Intraoperative monitoring of myocardial ischemia

Cardiovascular complications are commonly observed in surgical patients, and myocardial ischemia is the most important determinant of perioperative morbidity. The clinical criteria defining a patient population at increased risk for cardiovascular events are presented. The authors review the principles of monitoring and diagnosing myocardial ischemia, focusing on eletrocardiography and TransEsophageal Echocardiography. These patients must be closely followed long after the end of surgery, since the risk for cardiac morbidity is high for several hours postoperatively.     

Postoperative care and analgesia in vascular surgery

Patients undergoing major vascular surgery are high risk for myocardial infarction, renal failure, respiratory complications and death. Invasive procedures confer greater risk of complication, with patients undergoing open aortic surgery being at highest risk. Endovascular procedures are less invasive, yet not devoid of potentially serious complications. Reduction of myocardial oxygen demand is key, as is stabilizing cardiovascular parameters, maintaining normothermia, adequate volume resuscitation and effective analgesia. Continuation of preoperative risk-reduction strategies including aspirin, beta-blockers and statin therapies are critical, and should be continued in the postoperative period. Maintaining a high index of suspicion for procedure-specific complications is essential in order to reduce morbidity and mortality in these patients.     

Postoperative care and analgesia in vascular surgery

Patients undergoing major vascular surgery are high risk for myocardial infarction, renal failure, respiratory complications and death. Invasive procedures confer greater risk of complication, with patients undergoing open aortic surgery being at highest risk. Endovascular procedures are less invasive, yet not devoid of potentially serious complications. Reduction of myocardial oxygen demand is key: stabilizing cardiovascular parameters, maintaining normothermia, adequate volume resuscitation and effective analgesia. Continuation of preoperative risk-reduction strategies including aspirin, beta-blockers and statin therapies are critical, and should be continued in the postoperative period. Maintaining a high index of suspicion for procedure-specific complications is essential in order to reduce morbidity and mortality in these patients.     

Evaluation of perioperative risk in elderly patients

From a medical point of view, aging is characterized by a potential failure to maintain homeostasis under conditions of physiological stress. This failure is associated with an increase in vulnerability. Physiological changes associated with aging are progressive but concomitant injury or diseases may rapidly worsen the health status of the patient. Increasing age independently predicts morbidity and mortality. Hypertension and dyspnea are probably two of the most frequent risk factors in elderly patients. The history of the elderly patient should assess functional status, including cardiovascular reserve sufficient to withstand very stressful operations. The type of surgery has important implications for perioperative risk and emergency surgery, particularly in the elderly, is associated with a high risk of morbidity. Elderly patients who are otherwise acceptable surgical candidates should not be denied surgery based solely on their age and concerns for postoperative renal, cardiovascular, cognitive or pulmonary complications. Renal impairment becomes more prevalent with advancing age as the glomerular filtration rate decreases. The surgical site is the single most important predictor of pulmonary complications. Concerning postoperative comfort and neurological complications, age is the highest risk factor for developing dementia. Pain is underassessed and undermanaged. The elderly are at higher risk of adverse consequences from unrelieved or undertreated pain.     

Surgical management of hemodialysis patients

Ophthalmic surgeons can expect increased opportunities in the future to treat patients who undergo maintenance hemodialysis. Such patients often present with complex medical problems and carry high risk factors for surgery. Nevertheless, the full range of ophthalmic surgical procedures can be accomplished without increased morbidity when patient management is carefully organized between the ophthalmologist and nephrologist. In this report the physiology of the functionally anephric patient is reviewed. Attention is directed to the most commonly encountered complications: systemic hypertension, uremia, electrolyte imbalance, drug toxicity, and arteriovenous fistula thrombosis. Specific guidelines are then presented to reduce the risk of complications at each phase of hospitalization.     

Risk factors for mortality and morbidity related to radical cystectomy

OBJECTIVES

To evaluate the risk factors for mortality and morbidity related to radical cystectomy (RC) in a medium‐sized academic centre, and to analyse the rate and trends of perioperative morbidity and mortality, as although complications related RC to are lower in modern than historic series, RC is still associated with marked risks.

PATIENTS AND METHODS

The study included 258 patients undergoing RC for bladder cancer in Turku University Hospital in 1986–2005. Basic patient characteristics and in‐hospital, early (from hospital discharge to 3 months) and combined morbidity and mortality were analysed. Risk analysis included 16 risk factors for complications. Trends were analysed by comparing the two study decades (1986–1995 vs 1996–2005).

RESULTS

The total complication rate was 34%, with minor and major complications in 26%, and 11% of patients, respectively. There were no significant changes in total morbidity, but the number of myocardial infarctions and atrial fibrillations decreased significantly (P = 0.045). Operative mortality was 2.7%, with an insignificant decrease (4.2% to 0.9%, P = 0.11) over time. Salvage RC, high American Society of Anesthesiologists (ASA) score (≥3), extensive blood loss (>3 L), a high number of transfusions (five or more), several comorbidities (two or more), age (≥65 vs <65 years), and extravesical tumours were significant risk factors for major complications. An ASA score of ≥3 and five or more transfusions were the only factors associated with mortality. A high ASA score (odds ration 3.25, 95% confidence interval 1.08–9.74) and high number of transfusions (2.74, 1.05–7.15) were independent risk factors for major complications.

CONCLUSION

Although RC is associated with acceptable morbidity, attention should be given to risk factors identified at the time of patient selection, and to meticulous haemostasis at the time of surgery. A predictable outcome comparable to that in high‐volume centres is also possible in a medium‐sized hospital.     

Toward prospective identification of high-risk surgical patients

The purpose of this study was to explore the feasibility of prospectively identifying patients at high risk for surgical complications using automatable methods focused on patient characteristics. We used data from the Michigan Surgical Quality Collaborative (60,411 elective surgeries) performed between 2003 and 2008. Regression models for postoperative mortality, overall morbidity, cardiac, thromboembolic, pulmonary, renal, and surgical site infection complications were developed using preoperative patient and planned procedure data. Risk was categorized by quartiles of predicted probability: "low" risk corresponding to the bottom quartile, "average" to the middle two quartiles, and "high" to the top quartile. C-indices were calculated to measure discrimination; model validity was assessed by cross-validation. Models were repeated using only patient characteristics. Risk category was closely related to event rates; 80 to 90 per cent of mortality and cardiac, renal, and pulmonary complications occurred among the 25 per cent of "high-risk" patients. Although thromboembolisms and surgical site infections were less predictable, 60 to 70 per cent of events occurred among high-risk patients. Cross-validation results were consistent and only slightly attenuated when predictors were restricted to patient characteristics alone. Adverse postoperative events are concentrated among patients identifiable preoperatively as high risk. Preoperative risk assessment could allow for efficient interventions targeted to high-risk patients.     

Safety of total contact casting in high-risk patients with neuropathic foot ulcers

BACKGROUND: Total contact casting (TCC) is effective in offloading the plantar aspect of the foot in patients with diabetes and neuropathic ulcers. These patients are considered at high risk for skin-related complications during TCC because of sensory neuropathy. The purpose of this prospective study was to determine the frequency of complications during treatment of neuropathic ulcers with TCC. METHODS: Thirteen patients with 18 neuropathic ulcers were treated with TCC. The same orthopaedic surgeon applied a consecutive series of 82 total contact casts. The initial cast was changed in 3 to 4 days, while subsequent casts were changed weekly. RESULTS: Fourteen complications occurred during the 82 castings (17%). None of the complications required alteration in the treatment protocol. Thirteen of the 14 complications involved skin irritation and the other complication was from a cast that became too tight. Fifteen of the 18 neuropathic ulcers healed with TCC. CONCLUSIONS: TCC can be used safely in high-risk patients with neuropathic problems, but minor complications should be anticipated. Major complications that interfere with the treatment of the plantar ulcer can be minimized with careful technique, close follow-up, and thorough patient education.     

Laparoscopic colorectal surgery is safe in the high-risk patient: a NSQIP risk-adjusted analysis

BACKGROUND: Laparoscopic colectomy was considered initially to be contraindicated in patients at high risk for operative morbidity and mortality. We hypothesized that this procedure is safe to perform in high-risk patients, stratifying this risk using National VA Surgical Quality Improvement Program (NSQIP) algorithms. METHODS: A case-matched, comparative study was performed for high-risk veteran patients who underwent colectomy during the period October 2002-September 2004. Consecutive patients undergoing laparoscopic colectomy were matched to patients who underwent open colectomy during the same period for age, body mass index (BMI), procedure, and NSQIP-predicted risk. The groups were compared for risk-stratified, 30-day morbidity/mortality, length of stay (LOS), and operating time. RESULTS: Forty-five patients (23 laparoscopic and 22 open cases) were defined as at high risk for complications (predicted complication >0.15). The rate of major complications was significantly less in the laparoscopic group. There were 4 (18%) cases of postoperative respiratory failure in the open group and none in the laparoscopic group. There was no surgically related mortality in the laparoscopic group, compared with 2 deaths in the open group (P = .5). Median LOS was less in the laparoscopic group (5 days) compared with open (8 days) (P = .001). There were no significant differences in operating time or the number of minor complications. CONCLUSIONS: Our results suggest that the laparoscopic approach to colorectal diseases is safe in the population of patients at high risk for operative morbidity and mortality. Rather, this approach may represent a safer alternative to open access.     

Renal transplant complications. Minimally invasive management

Advancements in endourology, laparoscopic urology, and interventional radiology continue to influence the contemporary management of renal transplant complications. The successful implementation of these minimally invasive therapies significantly relies on careful patient selection; not all renal transplantation complications are suitable or amenable for this form of management--true for transplant ureteral complications and less so for other potential complications. With such a strategy, renal transplant complications can be managed efficiently and effectively with these minimally invasive modalities to minimize further recipient morbidity while also minimizing potential risk to the recipient and for the renal allograft.     

An analysis of iatrogenic complications from the total contact cast

BACKGROUND: Many physicians continue to fear iatrogenic complications of the total contact cast, and use of this modality has remained restricted to a segment of the orthopaedic and podiatric communities. I examined the actual rate of complications and the factors associated with them in a large consecutive series of total contact casts drawn from the practice of a single surgeon to determine whether this modality is safe for multiple conditions in the neuropathic foot and ankle. METHOD: A consecutive series of 398 total contact casts spanning a 28-month period from the practice of a single physician were analyzed. All casts were placed by the same team of orthotists. This study comprised 70 patients with severe peripheral neuropathy; an average of 5.69 sequential casts per patient were placed. Three-hundred and sixty-seven casts were placed in diabetic patients, and 31 in patients with idiopathic peripheral neuropathy. By protocol, the initial cast was changed at an interval of no more than 1 week. On occasion, subsequent casts were left on longer, but on average casts were left in place for 7.69 days. Logistic regression analysis was used to analyze the contribution of patient factors to the chance of ulceration. RESULTS: Complications occurred in 22 casts, including six new pretibial ulcers, six new midfoot ulcers, four forefoot or toe ulcers, five hindfoot ulcers, and one malleolar ulcer. In no case was a preexisting ulcer made worse. This corresponds to an overall complication rate of 5.52% per cast. Overall, 30% of patients suffered one complication during the course of their treatment. With one exception, all new ulcers healed with simple modalities within 3 weeks, often with continued total contact casting. A single cast led to a proximal interphalangeal ulceration that exposed the joint and eventually required toe amputation. The rate of permanent sequelae from cast-related injuries was therefore 0.25%. In no case were the resultant odds ratios statistically different from 1.0, but several trends were observed. Charcot arthropathy represented the highest risk (odds ratio 1.46), while the presence of neuropathic ulceration was surprisingly benign (odds ratio 0.69). The presence of diabetes as opposed to other causes of neuropathy was associated with increased risk (odds ratio 1.34). The use of a cast after deformity-correcting surgery in a neuropathic patient was remarkably safe (odds ratio 0.44), as were casts in which the patient was instructed to remain nonweightbearing (odds ratio 0.27). Patient age was not a factor (odds ratio 1.03). The length of time the cast was left on was not statistically important (odds ratio 0.99), although strict protocols for cast changing likely altered this data. CONCLUSION: A frequently changed total contact cast is a safe modality for the offloading and immobilization of the neuropathic foot, albeit with an expected constant rate of minor, reversible complications. Patients should be informed of these complications and risks before cast application.     

Management of thoracic and thoraco-abdominal aneurysms in the elderly

Repair of descending thoracic aneurysm or thoracoabdominal involves transient ischaemia of many organs with high risk of complications. The elderly patient may be more at risk depending on the presence or absence of significant comorbidity factors. Careful preoperative evaluation and patient selection considerably reduce the risk of operative mortality and morbidity. We review the management of thoracic and thoracoabdominal aneurysms in the elderly and briefly describe our surgical approach in order to minimize operative risk and improve surgical results.     

Risk factors in a community experience with carotid endarterectomy

Experience with 1035 carotid endarterectomies in a single community over a 2-year period was analyzed. Twenty-two surgeons working in six hospitals were involved. All surgeons had full-time or part-time appointments at the University of Rochester, 18 had special interest in vascular surgery, and eight had obtained a certificate of qualification in vascular surgery. Mortality rate was 1.4% (14 deaths), with additional permanent, nonfatal, neurologic morbidity of 3.4%. Mortality and morbidity were independent of surgeon, caseload, or hospital. Age and prior history of myocardial infarction influenced the incidence of postoperative myocardial infarction but not the incidence of death or neurologic morbidity. Factors that increased the risk of postoperative death or neurologic complication included hypertension; contralateral carotid disease as manifested by stroke, endarterectomy, or occlusion; whether the patient was a woman; and symptoms of crescendo ischemia. Lack of preoperative neurologic symptoms was correlated with decreased risk of myocardial infarction and neurologic complications. Overall mortality and neurologic morbidity associated with operation for "asymptomatic stenosis" was 3.1% (seven of 222 cases). However, the incidence of contralateral carotid disease was high in the patients in the asymptomatic group (60%), and all complications in this group occurred in patients with prior contralateral carotid endarterectomy or occlusion (p less than 0.05).     

Anesthesia in the patient with impaired liver function

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.     

Factors influencing mortality and morbidity following oesophageal resection

Operative mortality and morbidity following oesophageal resection has fallen in recent years. We have attempted to identify the factors responsible for this improvement by reviewing the results of surgery at this hospital over the last 6 years. Two hundred and two oesophageal resections were performed between January 1981 and June 1987 for carcinoma. Of these, 21 patients (10.4%) died before leaving hospital. Fourteen patients died of multisystem failure, 1 died of pure respiratory failure and 2 died of renal failure. Two died of surgical causes (other than anastomotic leak), 1 died of pulmonary embolus and 1 from a cerebro-vascular accident. No patient died of purely cardiac causes. The most significant risk factors in those dying (Chi-square test) were: postoperative respiratory failure, defined as reventilation after initial successful extubation, (P less than or equal to 0.001), reoperation as an emergency in the early postoperative period (P less than or equal to 0.001), anastomotic leak (P less than or equal to 0.01) and age over 70 (P less than or equal to 0.005). Less significant risk factors were chyle leak and histologically undifferentiated tumour. Of the 181 survivors, 103 left hospital with no complications of any kind. The mean stay in hospital for survivors was 15 days. Respiratory infection occurred in 22% of patients, prolonged gastric stasis in 8%, wound infection in 5% and empyema in 1%. As long as high risk groups are accepted for radical surgery, operation will carry a significant mortality in those groups. In others, we believe that perioperative monitoring and early aggressive treatment of complications can further reduce mortality and morbidity.     

Prevention of thromboembolism in surgery

Thromboembolic complications are one of the most common complications in patients undergoing major surgery or conservative treatment in cast. The incidence of thromboembolic complications is the highest in orthopedic and trauma surgery. Stasis in the deep veins of the lower extremity, intimal damage and disorders in blood coagulation are important factors in the pathogenesis of deep vein thrombosis. The most important predisposing risk factors are age, previous thrombosis, varices and the combination of oral contraceptives and smoking. 50% of thrombosis begins intraoperatively and 80-90% in the first 3-4 days after operation. The incidence of thromboembolic complications was significantly reduced after introduction of low-dose heparin and heparin with dihydroergotamine in the perioperative regimen. Recently various investigations demonstrated that low-molecular-weight heparin (LMWH) is equally as effective as a low-dose heparin regimen in preventing postoperative thromboembolic complications. Our own management of prophylaxis of thromboembolic complications is presented. In a prospective pilot study 100 trauma patients were evaluated. 84 patients received LMWH plus dihydroergotamine (DHE), 12 patients heparin alone because of contraindications for DHE and 4 patients received a low dose continuous intravenous heparin prophylaxis because of high risk. Two deep vein thrombosis occurred, one in a patient with high risk prophylaxis and one in a patient with a subcutaneously heparin prophylaxis. No thromboembolic complications occurred in patients with LMWH + DHE prophylaxis.     

Preoperative risk assessment in vascular surgery patients

The patient scheduled for peripheral vascular surgery is an increased anaesthetic challenge, mainly because of coexisting generalized cardiovascular atherosclerotic involvement leading to a high risk of perioperative cardiac complications. In clinical practice it is of importance preoperatively to predict, as accurately as possible, the potential risk of complications so that proper risk-reducing measures can be taken. Relevant clinical data, which have been included by Goldman and Detsky in multifactorial cardiac risk indices, are of potential value for differentiating between patients at low, intermediate, or high risk of perioperative cardiac morbidity and mortality. Patients with low risk scores can be accepted for surgery without further testing, thereby allowing more extensive cardiac testing, such as ambulatory ECG monitoring, exercise stress testing, echocardiography, dipyridamole thallium imaging, or coronary angiography, to be reserved for patients with higher risk scores or overt cardiac problems. The risk stratification is of importance not only for decisions on preoperative prophylactic therapeutic measures (e.g. optimization of medical therapies, coronary artery revascularization), but also for decisions on intraoperative anaesthetic management and postoperative care.     

Patient populations at risk for intra-abdominal hypertension and abdominal compartment syndrome

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are critical care conditions with significant morbidity and mortality. The surgical measure to treat ACS (decompressive laparotomy) is hazardous and results in an open abdomen with potential major complications such as fistulas, abscesses, and large ventral hernias. As a result of the complicated natural history of IAH/ACS as well as significant morbidity and mortality, prevention is a logical approach to this complex problem. Knowledge of the patient populations at high risk for developing IAH/ACS is crucial. The aim of this review is to discuss the high-risk populations for acute IAH/ACS among surgical patients.     

Management of the complications of radical prostatectomy

Over the past several years, the morbidity associated with radical prostatectomy has improved due to advances in surgical technique, better understanding of male pelvic anatomy, and improved perioperative care. Despite these advances, patients are still at risk for several complications both intraoperatively and in the postoperative course. These risks include significant blood loss, rectal injury, ureteral injury, thromboembolic events, urinary incontinence, impotence, and a perioperative death rate of less than 1%. These risks should be reviewed and discussed before treating the patient with prostate cancer.     

Perioperative issues: myocardial ischemia and protection--beta-blockade

Approximately one third of patients undergoing noncardiac surgery have coronary artery disease, and cardiovascular complications are an important cause of perioperative morbidity and mortality. Several algorithms are available to assess the risk for peri-operative cardiac events. Although preoperative risk assessment is useful in identifying patients at greatest risk for cardiac complications, recent investigations have provided additional guidance in choosing interventions to improve perioperative outcomes. These investigations show that perioperative beta-blockers significantly reduce morbidity and mortality in noncardiac surgery and appear to offer the greatest benefit to high-risk patients. Because of the lower complication rate in intermediate- and low-risk patients and the absence of large randomized controlled trials, the role of beta-blockers in this population is less well-defined.