Effect of intraoperative hyperoxia on the incidence of surgical site infections: a meta-analysis.

BACKGROUND: Whether supplemental intraoperative oxygen reduces surgical site infections remains unclear. Recent recommendations from the World Health Organization and Center for Disease Control to routinely use high inspired oxygen concentrations to reduce infection risk have been widely criticized. We therefore performed a meta-analysis to evaluate the influence of inspired oxygen on infection risk, including a recent large trial. METHODS: A systematic literature search was performed. Primary analysis included all eligible trials. Sensitivity analyses distinguished studies of colorectal and non-colorectal surgeries, and excluded studies with high risk of bias. Another post-hoc sensitivity analysis excluded studies from one author that appear questionable. RESULTS: The primary analysis included 26 trials (N=14,710). The RR [95%CI] for wound infection was 0.81 [0.70, 0.94] in the high vs. low inspired oxygen groups. The effect remained significant in colorectal patients (N=10,469), 0.79 [0.66, 0.96], but not in other patients (N=4,241), 0.86 [0.69, 1.09]. When restricting the analysis to studies with low risk of bias, either by strict inclusion criteria (N=5,047) or by researchers' judgment (N=12,547), no significant benefit remained: 0.84 [0.67, 1.06] and 0.89 [0.76, 1.05], respectively. CONCLUSIONS: When considering all available data, intraoperative hyperoxia reduced wound infection incidence. However, no significant benefit remained when analysis was restricted to objective- or investigator-identified low-bias studies, although those analyses were not as well-powered. Meta-analysis of the most reliable studies does not suggest that supplemental oxygen substantively reduces wound infection risk, but more research is needed to fully answer this question.

Prolonged concurrent hypotension and low bispectral index ('double low') are associated with mortality, serious complications, and prolonged hospitalization after cardiac surgery.

BACKGROUND: Low bispectral index (BIS) and low mean arterial pressure (MAP) are associated with worse outcomes after surgery. We tested the hypothesis that a combination of these risk factors, a 'double low', is associated with death and major complications after cardiac surgery. METHODS: We used data from 8239 cardiac surgical patients from two US hospitals. The primary outcomes were 30-day mortality and a composite of in-hospital mortality and morbidity. We examined whether patients who had a case-averaged double low, defined as time-weighted average BIS and MAP (calculated over an entire case) below the sample mean but not in the reference group, had increased risk of the primary outcomes compared with patients whose BIS and/or MAP were at or higher than the sample mean. We also examined whether a prolonged cumulative duration of a concurrent double low (simultaneous low MAP and BIS) increased the risk of the primary outcomes. RESULTS: Case-averaged double low was not associated with increased risk of 30-day mortality {odds ratio [OR] 1.73 [95% confidence interval (CI) 0.94-3.18] vs reference; P =0.01} or the composite of in-hospital mortality and morbidity [OR 1.47 (95% CI 0.98-2.20); P =0.01] after correction for multiple outcomes. A prolonged concurrent double low was associated with 30-day mortality [OR 1.06 (95% CI 1.01-1.11) per 10-min increase; P =0.001] and the composite of in-hospital mortality and morbidity [OR 1.04 (95% CI 1.01-1.07), P =0.004]. CONCLUSIONS: A prolonged concurrent double low, but not a case-averaged double low, was associated with higher morbidity and mortality after cardiac surgery.

Use of deep laryngeal oxygen insufflation during laryngoscopy in children: a randomized clinical trial.

BACKGROUND: Brief periods of haemoglobin oxygen desaturation are common in children during induction of general anaesthesia. We tested the hypothesis that oxygen insufflation during intubation slows desaturation. METHODS: Patients 1-17 yr old undergoing nasotracheal intubation were enrolled and randomly assigned to one of three groups: standard direct laryngoscopy (DL); laryngoscopy with Truview PCD videolaryngoscope (VLO2); or laryngoscopy with an oxygen cannula attached to the side of a standard laryngoscope (DLO2). The co-primary outcomes were time to 1% reduction in [Formula: see text] from baseline, and the slope of overall desaturation vs time. All three groups were compared against each other. RESULTS: Data from 457 patients were available for the final analysis: 159 (35%) DL; 145 (32%) DLO2; and 153 (33%) VLO2. Both VLO2 and DLO2 were superior to DL in both time to a 1% reduction in [Formula: see text] from baseline and the overall rate of desaturation (all P<0.001). The 25th percentile (95% confidence interval) of time to a 1% saturation decrease was 30 (24, 39) s for DL, 67 (35, 149) s for DLO2 and 75 (37, 122) s for VLO2. Mean desaturation slope was 0.13 (0.11, 0.15)% s(-1) for DL, 0.04 (0.02, 0.06)% s(-1) for DLO2 and 0.03 (0.004, 0.05)% s(-1) for VLO2. We did not find a correlation between decrease in [Formula: see text] percentage and BMI or age. CONCLUSIONS: Laryngeal oxygen insufflation increases the time to 1% desaturation and reduces the overall rate of desaturation during laryngoscopy in children. CLINICAL TRIAL REGISTRATION: NCT01886807.

Perioperative factors associated with acute kidney injury after partial nephrectomy.

BACKGROUND: Partial nephrectomy is performed with the aim to preserve renal function. But the occurrence of postoperative acute kidney injury (AKI) can interfere with this goal. Our primary aim was to evaluate associations between pre-specified modifiable factors and estimated glomerular filtration rate after partial nephrectomy. Our secondary aims were to evaluate associations between pre-specified modifiable factors and both serum creatinine concentration and type of nephrectomy. METHODS: The records of 1955 patients who underwent partial nephrectomy were collected. Postoperative estimated glomerular filtration rate (eGFR) was used as the primary outcome measure. Twenty modifiable risk factors were studied. A repeated-measures linear model with autoregressive within-subject correlation structure was used. The interaction between all the factors and type of nephrectomy was also studied. RESULTS: A total of 1187 (61%) patients had no kidney injury, 647 (33%) had stage I, 80 (4%) had stage II, and 41 (2%) had stage III injury. The mean eGFR increased an estimated 0.83 (99.76% CI 0.79-0.88) ml min(-1) 1.73 m(-2) for a unit increase in baseline eGFR. Mean eGFR was 2.65 (99.76% CI: 0.13, 5.18) ml min(-1) 1.73 m(-2) lower in patients with hypertension. Mean eGFR decreased 0.42 (99.76% CI: 0.22, 0.62) ml min(-1) 1.73 m(-2) for a 10-minute longer in duration of procedure and decreased 2.09 (99.76% CI: 1.39, 2.80) ml min(-1) 1.73 m(-2) for a 10-minute longer in ischemia time. It was 3.53 (99.76% CI: 0.83, 6.23) ml min(-1) 1.73 m(-2) lower for patients who received warm ischemia as compared to cold ischemia. CONCLUSION: Potentially modifiable factors associated with AKI in the postoperative period were identified as baseline renal function, preoperative hypertension, longer duration of surgical time and ischaemia time, and warm ischaemia.

A randomized, triple-masked, active-controlled investigation of the relative effects of dose, concentration, and infusion rate for continuous popliteal-sciatic nerve blocks in volunteers.

BACKGROUND: It remains unknown whether local anaesthetic dose is the only factor influencing continuous popliteal-sciatic nerve block effects, or whether concentration, volume, or both exert an influence as well. METHODS: Bilateral sciatic catheters were inserted in volunteers (n=24). Catheters were randomly assigned to ropivacaine of either 0.1% (8 ml h(-1)) or 0.4% (2 ml h(-1)) for 6 h. The primary endpoint was the tolerance to transcutaneous electrical stimulation within the tibial nerve distribution at hour 6. Secondary endpoints included current tolerance at other time points and plantar flexion maximum voluntary isometric contraction (22 h total). RESULTS: At hour 6, tolerance to cutaneous stimulation for limbs receiving 0.1% ropivacaine was [mean (standard deviation)] 27.0 (20.2) vs26.9 (20.4) mA for limbs receiving 0.4% [estimated mean difference 0.2 mA; 90% confidence interval (CI) -8.2 to 8.5; P=0.02 and 0.03 for lower and upper boundaries, respectively]. Because the 90% CI fell within the prespecified tolerance ±10 mA, we conclude that the effect of the two concentration/volume combinations were equivalent. Similar negative findings were found for the secondary outcomes. CONCLUSIONS: For continuous popliteal-sciatic nerve blocks, we found no evidence that local anaesthetic concentration and volume influence block characteristics, suggesting that local anaesthetic dose (mass) is the primary determinant of perineural infusion effects in this anatomic location. These findings suggest that for ambulatory perineural local anaesthetic infusion-for which there is usually a finite local anaesthetic reservoir-decreasing the basal rate while increasing the local anaesthetic concentration may allow for increased infusion duration without compromising postoperative analgesia. CLINICAL TRIAL REGISTRATION: NCT01898689.

Dexamethasone, light anaesthesia, and tight glucose control (DeLiT) randomized controlled trial.

BACKGROUND: The inflammatory response to surgical tissue injury is associated with perioperative morbidity and mortality. We tested the primary hypotheses that major perioperative morbidity is reduced by three potential anti-inflammatory interventions: (i) low-dose dexamethasone, (ii) intensive intraoperative glucose control, and (iii) lighter anaesthesia. METHODS: We enrolled patients having major non-cardiac surgery who were ≥40 yr old and had an ASA physical status ≤IV. In a three-way factorial design, patients were randomized to perioperative i.v. dexamethasone (a total of 14 mg tapered over 3 days) vs placebo, intensive vs conventional glucose control 80-110 vs 180-200 mg dl(-1), and lighter vs deeper anaesthesia (bispectral index target of 55 vs 35). The primary outcome was a collapsed composite of 15 major complications and 30 day mortality. Plasma high-sensitivity (hs) C-reactive protein (CRP) concentration was measured before operation and on the first and second postoperative days. RESULTS: The overall incidence of the primary outcome was about 20%. The trial was stopped after the second interim analysis with 381 patients, at which all three interventions crossed the futility boundary for the primary outcome. No three-way (P=0.70) or two-way (all P>0.52) interactions among the interventions were found. There was a significantly smaller increase in hsCRP in patients given dexamethasone than placebo [maximum 108 (64) vs 155 (69) mg litre(-1), P<0.001], but none of the other two interventions differentially influenced the hsCRP response to surgery. CONCLUSIONS: Among our three interventions, dexamethasone alone reduced inflammation. However, no intervention reduced the risk of major morbidity or 1 yr mortality. TRIAL REGISTRATION IDENTIFIER: NCT00433251 at www.clinicaltrials.gov.

Intra-operative rewarming with Hot Dog(®) resistive heating and forced-air heating: a trial of lower-body warming.

Resistive heating is an alternative to forced-air warming which is currently the most commonly used intra-operative warming system. We therefore tested the hypothesis that rewarming rates are similar with Hot Dog(®) (Augustine Biomedical) resistive and Bair Hugger(®) (Arizant) forced-air heating systems. We evaluated 28 patients having major maxillary tumour surgery. During the establishment of invasive monitoring, patients became hypothermic, dropping their core temperature to about 35 °C. They were then randomly assigned to rewarming with lower-body resistive (n = 14) or forced-air (n = 14) heating, with each system set to 'high'. Our primary outcome was the rewarming rate during active heating over a core temperature range from 35 to 37 °C. Morphometric characteristics were comparable in both groups. Temperature increased at twice the rate in patients assigned to forced-air warming, with an estimated mean (SE) slope of 0.49 (0.03) °C.h(-1) vs 0.24 (0.02) °C.h(-1) (p < 0.001). Resistive heating warmed at half the rate of forced air.

Complications of invasive video-EEG monitoring with subdural grid electrodes.

OBJECTIVE: To evaluate the risk factors, type, and frequency of complications during video-EEG monitoring with subdural grid electrodes. METHODS: The authors retrospectively reviewed the records of all patients who underwent invasive monitoring with subdural grid electrodes (n = 198 monitoring sessions on 187 patients; median age: 24 years; range: 1 to 50 years) at the Cleveland Clinic Foundation from 1980 to 1997. RESULTS: From 1980 to 1997, the complication rate decreased (p = 0.003). In the last 5 years, 19/99 patients (19%) had complications, including two patients (2%) with permanent sequelae. In the last 3 years, the complication rate was 13.5% (n = 5/37) without permanent deficits. Overall, complications occurred during 52 monitoring sessions (26.3%): infection (n = 24; 12.1%), transient neurologic deficit (n = 22; 11.1%), epidural hematoma (n = 5; 2.5%), increased intracranial pressure (n = 5; 2.5%), and infarction (n = 3; 1.5%). One patient (0.5%) died during grid insertion. Complication occurrence was associated with greater number of grids/electrodes (p = 0.021/p = 0.052; especially >60 electrodes), longer duration of monitoring (p = 0.004; especially >10 days), older age of the patient (p = 0.005), left-sided grid insertion (p = 0.01), and burr holes in addition to the craniotomy (p = 0.022). No association with complications was found for number of seizures, IQ, anticonvulsants, or grid localization. CONCLUSIONS: Invasive monitoring with grid electrodes was associated with significant complications. Most of them were transient. Increased complication rates were related to left-sided grid insertion and longer monitoring with a greater number of electrodes (especially more than 60 electrodes). Improvements in grid technology, surgical technique, and postoperative care resulted in significant reductions in the complication rate.

Simultaneous aortic replacement and renal artery revascularization: the influence of preoperative renal function on early risk and late outcome.

PURPOSE: We documented the postoperative complication rate and the late results of simultaneous infrarenal aortic replacement and renal artery (RA) revascularization at the Cleveland Clinic and correlated these findings with the preoperative serum creatinine level (S(Cr)) and other baseline risk factors. METHODS: A retrospective review of hospital charts and outpatient records was supplemented with a telephone canvass and the invitation to return for a complimentary RA duplex scan, when a scan had not been done within the previous year. Data were collected for 73 consecutive patients (mean age, 69 years) who underwent aortic procedures that were combined with the repair of RA stenosis from 1989 to 1997 (mean follow-up, 44 months). The preoperative S(Cr) was 2 mg/dL or lower in 45 patients (group R1; median, 1.5 mg/dL) and was higher than 2 mg/dL in the remaining 28 patients (group R2; median, 2.6 mg/dL). RESULTS: Forty-seven of the patients in this series had aortic aneurysms, 15 patients had aortoiliac occlusive disease, and 11 patients had both types of lesions. Bilateral RA revascularization was necessary for seven patients in group R1 (15%) and for eight patients in group R2 (29%). Group R2 contained more patients with medically resistant hypertension (57%) than group R1 (29%, P = .019). Although there was no statistically significant difference between the 30-day mortality rates (group R1, 2.2%; group R2, 11%), the related in-hospital mortality rate for 15 bilateral RA revascularizations (13%) was nearly twice that of 58 unilateral revascularizations (6.9%). Patients in group R2 were at a higher risk for postoperative dialysis than those in group R1 (36% vs 6.7%, P = .008), and patients in group R2 had longer lengths of stay in the hospital (median, 14 days vs 9 days; P = .004). By means of Kaplan-Meier analysis, the 5-year survival rate was lower for patients in group R2 (53%; 95% CI, 33%-73%) than for patients in group R1 (85%; 95% CI, 74%-96%; log rank P = .005). Despite all other liabilities in group R2 patients, however, their resistant hypertension was cured or improved in 88% of cases and their S(Cr) appeared to decline with time. CONCLUSION: The early postoperative risk of simultaneous aortic/RA procedures appears to be highest in patients who have an elevated S(Cr), bilateral RA stenosis or occlusion, and a comparatively low long-term survival rate. In this particular group, the adjunctive use of endovascular techniques might conceivably reduce the magnitude of the planned surgical procedure and thus enhance the overall outcome.

Outcome of adult cardiopulmonary resuscitations at a tertiary referral center including results of "limited" resuscitations.

BACKGROUND: The results of in-hospital resuscitations may depend on a variety of factors related to the patient, the environment, and the extent of resuscitation efforts. We studied these factors in a large tertiary referral hospital with a dedicated certified resuscitation team responding to all cardiac arrests. METHODS: Statistical analysis of 445 prospectively recorded resuscitation records of patients who experienced cardiac arrest and received advanced cardiac life support resuscitation. We also report the outcomes of an additional 37 patients who received limited resuscitation efforts because of advance directives prohibiting tracheal intubation, chest compressions, or both. MAIN OUTCOME MEASURES: Survival immediately after resuscitation, at 24 hours, at 48 hours, and until hospital discharge. RESULTS: Overall, 104 (23%) of 445 patients who received full advanced cardiac life support survived to hospital discharge. Survival was highest for patients with primary cardiac disease (30%), followed by those with infectious diseases (15%), with only 8% of patients with end-stage diseases surviving to hospital discharge. Neither sex nor age affected survival. Longer resuscitations, increased epinephrine and atropine administration, multiple defibrillations, and multiple arrhythmias were all associated with poor survival. Patients who experienced arrests on a nursing unit or intensive care unit had better survival rates than those in other hospital locations. Survival for witnessed arrests (25%) was significantly better than for nonwitnessed arrests (7%) (P =.005). There was a disproportionately high incidence of nonwitnessed arrests during the night (12 AM to 6 AM) in unmonitored beds, resulting in uniformly poor survival to hospital discharge (0%). None of the patients whose advance directives limited resuscitation survived. CONCLUSIONS: Very ill patients in unmonitored beds are at increased risk for a nonwitnessed cardiac arrest and poor resuscitation outcome during the night. Closer vigilance of these patients at night is warranted. The outcome of limited resuscitation efforts is very poor.

Reoperation for recurrent carotid stenosis: early results and late outcome in 199 patients.

PURPOSE: This study was undertaken to determine the safety and efficacy of reoperations for recurrent carotid stenosis (REDOCEA) at the Cleveland Clinic. MATERIALS AND METHODS: From 1989 to 1999, 206 consecutive REDOCEAs were performed in 199 patients (131 men, 68 women) with a mean age of 68 years (median, 69 years; range, 47-86 years). A total of 119 procedures (57%) were performed for severe asymptomatic stenosis, 55 (27%) for hemispheric transient ischemic attacks or amaurosis fugax, 26 (13%) for prior stroke, and 6 (3%) for vertebrobasilar symptoms. Eleven REDOCEAs (5%) were combined with myocardial revascularization, and another 19 (9%) represented multiple carotid reoperations (17 second reoperations and 2 third reoperations). Three REDOCEAs (1%) were closed primarily, and nine (4%) required interposition grafts, whereas the remaining 194 (95%) were repaired with either vein patch angioplasty (139 [68%]) or synthetic patches (55 [27%]). Three patients (2%) were lost to follow-up, but late information was available for 196 patients (203 operations) at a mean interval of 4.3 years (median, 3.9 years; maximum, 10.2 years). RESULTS: Considering all 206 procedures, there were 7 early (< 30 days) postoperative neurologic events (3.4%), including 6 perioperative strokes (2.9%) and 1 occipital hemorrhage (0.5%) on the 12th postoperative day. Seventeen additional neurologic events occurred during the late follow-up period, consisting of eight strokes (3.9%) and nine transient ischemic attacks (4.4 %). With the Kaplan-Meier method, the estimated 5-year freedom from stroke was 92% (95% CI, 88%-96%). There were two early postoperative deaths (1%), both from cardiac complications after REDOCEAs combined with myocardial revascularization procedures. With the Kaplan-Meier method, the estimated 5-year survival was 81% (range, 75%-88%). A univariate Cox regression model yielded the presence of coronary artery disease as the only variable that was significantly associated with survival (P =.024). The presence of pulmonary disease (P =.036), diabetes (P =.01), and advancing age (P =.006) was found to be significantly associated with stroke after REDOCEA. Causes of 53 late deaths were cardiovascular problems in 25 patients (47%), unknown in 14 (26%), renal failure in 4 (8%), stroke in 3 (6%), and miscellaneous in 7 (13%). CONCLUSIONS: We conclude that REDOCEA may be safely performed in selected patients with recurrent carotid stenosis and that most of these patients enjoy long-term freedom from stroke.

A study of consecutive autopsies in a medical ICU : a comparison of clinical cause of death and autopsy diagnosis.

OBJECTIVE: To determine the degree of concordance between clinical cause of death and autopsy diagnosis in a medical ICU (MICU) setting. DESIGN: Retrospective medical chart and autopsy report review. SETTING: MICU in a tertiary referral hospital. PATIENTS: Consecutive admissions to an MICU over a 2-year period from January 1, 1994, to December 31, 1995. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One thousand eight hundred patients were admitted to the MICU during the study period. There were 401 in-ICU deaths (22.3%). The autopsy rate was 22.7% (91 of 401). The mean +/- SD age of the autopsied patients (55.1 +/- 13.5 years) was lower than those without autopsy (62.4 +/- 15.2 years; p < 0.001). The two groups were otherwise similar with regard to sex, race, APACHE (acute physiology and chronic health evaluation) III scores, and lengths of stay in the MICU and hospital. The discordance between clinical and postmortem diagnoses was 19.8% (95% confidence interval, 12 to 29%). There were no differences in age, sex, APACHE III scores, predicted mortality, and lengths of stay in MICU hospital between patients with concordant and discordant diagnoses. In 44.4% (8 of 18) of the discordant cases, management would have been modified had the autopsied diagnosis been made premortem. Seven of the autopsied patients had organ transplantation. Three of the patients who had organ transplantation had discordant diagnoses, including two patients with disseminated fungal infection that was not diagnosed clinically. Although the observed discordance in transplant patients (43%) was higher than in those without transplant (19%), the difference was not statistically significant (p = 0.15). CONCLUSION: Younger patients tended to have a higher autopsy rate than older patients. The discordance between the clinical cause of death and postmortem diagnosis was 19.8%. In 44.4% of the discordant cases, knowledge of the correct diagnosis would have altered therapy.

Relation between perioperative hypertension and intracranial hemorrhage after craniotomy.

BACKGROUND: Previous data suggest that systemic hypertension (HTN) is a risk factor for postcraniotomy intracranial hemorrhage (ICH). The authors examined the relation between perioperative blood pressure elevation and postoperative ICH using a retrospective case control design. METHODS: The hospital's database of all patients undergoing craniotomy from 1976 to 1992 was screened. Coagulopathic and unmatchable patients were excluded. There were 69 evaluable patients who developed ICH postoperatively (n = 69). A 2-to-1 matched (by age, date of surgery, pathologic diagnosis, surgical procedure, and surgeon) control group without postoperative ICH was assembled (n = 138). Preoperative, intraoperative, and postoperative blood pressure records (up to 12 h) were examined. Incidence of perioperative HTN (blood pressure > or = 160/90 mmHg) and odds ratios for ICH were determined. RESULTS: Of the 11,214 craniotomy patients, 86 (0.77%) suffered ICH, and 69 fulfilled inclusion criteria. The incidence of preoperative HTN was similar in the ICH (34%) and the control (24%) groups. ICH occurred 21 h (median) postoperatively, with an interquartile range of 4-52 h. Sixty-two percent of ICH patients had intraoperative HTN, compared with only 34% of controls (P < 0.001). Sixty-two percent of the ICH patients had prehemorrhage HTN in the initial 12 postoperative hours versus 25% of controls (P < 0.001), with an odds ratio of 4.6 (P < 0.001) for postoperative ICH. Hospital stay (median, 24.5 vs. 11.0 days), and mortality (18.2 vs. 1.6%) were significantly greater in the ICH than in the control groups. CONCLUSIONS: ICH after craniotomy is associated with severely prolonged hospital stay and mortality. Acute blood pressure elevations occur frequently prior to postcraniotomy ICH. Patients who develop postcraniotomy ICH are more likely to be hypertensive in the intraoperative and early postoperative periods.

Surgical repair of aneurysms involving the suprarenal, visceral, and lower thoracic aortic segments: early results and late outcome.

OBJECTIVE: The purpose of this study is to review our experience with surgical repair of lower thoracoabdominal and suprarenal aortic aneurysms to determine early and late survival rates and identify factors influencing morbidity and survival among these patients. MATERIALS: From 1989 through 1998, 165 consecutive patients underwent repair of 108 thoracoabdominal (55 group III and 53 group IV) and 57 suprarenal aneurysms. The study group consisted of 109 men and 56 women with a mean age of 70 years (median, 70 years; range, 29-89 years). Mean aneurysm diameter was 6.9 cm (median, 6.5 cm; range, 4-12 cm). There were 125 aneurysms (76%) repaired electively; 40 repairs (24%) were nonelective. The cause of 12 aneurysms (7%) was chronic aortic dissection; the remaining 153 (93%) were degenerative aneurysms. RESULTS: The early postoperative (30-day) mortality rates were 7% (9/125) for elective and 23% (9/40) for nonelective operations (P =.016). For both elective and urgent procedures, early mortality was 1.8% (1/57) for suprarenal aneurysm repair, 11% (6/53) for group IV thoracoabdominal aneurysms, and 20% (11/55) for group III thoracoabdominal aneurysms (P =.013, suprarenal vs group III). Spinal cord ischemia occurred after 6% (10/165) of aneurysm repairs (4% paraplegia, 2% paraparesis). None of the 57 suprarenal aneurysm repairs were complicated by spinal cord ischemia, whereas it occurred in 2% (1/53) of group IV thoracoabdominal aneurysms and 16% (9/55) of group III thoracoabdominal aneurysms (P =.001, suprarenal vs group III; P =. 016, group IV vs group III). Three (25%) of the 12 patients with dissection developed spinal cord ischemia; this compared with seven (5%) of 153 patients with degenerative aneurysms (P =.027). The cumulative 3-year survival rate for the entire series was 71% (95% CI, 64%-79%), and 5-year survival was 50% (95% CI, 40%-60%). CONCLUSIONS: Aneurysms involving the suprarenal, visceral, and lower thoracic aorta may be repaired with acceptable perioperative mortality and late survival rates. The risk of spinal cord ischemia is increased for patients with aortic dissection and may be stratified according to the proximal extent of the aneurysm.

Small-dose dopamine increases epidural lidocaine requirements during peripheral vascular surgery in elderly patients.

UNLABELLED: We studied 20 patients over the age of 65 yr undergoing prolonged peripheral vascular surgery under continuous lidocaine epidural anesthesia, anticipating that the increased hepatic metabolism caused by small-dose IV dopamine would lower plasma lidocaine concentrations. Subjects were assigned (random, double-blinded) to receive either a placebo IV infusion or dopamine, 2 microg. kg(-1). min(-1) during and for 5 h after surgery. Five minutes after the IV infusion was started, 20 mL of 2% lidocaine was injected through the epidural catheter. One-half hour later, a continuous epidural infusion of 2% lidocaine at 10 mL/h was begun. The epidural infusion was temporarily decreased to 5 mL/h or 5 mL boluses were added to maintain a T8 analgesic level. Arterial blood samples were analyzed for plasma lidocaine concentrations regularly during and for 5 h after surgery. Plasma lidocaine concentrations increased continuously during the epidural infusion and, despite wide individual variation, were similar for the two groups throughout the observation period. During the observation period, the mean maximal plasma lidocaine concentration was 5.8 +/- 2.3 microg/mL in the control group and 5.7 +/- 1.2 microg/mL in the dopamine group. However, the mean hourly lidocaine requirement during surgery was significantly different, 242 +/- 72 mg/h for control and 312 +/- 60 mg/h for dopamine patients (P < 0.03). At the end of Hour 4, the last period when all 20 patients were still receiving the epidural lidocaine infusion, the total lidocaine requirement was significantly different, 1088 +/- 191 mg for the control group and 1228 +/- 168 mg for the dopamine group (P < 0.05). Despite very large total doses of epidural lidocaine (1650 +/- 740 mg, control patients, and 1940 +/- 400, dopamine patients) mean maximal plasma concentrations remained below 6 microg/mL, and no patient exhibited signs or symptoms of toxicity. We conclude that small-dose IV dopamine increased epidural lidocaine requirements, presumably as a consequence of increased metabolism. IMPLICATIONS: We tested dopamine, a drug that increases liver metabolism of the local anesthetic lidocaine to determine if it would prevent excessively large amounts of lidocaine in the blood during prolonged epidural anesthesia in elderly patients. Dopamine did not alter the blood levels of lidocaine, but it did increase the lidocaine dose requirement to maintain adequate epidural anesthesia.

Perioperative risk and late outcome of nonelective carotid endarterectomy.

PURPOSE: In an earlier report of our database for 1924 isolated carotid endarterectomies (CEAs) from 1989 to 1995, multivariable analysis results indicated that the urgency of operation unfavorably influenced the combined stroke and mortality rate (CSM). This study was conducted in an attempt to document the features that contribute to perioperative complications and late outcome in 314 patients for whom CEA was considered to be nonelective because of the severity of previous symptoms, carotid stenosis, or medical comorbidities. METHODS: All the hospital charts and outpatient records were reviewed retrospectively for the 209 men and 105 women who had undergone nonelective CEAs (median age, 69 years). Information regarding the clinical risk factors, the operative indications (CHAT classification), the severity and distribution of carotid disease, and the surgical management were analyzed to assess the impact on the 30-day CSM and on the long-term survival rate and neurologic events during a median follow-up period of 34 months. RESULTS: Previous symptoms had occurred in 285 patients (91%) and included cortical transient ischemic attacks in 47%, amaurosis fugax in 20%, completed strokes in 14%, unstable strokes in 2%, and nonspecific or miscellaneous symptoms in 8%. Preoperative angiography was performed in 308 patients (98%), which confirmed the presence of 80% to 99% ipsilateral carotid stenosis in 79% of the patients and >90% stenosis in 43%. The median interval between presentation and surgical treatment was 2 days, but 48% of the 314 CEAs were performed within 24 hours of presentation. The 30-day CSM was 6.7% and ranged from 3.4% for 29 patients with severe asymptomatic carotid stenosis to 14% for those patients with unstable strokes. The cardiac and pulmonary risk factors were the only variables that were related statistically to the CSM. During the follow-up period, the risk for ipsilateral stroke was significantly higher in women (risk ratio [RR], 2.38; 95% confidence interval [CI], 1.02 to 5.56; P =.04) and in patients with higher gradients of cardiac and pulmonary risk factors (RR, 2.8; 95% CI, 1.6 to 4.8 per gradient increase; P <.001). The risk was significantly lower in patients who had undergone vein patch angioplasty (RR, 0.29; 95% CI, 0.12 to 0. 71; P =.006) in comparison with synthetic patching. However, 38 of the 55 patients (69%) who underwent synthetic patching also had widespread atherosclerosis for which the saphenous veins already had been harvested for coronary bypass grafting surgery or infrainguinal revascularization. CONCLUSION: In our experience, the perioperative risk of nonelective CEA primarily is determined by incidental cardiopulmonary disease. Vein patch angioplasty appears to enhance late results, but the late stroke rate associated with synthetic patching also may have been influenced by the extent of vascular disease in our study group.

Acute pulmonary edema after lung transplantation: the pulmonary reimplantation response.

BACKGROUND: Although the development of noncardiogenic pulmonary edema or pulmonary reimplantation response (PRR) after lung transplantation has been well described, the incidence has not been established and the relationship of PRR to clinical risk factors has not been analyzed. STUDY OBJECTIVES: (1) To describe the incidence of PRR in lung transplant recipients, (2) to identify the predictors of PRR, (3) to examine the correlation of suspected predictors with the severity of PRR, and (4) to evaluate the impact of PRR on morbidity and mortality of lung transplant recipients. DESIGN: Retrospective review of clinical records and radiographic studies. SETTING: Tertiary care referral center. PATIENTS: Ninety-nine consecutive patients with end-stage lung disease undergoing lung transplantation between February 1990 and October 1995. METHODS: Review of clinical records and postoperative chest radiographs of all lung transplant recipients to identify patients who experienced PRR. Chest radiographs of patients with PRR were graded for severity on a scale of 0 (none) to 5 (very severe). Demographic, pre- and perioperative factors were also evaluated along with short- and long-term survival of patients with PRR. RESULTS: Fifty-six of 99 lung transplant recipients (57%) experienced PRR. The median ischemia time of patients with and without PRR was 168 and 180 min, respectively (p = 0.62). The incidence of PRR was 51% in patients without preoperative pulmonary hypertension, 78% in mild to moderate pulmonary hypertension, and 58% in patients with severe pulmonary hypertension (p = 0.10). Incidence and severity of PRR was similar in patients receiving right, left, or double-lung transplantation. Similarly, age and sex of the recipients and underlying lung disease did not affect the incidence or severity of PRR. The incidence and severity of PRR was higher in patients undergoing cardiopulmonary bypass during lung transplantation. Patients with PRR had prolonged duration of mechanical ventilation and ICU stay. Overall, PRR did not affect the survival of the patients. However, survival of female lung transplant recipients was significantly better than male recipients (median survival, 60 vs 21 months; p = 0.02). CONCLUSIONS: Acute pulmonary edema or PRR occurs frequently (57%) after lung transplantation. In this series, PRR was not associated with a prolonged ischemia time, preoperative pulmonary hypertension, the type of lung transplant, underlying lung disease, or age or sex of recipients. However, use of cardiopulmonary bypass during surgery was associated with increased incidence and severity of PRR. Also, the development of PRR resulted in prolonged mechanical ventilation and a longer ICU stay, but did not affect survival. Female lung transplant recipients survived significantly longer than male recipients. The reason for this difference in survival is unclear.

Elective surgical treatment of symptomatic chronic mesenteric occlusive disease: early results and late outcomes.

PURPOSE: The purpose of this study was to determine the safety and efficacy of the elective surgical treatment of symptomatic chronic mesenteric occlusive disease (SCMOD) and to identify the factors that influence the results of this procedure. METHODS: From 1977 to 1997, 85 patients (mean age, 62 years) underwent elective surgical treatment of SCMOD. The presenting symptoms were abdominal pain in 78 patients (92%) and weight loss in 74 patients (87%). The surgical procedures included retrograde bypass grafting in 34 patients (40%), antegrade bypass grafting in 24 patients (28%), transaortic endarterectomy in 19 patients (22%), local arterial endarterectomy with patch angioplasty in six patients (7%), thrombectomy alone in one patient (1%), and superior mesenteric artery reimplantation in one patient (1%). Thirty-five patients (41%) underwent concomitant aortic replacement. All the involved mesenteric vessels were revascularized in 21 patients (25%), whereas revascularization was incomplete for the remaining 64 patients (75%). Late information was available for all 85 patients at a mean interval of 4.8 years. RESULTS: There were seven early (<35 days) postoperative deaths (8%). The cumulative 5-year survival rate was 64% (95% confidence interval [CI], 53% to 75%), and the 3-year symptom-free survival rate was 81% (95% CI, 72% to 90%). Serious complications occurred in 28 patients (33%). The results of univariate analysis identified advancing age at operation (P <.001), cardiac disease (P =.03), hypertension (P =.03), and additional occlusive disease (P =.05) as variables associated with mortality. Concomitant aortic replacement (P =.037), renal disease (P =.011), advancing age ( P =.035), and complete revascularization ( P =.032) were associated with postoperative morbidity including mortality. Late recurrent mesenteric occlusive disease was seen in 21 patients (16 symptomatic and five asymptomatic). Nine patients (43%) died, and 8 patients (38%) required subsequent surgical or endovascular procedures to treat their recurrent lesions. The 3-year survival rate from recurrent mesenteric occlusive disease was 76% (95% CI, 66% to 86%). CONCLUSION: We conclude that the elective surgical treatment of SCMOD may be performed with reasonable early and late mortality rates and that most of the patients remain free from recurrent symptoms of mesenteric ischemia. Advancing age, cardiac disease, hypertension, and additional occlusive disease significantly influenced the overall mortality rates, and concomitant aortic replacement, renal disease, and complete revascularization were significantly associated with postoperative morbidity rates. Surveillance and appropriate correction of recurrent disease appear to be necessary for optimal long-term results.

Perioperative cardiovascular morbidity in patients with coronary artery disease undergoing vascular surgery after percutaneous transluminal coronary angioplasty.

OBJECTIVE: Patients with coronary artery disease (CAD) who undergo noncardiac surgery are at increased risk for perioperative myocardial infarction (PMI). Undergoing successful coronary artery bypass grafting (CABG) before such surgery has been shown to decrease perioperative cardiac morbidity and mortality. Percutaneous transluminal coronary angioplasty (PTCA) is an alternative treatment for these patients. Perioperative cardiac morbidity in patients with CAD who underwent PTCA before their vascular surgery was reviewed. SETTING: A tertiary care referral center for patients with cardiovascular heart disease. PARTICIPANTS: Review of vascular surgery database for patients who underwent vascular surgery preceded by PTCA between 1984 and 1995. Patients were excluded if they had a history of CABG within 2 years of surgery, had PTCA more than 18 months before surgery, or had incomplete data. MEASUREMENTS: Data were collected concerning cardiac history, left ventricular (LV) function, perioperative cardiac morbidity (angina, MI, congestive heart failure [CHF], and arrhythmias). MAIN RESULTS: Of 194 patients who underwent aortic abdominal surgery, carotid endarterectomy (CEA), or peripheral vascular surgery preceded by PTCA, 104 (54%) had a previous MI. Twenty-six patients (13.4%) had perioperative cardiac morbidity. Only one patient had an MI (0.5%; 95% confidence interval [CI], 0.0 to 2.8), whereas one patient died of CHF followed by multisystem organ failure (0.5%). The median interval between PTCA and surgery was 11 days (interquartile range, [IQR] 3 to 49 days). Patients who developed perioperative cardiac morbidity were older than those who did not (p = 0.02). Patients who had a history of CABG (before PTCA) had a higher incidence of postoperative angina (p = 0.04). The degree of preoperative LV dysfunction was linearly related to the incidence of new postoperative CHF (p = 0.01). Arrhythmias were more common in patients undergoing abdominal vascular surgery (17.9%) than in those undergoing CEA (2.5%; p = 0.03) or peripheral vascular surgery (5.2%; p = 0.02). CONCLUSION: High-risk cardiac patients undergoing vascular surgery who have had PTCA performed up to 18 months preoperatively have a low incidence of perioperative cardiac morbidity. Prophylactic PTCA may be beneficial in patients with CAD who are at high risk for perioperative cardiac complications.

Randomized controlled trial of physician-directed versus respiratory therapy consult service-directed respiratory care to adult non-ICU inpatients.

Although current evidence suggests that respiratory care protocols can enhance allocation of respiratory care services while conserving costs, a randomized trial is needed to address shortcomings of available studies. We therefore conducted a randomized controlled trial comparing respiratory care for adult non-ICU inpatients directed by a Respiratory Therapy Consult Service (RTCS) versus respiratory care by managing physicians. Eligible subjects were adult non-ICU inpatients whose physicians had prescribed specific respiratory care services. Consecutive eligible patients were approached for consent, after which a blocked randomization strategy was used to assign patients to (1) Physician-directed respiratory care, in which the prescribed physician respiratory care orders were maintained (n = 74), or (2) RTCS-directed respiratory care, in which the physician's respiratory care orders were preempted by a respiratory care plan generated by the RTCS (n = 71). Specifically, these patients were evaluated by an RTCS therapist evaluator whose respiratory care plan was based on sign/symptom-based algorithms drafted to comply with the American Association for Respiratory Care (AARC) Clinical Practice Guidelines. Appropriateness of respiratory care orders was assessed as agreement between the prescribed respiratory care plan and an algorithm-based "standard care plan" generated by an expert therapist who was blind to the patient's actual orders. The compared groups were similar at baseline regarding demographic features, admission diagnostic category, smoking status, and Triage Score (mean, 3.8 +/- 0.9 SD [RTCS] versus 3.7 +/- 1.0). Similarly, no differences were observed between RTCS-directed and physician-directed respiratory care regarding hospital mortality rate (5.7 versus 5.6%), hospital length of stay (7.9 +/- 9.0 versus 7.7 +/- 7.3 d), total number of respiratory care treatments delivered (30.3 +/- 30 versus 31.6 +/- 30.5), or days requiring respiratory care (4.2 +/- 5.2 versus 4.1 +/- 3.6). Notably, using both a stringent (S) and a liberal (L) criterion for agreement, RTCS-directed respiratory care demonstrated better agreement with the "standard care plan" (82 +/- 17% [S] and 86 +/- 16% [L]) than did physician-directed respiratory care (64 +/- 21% [S] and 72 +/- 23% [L]) (p < 0.001). Finally, the true cost of respiratory care treatments was slightly lower with RTCS-directed respiratory care (mean, $235.70 versus $255.70/pt, p = 0.61). We conclude that (1) compared with physician-directed respiratory care, the RTCS prescribed a similar number and duration of respiratory care services at a slight savings (that did not achieve statistical significance) and without any increased adverse events; and (2) compared with physician-directed respiratory care, RTCS-directed respiratory care showed greater agreement with Clinical Practice Guideline-based algorithms.