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.

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.

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.

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.

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.

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.

β-1 and β-2 adrenergic receptor polymorphism and association with cardiovascular response to orthostatic screening

Variation in the beta-1 and beta-2 adrenergic receptor genes (ADRB1 and ADRB2, respectively) may influence cardiovascular reactivity including orthostatic stress. We tested this hypothesis in a head-up tilt (HUT) screening protocol in healthy young adults without history of syncope. Following brachial arterial catheter insertion, 120 subjects (age 18-40, 72 females, Caucasian) underwent 5min 60° HUT. Polymorphisms tested were: Ser49/Gly and Arg389/Gly in ADRB1; and Arg16/Gly, Gln27/Glu, and Thr164/Ile in ADRB2. Three statistical models (recessive, dominant, additive) were evaluated using general linear models with analysis for each physiologic variable. A recessive model demonstrated a significant association between Arg16/Gly and: absolute supine and upright HR; HUT-induced change in cardiac index (CI), stroke index (SI) and systemic vascular resistance (SVR); and supine and upright norepinephrine values. Blood pressure was not influenced by genotype. Fewer associations were present for other polymorphisms: Ser49/Gly and the change in SI (dominant model), and Arg389/Gly and supine and HUT norepinephrine (additive model). We conclude that in this population, there is a robust association between Arg16/Gly and HUT responses, such that 2 copies of Arg16 increase supine and upright HR, and greater HUT-induced decreases in CI and SI, with greater increases in SVR and norepinephrine. ADRB1 gene variation appears to impact SI and plasma NE levels but not HR. Whether ADRB2 gene variation is ultimately disease-causing or disease-modifying, this study suggests an association between Arg16/Gly and postural hemodynamics, with sympathetic noradrenergic activity affected in a similar direction. This may have implications in the development of orthostatic disorders.

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.

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.

The correlation of emphysema or airway obstruction with the risk of lung cancer: a matched case-controlled study

A matched case-controlled study was conducted to determine if airway obstruction or emphysema were associated with an increased risk of lung cancer. Lung cancer cases (n=24) were identified through a low-dose spiral computed tomography (CT) screening trial from 1,520 participants. Four controls without lung cancer were selected for each case from the participants and matched by sex, age and smoking history. Emphysema was assessed by quantitative CT analysis. Conditional logistic regression was employed to assess results of spirometry and CT quantitative analysis as potential risk factors for lung cancer. The likelihood of lung cancer was found to be significantly increased for those with forced expiratory volume in one second (FEV1) < or = 40% of predicted. The results suggested that a lower percentage of predicted FEV1 was indicative of lung cancer. No compelling evidence was found to suggest that the percentage of emphysema was associated with lung cancer. These results suggest an increased risk of lung cancer associated with airway obstruction. However, percentage of emphysema as determined by computed tomography was not associated with an increased risk of lung cancer.

Nicotine patch use in pregnant smokers: smoking abstinence and delivery outcomes

OBJECTIVE

To describe smoking abstinence and fetal effects of pregnant smokers who received 8 weeks of nicotine patch therapy.

METHODS

One-sample study of 21 pregnant women smoking > or = 15 cigarettes/day during their third trimester of pregnancy despite physician advice to stop. Nicotine patch therapy (22 mg/24 h) was initiated during the first day of a 4-day in-hospital study and continued for a total of 8 weeks. Subjects returned weekly until delivery, at 4 weeks after delivery, and at 6 and 12 months after patch therapy. Fetal growth and well-being were assessed using ultrasound examinations and non-stress tests.

RESULTS

Eight of 21 subjects completed all 8 weeks of patch therapy according to the protocol. Five subjects (24%) discontinued using the nicotine patch, owing to adverse skin reactions. There were eight subjects (38%) who were biochemically confirmed abstinent from smoking at the time of delivery; of these, seven were continuously abstinent from the start of patch therapy. Centile weight for gestational age did not change significantly over time for 12 subjects with serial ultrasound measurements available at baseline, 4 weeks and 8 weeks following initiation of patch therapy. In all cases, non-stress tests remained reactive or became reassuring with observation. No significant preterm deliveries occurred (gestational ages of 36.3-41.1 weeks). Three infants suffered severe neonatal morbidity; however, these problems were unrelated to nicotine patch therapy.

CONCLUSION

Nicotine patch therapy has potential benefit for pregnant smokers who continue to smoke despite physician advice to stop.

Removal of bronchoalveolar cells augments the late eosinophilic response to segmental allergen challenge

BACKGROUND

In patients with quiescent asthma, macrophages are the most prevalent cells recovered by bronchoalveolar lavage (BAL). Through activation via their FcepsilonRII receptors or by acting as antigen-presenting cells, macrophages could, in theory, promote the late airway response to allergen.

OBJECTIVE

In order to investigate the importance of macrophages and other airway luminal cells in inducing the late airway response, a novel washout experiment was designed.

METHODS

Five patients with ragweed-allergic asthma underwent bronchoscopy and segmental bronchial challenge with either normal saline or short ragweed extract in two segments of one lung. In a third segment of the opposite lung, 12 successive BALs (25 mL each) were performed, followed by challenge with an identical dose of short ragweed (washed-challenged segment). After 24 h, all three challenged segments underwent BAL.

RESULTS

Initially, in the washed-challenged segment, over 80% (mean 80.4%, range 68-88%) of the recoverable airway dwelling cells were removed. Unexpectedly, 24 h later these same washed-challenged segments contained more eosinophils in the BAL than the challenged segments from the opposite lung (P = 0.033).

CONCLUSIONS

Removing the majority of airway luminal cells followed by allergen bronchoprovocation increased the number of eosinophils recovered 24 h after challenge. Our results suggest that in quiescent allergic asthma, the airway luminal cells are protective and attenuate the late eosinophilic response to allergen challenge.

Risk factors for ischemic optic neuropathy after cardiopulmonary bypass: a matched case/control study

Visual loss (acuity or field) secondary to ischemic optic neuropathy (ION) is a rare but devastating complication of cardiac surgery involving cardiopulmonary bypass (CPB). We determined clinical features and risk factors for ION by a retrospective time-matched, case-control study. ION was identified in 17 (0.06%) patients out of 27,915 patients who underwent CPB between January 1, 1976, and December 31, 1994. For each ION patient, two patients who underwent CPB exactly 2 wk before the ION patient were selected as controls. Data were analyzed by using conditional logistic regression with the 1:2 matched-set feature of 17 cases and 34 controls. Two-tailed P values < or =0.05 were considered significant. From bivariate analysis, smaller minimum postoperative hemoglobin concentration (odds ratio [OR] = 1.9, P = 0.047) and the presence of atherosclerotic vascular disease (OR = 7.0, P = 0.026) were found to be independently associated with ION after CPB, as were smaller minimum postoperative hemoglobin concentration (OR = 2.2, P = 0.027) and preoperative angiogram within 48 h of surgery (OR = 7.2, P = 0.042). In ION patients, 13 (76.5%) of 17 experienced a minimum postoperative hemoglobin value of < 8.5 g/dL, whereas only 14 (41.2%) of 34 control patients experienced values < 8.5 g/dL.

IMPLICATIONS

Patients with clinically significant vascular disease history or preoperative angiogram may be at increased risk for ischemic optic neuropathy after cardiac surgery, especially if the hemoglobin remains low in the postoperative period.

Regional anesthesia does not increase the risk of postoperative neuropathy in patients undergoing ulnar nerve transposition

The use of regional anesthetic techniques in patients with preexisting neuropathies has been widely debated. The possibility of needle- or catheter-induced trauma, local anesthetic toxicity, or neural ischemia during regional blockade may place patients with underlying mechanical, ischemic, or metabolic neurologic derangements at increased risk of progressive neural injury. We evaluated the safety of regional versus general anesthesia in patients with a preexisting ulnar neuropathy undergoing ulnar nerve transposition. All patients (n = 360) who underwent ulnar nerve transposition at the Mayo Clinic from 1985 to 1999 were retrospectively studied. A general anesthetic was performed in 260 (72%) patients. The remaining 100 (28%) patients received an axillary block, including 64 patients in whom an ulnar paresthesia or nerve stimulator motor response was elicited at the time of block placement. Patient characteristics, the severity of preoperative ulnar nerve dysfunction, and surgical variables were similar between groups. Anesthetic technique did not affect neurologic outcome (new or worsening pain, paresthesias, numbness, or motor weakness) immediately after surgery or at 2 or 6 wk after surgery. All six patients in the Axillary Block group who reported new or worsening neurologic symptoms after surgery had received bupivacaine in combination with either an ulnar paresthesia or motor response. By using logistic regression, bupivacaine was identified as an independent risk factor for worsening of ulnar nerve function compared with other local anesthetics. We conclude that axillary blockade is a suitable anesthetic technique for this procedure.

IMPLICATIONS

The use of regional anesthetic techniques in patients with preexisting neuropathies has been widely debated. Theoretical concerns include the risk of progressive nerve damage from direct needle trauma or local anesthetic toxicity. This investigation, however, supports the safety of axillary blockade in patients with preexisting ulnar neuropathy undergoing ulnar nerve transposition.

The effects of remifentanil on epileptiform discharges during intraoperative electrocorticography in patients undergoing epilepsy surgery

PURPOSE

High-dose i.v. opioids (e.g., alfentanil, 50 microg/kg bolus) are known to increase the intraoperative reading of epileptiform activity during epilepsy surgery (ES), thereby facilitating localization of the epileptogenic zone (i.e., the site of ictal onset and initial seizure propagation). However, this phenomenon has not been studied with remifentanil (i.e., a novel ultra-short acting opioid). The purpose of the present study was to evaluate the effect of remifentanil on electrocorticography (ECoG) during ES.

METHODS

After Institutional Review Board approval, 25 adult patients undergoing elective ECoG-guided anterior temporal corticectomy were enrolled. At the time of ECoG, anesthesia consisted of inhaled isoflurane < or =0.1% (end-tidal) in 50% N2O, and i.v. fentanyl, 2 microg/kg/h and vecuronium. Patients were maintained at normocapnia and normoxia during ECoG. After acquisition of baseline ECoG, bolus remifentanil, 2.5 microg/kg i.v., was administered. The number of epileptiform spikes occurring 5 min before and after this bolus were compared by using a one-sided sign test; p values < or =0.05 were considered statistically significant.

RESULTS

When compared with baseline ECoG, bolus i.v. remifentanil significantly increased the frequency of single spikes or repetitive spike bursts in the epileptogenic zone while suppressing activity in surrounding normal brain.

CONCLUSIONS

During ES, remifentanil enhanced epileptiform activity during intraoperative ECoG. Such observations facilitate localization of the epileptogenic zone while minimizing resection of nonepileptogenic eloquent brain tissue. Although not specifically evaluated in this study, we speculate that remifentanil's short elimination half-life will facilitate neurologic function testing immediately after ES. Should this be the case, we envision remifentanil has the potential to supplant other opioids (e.g., alfentanil) during ECoG-guided ES.

Polymyositis-dermatomyositis-associated interstitial lung disease

We report findings in 70 patients with both diffuse interstitial lung disease and either polymyositis (PM) or dermatomyositis (DM). Initial presentations were most commonly either musculoskeletal (arthralgias, myalgias, and weakness) or pulmonary (cough, dyspnea, and fever) symptoms alone; in only 15 patients (21.4%) did both occur simultaneously. Pulmonary disease usually took the form of acute to subacute antibiotic-resistant community-acquired pneumonia. Chest radiographs and computed tomography most commonly demonstrated bilateral irregular linear opacities involving the lung bases; occasionally consolidation was present. Jo-1 antibody was present in 19 (38%) of 50 patients tested. Synchronous associated malignancy was present in 4 of 70 patients (5.7%). Surgical lung biopsies disclosed nonspecific interstitial pneumonia (NSIP) in 18 of 22 patients (81.8%), organizing diffuse alveolar damage (DAD) in 2, bronchiolitis obliterans organizing pneumonia (BOOP) in 1, and usual interstitial pneumonia (UIP) in 1. Treatment usually included prednisone in 40-60 mg/d dosages for initial control, followed by lower dose prednisone plus an immunosuppressive agent such as azathioprine or methotrexate for disease suppression. Survival was significantly better than that observed for historical control subjects with idiopathic UIP, and was more consistent with survival previously reported in idiopathic NSIP. There was no difference in survival between Jo-1 positive and Jo-1 negative groups.

A community-wide smoking cessation program: Quit and Win 1998 in Olmsted county

BACKGROUND

Quit and Win is a community-wide stop smoking contest to help cigarette smokers stop smoking and educate the general public concerning smoking hazards.

METHODS

All community residents, 15 years of age or older, were eligible to participate in either the stop smoking contest or the supporter contest. A random telephone survey to local households was conducted before and after the Quit and Win contest to assess the level of knowledge and attitude changes about smoking.

RESULTS

Of the 304 smokers enrolled in the contest, 42% self-reported continuous tobacco abstinence for the 4-week contest period and 11% were abstinent at 1 year postcontest. Significant predictors for tobacco abstinence during the contest were formal education beyond high school, absence of other smokers in the household, having a support person enrolled in the support person contest, and the type of relationship that the support person had with their smoker. Survey results showed that this contest changed some local attitudes and increased general knowledge of smoking hazards.

CONCLUSIONS

Community-wide stop smoking contests can be used to engage smokers and their support in the community and can be successful in reducing tobacco use.

Perianaesthetic risks and outcomes of abdominal surgery for metastatic carcinoid tumours

Patients with metastatic carcinoid tumours often undergo surgical procedures to reduce the tumour burden and associated debilitating symptoms. These procedures and anaesthesia can precipitate a life-threatening carcinoid crisis. To assess perioperative outcomes, we studied retrospectively the medical records of adult patients from 1983 to 1996 who underwent abdominal surgery for metastatic carcinoid tumours. Preoperative risk factors, intraoperative complications and complications occurring in the 30 days after surgery were recorded. Perioperative complications or death occurred in 15 of 119 patients (12.6%, exact confidence interval 7.2-19.9). None of the 45 patients who received octreotide intraoperatively experienced intraoperative complications compared with eight of the 73 patients (11.0%) who did not receive octreotide (P=0.023). The presence of carcinoid heart disease and high urinary output of 5-hydroxyindoleacetic acid preoperatively were statistically significant risk factors for perioperative complications.

Bupropion for Smoking Cessation

OBJECTIVES

To identify predictors of smoking abstinence at the end of medication use that could assist in the optimal use of a sustained-release (SR) form of bupropion for treating cigarette smokers.

DESIGN

A double-blind, placebo-controlled, dose-response trial.

SETTING

Multicenter (three sites) study conducted in the United States.

PARTICIPANTS

Six hundred fifteen healthy men and women (> or = 18 years of age) who were smoking > or = 15 cigarettes per day and who were motivated to stop smoking.

INTERVENTION

Random assignment of patients to placebo or SR bupropion treatment, 100, 150, or 300 mg/d, for 7 weeks (total duration of study was 52 weeks: 7 weeks of treatment and 45 weeks of follow-up).

MEASUREMENTS AND RESULTS

Logistic regression was used to identify predictors of abstinence at the end of the medication phase. Univariate predictors included the following: bupropion dose (p < 0.001); older age (p = 0.024); lower number of cigarettes smoked per day (cpd) (p < 0.001); lower Fagerström Tolerance Questionnaire score (p = 0.011); longest time previously abstinent that was < 24 h or > 4 weeks (p < 0.001); absence of other smokers in the household (p = 0.021); greater number of previous stop attempts (p = 0.019); and study site (p = 0.004). Multivariate predictors of abstinence at the end of the medication phase were the following: higher bupropion dose (p < 0.001); lower number of cpd (p < 0.001); longest time previously abstinent from smoking (p = 0.002); male gender (p = 0.014); and study site (p = 0.021).

CONCLUSION

Bupropion SR therapy was effective in treating cigarette smokers independently of all other characteristics studied. Lower smoking rate, brief periods (ie, < 24 h) or long periods (ie, > 4 weeks) of abstinence with previous attempts to stop smoking, and male gender were predictive of better outcomes, independent of the dose of bupropion that was used.

The effect of changing transfusion practice on rates of perioperative stroke and myocardial infarction in patients undergoing carotid endarterectomy: a retrospective analysis of 1114 Mayo Clinic patients. Mayo Perioperative Outcomes Group

OBJECTIVE

To evaluate changes in the institution's red blood cell (RBC) transfusion practice during the past 15 years and the influence of these changes on neurologic or cardiac morbidity after carotid endarterectomy.

PATIENTS AND METHODS

Based on a retrospective analysis of the Mayo Clinic database, 1,114 patients who underwent carotid endarterectomy were stratified into 1 of 2 groups: (1) 1980 to 1985 (ie, pre-human immunodeficiency virus screening, early-practice group [n=552]) and (2) 1990 to 1995 (ie, recent-practice group [n=562]). Data were compared between time periods using the chi2 test for categorical variables and the rank sum test for continuous variables. Logistic regression was used to assess the association between perioperative transfusion practice and the occurrence of stroke or myocardial infarction. Two-tailed P values < or = 05 were considered statistically significant.

RESULTS

Patients in the recent-practice group were significantly older (mean +/- SD age, 69.6 +/- 8.7 years) vs 65.9 +/- 8.3 years in the early-practice group (P<.001). The proportion of patients receiving perioperative RBC transfusion decreased dramatically from 72.9% in 1980-1985 to 8.7% in 1990-1995 (P<.001). Additionally, the mean +/- SD number of RBC units transfused decreased from 1.10 +/- 1.30 U in 1980-1985 to 0.27 +/- 1.22 U in 1990-1995 (P<.001). Mean +/- SD discharge hemoglobin concentration decreased from 13.7 +/- 1.4 g/dL in 1980-1985 to 11.8 +/- 1.5 g/dL in 1990-1995 (P<.001). Rates of perioperative stroke and myocardial infarction did not differ between the 2 time periods (early-practice group vs recent-practice group: stroke, 5.1% vs 3.6% [P=.22]; myocardial infarction, 1.5% vs 2.3% [P=.29]).

CONCLUSIONS

Our results suggest that elderly patients undergoing carotid endarterectomy (ie, individuals known to be at high risk for cerebral and cardiac ischemia) can tolerate modest perioperative anemia despite a considerable change in the institution's transfusion practice (lower "transfusion trigger," the hemoglobin concentration or hematocrit value below which RBC transfusion is indicated).

High short-term mortality following lung biopsy for usual interstitial pneumonia

Usual interstitial pneumonia (UIP) is a specific histological pattern of interstitial pneumonia most often associated with the clinical syndrome of idiopathic pulmonary fibrosis (IPF). There is controversy regarding the use of surgical lung biopsy in the diagnosis of UIP, and the risk of lung biopsy in these patients is largely unknown. This study investigated the 30 day surgical mortality rate in patients undergoing surgical lung biopsy for UIP. Patients undergoing surgical lung biopsy over a 10-yr period from 1986-1995 with the ultimate diagnosis of UIP (with or without underlying connective tissue disease) were identified. Pathology, computed tomography, medical records, and survival were assessed. Ten of sixty patients with usual interstitial pneumonia were found to be dead within 30 days of surgical biopsy. All of these were patients with idiopathic UIP, unassociated with connective tissue disease (clinical condition of IPF). In conclusion, patients with usual interstitial pneumonia of the idiopathic type, who present with atypical features, may be at higher risk for death following surgical biopsy than patients presenting with more typical features or patients with other interstitial illnesses.

Production, isolation and structure determination of novel fluoroindolocarbazoles from Saccharothrix aerocolonigenes ATCC 39243

Saccharothrix aerocolonigenes ATCC 39243 produces an indolocarbazole antitumor agent rebeccamycin under submerged fermentation conditions. Adding DL-6-fluorotryptophan to culture of S. aerocolonigenes ATCC 39243 induces the formation of two novel indolocarbazoles, fluoroindolocarbazoles A and B. Feeding DL-5-fluorotryptophan to culture of S. aerocolonigenes ATCC 39243 induces the production of a novel indolocarbazole, fluoroindolocarbazole C. These fluoroindolocarbazoles have been isolated from culture broth and purified to homogeneity by vacuum liquid chromatography and column chromatography. All three fluoroindolocarbazoles are more potent than rebeccamycin against P388 leukemia by ip route in murine model.

Requirements for muscle relaxants during radical retropubic prostatectomy

BACKGROUND

The need for the routine use of muscle relaxants to provide an adequate surgical field for intraabdominal surgery has not been established. This study tested the hypothesis that vecuronium decreases the frequency of unacceptable operating conditions for patients undergoing radical retropubic prostatectomy who are anesthetized with isoflurane and fentanyl.

METHODS

After obtaining informed consent, patients in this blinded, placebo-controlled study were randomized to receive either an infusion of vecuronium or saline (placebo) beginning 5 min after fascial incision during the maintenance of anesthesia with at least 1 minimum alveolar concentration end-tidal isoflurane and fentanyl infusion. The surgical field was graded from 1 (excellent) to 4 (unacceptable) by the surgeons at 15-min intervals. If a grade 4 rating occurred (defined as a treatment failure), the patient received rescue vecuronium.

RESULTS

A total of 120 patients are included in this report (59 in the vecuronium group and 61 in the placebo group). The frequency of treatment failure in the placebo group was 17 of 61 (27.9%) versus 1 of 59 (1.7%) in the control group who received vecuronium (P < 0.001). Thirty-eight patients (62.3%) in the placebo group and 52 patients (88.1%) in the vecuronium group had surgical field ratings of < or = 2 (good to excellent) at each time assessed throughout the procedure.

CONCLUSION

The study hypothesis was confirmed. However, an isoflurane-fentanyl anesthetic alone produced a good to excellent surgical field in approximately two thirds of patients undergoing radical retropubic prostatectomy without the use of muscle relaxants. Thus, the routine use of muscle relaxants in adequately anesthetized patients undergoing this procedure may not be indicated.

Desmopressin does not reduce bleeding and transfusion requirements in congenital heart operations

BACKGROUND

Desmopressin (DDAVP) has been evaluated in many randomized clinical trials as a means to reduce blood loss and transfusion of allogeneic blood in cardiac operation requiring cardiopulmonary bypass. Desmopressin reduces blood loss in adult patients with excessive bleeding after cardiac operation. Its usefulness in patients undergoing complex congenital heart repair with cardiopulmonary bypass is unproved.

METHODS

Sixty patients younger than 40 years of age scheduled for complex congenital heart operation (44 redo, 16 primary) were enrolled in this prospective, randomized, double-blind trial. Desmopressin 0.3 microg/kg or placebo was administered 10 minutes after protamine administration. Transfusion requirements and postoperative blood loss were recorded. Differences were analyzed using analysis of variance with a p value of 0.05 or less used to denote statistical significance.

RESULTS

There were no differences in demographic or surgical characteristics between the DDAVP or placebo groups. There was no difference in blood loss and transfusion requirements between the DDAVP and placebo groups. During the intraoperative postinfusion time period, the median blood loss for redo patients was 343 versus 357 mL/m2 for placebo versus DDAVP, respectively, and for primary patients, the median blood loss was 277 versus 228 mL/m2.

CONCLUSIONS

The prophylactic use of DDAVP to reduce excessive bleeding or transfusion requirements in patients undergoing complex congenital heart operations is not warranted.

Perianesthetic risks and outcomes of pheochromocytoma and paraganglioma resection

Pheochromocytomas and paragangliomas are often surgically curable. However, resection of these tumors can be life threatening. We undertook this study to determine the frequency of, and risk factors for, perioperative complications in patients undergoing resection of pheochromocytoma or paraganglioma. We retrospectively reviewed the medical records of patients during 1983-1996 who underwent surgical resection of catecholamine-secreting pheochromocytoma or paraganglioma. Preoperative risk factors, adverse intraoperative events, and complications occurring in the 30 days after operation were recorded. Blood pressures were collected from manual records. The ranked sum test and Fisher's exact test were used for analyses. Adverse perioperative events or complications occurred in 45 of 143 patients (31.5%; exact 95% confidence interval, 24.0% to 39.8%). Of these 45 patients, 41 experienced one or more adverse intraoperative events. The most common adverse event was sustained hypertension (36 patients). There were no perioperative deaths, myocardial infarctions, or cerebrovascular events. Preoperative factors univariately associated with adverse perioperative events included larger tumor size (P: = 0.007), prolonged duration of anesthesia (P: = 0.015), and increased levels of preoperative urinary catecholamines and catecholamine metabolites: vanillylmandelic acid (P: = 0.019), metanephrines (P: = 0.004), norepinephrine (P: = 0. 014), and epinephrine (P: = 0.004). Despite premedication of most patients with phenoxybenzamine and a beta-adrenergic blocker, varying degrees of intraoperative hemodynamic lability occurred.

IMPLICATIONS

Few patients who had pheochromocytoma or paraganglioma resection experienced significant perioperative morbidity and none died in the largest retrospective study on this topic to date. This study confirms the very good perioperative outcomes demonstrated in smaller studies on this high-risk population, and identifies several risk factors for adverse outcomes.

Lower extremity neuropathies associated with lithotomy positions

BACKGROUND

The goal of this project was to study the frequency and natural history of perioperative lower extremity neuropathies.

METHODS

A prospective evaluation of lower extremity neuropathies in 991 adult patients undergoing general anesthetics and surgical procedures while positioned in lithotomy was performed. Patients were assessed with use of a standard questionnaire and neurologic examination before surgery, daily during hospital stay in the first week after surgery, and by phone if discharged before 1 postoperative week. Patients in whom lower extremity neuropathies developed were observed for 6 months.

RESULTS

Lower extremity neuropathies developed in 15 patients (1.5%; 95% confidence interval, 0.8-2.5%). Unilateral or bilateral nerves were affected in patients as follows: obturator (five patients), lateral femoral cutaneous (four patients), sciatic (three patients), and peroneal (three patients). Paresthesia occurred in 14 of 15 patients, and 4 patients had burning or aching pain. No patient had weakness. Symptoms were noted within 4 h of completion of the anesthetic in all 15 patients. These symptoms resolved within 6 months in 14 of 15 patients. Prolonged positioning in a lithotomy position, especially for more than 2 h, was a major risk factor for this complication (P = 0.006).

CONCLUSIONS

In this surgical population, lower extremity neuropathies were infrequent complications that were noted very soon after surgery and anesthesia. None resulted in prolonged disability. The longer patients were positioned in lithotomy positions, the greater the chance of development of a neuropathy. These findings suggest that a reduction of duration of time in lithotomy positions may reduce the risk of lower extremity neuropathies.

Influence of social deprivation on intensive care outcome

OBJECTIVE

To assess the influence of social deprivation on outcome from admission to the intensive care unit.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral centre mixed adult intensive care unit (ICU).

PATIENTS

Seven hundred seventy-four consecutive admissions to the ICU over a 2-year period.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Age, admission illness severity measured by APACHE II score, predicted hospital mortality, actual hospital mortality and length of ICU stay were obtained for all patients. Social deprivation was assessed by Carstairs Score for postcode sector of residence categorised from 1 (most affluent ) to 7 (most deprived). Carstairs Scores were obtained for 716 patients. When patients in categories 6 and 7 were compared with the others there were no significant differences in age, admission illness severity, predicted or actual hospital mortality and length of ICU stay. On multivariate analysis there was no evidence of an increased mortality risk for patients in categories 6 and 7 (p = 0.256, odds ratio 1.2, 95% confidence interval 0.9-1.7).

CONCLUSIONS

Social deprivation does not influence outcome in patients admitted to the ICU.

Idiopathic pulmonary fibrosis: Impact of oxygen and colchicine, prednisone, or no therapy on survival

The clinical records of 487 patients seen at Mayo Clinic Rochester (MCR) during 1994 through 1996 who were diagnosed as having idiopathic pulmonary fibrosis of the usual interstitial pneumonia type (IPF/UIP) were reviewed. Computed tomography (CT) had been done in 94.7% of patients and surgical open lung biopsy (OLB) in 20.3%. Median survival was 3.2 yr. We compared survival as a function of treatment program, based on intent to treat at the time of the initial contact within the study window. Treatment advised included colchicine alone in 167, no therapy in 157, prednisone at maintenance dosages alone in 54, colchicine plus prednisone in 71, and other programs in 38. Oxygen therapy was advised in 133 patients. By univariate analysis, worse survival was associated with prednisone therapy compared with no therapy, and with oxygen therapy compared with no oxygen therapy. However, on multivariate analysis, worse survival was associated with older age, male gender, lower diffusing capacity for carbon monoxide (DL(CO)), lower alveolar volume (VA), and a history of worsening pulmonary function. When adjustment was made for these factors, there was no significant difference in survival between those patients treated with colchicine or prednisone and those on no therapy, and no difference between those on oxygen therapy and those without oxygen.

Does intraoperative hetastarch administration increase blood loss and transfusion requirements after cardiac surgery?

Hetastarch is used for intravascular volume expansion in cardiac surgery. Studies show conflicting effects of intraoperative hetastarch administration on postoperative bleeding. Hetastarch was routinely used for volume expansion during cardiovascular surgeries at our institution until its use was discontinued intraoperatively. We performed a retrospective chart review on patients undergoing primary coronary artery bypass grafting, valve repair or replacement requiring cardiopulmonary bypass (n = 444), 234 of which received intraoperative hetastarch and 210 did not. There was no difference in demographics, cardiac surgery, or cardiopulmonary bypass duration between the two groups. Blood loss for 0-4 h postoperatively was 377 +/- 244 mL in the group not receiving hetastarch compared with 515 +/- 336 mL in the group that received hetastarch (P < 0.001). For 0-24 h postoperatively, blood loss was 923 +/- 473 mL versus 1,283 +/- 686 mL in the absence and presence of hetastarch, respectively (P < 0.001). Allogeneic transfusion requirements (cryoprecipitate, fresh frozen plasma, and platelets) were larger in the hetastarch group (all P < 0.001). Nearly all (99%) patients in the hetastarch group received less than the manufacturer's recommended dose (20 mL/kg) of hetastarch.

IMPLICATIONS

Our large retrospective study suggests that intraoperative use of hetastarch in primary cardiac surgery with cardiopulmonary bypass may increase bleeding and transfusion requirements. A large prospective study is needed to determine if intraoperative administration of hetastarch should be avoided during cardiovascular surgery.

Effect of three smoking cessation treatments on nicotine withdrawal in 141 abstinent alcoholic smokers

This prospective study examined the effect of three behavioral smoking interventions and reductions in cigarettes smoked per day on nicotine withdrawal symptoms in 141 abstinent alcoholic smokers (73 men, 68 women). The participants' mean +/- SD age was 41.4 +/- 9.2 years. They smoked an average of 27.7 +/- 12.1 cigarettes per day and reported 4.1 +/- 4.3 years of current abstinent from alcohol and other drugs of dependence. Participants were randomly assigned to a 12-week program of standard treatment (ST, n = 61), behavioral counseling plus exercise (BEX, n = 39), or behavioral counseling plus nicotine gum (BNIC, n = 41). All three conditions included instructions to reduce the number of cigarettes smoked per day prior to the target quit date (TQD). The TQD was week 4 for ST subjects and week 8 for those in the BEX and BNIC groups. The post-treatment assessment occurred one week after TQD. The Profile of Mood States (POMS) and the Beck Depression Inventory were administered at baseline and posttreatment to assess nicotine withdrawal. Significant increases were detected for the POMS total mood disturbance score, and the depression, tension, anger and confusion subscales, while vigor scores decreased (all p < 0.03). Withdrawal change scores were not found to be associated with treatment condition or percentage reduction in cigarettes, and there was no evidence of a significant interaction of treatment and cigarette reduction. Results are discussed in relation to implications for treatment and for future research.

Detectable blood alcohol after a motor vehicle crash and screening for alcohol abuse/dependence

OBJECTIVE

To determine the percentage of patients hospitalized after an alcohol-related motor vehicle crash (MVC) who underwent a screening evaluation for alcohol abuse/dependence and had a diagnosis of alcohol abuse/dependence.

PATIENTS AND METHODS

Medical and emergency trauma records were reviewed retrospectively for 1994 through 1996 to identify patients who were hospitalized as a result of being involved in an MVC with any detected blood alcohol at the time of admission to a large midwestern Level I trauma center. The primary outcome measure was the performance of alcohol abuse/dependence screening by a psychiatrist or a chemical dependency counselor. A univariate analysis was performed to identify factors associated with the performance of alcohol abuse/dependence screening. The Fisher exact test and the 2-sample rank sum test were used in the analyses.

RESULTS

Of the 294 study patients, 78 (26.5%) underwent a screening evaluation for alcohol abuse/dependence by a psychiatrist or a chemical dependency counselor during hospitalization, and 69 (88%) of the 78 patients screened had a diagnosis of alcohol abuse/dependence. Factors associated with the performance of alcohol abuse/dependence evaluation included a known prior history of alcohol abuse, suspicion of alcohol consumption documented by emergency department personnel, higher blood alcohol level at admission, and longer length of hospitalization (all P < .001).

CONCLUSION

While the high rate of alcohol abuse/dependence may be explained partially by distinguishing factors in those screened, these findings suggest that routine alcohol abuse/dependence screening of persons presenting with a detectable blood alcohol level following an MVC may identify patients who would benefit from a chemical dependency intervention.

Risk of surgery and anesthesia for ischemic stroke

BACKGROUND

The goal of this study was to determine if the combination of surgery and anesthesia is an independent risk factor for the development of incident (first-time) ischemic stroke.

METHODS

All residents of Rochester, MN, with incident ischemic stroke from 1960 through 1984 (1,455 cases and 1,455 age- and gender-matched controls) were used to identify risk factors associated with ischemic stroke. Cases and controls undergoing surgery involving general anesthesia or central neuroaxis blockade before their stroke/index date of diagnosis were identified. A conditional logistic regression model was used to estimate the odds ratio of surgery and anesthesia for ischemic stroke while adjusting for other known risk factors.

RESULTS

There were 59 cases and 17 controls having surgery within 30 days before their stroke/index date. After adjusting for previously identified risk factors, surgery within 30 days before the stroke/index date (perioperative period) was found to be an independent risk factor for stroke (P<0.001; odds ratio, 3.9; 95% confidence interval, 2.1-7.4). In an analysis that excluded matched pairs where the case and/or control underwent surgery considered "high risk" for stroke (cardiac, neurologic, or vascular procedures), "non-high-risk surgery" was also found to be an independent risk factor for perioperative stroke (P = 0.002; odds ratio, 2.9; 95% confidence interval, 1.5-5.7).

CONCLUSION

Our results suggest that there is an increased risk of ischemic stroke in the 30 days after surgery and anesthesia. This risk remains elevated even after excluding surgeries (cardiac, neurologic, and vascular surgeries) considered to be high risk for ischemic stroke.

Response to nicotine dependence treatment in smokers with current and past alcohol problems

Smoking prevalence among alcoholics is high, and evidence indicates that smokers with a history of alcohol abuse may have more difficulty quitting cigarette smoking. This study is a post hoc analysis comparing the smoking cessation rates of smokers with active or past alcohol problems to the rates in smokers with no history of alcohol problems who were participants in a randomized, controlled trial of smoking cessation therapy. Subjects received either 44 mg/24 hour or 22 mg/24 hour nicotine patch for 4 or 6 weeks, respectively, followed by a tapering schedule to complete 8 weeks of therapy and a randomly assigned behavioral intervention (minimal, brief individual counseling, group therapy). The Self-Administered Alcoholism Screening Test (SAAST) score was used to determine alcohol group assignment (no alcohol problems < 7; active alcohol problems > or = 7 and still drinking; past alcohol problems if not drinking due to a past history of alcohol problems). Among 382 subjects (171 men and 211 women), 281 had no alcohol problems (74%), 53 had past alcohol problems (14%), and 48 had active alcohol problems (13%). Smoking cessation rates assessed at both weeks 4 and 8 were significantly different across groups (p = 0.026 and 0.002 at weeks 4 and 8, respectively) with lower rates in the groups with past and active alcohol problems when compared to the "no problem" group. At week 26, subjects with past alcohol problems were less likely to be abstinent from smoking than no problem group subjects, but this was not statistically significant (odds ratio = 0.49, 95% confidence interval 0.22-->1.08). In the short term, smokers with past or active alcohol problems are less likely to quit smoking compared to those with no alcohol problems when treated with nicotine patch therapy for smoking cessation.

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.

Over-the-counter nicotine patch therapy for smoking cessation: results from randomized, double-blind, placebo-controlled, and open label trials

OBJECTIVES

The purpose of this study was to determine the efficacy and safety of the nicotine patch for smoking cessation in an over-the-counter environment. The years of study were 1994 to 1995.

METHODS

Parallel 6-week trials were conducted: a placebo-controlled trial of no-cost 22-mg, 24-hour nicotine patch therapy and an open label trial of the same therapy with patches purchased by subjects. Participants (n = 958) were 18 years or older, had smoked at least 15 cigarettes daily for at least 6 months, and were enrolled at 3 study sites. The main outcome measure was self-reported smoking abstinence confirmed by expired carbon monoxide measurements.

RESULTS

Smoking cessation rates in the placebo-controlled trial were 16.8% and 9.6% at week 6 and 8.7% and 4.3% at week 24 for the active patch and placebo groups, respectively. Smoking cessation rates in the open label-pay trial were 19.0% and 10.8% at weeks 6 and 24, respectively. A slight increase in adverse cardiovascular events was noted only in the open label-pay group in comparison with the placebo group.

CONCLUSIONS

In an over-the-counter environment, the 22-mg, 24-hour nicotine patch is effective and safe for smoking cessation treatment.

Nicotine patch use in pregnant smokers: nicotine and cotinine levels and fetal effects

OBJECTIVE

The aims of this study were (1) to determine whether nicotine patch therapy for pregnant women smokers acutely compromises fetal well-being and (2) to determine the serum and urine nicotine and cotinine levels in pregnant women while smoking, while abstinent from smoking, and while receiving nicotine patch therapy compared with levels in a historical control group of nonpregnant women smokers who abstained from smoking while receiving comparable doses of nicotine patch therapy.

STUDY DESIGN

Pregnant cigarette smokers (n = 21) aged >/=18 years whose fetuses were beyond 24 weeks' gestational age were recruited for this 1-sample, repeated-measures study. Serial measurements of the mother and fetus were made at baseline while the mother was smoking, while abstaining from smoking, and while using nicotine patch therapy for 4 days in a special care hospital unit. Nonpregnant women smokers of similar age were used for comparison. Morning and afternoon serum and 24-hour urine levels of nicotine and cotinine were obtained during hospitalization. Indicators of fetal well-being assessed were fetal heart rate and reactivity, systolic/diastolic ratio of blood flow in the umbilical artery, and fetal activity seen on ultrasonography and quantitated as biophysical profiles.

RESULTS

No evidence of fetal compromise was seen during the inpatient phase while nicotine patch therapy was administered. Steady state (inpatient day 4) serum levels of nicotine were similar to smoking levels and to those seen in historical control subjects (ie, nonpregnant women of child-bearing age who were abstinent from smoking and who used the same nicotine patch). Morning serum cotinine levels were significantly higher (P =.038) in the nonpregnant subjects than in the pregnant subjects, whereas afternoon levels were not significantly different. Steady state urinary levels of nicotine and cotinine were also not significantly different in pregnant versus nonpregnant patients. On inpatient days 2, 3, and 4, when the women were not smoking and were wearing the nicotine patch, the morning fetal heart rates were significantly reduced relative to baseline when the subjects were smoking.

CONCLUSIONS

Nicotine patch therapy was not found to be associated with indications of fetal compromise during the in-hospital phase of nicotine patch therapy in pregnant smokers who were abstaining. Although not conclusive because of the small sample sizes, serum nicotine levels (morning and afternoon) appear similar in pregnant and nonpregnant subjects and similar for both groups when smoking (baseline) as compared to the steady state of nicotine patch use.

Epidural anesthesia and analgesia are not impaired after dural puncture with or without epidural blood patch

Previous reports have noted a decrease in the success of subsequent epidural anesthesia and analgesia in patients who have undergone prior dural puncture with or without an epidural blood patch. Our retrospective study evaluated the success of epidural anesthesia and analgesia in all patients at the Mayo Clinic who had received a prior epidural blood patch over a 12-yr period. Each epidural blood patch patient was matched to two patients undergoing epidural anesthesia after previous dural puncture (without epidural blood patch) and to two patients undergoing epidural anesthesia after previous epidural anesthetic (without dural puncture/blood patch). These patients were matched for the duration of time between the initial procedure and subsequent epidural anesthetic and the indication (surgery, labor analgesia, postoperative analgesia) for which the subsequent epidural was performed. Subsequent epidural anesthesia was successful in 28 of 29 (96.6%, exact 95% CI 82.2%-99.9%) patients who had undergone prior blood patch, 55 of 58 (94.8%, 85.6%-98.9%) patients with a history of dural puncture, and 55 of 58 (94.8%, 85.6%-98.9%) patients who had had previous epidural anesthesia. There was no significant difference in the success rate of subsequent epidural anesthesia among groups. We conclude that prior dural puncture, with or without epidural blood patch, does not affect the success rate of subsequent epidural anesthesia.

IMPLICATIONS

Patients with postdural puncture headache should not be denied the benefits of an epidural blood patch because of concerns about the impairment of subsequent epidural anesthetics. The success rate of subsequent epidural anesthesia and analgesia in patients who have undergone dural puncture with or without epidural blood patch is similar to that of patients who have undergone two prior epidural anesthetics.

Epidemiology of anaphylaxis in Olmsted County: A population-based study

BACKGROUND

Awareness of the clinical features of anaphylaxis and its causative triggers is important if recurrent episodes are to be avoided. The incidence of anaphylaxis in the general population is often underreported, and epidemiologic studies are few. Because an accurate profile of anaphylaxis could heighten awareness of this problem, we investigated the epidemiology of anaphylaxis in the general population of Olmsted County, Minn.

OBJECTIVE

The purpose of this study was to describe the epidemiology of anaphylaxis in Olmsted County residents from 1983 through 1987.

METHODS

This was a retrospective population-based cohort study. The medical records of 1255 Olmsted County residents identified by computer-linked, medical diagnostic indices (the Rochester Epidemiology Study) were reviewed retrospectively to identify residents whose clinical episodes met the criteria for anaphylaxis. We determined the incidence and rate of occurrence of anaphylaxis, rate of recurrence, prevalence of atopy, cause of anaphylaxis, frequency of referral to an allergy specialist, hospital admission rate, and case-fatality rate.

RESULTS

There were 133 residents who experienced 154 anaphylactic episodes during the 5-year period: 116 residents had 1 episode of anaphylaxis, 13 residents had 2 episodes, and 4 residents had 3 episodes. The anaphylaxis occurrence rate was 30 per 100,000 person-years (95% confidence interval, 25-35). There were 110 residents who had a first lifetime episode of anaphylaxis (that was medically evaluated) during the years 1983 to 1987. The average annual incidence rate of anaphylaxis was 21 per 100,000 person-years (95% confidence interval, 17-25). Atopy was present in 53% of the cohort, and allergy consultation was obtained in 52%. A suspect allergen was identified in 68% of the cohort, most frequently a food, medication, or insect sting. The hospitalization rate was 7%, and 1 patient died.

CONCLUSION

The incidence of anaphylaxis is less than 1%, and death rarely occurs. People with atopy experience anaphylaxis more frequently than people without atopy. Anaphylaxis frequently is not recognized by patients and physicians.

Probable alcohol abuse or dependence: a risk factor for intensive-care readmission in patients undergoing elective vascular and thoracic surgical procedures. Mayo Perioperative Outcomes Group

OBJECTIVE

To determine whether alcohol abuse or dependence is a risk factor for perioperative complications, increased duration of hospital stay, and increased utilization of nursing resources in patients undergoing thoracic and vascular surgical procedures.

MATERIAL AND METHODS

We conducted a prospective study of all adult patients who underwent an elective vascular or thoracic surgical procedure and who received postoperative care in an intensive-care setting. Patients were screened for alcohol abuse or dependence, and actual versus expected durations of stay were evaluated. The patients' medical records were reviewed for preoperative comorbidities and perioperative complications. Fisher's exact test and the rank sum test were used in the analyses.

RESULTS

Of 321 study subjects, 290 were classified as nonalcoholic and 31 as probable alcoholic patients. Patients in the probable alcohol abuse group had a significantly increased rate of alcohol withdrawal (12.9% versus 1.7%; P = 0.006) in comparison with patients in the nonalcoholic group. Patients in the probable alcohol abuse group were readmitted to an intensive-care unit more frequently (19.4% versus 7.9%; P = 0.047) and required sedation more often (32.3% versus 13.5%; P = 0.014) than those in the nonalcoholic group. No significant differences were found between the two study groups in intensive-care unit and hospital durations of stay or in utilization of nursing resources. A dismissal diagnosis of alcoholism was recorded for only one of four patients who had a documented withdrawal episode among those categorized in the probable alcoholic group and for three of five patients with alcohol withdrawal symptoms categorized in the nonalcoholic group.

CONCLUSION

Except for the occurrence of alcohol withdrawal syndrome, study patients classified in the probable alcohol abuse group did not have more medical or surgical perioperative complications than patients in the nonalcoholic group. They did have significantly more intensive-care setting readmissions. Patients with documented alcohol withdrawal episodes frequently were dismissed without a diagnosis of substance abuse or dependence.

Perianesthetic dental injuries: frequency, outcomes, and risk factors

BACKGROUND

Dental injury is well-recognized as a potential complication of laryngoscopy and tracheal intubation. However, the frequency, outcomes, and risk factors for this problem have not been documented in a well-defined patient population.

METHODS

The authors analyzed the dental injuries of 598,904 consecutive cases performed on patients who required anesthetic services from 1987 through 1997. Dental injuries were defined as perianesthetic events (those occurring within 7 days) that required dental interventions to repair, stabilize, or extract involved dentition or support structures. A 1:3 case-control study of 16 patient and procedural characteristics was performed for cases that occurred during the first 5 yr of the study. Conditional logistic regression was used for data analysis.

RESULTS

There were 132 cases (1:4,537 patients) of dental injury. One half of these injuries occurred during laryngoscopy and tracheal intubation. The upper incisors were the most commonly involved teeth, and most injuries were crown fractures and partial dislocations and dislodgements. Multivariate risk factors for dental injury in the case control study included general anesthesia with tracheal intubation (odds ratio [OR] = 89), preexisting poor dentition (OR = 50), and increased difficulty of laryngoscopy and intubation (OR = 11).

CONCLUSIONS

Based on these data from a large surgical population at a single training institution, approximately 1:4,500 patients who receive anesthesia services sustain a dental injury that requires repair or extraction. Patients most at risk for perianesthetic dental injury include those with preexisting poor dentition who have one or more risk factors for difficult laryngoscopy and tracheal intubation.

The effect of anesthetic patient education on preoperative patient anxiety

BACKGROUND AND OBJECTIVES

Preoperative time spent with patients has been abbreviated with the advent of same-day admission requirements and outpatient surgery. This study was conducted to evaluate the effects that materials mailed to the home relating to anesthetic-focused patient education may have on preoperative patient anxiety.

METHODS

Patients scheduled for a total hip arthroplasty or for a total knee arthroplasty were screened via telephone for inclusion in a prospective, randomized study. Patients were asked about their access to a video cassette recorder/player (VCR) and their limitations regarding hearing or vision. Subjects were randomly assigned to either the intervention group and received two pamphlets and a video describing general and regional anesthesia or to the usual care group. All subjects were mailed a preoperative demographic questionnaire and a State Trait Anxiety Inventory (STAI), as developed by CD Spielberger. Questionnaires were completed at least 96 hours prior to admission and again preoperative on the day of surgery.

RESULTS

Of 236 patients screened, 26 had no access to a VCR, 6 were hearing or visually impaired, and 4 declined participation. Of 200 subjects randomized, 134 completed both sets of questionnaires and thus form the basis of this report. A statistically significant difference between the subjects who received the video and pamphlets and the usual care subjects was detected with respect to change in STAI-assessed anxiety from baseline to immediately prior to surgery (P = .035). The intervention subjects experienced a smaller mean increase in anxiety. Forty-nine percent of the usual care subjects expressed interest in having additional information.

CONCLUSIONS

Increase in preoperative anxiety is diminished when additional anesthesia information in printed and video format is made available. Useful information can be provided to patients to view or read prior to surgery.

The risk of persistent paresthesia is not increased with repeated axillary block

Neurologic deficits are noted on physical examination in approximately 0.2%-19% of patients after regional anesthetic techniques. Laboratory and clinical studies suggest that a subclinical neuropathy occurs much more often. Performing a regional anesthetic technique during this period may result in additional nerve trauma. We evaluated the frequency of neurologic complications in patients undergoing repeated axillary block. A total of 1614 blocks were performed on 607 patients. The median number of blocks per patient was two (range 2-10 blocks). The median interval between blocks was 12.6 wk, including 188 (31%) patients who received multiple blocks within 1 wk. Sixty-two neurologic complications occurred in 51 patients for an overall frequency of 8.4%. Of the 62 nerve injuries, 7 (11.3%) were related to the anesthetic technique; the remaining 55 (88.7%) were a result of the surgical procedure. Patient age and gender, the presence of preexisting neurologic conditions, a surgical procedure to a nerve, and total number of blocks did not increase the risk of neurologic complications. No regional anesthetic technique risk factors, including elicitation of a paresthesia, selection of local anesthetic, or addition of epinephrine, were identified. The success rate was higher with the paresthesia technique than with nerve stimulator technique or transarterial injection, and with use of mepivacaine versus bupivacaine. We conclude that the frequency of neurologic complications in patients undergoing repeated axillary block is similar to that in patients receiving a single regional technique. These patients are not likely to be at increased risk of neurologic complications.

IMPLICATIONS

The risk of neurologic complications was not increased in patients who underwent multiple axillary blocks, even within a 1-wk interval. No risk factors for anesthetic-related complications were identified. However, block success rate was increased with the paresthesia technique and the injection of mepivacaine versus bupivacaine.

Efficacy of bupropion for smoking cessation in smokers with a former history of major depression or alcoholism

BACKGROUND

A past history of major depression or alcoholism has been associated with poorer smoking treatment outcomes.

AIM

To evaluate the efficacy of bupropion for smoking cessation in smokers with a former history of major depression or alcoholism, and changes in depressive symptoms during smoking abstinence.

METHOD

Data were drawn from a multicentre trial of bupropion for smoking cessation. Smokers (n = 615) received placebo or bupropion sustained-release at 100, 150, or 300 mg/day for six weeks after target quit date (TQD). The primary outcome was the point prevalence smoking abstinence at the end of treatment and at one year. The Beck Depression Inventory (BDI) was used to assess depressive symptoms.

RESULTS

A significant dose-response effect of bupropion for smoking cessation was found. This was independent of history of major depression or alcoholism. Among those continuously abstinent from smoking for two weeks following TQD, an increase in BDI score was associated with a return to smoking at end of treatment.

CONCLUSIONS

Bupropion is efficacious for smoking cessation independently of a former history of major depression or alcoholism. Increases in depressive symptoms during an initial period of abstinence are associated with a return to smoking.

Neurologic complications after placement of cerebrospinal fluid drainage catheters and needles in anesthetized patients: implications for regional anesthesia. Mayo Perioperative Outcomes Group

Subarachnoid or epidural needle placement in an anesthetized patient is controversial because general anesthesia and muscle relaxation may mask neural trauma. However, placement of a needle or catheter in the subarachnoid space for the purpose of cerebral spinal fluid (CSF) drainage is frequently performed in anesthetized patients undergoing neurosurgery. The records from 530 consecutive transsphenoidal surgeries performed with lumbar CSF drainage were reviewed to determine the types of neurologic complications attributable to spinal drainage and their rates of occurrence. All patients were anesthetized during CSF drain placement. A 19-gauge malleable needle was placed in 473 (89%) patients. Subarachnoid catheters (20- or 16-gauge catheters placed via 18- or 14-gauge epidural needles, respectively) were placed in 17 (3%) patients. In 40 (8%) patients, the type of drain was unspecified. No new neurologic deficits attributable to spinal drain insertion were detected in the immediate postoperative period or within 1 yr of surgery. Thirteen patients developed postdural puncture headache (2.5%, exact 95% confidence interval 1.3%-4.2%); seven required epidural blood patch (1.3%, 0.5%-2.7%). The low incidence (0%, 0.0%-0.7%) of neurologic injury from spinal drain insertion in anesthetized patients from this study is similar to the incidence of neurologic complications historically reported for both CSF drain insertion and spinal anesthesia.

IMPLICATIONS

The performance of regional anesthesia in an anesthetized patient is controversial due to the possibility of unrecognized nerve injury. We report no cases of nerve injury caused by the placement of cerebrospinal fluid drainage needles and catheters in 530 anesthetized patients undergoing neurosurgery.