Events In Postoperative Patients Research Articles

Frequent respiratory events in postoperative patients aged 60 years and above.

There is limited information on the occurrence of respiratory events in postoperative patients after discharge from the postanesthesia care unit. We studied the respiratory rate (RR) of 68 patients aged 60 years and above during the first 6 hours following elective surgery under general anesthesia to assess the frequency of respiratory events in the care unit and on the ward. RR was derived from the continuous RR counter RespiR8, measuring RR by quantifying the humidity of exhaled air. One-minute-averaged RRs were collected and analyzed to assess the frequency of postoperative bradypnea (RR 1–6 breaths/minute) and apnea (cessation of inspiratory flow ≥60 seconds). Values were median (interquartile range) or mean (SD). The median RR was 13 (10–15) breaths/minute. In the 6-hour postoperative period, 78% and 57% of patients experienced at least one bradypnea or apnea event, respectively. A median of ten (3.5–24) bradypnea and three (1–11) apnea events were detected per patient. The occurrence of respiratory events in the postanesthesia care unit (PACU) was a predictor of events on the ward (bradypnea, r2=0.4, P<0.001; apnea, r2=0.2, P<0.001). Morphine consumption correlated weakly with respiratory events in the PACU, but not on the ward. Patients with apnea had significantly larger neck circumference than patients without (39.6 [0.7] versus 37.4 [0.8] cm, P<0.05). Bradypneic or apneic respiratory events are frequent in postoperative elderly patients and even occur relatively late after surgery. Continuous respiratory monitoring on the ward, especially in patients with risk factors, such as early occurrence of events, opioid use, and larger neck circumference, is likely warranted.

Frailty Is Predictive of Adverse Postoperative Events in Patients Undergoing Lumbar Fusion.

Study Design:Retrospective study of prospectively collected data.Objective:To analyze the modified frailty index (mFI) as a predictor of adverse postoperative events following posterior lumbar fusion.Methods:The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database including all adult patients undergoing posterior lumbar interbody fusion or transforaminal lumbar interbody fusion between 2005 and 2012. Outcomes measured included mortality, postoperative complications, length of stay, reoperations, and readmissions. The previously described mFI was calculated, and univariate and multivariate logistic regression analysis were used to analyze risk factors associated with morbidity, mortality, and adverse postoperative events. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board.Results:A total of 6094 patients met inclusion criteria. The mean mFI was 0.087(0-0.545). Increasing mFI score was associated with increased complications, reoperations, prolonged length of stay (LOS), and morbidity (P < .05). As the mFI score increased from 0.27 (3/11 variables present) to ≥0.36 (4/11), the rate of any complication increased from 26.8% to 35% (P < .0001), sepsis 2.4% to 5.2% (P < .0001), wound complications 4.4% to 6.5% (P < .0001), unplanned readmissions 4.7% to 20% (P = .02), and urinary tract infection 4.1% to 10.4% (P < .0001). An mFI of ≥0.36 was an independent predictor of any complication (odds ratio [OR]= 2.2, 95% confidence interval [CI] = 1.3-3.7), sepsis (OR = 6.3, 95%, CI = 1.8-21), wound complications (OR = 2.9, 95% CI = 1.1-8.2), prolonged LOS (OR = 2.3, 95% CI = 1.4-3.7), and readmission (OR = 4.3, 95% CI = 1.5-12.7).Conclusion:Patients with higher mFI scores (≥ 4/11 variables) are at a significantly higher risk of major complications, readmissions, and prolonged LOS following lumbar fusion.

Frailty Index as a Predictor of Adverse Postoperative Outcomes in Patients Undergoing Cervical Spinal Fusion.

Retrospective study of prospectively collected data. To investigate the applicability of the modified frailty index (mFI) as a predictor of adverse postoperative events in patients undergoing anterior cervical discectomy and fusion (ACDF) or posterior cervical fusion (PCF). Prior studies have investigated the mFI and shown it as an independent predictor of adverse postoperative outcomes across multiple surgical specialties. However, this topic has not still been studied in patients undergoing cervical fusion or in spinal surgery. The National Surgical Quality Improvement Program is a multicenter clinical registry that prospectively collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from about 400 hospitals nationwide. Current Procedural Terminology codes were used to query the database for adults who underwent elective ACDF and PCF between 2005 and 2012. The mFI was calculated for each patient. Univariate analysis and multivariate logistic regression were used to analyze the mFI as a predictor for postoperative complications. For ACDF group, Clavien-Dindo grade IV complications rate increased from 0.8% to 9.0% as mFI increased from 0 to ≥0.27, and mFI = 0.27 was found to be an independent predictor of Clavien-Dindo grade IV complications (odds ratio, OR, = 4.67, 95% confidence interval, CI, = 2.27-9.62, P < 0.001). For PCF groups, Clavien-Dindo grade IV complications rate increased from 0.7% to 20.0% as mFI increased from 0 to ≥0.36, and mFI ≥ 0.36 was identified as an independent predictor of Clavien-Dindo grade IV complications (OR = 41.26, 95% CI = 6.62-257.15, P < 0.001). The mFI was shown to be an independent predictor of Clavien-Dindo grade IV complications in patients undergoing ACDF or PCF. The mFI itself may be used to stratify risks in patients undergoing cervical fusion, or, the mFI scheme could be used as a platform upon which more efficient risk stratification could be done with addition of other variables. 4.

Diabetes as an Independent Predictor for Extended Length of Hospital Stay and Increased Adverse Post-Operative Events in Patients Treated Surgically for Cervical Spondylotic Myelopathy.

Diabetes as an independent driver of peri-operative outcomes, and whether its severity impacts indications is conflicted in the research. The purpose of this study is to evaluate diabetes as a predictor for postoperative outcomes in cervical spondylotic myelopathy (CSM) patients. A retrospective review was performed of patients treated surgically for CSM (ICD-9 721.1) from 2010-2012 in the prospectively-collected American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Outcome measures were length of stay, and the presence of complications. Diabetic patients were stratified based on whether or not their diabetes was insulin- or non-insulin-dependent. A total of 5,904 surgical CSM patients were included, 1101 (19%) had diabetes. 722 (65%) were non-insulin-dependent diabetics, and 381 (35%) were insulin-dependent diabetics. Diabetes was found to be an independent predictor of extended LOS (OR: 1.878[2.262-1.559], p<0.001) as well as of developing a complication (OR: 1.666[2.217-1.253], p<0.001) after controlling for associated variables like BMI. Type of diabetes (insulin- vs. non-insulin-dependent) showed little significant difference between the groups (p>0.05), however, patients with insulin-dependent diabetes were associated with an increased incidence of wound complications (p=0.027); severity of diabetes was not associated with any other individual complications. Type and severity of diabetes is not a predictor for complication. Diabetes is associated with extended LOS and peri-operative morbidity. Level of evidence: Class 2b. Clinical relevance: Our findings support the view of many spine surgeons, who believe that diabetes has a negative impact on the outcome of surgery for CSM. Our findings support those cohort studies that found an association between diabetes and worst post-operative outcomes following surgical treatment of CSM. These findings lend support to the importance of monitoring preoperative serum glucose levels, as prevention of peri-operative hyperglycemia has been linked to improved postoperative outcomes in spine, joint and colon surgery.

Frailty is associated with morbidity in adults undergoing elective anterior lumbar interbody fusion (ALIF) surgery

Background ContextPrior studies have suggested no significant differences in functional status and postoperative complications of elderly versus nonelderly patients undergoing posterior lumbar interbody fusion; however, similar studies have not been comprehensively investigated in the setting of anterior lumbar interbody fusion (ALIF). PurposeThe objective was to quantify the ability of the modified Frailty Index (mFI) to predict postoperative events in patients undergoing ALIF. Study DesignSecondary analysis of prospectively collected data. Patient SamplePatients undergoing ALIF in the National Surgical Quality Improvement Program (NSQIP) participant files for the period 2010 through 2014. Outcomes MeasuresOutcome measures included any postoperative complication, return to operating room (OR), and length of stay >5 days. MethodsNSQIP participant files from 2010 to 2014 were used to identify patients undergoing ALIF. The mFI used in the present study is an 11-variable assessment that maps 16 NSQIP variables to 11 variables in the Canadian Study of Health and Ageing Frailty Index. Univariate analysis and multivariable logistic regression models were used to compare the relative strength of association between mFI with outcome variables of interest. ResultsIn total, 3,920 ALIF cases were identified and grouped according to their mFI score: 0 (n=2,025), 0.09 (n=1,382), 0.18 (n=464), or ≥0.27 (n=49). As the mFI increased from 0 (no frailty-associated variables) to 0.27 (4 of 11) or higher, there was a significant stepwise increase in any complication from 10.8% to 32.7%. After multivariable regression analysis, no significant association was found between higher mFI scores with urinary tract infections and venous thromboembolism. High frailty scores were significant predictors of any complication (mFI of ≥0.27 [reference: 0]; OR 2.4; p=.040) and pulmonary complications (mFI score ≥0.27; OR 7.5; p=.001). ConclusionsIn summary, high mFI scores were found to be independently associated with any complication and pulmonary complications in patients who underwent ALIF. The use of mFI together with traditional risk factors may help better identify high-surgical risk patients, which may be useful for preoperative and postoperative care optimization.

Coronary artery calcium score and coronary computed tomographic angiography for major perioperative cardiovascular complications in symptomatic diabetic patients undergoing trans-femoral amputation

ObjectivePerioperative risk for major cardiovascular events (MACE) is particularly high in patients with type 2 diabetes undergoing surgery for trans-femoral amputation (TFA). The aim of this study was to identify prognostic value of coronary calcium score (CACS) and coronary computed tomographic angiography (CCTA) for perioperative MACE in these patients. MethodsIn this prospective single center interventional cohort study, we evaluated 331 consecutive symptomatic patients with diabetes and without history of coronary intervention or myocardial infarction (MI) undergoing TFA in 2013. 179/331 patients (54%) had no contraindications for CCTA and were included in the study cohort. ResultsAll patients had revised cardiac risk index score of 3 or more points (class IV with MACE rate of 11%). Increasing calcium score was associated with increasing severity of CAD by CCTA and incidence of cardiovascular complications. During 25weeks of follow-up, there were 43 MACE (24%), 28(15.6%) of them cardiac death. Post-operative event rate increased in patients with increasing CACS from 10% with CACS 1–99 to 84% with CACS>1000 (p<0.001). Similarly, there were more post-operative events in patients with 3- and 2-vessels disease compared to 1-vessel obstructive and non-obstructive CAD (74.1% and 34.1% vs. 10.5% and 6.5%, p<0.001). ConclusionsPredicative value of CCTA and CACS is high for perioperative MI and death in patients with type 2 diabetes undergoing non-cardiac surgery for TFA. It may be considered as a valuable tool for preoperative risk assessment in these patients, where stress tests are not feasible and more sophisticated technical equipment is not available.

Clinical thromboembolic detterrent stockings application: are thromboembolic detterrent stockings in practice matching manufacturers application guidelines.

Thromboembolic detterrent (TED) stockings have been shown to be effective in the reduction of thromboembolic events in post operative patients. These manufactured stockings create graduated compression from ankle to calf. To assess whether the manufacturers' recommendations for application were being met in a District general hospital setting and whether this achieved the desired gradient of compression. We carried out pressure measurements on 100 legs in post-operative patients and recorded reasons for poorly fitting stockings. Pressure measurements were taken at standard positions around calf and ankle using a pre-calibrated subbandage pressure measuring device. About 20% of stockings were worn incorrectly by patients. Median pressure applied at the ankle was 13 mmHg (range, 6.5-18.5) compared to the manufacturers' intended compression of 18 mmHg. Only 14% of the stockings showed an acceptable gradation of reduced pressure between ankle and calf. About 23% of the stockings exerted a positive pressure at calf level compared to the ankle. Most TED stockings do not produce a standardised Siegel profile pressure gradient decrease from ankle to calf. This may be due in part to fluid changes after surgery in combination with the large variation in size of lower limbs. Our District general hospital utilises three of the six sizes of TED stocking, and remeasurement was not taking place every 24 h as per guidance. This as the result show not only negates the benefit of TED stockings but may also exert harm in terms of venous thromboembolism risk. This finding adds further weight to the argument of whether TED stockings may not be having the desired prophylactic effect and may even be resulting in harm in select cases.

Heparin Dose and Postoperative Bleeding in Patients Undergoing Cardiopulmonary Bypass

Heparin is the most widely used anticoagulant for cardiopulmonary bypass (CPB). Several authors suggest that lower doses of heparin during CPB would produce lower postoperative chest tube losses and fewer transfusion events. In the present study, a heparin dose–response (HDR) test was used to determine the heparin dose for each patient. We hypothesize that higher doses of heparin do not cause increased postoperative bleeding and transfusion events in postoperative patients undergoing CPB when the heparin dose is determined by a HDR test. This prospective observational study followed 66 patients undergoing CPB-supported primary coronary artery bypass grafting. Patients were placed in one of two groups, sensitive (n = 37) or resistant (n = 29) based on the result of a HDR test slope. Data on patient characteristics, secondary outcomes, transfusion, and the primary outcome, chest tube losses, were collected. Patient characteristics differed in the baseline activated coagulation time (ACT) and thromboelastograph G parameter as well as number of patients with hypercholesterolemia. The resistant group had lower postheparin and postprotamine ACTs and heparin sensitivity index. Initial heparin dose, total heparin dose, heparin dose per kilogram, HDR, and protamine dose were higher in the heparin-resistant group. The primary outcome, postoperative chest tube loss volume, was collected at four time points and the two groups were then compared. The heparin-resistant group was noninferior to the sensitive group and had clinically fewer transfused patients and transfusion events. The resistant group was noninferior to the sensitive group with respect to chest tube losses at all measured time points. Higher doses of heparin determined by a HDR test do not cause increased postoperative chest tube losses or increased transfusion events.

From Creatine Kinase-MB to Troponin

From Creatine Kinase-MB to Troponin

Blood Transfusion and its Effect on the Clinical Outcomes of Patients Undergoing Major Lower Extremity Amputation

Patients in need of lower extremity amputation are often debilitated and have coronary artery disease and underlying anemia. The transfusion of blood is a common practice in the perioperative management of these patients. However, blood transfusion has been reported to have a negative effect on the incidence of perioperative complications in other patient populations. We undertook this study to determine the effect of blood transfusion on the incidence of adverse postoperative events in patients undergoing major amputations. We conducted a retrospective review of 300 consecutive patients undergoing either above-knee or below-knee amputation over a 5-year period at our institution. The demographic variables, medical comorbidities, need for blood transfusion, and clinical outcomes were recorded. The impact of blood transfusion on clinical outcome was analyzed. Of the 300 patients undergoing major amputation, 191 (64%) had one or more blood transfusions. The demographic variables and incidence of medical comorbidities were comparable between the two groups. Patients undergoing blood transfusion were 2.5 more likely to suffer from a postoperative cardiac arrhythmia, 12.8 times more likely to develop acute renal failure, 5.7 times more likely to have pneumonia, and 2.2 times more likely to have a urinary tract infection. Each of these adverse postoperative events was statistically more likely in the transfused group. The postoperative mortality was 13% for the transfused group and 6% for those not transfused, which was a nonsignificant difference. The intensive care unit stay and overall hospital stay were significantly longer in patients who had blood transfusions (difference of 2.1 and 5.4 days, respectively). Blood transfusion in patients undergoing major lower extremity amputation is associated with an increased incidence of adverse postoperative events and prolonged intensive care unit and hospital stays. We therefore suggest a restricted approach to blood transfusion in patients requiring major amputation.

Elevated C-reactive protein levels are associated with postoperative events in patients undergoing lower extremity vein bypass surgery

Elevated C-reactive protein levels are associated with postoperative events in patients undergoing lower extremity vein bypass surgery

Elevated C-reactive protein levels are associated with postoperative events in patients undergoing lower extremity vein bypass surgery

Inflammatory markers such as high-sensitivity C-reactive protein (hsCRP) are associated with an increased risk of cardiovascular events and with the severity of peripheral arterial disease. The effects of inflammation on the development of vein graft disease remain speculative. We hypothesized that high levels of inflammatory markers would identify patients at increased risk for adverse events (graft failure, major cardiovascular events) after lower extremity bypass surgery. Patients (n = 91) scheduled to undergo lower extremity bypass using autogenous vein were enrolled into a prospective study at two institutions. Exclusion criteria included the presence of major infection. A baseline plasma sample was obtained on the morning of lower extremity bypass. Biomarkers for inflammation included hsCRP, fibrinogen, and serum amyloid A (SAA). Values between patients with and without critical limb ischemia were compared. Proportions of events among dichotomized populations (upper limit of normal of each laboratory assay) were compared by log-rank test. Of the patients undergoing lower extremity bypass, 69% were men, 53% were diabetic, 81% were smokers, and their mean ankle-brachial index was 0.51 +/- 0.19. The indication for lower extremity bypass was critical limb ischemia in 55%. There were no perioperative deaths and two early graft occlusions. During a mean follow-up of 342 days (range, 36-694 days) there were four deaths, 27 graft-related events, and 10 other cardiovascular events. No relationships were found between events and demographics, comorbidities, baseline ankle-brachial index, or statin use. High-sensitivity CRP (P = .005), fibrinogen (P < .001), and SAA (P = .0001) levels were associated with critical limb ischemia at presentation. Among patients with an elevated hsCRP (>5 mg/L) immediately before surgery, major postoperative vascular events occurred in 60% (21/35), compared with a 32% (18/56) rate in those with a baseline CRP <5 mg/L (P = .004, log-rank test). On multivariable analysis, only elevated hsCRP correlated with adverse graft-related or cardiovascular events (P = .018). The inflammatory biomarkers of hsCRP, fibrinogen, and SAA correlate with peripheral arterial disease severity at presentation in patients undergoing lower extremity bypass. Patients with elevated hsCRP are at increased risk for postoperative vascular events, most of which are related to the vein graft. These findings suggest a potential relationship between inflammation and outcomes after lower extremity vein bypass surgery.

Assessment of cardiac risk before nonvascular surgery: Dobutamine stress echocardiography in 530 patients

OBJECTIVEThis study evaluated the incremental value of dobutamine stress echocardiography (DSE) for assessment of cardiac risk before nonvascular surgery.BACKGROUNDLimited information exists regarding the preoperative assessment of cardiac risk in patients with known or suspected coronary artery disease who are to undergo nonvascular surgery.METHODSAll patients (303 men, 227 women) who underwent DSE before nonvascular surgery and did not sustain an intervening event (coronary revascularization or cardiac event) were studied. Clinical, electrocardiographic and rest and stress echocardiographic variables were evaluated to identify predictors of postoperative cardiac events.RESULTSEvents occurred in 6% of patients: 1 cardiac death and 31 nonfatal myocardial infarctions. All of these patients had inducible ischemia on DSE (sensitivity 100%, specificity 63%). Multivariate predictors of postoperative events in patients with ischemia were history of congestive heart failure (p = 0.006; odds ratio = 4.66; confidence interval 1.55 to 14.02) and ischemic threshold less than 60% of age-predicted maximal heart rate (p = 0.0001; odds ratio 7.002; confidence interval 2.79 to 17.61). Clinical variables of Eagle’s index identified 21% of patients as low, 68% as intermediate and 11% as high risk preoperatively; the postoperative event rates were 3%, 6% and 14%, respectively. Dobutamine stress echocardiography identified 60% of patients as low (no ischemia), 32% as intermediate (ischemic threshold 60% or more) and 8% as high risk (ischemic threshold < 60%); postoperative event rates were 0%, 9% and 43%, respectively.CONCLUSIONSIn this population of patients with known or suspected coronary artery disease evaluated before nonvascular surgery, DSE had incremental value over clinical, electrocardiographic and rest echocardiographic variables for identifying patients at low, intermediate and high risk for postoperative cardiac events. Ischemia occurring at less than 60% of age-predicted maximal heart rate identified patients at highest risk.