Postoperative complications and mortality in older patients having non-cardiac surgery at three Melbourne teaching hospitals

Postoperative mortality and complications

Recent publications not only underline the risks of age and disease during surgery but also help us quantify the risks with greater precision. Importantly, patient factors often have a stronger association with postoperative mortality than surgical factors. Important factors preoperatively are: age, American Society of Anaesthesiologist (ASA) physical status, emergency surgery, and plasma albumin concentration. There is emerging work on quantifying frailty as a further risk factor for perioperative complication and mortality as well as need for higher level of care after discharge from hospital. Important postoperative complications include sepsis and kidney injury. Preventing, detecting and managing complications and mortality is the greatest challenge facing those caring for surgical patients, including anaesthetists. Evidence for the long term effects of perioperative complications adds further importance to minimizing perioperative complications. Newer approaches in patient care, particularly co-management during the postoperative phase by different specialities are emerging. Managing high-risk patients should also be enhanced with greater surveillance and more rapid and appropriate response; ensuring we do not fail to rescue our patients.

Systemic inflammation in the elderly

Inflammation is an adaptive response to surgery. When the pro-inflammatory responses are unregulated and become over reactive, systemic inflammatory response syndrome may occur. Postoperative systemic inflammation is more common than is generally acknowledged and is observed in about 10-15% of elderly patients undergoing major surgery. Although the vast majority of systemic inflammation is related to infections, other important predisposing risk factors, such as extent of trauma and haemorrhage, should not be overlooked. Increased awareness, modification of risk factors and early recognition are the key elements in the management of systemic inflammation. Prompt resuscitation aiming to correct hypotension, hypovolaemia and tissue hypoxia may improve outcome. Future large prospective observational studies are needed to define the incidence, risk factors and impact of systemic inflammatory syndrome in the elderly surgical patients. A better understanding of the molecular events during the systemic inflammatory response syndrome is required for future development of specific immunotherapy.

Markers of coagulation activation after hepatic resection for cancer: evidence of sustained upregulation of coagulation

We investigated the possibility that despite postoperative derangements of routine laboratory coagulation tests, markers of coagulation activation and thrombin generation would be normal or increased in patients undergoing hepatic resection for cancer In addition to the conventional coagulation tests prothrombin time and activated partial thromboplastin time, we measured select markers of coagulation activation prothrombin fragments 1 and 2 (PF1 + 2), thrombin-antithrombin complexes and plasma von Willebrand Factor antigen in 21 patients undergoing hepatic resection. The impact of hepatic resection on coagulation and fibrinolysis was studied with thromboelastography. Preoperatively, routine laboratory coagulation and liver function tests were normal in all patients. On the first postoperative day, prothrombin time was prolonged (range 16 to 22 seconds) in eight patients (38%). For these patients, thromboelastography was normal in six (75%), PF1 + 2 was elevated in four (50%), and thrombin-antithrombin complexes and von Willebrand Factor antigen were elevated in all, which was evidence of acute phase reaction, sustained coagulation factor turnover and activation. By the fifth postoperative day, despite normalisation of prothrombin time, markers of increased coagulation activity remained greater than 85% of baseline values. The findings indicate that in patients undergoing liver resection for cancer, there is significant and prolonged postoperative activation of the haemostatic system despite routine coagulation tests being normal or even prolonged. Before considering therapeutic interventions an integrated approach to interpreting haematological data with clinical correlation is essential.

Using National Surgical Quality Improvement Program (NSQIP) data for risk adjustment to compare Clavien 4 and 5 complications in open and laparoscopic colectomy

BACKGROUND

Laparoscopic colectomy has been associated with fewer postoperative complications than open colectomy. However, it is unclear whether this is true for the most severe complications typically requiring treatment in an intensive care unit (ICU). The authors hypothesized that laparoscopic colectomy patients have fewer of the most severe complications even after adjustment for comorbidity risk.

METHODS

Using the National Surgical Quality Improvement Program (NSQIP) public use files for 2005-2008, the authors identified all laparoscopic (n = 12,455) and open (n = 33,190) colectomies by current procedural terminology (CPT) code. Using the Clavien classification for postoperative complications, they identified NSQIP data points most consistent with Clavien grade 4 complications requiring ICU care (postoperative septic shock, postoperative dialysis, pulmonary embolism, myocardial infarction, cardiac arrest, prolonged ventilatory requirements, need for reintubation) or grade 5 complication (mortality). Statistical analysis was performed using SPSS software. Odds ratios were calculated to compare laparoscopic and open colectomy regarding the probability of having any Clavien class 4 or 5 complication. Logistic regression was performed to account for the effect of preoperative conditions (American Society of Anesthesiology class, wound class, gender, preoperative functional status, preoperative albumin level, azotemia, thrombocytopenia, emergency case, and age >70 years) on complications.

RESULTS

The univariate odds ratio showed a 2.27- to 5.52-fold greater likelihood that a patient would have a complication requiring ICU admission if open rather than laparoscopic surgery was performed (p < 0.001). Multivariate logistic regression accounting for preoperative comorbidities that might affect outcome showed persistence of an increase in complications, with an odds ratio range of 1.63 to 2.21.

CONCLUSION

Evaluation of the NSQIP database demonstrated that laparoscopic colectomy confers an independent protective effect on the frequency of ICU-level (Clavien grade 4) complications and mortality. The protective effect remained evident after correction for preoperative conditions that might have affected outcome.

Risk factors for mortality in major digestive surgery in the elderly: a multicenter prospective study

OBJECTIVE

To identify the mortality risk factors of elderly patients (≥65 years old) during major digestive surgery, as defined according to the complexity of the operation.

BACKGROUND

In the aging populations of developed countries, the incidence rate of major digestive surgery is currently on the rise and is associated with a high mortality rate. Consequently, validated indicators must be developed to improve elderly patients' surgical care and outcomes.

METHODS

We acquired data from a multicenter prospective cohort that included 3322 consecutive patients undergoing major digestive surgery across 47 different facilities. We assessed 27 pre-, intra-, and postoperative demographic and clinical variables. A multivariate analysis was used to identify the independent risk factors of mortality in elderly patients (n = 1796). Young patients were used as a control group, and the end-point was defined as 30-day postoperative mortality.

RESULTS

In the entire cohort, postoperative mortality increased significantly among patients aged 65-74 years, and an age ≥65 years was by itself an independent risk factor for mortality (odds ratio [OR], 2.21; 95% confidence interval [CI], 1.36-3.59; P = 0.001). The mortality rate among elderly patients was 10.6%. Six independent risk factors of mortality were characteristic of the elderly patients: age ≥85 years (OR, 2.62; 95% CI, 1.08-6.31; P = 0.032), emergency (OR, 3.42; 95% CI, 1.67-6.99; P = 0.001), anemia (OR, 1.80; 95% CI, 1.02-3.17; P = 0.041), white cell count > 10,000/mm³ (OR, 1.90; 95% CI, 1.08-3.35; P = 0.024), ASA class IV (OR, 9.86; 95% CI, 1.77-54.7; P = 0.009) and a palliative cancer operation (OR, 4.03; 95% CI, 1.99-8.19; P < 0.001).

CONCLUSION

Characterization of independent validated risk indicators for mortality in elderly patients undergoing major digestive surgery is essential and may lead to an efficient specific workup, which constitutes a necessary step to developing a dedicated score for elderly patients.

Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia

BACKGROUND & AIMS

Large sessile colonic polyps usually are managed surgically, with significant morbidity and potential mortality. There have been few prospective, intention-to-treat, multicenter studies of endoscopic mucosal resection (EMR). We investigated whether endoscopic criteria can predict invasive disease and direct the optimal treatment strategy.

METHODS

The Australian Colonic Endoscopic (ACE) resection study group conducted a prospective, multicenter, observational study of all patients referred for EMR of sessile colorectal polyps that were 20 mm or greater in size (n=479, mean age, 68.5 y; mean lesion size, 35.6 mm). We analyzed data on lesion characteristics and procedural, clinical, and histologic outcomes. Multiple logistic regression analysis identified independent predictors of EMR efficacy and recurrence of adenoma, based on findings from follow-up colonoscopy examinations.

RESULTS

Risk factors for submucosal invasion were as follows: Paris classification 0-IIa+c morphology, nongranular surface, and Kudo pit pattern type V. The most commonly observed lesion (0-IIa granular) had a low rate of submucosal invasion (1.4%). EMR was effective at completely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a prior attempt at EMR (odds ratio [OR], 3.8; 95% confidence interval, 1.77-7.94; P=.001) and ileocecal valve involvement (OR, 3.4; 95% confidence interval, 1.20-9.52; P=.021). Independent predictors of recurrence after effective EMR were lesion size greater than 40 mm (OR, 4.37; 95% confidence interval, 2.43-7.88; P<.001) and use of argon plasma coagulation (OR, 3.51; 95% confidence interval, 1.69-7.27; P=.0017). There were no deaths from EMR; 83.7% of patients avoided surgery.

CONCLUSIONS

Large sessile colonic polyps can be managed safely and effectively by endoscopy. Endoscopic assessment identifies lesions at increased risk of containing submucosal cancer. The first EMR is an important determinant of patient outcome-a previous attempt is a significant risk factor for lack of efficacy.

Perioperative mortality score: data collection and cost

The perioperative mortality score aims to predict mortality in elderly patients undergoing noncardiac surgery using three preoperative risk factors (age, albumin and American Society of Anesthesiologists physical status) and then modify this risk assessment if any of three postoperative complications occur (unplanned intensive care unit admission, systemic inflammation and acute renal failure). In order to determine the cost of routine perioperative mortality score calculation in future research, we audited the incidence of clinician-initiated preoperative albumin, pre- and postoperative creatinine and postoperative white cell count testing in patients aged > or = 70 years presenting for elective and emergency noncardiac surgery requiring at least overnight admission over a three-month period. We recruited 637 noncardiac surgical patients. All laboratory tests required for perioperative mortality score calculation were performed in only 47% of patients and the total cost of testing all untested patients was A$12,057 (A$18,927 per 1000 patients). Preoperative hypoalbuminaemia was present in 11% of tested patients, acute renal impairment in 24% of tested patients and high white cell count in 33% of tested patients. These results may be used to inform future research or clinical use of the score.

Defining higher-risk surgery

PURPOSE OF REVIEW

Defining the contemporary high-risk noncardiac surgical population using objective clinical outcomes data is paramount for the rational allocation of healthcare resources, truly informed patient consent and improving patient-centered outcomes.

RECENT FINDINGS

Data from independent healthcare systems have identified that the development, and consequences, of postoperative morbidity extend beyond the immediate postoperative hospital period and confer substantially increased risk of death. Cardiac insufficiency, rather than the relatively heavily explored paradigm of perioperative cardiac ischemia, is emerging as the dominant factor associated with excess risk of prolonged postoperative morbidity. The development of prospective, validated, time-sensitive morbidity data collection tools has also helped define patients at higher risk of noncardiac morbidities and short-term perioperative outcomes.

SUMMARY

Higher risk surgical patients present an increasingly major challenge for healthcare resource utilization. Detailed outcome studies using validated morbidity tools are urgently required to establish the extent to which postoperative morbidity may be predicted. Robust identification of patients at the highest risk of perioperative morbidity may permit further clinic-to-bench translational understanding of the pathophysiologic mechanisms underlying postoperative organ dysfunction. Defining the high-risk surgical patient population is as critically important for global public health planning as it is for the perioperative team.

[In-hospital mortality in surgical patients. Predictive factors]

OBJECTIVE

To analyze the value of patient and surgical variables as predictors of the survival until discharge of hospitalized surgical patients in a tertiary care hospital over the course of 1 year.

MATERIAL AND METHODS

The hospital records for patients admitted for surgery between January 1 and December 31, 2007, were consulted to extract age, sex, ASA physical status classification of the patient, type of admission and surgery (scheduled or emergency), surgical department assigned, and date of discharge or exitus. The data were subjected to multivariate survival analysis using the Cox regression model.

RESULTS

A total of 4184 patients underwent surgery in 2007; the median (25th-75th percentile) patient age was 56 (39-71) years. In 77.5% of the cases (3244 patients) surgery was scheduled; 23.1% of those patients had been admitted by the emergency department. The ASA classification was 1 for 21.8%, 2 for 44.2%, 3 for 28%, and 4 for 6%. Of patients classified as ASA 1-3, a total of 33.2% were aged 65 years or older; in contrast, 78.7% of ASA 4 patients were in that age bracket. Eighty-nine (2.1%) surgical patients died. Cox regression survival analysis showed that variables related to a lower likelihood of survival to discharge were a physical status classification of ASA 4, age 65 years or older, and emergency surgery (P < .0005 for all comparisons).

CONCLUSIONS

Patients over the age of 65 years, in an ASA 4 anesthetic risk category, admitted on an emergency basis for emergency surgery were at higher risk of death. Greater vigilance in the perioperative care of patients with these risk factors is advisable in the interest of reducing mortality.

Revised cardiac risk index and postoperative morbidity after elective orthopaedic surgery: a prospective cohort study

BACKGROUND

The revised cardiac risk index (RCRI) is associated strongly with increased cardiac ischaemic risk and perioperative death. Associations with non-cardiac morbidity in non-cardiac surgery have not been explored. In the elective orthopaedic surgical population, morbidity is common but preoperative predictors are unclear. We hypothesized that RCRI would identify individuals at increased risk of non-cardiac morbidity in this surgically homogenous population.

METHODS

Five hundred and sixty patients undergoing elective primary (>90%) and revision hip and knee procedures were studied. A modified RCRI (mRCRI) score was calculated, weighting intermediate and low risk factors. The primary endpoint was the development of morbidity, collected prospectively using the Postoperative Morbidity Survey, on postoperative day (POD) 5.

RESULTS

Morbidity on POD 5 was more frequent in patients with mRCRI ≥ 3 {relative risk 1.7, [95% confidence interval (CI): 1.4-2.1]; P<0.001}. Time to hospital discharge was delayed in patients with mRCRI score ≥ 3 (log-rank test, P=0.0002). Pulmonary (P<0.001), infectious (P=0.001), cardiovascular (P=0.0003), renal (P<0.0001), wound (P=0.02), and neurological (P=0.002) morbidities were more common in patients with mRCRI score ≥ 3. Pre/postoperative haematocrit, anaesthetic/analgesic technique, and postoperative temperature were similar across mRCRI groups. There were significant associations with hospital stay, as measured by the area under the receiver-operating characteristic curves for mRCRI 0.64 (95% CI: 0.58-0.70) and POSSUM 0.70 (95% CI: 0.63-0.75).

CONCLUSIONS

mRCRI score ≥ 3 is associated with increased postoperative non-cardiac morbidity and prolonged hospital stay after elective orthopaedic procedures. mRCRI can contribute to objective risk stratification of postoperative morbidity.

Pharmacoeconomics of Volatile Inhalational Anaesthetic Agents: An 11-Year Retrospective Analysis

With continuously increasing expenditure on health care resources, various cost containment strategies have been suggested in regard to controlling the cost of inhalational anaesthetic agents. We performed a cost identification analysis assessing inhalational anaesthetic agent expenditure at a tertiary level hospital, along with an evaluation of strategies to contain the cost of these agents.

The number of bottles of isoflurane, sevoflurane and desflurane used during the financial years 1997 to 2007 was retrospectively determined and the acquisition costs and cumulative drug expenditure calculated. Pharmacoeconomic modelling using low fresh gas flow anaesthesia was performed to evaluate practical methods of cost reduction.

The use of isoflurane decreased from 384 bottles during 1997 to 204 in 2007. In contrast, use of sevoflurane increased from 226 bottles during 1998 to 875 during 2007. Desflurane use increased from 34 bottles per year during 2002 (its year of introduction) to 163 bottles per year in 2007. While the inflation-adjusted cumulative expenditure for these inhalational agents (Australian dollars) increased from $132,000 in 1997 to over $326,000 in 2007, an increase of 168%, patient workload over the same period increased by only 11%. Pharmacoeconomic modelling demonstrated that sevoflurane at 2 l/minute costs 19 times more than isoflurane at 0.5 l/minute.

For the financial years 1997 to 2007, we found a progressive shift from the cheaper isoflurane to the more expensive agents, sevoflurane and desflurane, a shift associated with marked increases in costs. Low flow anaesthesia with isoflurane is one strategy to reduce costs.

Anti-Emetic Dexamethasone and Postoperative Infection Risk: A Retrospective Cohort Study

Nausea and vomiting are common complications of anaesthesia. Dexamethasone is an effective prophylaxis but is immunosuppressive and may increase postoperative infection risk. This retrospective cohort study examined the association between the administration of a single intraoperative anti-emetic dose of dexamethasone (4 to 8 mg) and postoperative infection in 439 patients undergoing single procedure, non-emergency surgery in a university trauma centre. Exclusion criteria included comorbidities, immunosuppressive medications or procedures that confer an increased infection risk. In the 10-week study period and three-month follow-up period, there were 98 documented infections (22.3% of the cohort), of which 43 were detected only on post-discharge follow-up. Anti-emetic dexamethasone was given to 108 patients (24.6%). Stepwise, multivariate logistic regression modelling identified significant associations between female gender, symptomatic reflux, respiratory disease and the risk of infection. The adjusted odds ratio for dexamethasone was 0.88 (0.5 to 1.5, P=0.656). We did not demonstrate an association between anti-emetic doses of dexamethasone and postoperative infection.

Single dose Dexamethasone for Postoperative Nausea and Vomiting – a Matched Case-Control Study of Postoperative Infection Risk

Dexamethasone is an effective prophylaxis against postoperative nausea and vomiting but is immunosuppressive and may predispose patients to an increased postoperative infection risk. This matched case-control study examined the association between the administration of a single intraoperative anti-emetic dose of dexamethasone (4 to 8 mg) and postoperative infection in patients undergoing non-emergency surgery in a university trauma centre. Cases were defined as patients who developed infection between one day and one month following an operative procedure under general anaesthesia. Controls who did not develop infection were matched for procedure, age and gender. Exclusion criteria included immunosuppressive medications, chronic glucocorticoid therapy, cardiac surgical and solid-organ transplantation procedures. Sixty-three cases and 172 controls were identified. Cases were more likely to have received dexamethasone intraoperatively (25.4 vs 11%, P=0.006), and less likely to have received perioperative antibiotic prophylaxis (60.3 vs 84.3%, P=0.001). Stepwise, multivariate conditional logistic regression confirmed these associations, with adjusted odds ratios of 3.03 (1.06 to 19.3, P=0.035) and 0.12 (0.02 to 0.7, P=0.004) respectively for the associations between dexamethasone and perioperative antibiotic prophylaxis, with postoperative infection. We conclude that intraoperative administration of dexamethasone for anti-emetic purposes may confer an increased risk of postoperative infection.

Interpleural analgesia for attenuation of postoperative pain after hepatic resection

SUMMARY

We performed a prospective randomised trial to evaluate the analgesic efficacy of interpleural analgesia in patients undergoing hepatic resection. The control group (n = 25) received multimodal analgesia with intravenous morphine patient-controlled analgesia; in addition, the interventional group (n = 25) received interpleural analgesia with a 20-ml loading dose of levo bupivacaine 0.5% followed by a continuous infusion of levobupivacaine 0.125%. Outcome measures included pain intensity on movement using a visual analogue scale over 24 h, cumulative morphine and rescue analgesia requirements, patient satisfaction, hospital stay and all adverse events. Patients in the interpleural group were less sedated and none required treatment for respiratory depression compared to 6 (24%) in the control group (p< 0.01). Patients in the interpleural group also had lower pain scores during movement in the first 24 h. Patients' satisfaction, opioid requirements and duration of hospital stay were similar. We conclude that continuous interpleural analgesia augments intravenous morphine analgesia, decreases postoperative sedation and reduces respiratory depression after hepatic resection.

Elderly POSSUM, a dedicated score for prediction of mortality and morbidity after major colorectal surgery in older patients

BACKGROUND

Several scores have been developed to evaluate surgical unit mortality and morbidity. The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and derivatives use preoperative and intraoperative factors, whereas the Surgical Risk Scale (SRS) and Association Française de Chirurgie (AFC) score use four simple factors. To allow for advanced age in patients undergoing colorectal surgery, a dedicated score-the Elderly (E) POSSUM-has been developed and its accuracy compared with these scores.

METHODS

From 2002 to 2004, 1186 elderly patients, at least 65 years old, undergoing major colorectal surgery in France were enrolled. Accuracy was assessed by calculating the area under the receiver operating characteristic curve (AUC) (discrimination) and calibration.

RESULTS

The mortality and morbidity rates were 9 and 41 per cent respectively. The E-POSSUM had both a good discrimination (AUC = 0.86) and good calibration (P = 0.178) in predicting mortality and a reasonable discrimination (AUC = 0.77) and good calibration (P = 0.166) in predicting morbidity. The E-POSSUM was significantly better at predicting mortality and morbidity than the AFC score (P(c) = 0.014 and P(c) < 0.001 respectively).

CONCLUSION

The E-POSSUM is a good tool for predicting mortality, and the only efficient scoring system for predicting morbidity after major colorectal surgery in the elderly.

Perioperative fluid prescription, complications and outcomes in major elective open gastrointestinal surgery

Perioperative fluid therapy and associated outcomes of patients undergoing major elective open gastrointestinal surgery are poorly understood. This study measured perioperative fluid therapy, complication rates and outcomes for major elective open gastrointestinal surgery in a tertiary care hospital. We obtained demographic data, operative details, fluid prescription, complications and outcomes in 100 patients. Patients were elderly and had multiple comorbidities. Median delivered intraoperative fluid volume was 4.2 litres, followed by 6.3 litres over the subsequent 24 hours. Perioperative fluid prescription was associated with a positive fluid balance. Complications occurred in 57% of patients with 32% experiencing at least one major complication. Serious complications were substantially more frequent in patients having non-colorectal operations. The most common adverse events were pulmonary oedema (21%), ileus (18%), serious sepsis (17%), pneumonia (17%), arrhythmias (14%), delirium (14%) and wound healing problems (infections 13%, anastomotic leaks 12%). Mortality at 30 days was 2%. This study provides planning data for future interventional studies.

Predictors of length of stay following colorectal resection for neoplasms in 183 Veterans Affairs patients

BACKGROUND

There is increasing pressure to reduce the length of stay in hospital (LOS) after colorectal surgery. The aim of this study was to identify factors that prolong LOS after colorectal surgery in a population of veterans.

METHODS

Retrospective analysis was performed of all patients undergoing colorectal resection for a neoplasm at a single Veterans Affairs (VA) hospital (2002-2007). Data collected included demographics, co-morbidities, operative management, postoperative morbidity and mortality, nutritional status, and LOS. Statistical analysis included descriptive statistics, univariate analysis, and multivariate analysis.

RESULTS

A total of 186 patients were identified. Three patients had an LOS of more than 100 days and were omitted from the analysis. The median LOS was 8 days. Multivariate analysis showed only two variables: coronary artery disease (CAD) and postoperative complications were predictive of prolonged LOS. Chronic obstructive pulmonary disease (COPD) was the only preoperative morbidity predictive of complications.

CONCLUSIONS

The aim of this study was to identify factors that prolong LOS after colorectal surgery in a VA population. We found that CAD and postoperative complications were the only variables predictive of prolonged LOS after colorectal resection, and COPD was the only factor predictive of postoperative complications.

Cardiac complications and mortality rates in diabetic patients following non-cardiac surgery in an Australian teaching hospital

This retrospective study of diabetic patients undergoing non-cardiac surgery has identified that a greater number of patients are at risk of cardiac complications and death in the perioperative period than had previously been suggested. As well as insulin-dependent diabetic patients and patients with elevated creatinine (> 178 micromol/l) as previously found, our study suggests that non-insulin-dependent diabetic patients and patients with creatinine > 120 micromol/l are also at increased risk of cardiac complications and death following non-cardiac surgery. This increases by a factor of six those diabetic patients at risk of perioperative complications from non-cardiac surgery and also increases the number of patients with renal failure similarly at risk. The study confirms similar risks of cardiac complications and death to other recently published data and suggests ongoing comparisons will contribute to quality assurance activities in anaesthesia and surgery.

Effect of subjective preoperative variables on risk-adjusted assessment of hospital morbidity and mortality

OBJECTIVE

To examine the influence of American Society of Anesthesiologists Physical Status Classification (ASA) and preoperative Functional Health Status (FHS) variables on risk-adjusted estimates of surgical quality and to assess whether classifications are inflated at some hospitals.

BACKGROUND

ASA and FHS are influential in risk-adjusted comparisons of surgical quality. However, because ASA and FHS are subjective they can be inflated, making patients appear more ill than they actually are, and crediting hospitals for a sicker patient population.

METHODS

We identified 28,751 colorectal surgery patients at 170 hospitals participating in the American College of Surgeon's National Surgical Quality Improvement Program (ACS NSQIP) during 2006 to 2007. Logistic regression models were developed for morbidity and mortality with and without inclusion of ASA and FHS. Hospital quality rankings from the different models were compared.

RESULTS

Morbidity and mortality rates were 24.3% and 3.9%, respectively. Percents of patients in ASA classes I through V were 3.3%, 46.4%, 41.5%,8.3%, and 0.7% and that were independent or partially or totally dependent were 89.2%, 7.2%, and 3.6%, respectively. Models that included ASA and FHS exhibited slightly better fit (Hosmer-Lemshow statistic) and discrimination(c-statistic) than models without both these variables, though magnitudes of differences were consistent with chance. There was inconsistent evidence for improper assignment of ASA and FHS.

CONCLUSIONS

The small improvements in model quality when both ASA and FHS are present versus absent, suggest that they make a unique contribution to assessing severity of preoperative risk. With little indication that these subjective variables are subject to an important level of institutional bias, it is appropriate that they be used to assess risk-adjusted surgical quality. Periodic monitoring for inappropriate inflation of ASA status is warranted.

Perioperative Mortality Risk Score using Pre- and Post-operative Risk Factors in Older Patients

We developed a risk score for 30-day postoperative mortality: the Perioperative Mortality risk score. We used a derivation cohort from a previous study of surgical patients aged 70 years or more at three large metropolitan teaching hospitals, using the significant risk factors for 30-day mortality from multivariate analysis. We summed the risk score for each of six factors creating an overall Perioperative Mortality score. We included 1012 patients and the 30-day mortality was 6%.

The three preoperative factors and risk scores were (“three A's”): 1) age, years: 70 to 79=1, 80 to 89=3, 90+=6; 2) ASA physical status: ASA I or II=0, ASA III=3, ASA IV=6, ASA V=15; and 3) preoperative albumin <30 g/l=2.5.

The three postoperative factors and risk scores were (“three I's”) 1) unplanned intensive care unit admission =4.0; 2) systemic inflammation =3; and 3) acute renal impairment=2.5. Scores and mortality were: <5=1%, 5 to 9.5=7% and ≥10=26%.

We also used a preliminary validation cohort of 256 patients from a regional hospital. The area under the receiver operating characteristic curve (C-statistic) for the derivation cohort was 0.80 (95% CI 0.74 to 0.86) similar to the validation C-statistic: 0.79 (95% CI 0.70 to 0.88), P=0.88. The Hosmer-Lemeshow test (P=0.35) indicated good calibration in the validation cohort. The Perioperative Mortality score is straightforward and may assist progressive risk assessment and management during the perioperative period. Risk associated with surgical complexity and urgency could be added to this baseline patient factor Perioperative Mortality score.

Postoperative complications in elderly patients and their significance for long-term prognosis

PURPOSE OF REVIEW

To outline perioperative risk factors for postoperative mortality in older patients, the relationship of these factors with long-term mortality, and to examine possible strategies to reduce mortality.

RECENT FINDINGS

For patients aged 70 years and over 30-day mortality is about 6%, whereas 20% are likely to have at least one complication during their hospital stay. The mortality risk increases by 10% for every year after age 70. Mortality is also strongly associated with preoperative status and postoperative complications, particularly systemic inflammation and renal impairment. Unplanned postoperative intensive care unit admission is an important predictor for mortality. Requirement for postoperative vasopressors or inotropes is associated with 50% mortality in patients aged 80 years or more. Early postoperative complications are likely to be associated with an increased long-term (a year or more later) mortality. Strategies such as critical care outreach may decrease both 30-day and long-term mortality.

SUMMARY

Strategies are needed to prevent, or at least adequately manage, complications in elderly patients. Agreed international definitions for risks and complications can help in assessing risks and benefits.