): 1032-1036.
  42. Harari D, Hopper A, Dhesi J, BabicIllman G, Lockwood L, et al. (2007) Proactive care of older people undergoing surgery (‘POPS’): designing, embedding, evaluating and funding a comprehensive geriatric assessment service for older elective surgical patients. Age Ageing 36(2): 190- 196.
  43. Braude P, Goodman A, Elias T, Babic Illman G, Challacombe B, et al. (2017) Evaluation and establishment of a ward-based geriatric liaison service for older urological surgical patients: Proactive care of Older People undergoing Surgery (POPS)-Urology. BJU Int 120(1): 123-129.
  44. Ellis G, Spiers M, Coutts S, Fairburn P, Mc Cracken L (2012) Preoperative assessment in the elderly: evaluation of a new clinical service. Scott Med J 57(4): 212-216.
  45. Gupta A (2014)The effectiveness of geriatrician led comprehensive hip fracture collaborative care in a new acute hip unit based in a general hospital setting in the UK. J R Coll Physicians Edinb 44(1): 20-26.
  46. Walke LM, Rosenthal RA, Trentalange M, Perkal MF, Maiaroto M, et al. (2014) Restructuring care for older adults undergoing surgery: preliminary data from the Co-Management of Older Operative Patients En Route Across Treatment Environments (CO-OPERATE) model of care. J Am Geriatr Soc 62(11): 2185-2190.
  47. Morgan DJ, Ho KM, Armstrong J, Baker S (2015) Incidence and risk factors for intensive care unit admission after bariatric surgery: a multicentre population-based cohort study. Br J Anaesth 115(6): 873-882.
  48. Gibson AA, Hay AW, Ray DC (2014) Patients with hip fracture admitted to critical care: epidemiology interventions and outcome. Injury 45(7): 1066-1070.
  49. Vester Andersen M, Lundstrom LH, Moller MH, Waldau T, Rosenberg J, et al. (2014) Mortality and postoperative care pathways after emergency gastrointestinal surgery in 2904 patients: a population-based cohort study. Br J Anaesth 112(5): 860-870.
  50. VEveleigh MO, Howes TE, Peden CJ, Cook TM (2016) Estimated costs before during and after the introduction of the emergency laparotomy pathway quality improvement care (ELPQuIC) bundle. Anaesthesia 71(11): 1291-1295.
  51. Lau TW, Leung F, Siu D, Wong G, Luk KD (2010) Geriatric hip fracture clinical pathway: the Hong Kong experience. Osteoporos Int 21(Suppl 4): 627-636.
  52. Lau TW, Fang C, Leung F (2013) The effectiveness of a geriatric hip fracture clinical pathway in reducing hospital and rehabilitation length of stay and improving short-term mortality rates. Geriatr Orthop Surg Rehabil 4(1): 3-9.
  53. Liu LL, Leung JM (2000) Predicting adverse postoperative outcomes in patients aged 80 years or older. J Am Geriatr Soc 48(4): 405-412.
  54. Leung JM, Dzankic S (2001) Relative importance of preoperative health status versus intraoperative factors in predicting postoperative adverse outcomes in geriatric surgical patients. J Am Geriatr Soc 49(8): 1080- 1085.
  55. Mehta HB, Dimou F, Adhikari D, Tamirisa NP, Sieloff E, et al. (2016) Comparison of Comorbidity Scores in Predicting Surgical Outcomes. Med Care 54(2): 180-187.
  56. Chang CM, Yin WY, Wei CK, Wu CC, Su YC, et al. (2016) Adjusted Age-Adjusted Charlson Comorbidity Index Score as a Risk Measure of Perioperative Mortality before Cancer Surgery. PLoS One 11(2): e0148076.
  57. Abdullah M, Al Salamah SM (2009) Impact of Comorbidity on outcome among acute non traumatic surgical patients. Evaluation of Charlson comorbidity index Saudi Med J. 30(2): 228-233.
  58. Grossman R, Mukherjee D, Chang DC, Bennett R, Brem H, et al. (2011) Preoperative charlson Comorbidity score predicts postoperative outcomes among older intracranial meningioma patients. World Neurosurg. 75(2): 279-285.
  59. Grabowska I, Scislo L, Pietruszka S, Walewska E, Paszko A, et al. (2017) The model of perioperative risk assessment in elderly patients interim analysis. Pol Merkur Lekarski 42(250): 151-157.
  60. Partridge JS, Harari D, Dhesi JK (2012) Frailty in the older surgical patient: a review. Age Ageing 41(2): 142-147.
  61. Adams P, Ghanem T, Stachler R, Hall F, Velanovich V, et al. (2013) Frailty as a predictor of morbidity and mortality in inpatient head and neck surgery. JAMA Otolaryngol Head Neck Surg 139(8): 783-789.
  62. Velanovich V, Antoine H, Swartz A, Peters D, Rubinfeld I (2013) Accumulating deficits model of frailty and postoperative mortality and morbidity: its application to a national database. J Surg Res 183(1): 104-110.
  63. Li JL, Henderson MA, Revenig LM, Sweeney JF, Kooby DA, et al. (2016) Frailty and one-year mortality in major intra-abdominal operations. J Surg Res 203(2): 507-12.
  64. Makary MA, Segev DL, Pronovost PJ, Syin D, Bandeen Roche K, et al. (2010) Frailty as a predictor of surgical outcomes in older patients. J Am Coll Surg 210(6): 901-918.
  65. Rolfson DB, Majumdar SR, Tsuyuki RT, Tahir A, Rockwood K (2006) Validity and reliability of the Edmonton Frail Scale. Age Ageing 35(5): 526- 529.

© 2018 Zhaosheng Jin,. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and build upon your work non-commercially.