Gravid status is not associated with postoperative nausea and vomiting: a matched case-control study.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common and unpleasant complication of general anesthesia. There are well-known risk factors that predispose a patient to develop PONV. While studies exist that explore PONV incidence in gravid and non-gravid women separately, limited studies exist to compare the two cohorts to identify if pregnancy is associated with increased risk for PONV or differences in PONV prophylaxis and treatment. METHODS: This is a retrospective case-control cohort study, with 1:2 matching based on age, year of surgery, and surgical procedure. Electronic medical records were abstracted for demographic information, predisposing risk factors, prophylactic antiemetics, PONV documentation, rescue antiemetics, PACU stay, and length of hospitalization. Analyses of risk factors for PONV were performed using logistic and multinomial logistic regression analyses. RESULTS: 237 gravid women who underwent non-obstetric procedures with general anesthesia were identified and matched with 474 non-gravid women. PONV complicated the course of 51 (21.5%) gravid and 72 (15.2%) non-gravid women. The number of prophylactic antiemetics was fewer among gravid (median 2 [1, 2]) than non-gravid (3 [2, 3]) women (P < 0.001). No association was found between gravid status and risk for PONV (adjusted odds ratio 1.35 [95%CI 0.84, 2.17], P = 0.222). Gravid women had longer hospital lengths of stay (P < 0.001), despite having shorter surgical duration (P = 0.015). CONCLUSIONS: The risk for PONV is similar between gravid and similarly aged women. However, anesthesiologists administer fewer prophylactic antiemetics to gravid women during non-obstetric surgery.

Pattern of perioperative gabapentinoid use and risk for postoperative naloxone administration.

BACKGROUND: Single preoperative gabapentinoid (gabapentin and pregabalin) administration has been associated with respiratory depression during Phase I anaesthesia recovery. In this study, we assess for associations between chronic (home) use and perioperative administration (preoperative and postoperative) of gabapentinoids, and risk for severe over-sedation or respiratory depression as inferred from the use of naloxone. METHODS: From 2011 to 2016, we identified patients undergoing general anaesthesia discharged to standard postoperative wards and administered naloxone within 48 h of surgery in a single centre. These patients were 2:1 matched on age, sex, and type of procedure. Patient and perioperative characteristics were abstracted and compared to assess for risk for naloxone administration. RESULTS: We identified 128 patients that received naloxone after operation [odds ratio 1.2; 95% confidence interval (CI) 1.0, 1.4 per 1000 general anaesthetics]. Patients on chronic or postoperative gabapentinoid therapy were at significantly higher risk for receiving naloxone after operation. Multivariable analysis detected significant interactions between chronic and postoperative use of gabapentinoids, where continuation of chronic gabapentinoid medications into the postoperative period was associated with an increased rate of naloxone administration (6.30, 95% CI 2.4, 16.7; P=0.001). Obstructive sleep apnoea (P=0.005) and preoperative disability (P=0.003) were also associated with an increased risk for postoperative naloxone administration. Patients who received naloxone had longer hospital stays and higher rates of postoperative delirium. CONCLUSIONS: Continuation of chronic gabapentinoid medications into the postoperative period is associated with the increased use of naloxone to reverse over-sedation or respiratory depression. Such patients requiring this therapy warrant high levels of postoperative monitoring.

Association between exposure to anaesthesia and surgery and long-term cognitive trajectories in older adults: report from the Mayo Clinic Study of Aging.

BACKGROUND: The link between exposure to general anaesthesia and surgery (exposure) and cognitive decline in older adults is debated. We hypothesised that it is associated with cognitive decline. METHODS: We analysed the longitudinal cognitive function trajectory in a cohort of older adults. Models assessed the rate of change in cognition over time, and its association with exposure to anaesthesia and surgery. Analyses assessed whether exposure in the 20 yr before enrolment is associated with cognitive decline when compared with those unexposed, and whether post-enrolment exposure is associated with a change in cognition in those unexposed before enrolment. RESULTS: We included 1819 subjects with median (25th and 75th percentiles) follow-up of 5.1 (2.7-7.6) yr and 4 (3-6) cognitive assessments. Exposure in the previous 20 yr was associated with a greater negative slope compared with not exposed (slope: -0.077 vs -0.059; difference: -0.018; 95% confidence interval: -0.032, -0.003; P=0.015). Post-enrolment exposure in those previously unexposed was associated with a change in slope after exposure (slope: -0.100 vs -0.059 for post-exposure vs pre-exposure, respectively; difference: -0.041; 95% confidence interval: -0.074, -0.008; P=0.016). Cognitive impairment could be attributed to declines in memory and attention/executive cognitive domains. CONCLUSIONS: In older adults, exposure to general anaesthesia and surgery was associated with a subtle decline in cognitive z-scores. For an individual with no prior exposure and with exposure after enrolment, the decline in cognitive function over a 5 yr period after the exposure would be 0.2 standard deviations more than the expected decline as a result of ageing. This small cognitive decline could be meaningful for individuals with already low baseline cognition.

Postoperative delirium in elderly patients is associated with subsequent cognitive impairment.

BACKGROUND: We examined the risk for postoperative delirium (POD) in patients with mild cognitive impairment (MCI) or dementia, and the association between POD and subsequent development of MCI or dementia in cognitively normal elderly patients. METHODS: Patients ≥65 yr of age enrolled in the Mayo Clinic Study of Aging who were exposed to any type of anaesthesia from 2004 to 2014 were included. Cognitive status was evaluated before and after surgery by neuropsychological testing and clinical assessment, and was defined as normal or MCI/dementia. Postoperative delirium was detected with the Confusion Assessment Method for the intensive care unit. Logistic regression analyses were performed. RESULTS: Among 2014 surgical patients, 74 (3.7%) developed POD. Before surgery, 1667 participants were cognitively normal, and 347 met MCI/dementia criteria. The frequency of POD was higher in patients with pre-existing MCI/dementia compared with no MCI/dementia {8.7 vs 2.6%; odds ratio (OR) 2.53, [95% confidence interval (CI) 1.52-4.21]; P <0.001}. Postoperative delirium was associated with lower education [OR, 3.40 (95% CI, 1.60-7.40); P =0.002 for those with <12 vs ≥16 yr of schooling]. Of the 1667 patients cognitively normal at their most recent assessment, 1152 returned for postoperative evaluation, and 109 (9.5%) met MCI/dementia criteria. The frequency of MCI/dementia at the first postoperative evaluation was higher in patients who experienced POD compared with those who did not [33.3 vs 9.0%; adjusted OR, 3.00 (95% CI, 1.12-8.05); P =0.029]. CONCLUSIONS: Mild cognitive impairment or dementia is a risk for POD. Elderly patients who have not been diagnosed with MCI or dementia but experience POD are more likely to be diagnosed subsequently with MCI or dementia.

Association between neuraxial analgesia, cancer progression, and mortality after radical prostatectomy: a large, retrospective matched cohort study.

BACKGROUND: Systemic opioids are immunosuppressive, which could promote tumour recurrence. We, therefore, test the hypothesis that supplementing general anaesthesia with neuraxial analgesia improves long-term oncological outcomes in patients having radical prostatectomy for adenocarcinoma. METHODS: Patients who had general anaesthesia with neuraxial analgesia (n=1642) were matched 1:1 based on age, surgical year, pathological stage, Gleason scores, and presence of lymph node disease with those who had general anaesthesia only. Medical records were reviewed. Outcomes of interest were systemic cancer progression, recurrence, prostate cancer mortality, and all-cause mortality. Data were analysed using stratified proportional hazards regression, the Kaplan-Meier method, and log-rank tests. The median follow-up was 9 yr. RESULTS: After adjusting for comorbidities, positive surgical margins, and adjuvant hormonal and radiation therapies within 90 postoperative days, general anaesthesia only was associated with increased risk for systemic progression [hazard ratio (HR)=2.81, 95% confidence interval (CI) 1.31-6.05; P=0.008] and higher overall mortality (HR=1.32, 95% CI 1.00-1.74; P=0.047). Although not statistically significant, similar findings were observed for the outcome of prostate cancer deaths (adjusted HR=2.2, 95% CI 0.88-5.60; P=0.091). CONCLUSIONS: This large retrospective analysis suggests a possible beneficial effect of regional anaesthetic techniques on oncological outcomes after prostate surgery for cancer; however, these findings need to be confirmed (or refuted) in randomized trials.

Obesity trends in the surgical population at a large academic center : a comparison between 1989-1991 to 2006-2008 epochs.

BACKGROUND: Changes in the prevalence of obesity of surgical patients overtime and in relation to the general population have not been well characterized. METHODS: Height, weight, age and gender data of adult patients who underwent general anesthesia at our institution were abstracted. Reliable data was available for the years 1989-1991 and 2006-2008, and comparisons were made between these epochs. Additional comparisons were made between our Minnesota surgical patients and the general Minnesota population. RESULTS: Substantial changes in patient weight occurred with a decline in normal weight patients (body mass index [BMI] < or =25.0) from 41.6% to 30.9% (P <0.001), while the prevalence of obesity (BMI 30-34.9) increased from 14.9% to 20.6% (P <0.001) and morbidly obesity (BMI > 35) from 7.1% to 14.8% (P <0.001). Minnesota surgical patients had a higher prevalence of obesity in every demographic category (P <0.001) compared to the general population. CONCLUSION: A substantial increase in the prevalence of obesity and morbid obesity among surgical patients at our institution occurred and the prevalence of obesity in our contemporary practice is higher than the general population. These observations most likely have profound implications on healthcare delivery resources, though its impact has yet to be determined.

Social Determinants of Health among Older Adults with Dementia in Urban and Rural Areas.

BACKGROUND: Social determinants of health (SDOH) may influence health in people living with dementia. Little is known about SDOH differences in urban compared to rural dwelling people living with dementia. OBJECTIVES: To explore urban-rural differences in SDOH in people living with mild cognitive impairment (MCI) and dementia. DESIGN: Descriptive study. SETTING/PARTICIPANTS: People ≥55 years with MCI or dementia empaneled to Community Internal Medicine at Mayo Clinic (Rochester, MN, USA) who completed SDOH questions between June 1, 2019 and June 30, 2021 were included. MEASUREMENTS: SDOH questions addressed education, depression, alcohol use, financial strain, food insecurity, physical activity, social connections, stress and transportation. SDOH data were compared by location based on Rural-Urban Commuting Areas Codes. RESULTS: Of 3552 persons with MCI (n=1495) or dementia (n=2057), 62% lived in urban areas, 19% in large rural, 10% in small rural and 9% in isolated areas. Approximately 60% were physically inactive, 20% socially isolated and 30% had stress concerns. Rural patients experienced greater financial strain (p=0.003). CONCLUSION: Social isolation, stress and physical inactivity are common in people living with MCI and dementia across urban and rural areas. Targeted interventions to improve physical and psychosocial health could have great impact in this population.

Obstructive sleep apnoea and perioperative complications in bariatric patients.

BACKGROUND: The objective of this study was to determine the relationship between perioperative complications and the severity of obstructive sleep apnoea (OSA) in patients undergoing bariatric surgery who had undergone preoperative polysomnography (PSG). METHODS: The records of 797 patients, age >18 yr, who underwent bariatric operations (442 open and 355 laparoscopic procedures) at Mayo Clinic and were assessed before operation by PSG, were reviewed retrospectively. OSA was quantified using the apnoea-hypopnoea index (AHI) as none (≤ 4), mild (5-15), moderate (16-30), and severe (≥ 31). Pulmonary, surgical, and 'other' complications within the first 30 postoperative days were analysed according to OSA severity. Logistic regression was used to assess the multivariable association of OSA, age, sex, BMI, and surgical approach with postoperative complications. RESULTS: Most patients with OSA (93%) received perioperative positive airway pressure therapy, and all patients were closely monitored after operation with pulse oximetry on either regular nursing floors or in intensive or intermediate care units. At least one postoperative complication occurred in 259 patients (33%). In a multivariable model, the overall complication rate was increased with open procedures compared with laparoscopic. In addition, increased BMI and age were associated with increased likelihood of pulmonary and other complications. Complication rates were not associated with OSA severity. CONCLUSIONS: In obese patients evaluated before operation by PSG before bariatric surgery and managed accordingly, the severity of OSA, as assessed by the AHI, was not associated with the rate of perioperative complications. These results cannot determine whether unrecognized and untreated OSA increases risk.

Comparison of two ventilatory strategies in elderly patients undergoing major abdominal surgery.

BACKGROUND: 'Open lung' ventilation is commonly used in patients with acute lung injury and has been shown to improve intraoperative oxygenation in obese patients undergoing laparoscopic surgery. The feasibility of an 'open lung' ventilatory strategy in elderly patients under general anaesthesia has not previously been assessed. METHODS: 'Open lung' ventilation (recruitment manoeuvres, tidal volume 6 ml kg(-1) predicted body weight, and 12 cm H(2)O PEEP) (RM group) was compared with conventional ventilation (no recruitment manoeuvres, tidal volume 10 ml kg(-1) predicted body weight, and zero end-expiratory pressure) in elderly patients (>65 yr) undergoing major open abdominal surgery with regard to oxygenation, respiratory system mechanics, and haemodynamic stability. We also monitored the serum levels of the interleukins (IL)-6 and IL-8 before and after surgery to determine whether the systemic inflammatory response to surgery depends on the ventilatory strategy used. RESULTS: Twenty patients were included in each group. The RM group tolerated open lung ventilation without significant haemodynamic instability. Intraoperative Pa(o(2)) improved in the RM group (P<0.01) and deteriorated in controls (P=0.01), but postoperative Pa(o(2)) was similar in both groups. The RM group had improved breathing mechanics as evidenced by increased dynamic compliance (36%) and decreased airway resistance (21%). Both IL-6 and IL-8 significantly increased after surgery, but the magnitude of increase did not differ between the groups. CONCLUSIONS: A lung recruitment strategy in elderly patients is well tolerated and improves intraoperative oxygenation and lung mechanics during laparotomy.

Intraoperative ventilator settings and acute lung injury after elective surgery: a nested case control study.

BACKGROUND: While acute lung injury (ALI) is among the most serious postoperative pulmonary complications, its incidence, risk factors and outcome have not been prospectively studied. OBJECTIVE: To determine the incidence and survival of ALI associated postoperative respiratory failure and its association with intraoperative ventilator settings, specifically tidal volume. DESIGN: Prospective, nested, case control study. SETTING: Single tertiary referral centre. PATIENTS: 4420 consecutive patients without ALI undergoing high risk elective surgeries for postoperative pulmonary complications. MEASUREMENTS: Incidence of ALI, survival and 2:1 matched case control comparison of intraoperative exposures. RESULTS: 238 (5.4%) patients developed postoperative respiratory failure. Causes included ALI in 83 (35%), hydrostatic pulmonary oedema in 74 (31%), shock in 27 (11.3%), pneumonia in nine (4%), carbon dioxide retention in eight (3.4%) and miscellaneous in 37 (15%). Compared with match controls (n = 166), ALI cases had lower 60 day and 1 year survival (99% vs 73% and 92% vs 56%; p<0.001). Cases were more likely to have a history of smoking, chronic obstructive pulmonary disease and diabetes, and to be exposed to longer duration of surgery, intraoperative hypotension and larger amount of fluid and transfusions. After adjustment for non-ventilator parameters, mean first hour peak airway pressure (OR 1.07; 95% CI 1.02 to 1.15 cm H(2)O) but not tidal volume (OR 1.03; 95% CI 0.84 to 1.26 ml/kg), positive end expiratory pressure (OR 0.89; 95% CI 0.77 to 1.04 cm H(2)O) or fraction of inspired oxygen (OR 1.0; 95% CI 0.98 to 1.03) were associated with ALI. CONCLUSION: ALI is the most common cause of postoperative respiratory failure and is associated with markedly lower postoperative survival. Intraoperative tidal volume was not associated with an increased risk for early postoperative ALI.

Experience and expectations of patients on weight loss: The Learning Health System Network Experience.

OBJECTIVE: Weight perception and degree of confidence in achieving healthy lifestyle can be determinants of engagement in obesity interventions. This study explored patients' perceived need for weight loss and the degree of self-confidence in ability to lose weight and sought to identify factors associated with patients' self-confidence in ability to lose weight. METHODS: The authors analysed data from a survey mailed to primary care patients within five sites of the Learning Health Systems Network that explored participants' prior experience with weight management. RESULTS: Among the 2,263 participants who completed the survey section on 'Patients' Experience with Weight Management', perceived need to lose 51 lb or more was statistically significant among those with class III obesity compared with other body mass index (BMI) groups (p value < 0.001). Reported desire to lose weight was also significantly higher among those with the highest BMI than those who were overweight (p value < 0.001). However, this same group had the lowest belief in ability to lose weight (p value < 0.001). In a multiple regression analysis, female gender, higher BMI and need to lose >10 lb were each independently associated with less belief in being able to lose weight. CONCLUSIONS: Patients had varying perceptions on weight loss; those with category III obesity had the highest desire to lose weight but had the least confidence in ability to lose weight. Higher BMI, female gender and need to lose >10 lb were associated with decreased self-confidence in ability to lose weight.

The effect of in vitro recombinant factor VIIA on coagulation parameters for blood taken during liver transplantation.

Recombinant factor VIIa (rFVIIa) has been utilized in pilot studies in orthotopic liver transplantation (OLT) when administered to patients at doses of 68.37 microg/kg and 80 microg/kg. Although some effectiveness in normalizing measurements of coagulation has been demonstrated, the optimal dose for patients undergoing OLT has not been established. This study evaluated the effects of an in vitro equivalent dose of 120 microg/kg of rFVIIa on coagulation parameters when applied to the blood drawn from patients undergoing OLT. Coagulation function was assessed in 10 patients at four points during OLT. These time points were baseline, 5 minutes prior to reperfusion, 10 minutes after reperfusion, and 70 minutes after reperfusion. These patients did not receive rFVIIa perioperatively. At each of these four time points, a native sample was analyzed for prothrombin time (PT) and thromboelastogram. The rFVIIa (6.1 microg/kg or the approximate equivalent dose of 120 microg/kg for a 70 kg patient) was added to a second sample from the same patient. This second sample was also analyzed for PT and thromboelastogram. There was a statistically significant difference in baseline PT between native versus rFVIIa supplemented samples (15.8 +/- 3.21 vs 13.6 +/- 2.36 seconds, P < .02). The maximum amplitude of the thromboelastogram was larger in the native samples at 5 minutes prior to reperfusion (53.5 mm vs 39 mm, P < .02). No significant differences existed in the variables at any of the other sampling times. This study failed to demonstrate a consistent in vitro effect of rFVIIa on the blood taken from patients during OLT.

Retrospective Derivation and Validation of an Automated Electronic Search Algorithm to Identify Post Operative Cardiovascular and Thromboembolic Complications.

BACKGROUND: With increasing numbers of hospitals adopting electronic medical records, electronic search algorithms for identifying postoperative complications can be invaluable tools to expedite data abstraction and clinical research to improve patient outcomes. OBJECTIVES: To derive and validate an electronic search algorithm to identify postoperative thromboembolic and cardiovascular complications such as deep venous thrombosis, pulmonary embolism, or myocardial infarction within 30 days of total hip or knee arthroplasty. METHODS: A total of 34 517 patients undergoing total hip or knee arthroplasty between January 1, 1996 and December 31, 2013 were identified. Using a derivation cohort of 418 patients, several iterations of a free-text electronic search were developed and refined for each complication. Subsequently, the automated search algorithm was validated on an independent cohort of 2 857 patients, and the sensitivity and specificities were compared to the results of manual chart review. RESULTS: In the final derivation subset, the automated search algorithm achieved a sensitivity of 91% and specificity of 85% for deep vein thrombosis, a sensitivity of 96% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 95% for myocardial infarction. When applied to the validation cohort, the search algorithm achieved a sensitivity of 97% and specificity of 99% for deep vein thrombosis, a sensitivity of 97% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 99% for myocardial infarction. CONCLUSIONS: The derivation and validation of an electronic search strategy can accelerate the data abstraction process for research, quality improvement, and enhancement of patient care, while maintaining superb reliability compared to manual review.

Amantadine treatment is an independent predictor of improved survival in Parkinson's disease.

Amantadine has been used for more than 20 years in the symptomatic treatment of Parkinson's disease (PD). Several recent discoveries suggest that amantadine could also have a neuroprotective effect in PD. We studied survival in all parkinsonism (including PD and other parkinsonian syndromes) patients attending a single clinic, employing standard survival curves and a Cox regression model, to identify independent predictive variables for survival (while taking into account factors potentially associated with both outcome and treatment selection). Amantadine-treated patients (n = 250) were similar to the patients not treated with amantadine (n = 586) in terms of age, gender, type of parkinsonism, Hoehn and Yahr stage and dementia status at initial neurological visit. Amantadine use was an independent predictor of improved survival (p < 0.01). Improved survival was also associated with a higher 10-year expected survival (based on age, gender, and birth year), absence of dementia, type of parkinsonism = PD, and low Hoehn and Yahr stage (I or II) at initial neurologic visit (all p < 0.01); these additional factors occurred in statistically similar proportions in the groups that were and were not treated with amantadine. The association of improved survival with amantadine use may stem from symptomatic benefit or may reflect a "neuroprotective" effect, mediated through N-methyl-D-aspartate (NMDA) receptor antagonism, dopamine uptake blockade activity, or other mechanisms. Our preliminary findings suggest that a prospective, controlled, randomized trial of amantadine's effects on PD progression is warranted.

Effect of age, gender, and platelet count on Sonoclot coagulation analysis in patients undergoing orthopedic operations.

OBJECTIVE: To assess the relationship between Sonoclot coagulation variables and age, gender, or platelet count in surgical patients without coagulation disorders. MATERIAL AND METHODS: This study included 136 patients undergoing orthopedic surgical procedures under spinal or epidural anesthesia. Whole blood was withdrawn preoperatively from each patient, and a Sonoclot analysis was performed within 2 minutes after the sample was obtained. The Sonoclot results were considered investigational and not used in the perioperative management of the patients. Variables from the Sonoclot graphs were analyzed statistically to determine any associations with age, gender, or platelet count. RESULTS: The Sonoclot baseline height was decreased in patients with lower hemoglobin levels, older age, and female gender. The upward slope from baseline to inflection (R1) was increased in female patients and older patients. In comparison with patients who had lower platelet counts, patients with higher platelet counts exhibited a shorter time to inflection, increased upward slope from inflection to peak (R2), shorter time to peak, increased downward slope from peak to plateau (R3), decreased time to plateau, and lower plateau height (P < or = 0.01 for all relationships). CONCLUSIONS: Sonoclot coagulation analysis reliably evaluates platelet count as an indicator of platelet function. Controlled studies are needed to examine the clinical usefulness of Sonoclot coagulation analysis in the diagnosis and treatment of perioperative coagulopathies and hemorrhagic complications.

Effect of intraoperative anesthetic events on postoperative patient satisfaction.

OBJECTIVE: To assess overall perioperative and anesthetic care-specific patient satisfaction. DESIGN: We mailed questionnaires postoperatively to three groups of surgical patients (those who underwent anesthesia without complications, those who experienced airway management difficulties, and those who had cardiovascular perturbations) and analyzed the responses. MATERIAL AND METHODS: All patients 18 to 75 years of age who underwent hospital-based surgical procedures in our acute-care hospitals during the interval from January to September 1993 were eligible for this investigation. We asked a total of 315 patients--105 in each of the three study groups--about their satisfaction with perioperative care. Specific positive or negative comments that the patients returned in their questionnaires were tabulated into the following sub-categories: physician, nurse, technique, time, and institution concerns. RESULTS: Of the 315 questionnaires sent to patients, 239 (75.9%) were returned. No difference in overall patient satisfaction (defined as very satisfied or a combination of very satisfied and satisfied) was noted among the groups. No patients identified themselves as dissatisfied or very dissatisfied with their overall care, although a small percentage expressed dissatisfaction because of time delays. The specific patient comments suggested that the positive interactions with physicians and nurses outweighed the concerns about time delays. CONCLUSION: This study showed that intraoperative anesthetic events did not affect patient satisfaction. Interactions with physicians and nurses dominated the decision about patient satisfaction, and time delays were the most frequently cited negative comment.

Outcomes of patients with no laboratory assessment before anesthesia and a surgical procedure.

OBJECTIVE: To estimate the frequency of perioperative morbidities in patients who underwent anesthesia and a surgical procedure with no preoperative laboratory testing. MATERIAL AND METHODS: We conducted an electronic database search of medical records of 56,119 patients who underwent surgical or diagnostic procedures and anesthesia at Mayo Clinic Rochester in 1994 and found 5,120 who had no laboratory tests done within 90 days before the procedure. From this group, we randomly selected 1,044 patients (87 from each month) to document the absence of preoperative tests, the presence of preexisting disease (by organ system), the type of anesthetic agent, and the outcomes and tests intraoperatively and postoperatively. RESULTS: The 1,044 patients ranged in age from 0 to 95 years (median age, 21). No deaths or major perioperative morbidities occurred (0.0%; exact 95% confidence interval, 0.00 to 0.35%). Although 10 patients underwent blood typing and screening for antibodies immediately preoperatively, no blood transfusions were necessary. Intraoperatively, 17 laboratory tests and 1 electrocardiogram were obtained, and 3 results were abnormal. Postoperatively, 42 blood tests and 2 electrocardiographic procedures were performed. Five of the 42 blood tests showed abnormal results (hemoglobin levels in 3, serum sodium in 1, and arterial blood gases in 1). One electrocardiogram showed normal findings, and the other revealed normal results except for premature ventricular contractions. No laboratory test done intraoperatively or postoperatively was found to change surgical or medical management substantially. One patient who had unanticipated blood loss during an outpatient procedure was admitted to the hospital for observation. CONCLUSION: All 1,044 patients, 97% of whom were relatively healthy, with no recent laboratory testing safely underwent anesthesia and an operation. We conclude that patients who have been assessed by history and physical examination and determined to have no preoperative indication for laboratory tests can safely undergo anesthesia and operation with tests obtained only as indicated intraoperatively and post-operatively. Current anesthetic and medical practices rapidly identify perioperative indications for laboratory evaluation as they arise.

Outcomes of noncardiac surgical procedures in children and adults with congenital heart disease. Mayo Perioperative Outcomes Group.

OBJECTIVE: To assess the outcomes and risk factors for morbidity associated with anesthesia and noncardiac surgical procedures in children and adults with congenital heart disease. DESIGN: We conducted a retrospective cohort study of the 6-year period from January 1987 through November 1992 at one of the Mayo-affiliated hospitals in Rochester, Minnesota. MATERIAL AND METHODS: In all children and adults 50 years of age or younger with congenital heart disease who underwent one or more noncardiac surgical or diagnostic procedures and anesthesia, we analyzed the risk factors for 30-day perioperative morbidity and mortality. RESULTS: The overall frequency of complications among the 276 patients who underwent 480 noncardiac surgical procedures and anesthesia was 5.8% (28 of 480), and only 1 patient died intraoperatively. Major risk factors univariately associated with complications for the first procedures (15 of 276 patients or 5.4%) included the presence of cyanosis (P = 0.002), current treatment for congestive heart failure (P<0.001), poor general health (P<0.001), and younger age at the time of the procedure (P = 0.027). Procedures performed on the respiratory and nervous systems also were associated with high frequencies of complications. Complications in patients undergoing ambulatory surgical procedures were infrequent (1.7%). CONCLUSION: The frequency of perioperative complications in children and adults who have congenital heart disease and undergo noncardiac surgical procedures and anesthesia is low. Patients who have pulmonary hypertension, congestive heart failure, or cyanosis and children with congenital heart disease who are younger than 2 years of age have an increased frequency of perioperative morbidity.

Possible guidelines for autologous red blood cell donations before total hip arthroplasty based on the surgical blood order equation.

OBJECTIVES: To determine, in patients undergoing total hip arthroplasty (THA), clinical predictive criteria for preoperative autologous blood donation and to propose guidelines to increase the efficiency and reduce the cost of preoperative autologous blood donation. PATIENTS AND METHODS: In this retrospective analysis of 165 adult patients undergoing primary THA, a stepwise regression analysis was used to determine which clinical variables predict erythropoiesis in patients donating autologous blood before THA. The surgical blood order equation (SBOE), which includes values for hemoglobin lost at surgery, preoperative hemoglobin level, and minimal acceptable hemoglobin level, was used to estimate the number of units of red blood cells (RBCs) needed for each patient at surgery and thus identify which patients should have made preoperative autologous blood donations. RESULTS: The statistically significant indicators for RBC production were predonation hemoglobin concentration (P<.001) and male sex (P=.003). Combining the regression equation for erythropoiesis with the SBOE allowed development of guidelines for the use of preoperative autologous RBC donation and erythropoietic therapy. For primary THA surgery, a patient with a predonation hemoglobin level higher than 14.7 g/dL does not need preoperative autologous donation. Preoperative autologous RBC donation would be effective for men with hemoglobin concentrations of 14.7 g/dL or less and for women with predonation hemoglobin levels of 13.2 to 14.7 g/dL. In women whose hemoglobin level is less than 13.2 g/dL, erythropoietic therapy should accompany autologous donation. CONCLUSION: Incorporation of patient factors with the SBOE system may result in increased efficiency and decreased cost of autologous blood ordering practices before THA.

Cost-effectiveness of treating nicotine dependence: the Mayo Clinic experience.

OBJECTIVE: To estimate the cost-effectiveness of treating nicotine dependence, expressed as cost per net year of life gained by smoking cessation. DESIGN: A cost-effectiveness analysis was conducted of a cohort of consecutive adult patients treated for nicotine dependence from April 1988 through December 1992 at the Mayo Clinic Nicotine Dependence Center (NDC). MATERIAL AND METHODS: The study cohort consisted of 5,544 patients (50.8% female; mean age, 47.8 years) with a mean baseline smoking rate of 25.4 cigarettes per day. After an initial consultation, a nonphysician counselor developed an individual nicotine dependence treatment plan, which could include follow-up counseling, nicotine replacement therapy (patches or gum), group therapy, or an inpatient program. A relapse-prevention program included telephone calls and a series of letters to the patient. We computed the years of life gained for each person specific to age, gender, smoking rate at entry, and 6-month smoking status by using published mortality rates for current and former cigarette smokers. The 6-month smoking status was assumed to be applicable at 1 year. For subsequent determinations, we modeled by computer simulation the year-by-year (to age 100) smoking status by using published relapse and late cessation rates. Coupled with treatment costs, this information allowed the expression of cost per net year of life gained by stopping smoking. Net years of life gained, discounted 0, 3, and 5%, were computed with use of cessation and relapse rates expected for patients not seen in the NDC. Treatment costs were based on 1993 rates for the intervention services but did not include any tobacco product cost savings associated with smoking cessation. RESULTS: The 1-year smoking-cessation rate was 22.2%. With all NDC patients included, the estimated net years of life gained, with use of a 5% rate of discount for benefits, was 0.058, and the corresponding cost was $6,828 per net year of life gained. CONCLUSION: In comparison with the cost-effectiveness of other medical services, the cost of $6,828 per net year of life gained by treatment of nicotine dependence is relatively inexpensive. Such cost-outcome data are important as economic considerations are applied for optimal allocation of limited health-care resources. Nonphysician health-care professionals can assume a key role in the provision of cost-effective nicotine dependence intervention.