Association of metabolic syndrome and surgical factors with pulmonary adverse events, and longitudinal mortality in bariatric surgery.

BACKGROUND: Postoperative pulmonary complications (PPC) in bariatric surgery have not been well studied. Additionally, many bariatric patients suffer from the metabolic syndrome (MetS), contributing to surgical risk. We examined the incidence of PPC and MetS in a large national bariatric database. Furthermore, we analysed the relationships between morbidity, mortality, PPC, MetS, and several other comorbidities and also surgical factors. METHODS: The Bariatric Outcomes Longitudinal Database (BOLD™) is a registry that includes up to 365 day outcomes. We analysed data between January 2008 and October 2010. The PPC tracked included pneumonia, atelectasis, pleural effusion, pneumothorax, adult respiratory distress syndrome, and respiratory failure. A composite pulmonary adverse event (CPAE) included the occurrence of any of these. MetS was defined as the combination of hypertension, dyslipidaemia, and diabetes mellitus. The association of MetS and additional comorbibities, procedural data, and patient characteristics with CPAEs was examined with appropriate statistical tests. RESULTS: A total of 158 405 patients had a low incidence of PPC (0.91%) and a low mortality (0.6%) after bariatric surgery. MetS was prevalent in 12.7%, and was a significant risk factor for CPAE and mortality. Age, BMI, ASA physical status classification, surgical duration, procedure type, MetS (P<0.001), and additional comorbidities were significantly associated with CPAEs. CONCLUSIONS: The incidence of PPC was low after bariatric surgery. Increasing age, BMI, ASA status, MetS, obstructive sleep apnoea, asthma, congestive heart failure, surgical duration, and procedure type were independently significantly associated with PPC. Pulmonary complications and MetS were significantly associated with increased postoperative mortality.

Regulatory challenges facing closed-loop anesthetic drug infusion devices.

Closed-loop anesthetic drug infusion devices show great promise for improving the consistency and safety of general anesthesia. Despite the numerous reports demonstrating the feasibility and potential advantages of these systems in a research setting, a wide range of regulatory, business, and clinical issues will need to be resolved before a closed-loop anesthesia delivery product can be successfully introduced into the market and incorporated into general practice.

Using process evaluation to describe a hospital-based clinic for children coping with medical stressors.

OBJECTIVE: To use process evaluation methods to describe the development of a hospital-based mental health clinic for children facing medical stressors. METHODS: Over a 21-month time period, we collected data regarding presenting concern, service use, and referral source using hospital administrative, clinic intake, and clinical records for 356 children. RESULTS: Nearly 90% of the children were referred to the clinic from sources within the hospital. With the exception of single session interventions, there were no differences in average length of services according to presenting concern. Hospital pediatric specialists and psychology consultants were the primary referrers to the program. Pediatric specialists referred more often for procedural concerns and chronic illness than other hospital referrers. CONCLUSIONS: These findings support the feasibility and usefulness of a process evaluation approach in shaping clinical program directions, creating opportunities for collaboration with medical providers, and planning effectiveness research.

Critical oxygen delivery in conscious humans is less than 7.3 ml O2 x kg(-1) x min(-1).

BACKGROUND: The "critical" level of oxygen delivery (DO2) is the value below which DO2 fails to satisfy the metabolic need for oxygen. No prospective data in healthy, conscious humans define this value. The authors reduced DO2 in healthy volunteers in an attempt to determine the critical DO2. METHODS: With Institutional Review Board approval and informed consent, the authors studied eight healthy, conscious volunteers, aged 19-25 yr. Hemodynamic measurements were obtained at steady state before and after profound acute isovolemic hemodilution with 5% albumin and autologous plasma, and again at the reduced hemoglobin concentration after additional reduction of DO2 by an infusion of a beta-adrenergic antagonist, esmolol. RESULTS: Reduction of hemoglobin from 12.5+/-0.8 g/dl to 4.8+/-0.2 g/dl (mean +/- SD) increased heart rate, stroke volume index, and cardiac index, and reduced DO2 (14.0+/-2.9 to 9.9+/-20 ml O2 x kg(-1) x min(-1); all P<0.001). Oxygen consumption (VO2; 3.0+/-0.5 to 3.4+/-0.6 ml O2 x kg(-1) x min(-1); P<0.05) and plasma lactate concentration (0.50+/-0.10 to 0.62+/-0.16 mM; P<0.05; n = 7) increased slightly. Esmolol decreased heart rate, stroke volume index, and cardiac index, and further decreased DO2 (to 7.3+/-1.4 ml O2 x kg(-1) x min(-1); all P<0.01 vs. before esmolol). VO2 (3.2+/-0.6 ml O2 x kg(-1) x min(-1); P>0.05) and plasma lactate (0.66+/-0.14 mM; P>0.05) did not change further. No value of plasma lactate exceeded the normal range. CONCLUSIONS: A decrease in DO2 to 7.3+/-1.4 ml O2 x kg(-1) min(-1) in resting, healthy, conscious humans does not produce evidence of inadequate systemic oxygenation. The critical DO2 in healthy, resting, conscious humans appears to be less than this value.

Pediatric solid organ transplantation.

Solid organ transplantation offers hope for long-term survival and more normal lifestyles for children. Many of the procedures used are scaled-down versions of those used in adults and are associated with distinct challenges in children. Recent studies have provided insights into how transplantation can best serve these patients.

Ophthalmic complications after spinal surgery.

STUDY DESIGN: A retrospective review of 3450 spinal surgeries was performed. OBJECTIVES: To review ophthalmic complications and their etiologies, as well as treatments and outcomes, in patients who have undergone spinal surgery. SUMMARY OF BACKGROUND DATA: Ophthalmic complications after major spinal reconstructive surgery are rare and have not been adequately addressed in the orthopedic literature. METHODS: In a series of 3450 spinal surgeries at three institutions, the authors identified seven patients (incidence = 0.20%) whose postoperative course was complicated by loss of visual acuity. These perioperative ophthalmic complications included posterior optic nerve ischemia, occipital lobe infarcts, and central retinal vein thrombosis. Operative time, estimated blood loss, and medical history of peripheral vascular, cardiovascular, or ophthalmic disease were obtained from the charts, as were follow-up data. RESULTS: Three patients recovered completely, and one had partial return of visual function. In the remaining three patients, significant visual loss persisted. CONCLUSIONS: The risk of ophthalmic complications with spinal surgery has not been fully appreciated. Because ophthalmic complications in spinal surgery may be reversed with prompt recognition and intervention, it is important for clinicians to be aware of their possible occurrence.

Immediate tracheal extubation after liver transplantation: experience of two transplant centers.

Early tracheal extubation has been safely performed after large operative procedures, questioning the need for routine postoperative ventilation. Because immediate postoperative tracheal extubation of liver transplantation patients has not been previously reported, we performed preliminary studies at two institutions to evaluate potential risk and cost benefit. At the University of Colorado (UC), extubation criteria were derived from the retrospective analysis of patients who were ventilated less than 8 h and experienced an intensive care unit stay less than 48 h in 1994. Preoperative criteria for age, severity of illness, and absence of encephalopathy and coexistent disease were used in a subsequent prospective study in 1995. Donor graft function, blood use, hemodynamic stability, and alveolar-arterial oxygen gradient served as intraoperative criteria. Cost of intensive care services was compared for the 1994 ventilated patients and the 1995 patients whose tracheas were extubated immediately postoperatively. At the second institution, University of California at San Francisco (UCSF), patients were tracheally extubated immediately postoperatively, based on clinical judgment by the anesthesiologist. A retrospective analysis was then completed. Sixteen of 67 patients at UC and 25 of 106 patients at UCSF were tracheally extubated. There were no reintubations at UC, while 2 of 25 patients at UCSF required reintubation. Prior encephalopathy, poor donor liver function, and an increased alveolar-arterial oxygen gradient were present in the patients who suffered perioperative respiratory failure. Seventeen of 25 patients at UCSF did not have all criteria used at UC but did not require reintubation. Wider limits on age and severity of illness did not preclude successful extubation. Cost analysis at UC showed a significant reduction in intensive care unit services and associated cost for extubated patients. We conclude that immediate postoperative tracheal extubation of selected liver transplantation patients is safe and cost effective.

Surgical and anesthetic management of patients undergoing major hepatectomy using total vascular exclusion.

Total vascular exclusion (TVE) of the liver is accomplished by complete occlusion of inflow and outflow of the liver during hepatectomy. It affords the opportunity for bloodless, anatomically precise parenchymal transection but has not been widely used in this country. TVE should make it possible to treat large or unfavorably located lesions safely. To evaluate the benefit of this modality, we have examined the results of TVE in 49 major resections. Forty-nine patients with liver tumors (mean age, 50 +/- 17 years; range 3 to 75 years) were treated by the authors over 5 years with a mean age of 50 +/- 17 years (range 3-75). Thirty-five (71%) patients were females and 38 (78%) had malignant tumors (hepatocellular CA n = 15, liver metastases n = 20, other n = 3), whereas 11 (22%) had benign tumors (hemangiomas n = 7 other n = 4). Six (12%) had histological cirrhosis but normal liver function test results. Twenty two (45%) had previous surgery. Forty-seven (96%) underwent total or extended lobectomies. Two patients had segmental resection of benign tumors (one in segment 4 and one in segment 8). Mean surgical time was 4.7 hours (2.5-8.3 hours) and mean red blood cell requirement was 2.2 U (0 to 11). Twenty-two (45%) procedures were performed without transfusions. Hospital mortality rates were 0%. The mean postoperative hospital duration was 11 days (5 to 41 years). Complications occurred in 18 (36%), requiring reoperation in 1 case for wound debridement and in another for lysis of postoperative adhesions. Hepatic insufficiency occurred transiently in 2 patients with prolongation of protime and cholestasis and resolved within 4 days in 1 patient and 10 days in the other (with cirrhosis). The perception of hepatic resection as a prohibitive undertaking with high mortality rate may limit the use of resection in patients who might benefit from this modality. Our data document the effectiveness and safety of major hepatectomy even in cirrhotic patients using TVE. Expanded use of TVE and other advances in liver surgery should be considered to decrease the morbidity rate of resection and make the benefits of this therapy more widely available.

Recovery of hepatic drug extraction after hypothermic preservation.

BACKGROUND: To determine whether liver preservation before transplantation impairs hepatic drug metabolism, hepatic extraction of drugs with different metabolic pathways (fentanyl, morphine, and vecuronium) in isolated rat livers was measured either immediately or after 24 h of hypothermia at 4 degrees C using a standard preservation-reperfusion sequence. METHODS: Isolated rat livers were perfused via the portal vein for 30 min to document initial viability. Test livers (n = 5) were perfused with iced Belzer solution, stored for 24 h at 4 degrees C, and flushed with 6% hetastarch. After hypothermic preservation for 24 h, or in control livers (n = 5) immediately after the 30-min perfusion, livers were perfused single-pass at a constant flow rate with solutions containing fentanyl, morphine, and vecuronium at 37 degrees C. Perfusate and bile samples were obtained at regular intervals for 64 min, after which liver tissue was harvested for analysis. Drug concentrations were measured using radioimmunoassay and gas chromatography. Metabolic capacity of the liver was estimated from the extraction fraction of each drug at steady-state. RESULTS: After warming to 37 degrees C, preserved livers consumed oxygen and produced bile at rates similar to that of control livers. Hypothermic preservation did not affect extraction of fentanyl and morphine. Vecuronium extraction was initially less in preserved livers, but this difference disappeared as the preserved livers returned to 37 degrees C (< 16 min). Biliary excretion and tissue concentrations of vecuronium were similar in each group. CONCLUSIONS: Hypothermic preservation does not significantly impair extraction of these drugs in this liver preservation model. If these results apply to human liver transplantation, little danger of drug accumulation exists during the early postoperative period if hepatic function is normal.

Vocational integration services in community mental health: professionals' perceptions of training needs.

Vocational integration in mental health is part of a national initiative to make quality, community-based work a possibility for persons with psychiatric disabilities. While effective delivery of these services requires trained staff, preparing professionals to provide relevant vocationally oriented services is complex and challenging. This study examines perceived priority training needs in vocational integration services from the perspectives of professionals in mental health, rehabilitation, and education organizations in Mississippi. Findings suggest that vocational integration activities are perceived differently across organizations and across occupational specialties. Implications for staff development in community support and psychosocial rehabilitation programs are discussed.

Special issues in prenatal care outreach.

Approaches to prenatal care outreach taken by public providers vary widely. To date, few have evolved from systematic, data-based casefinding strategies. The following case study describes the findings of a research project concerned with both care seeking and care getting behaviors of low income women and the relationship between those behaviors and birthweight outcomes. Analysis of project data reveals that the greater the delay between seeking and getting care, the greater the likelihood of low birthweight. Application of this research data has yielded information useful to outreach planning, staff development and program evaluation procedures.

The effect of x-irradiation on cell loss in five solid murine tumours, as determined by the 125IUdR method.

The rate of cell loss in irradiated RIF-1, EMT6, KHJJ, B16 and KHT tumours was studied using the 125IUdR loss technique. Administration of 125IUdR preceded localized tumour irradiation by 2 days. Loss of tumour radioactivity was measured for 6-8 days after irradiation. The blood flow to some tumours was occluded during, and for 30 min following, injection of the label to measure the amount of radioactivity entering the tumour as a result of reutilization of label from the gut epithelia and influx of labelled host cells. Irradiation did not significantly alter the amount of radioactivity entering these clamped tumours during the 8-10 days after injection of 125IUdR. This permitted comparison of irradiated and control groups based on the loss of radioactivity from the non-occluded tumours. Irradiation of RIF-1, EMT6, KHJJ or B16 tumours with doses of 600, 1400, 2400 or 4400 rads produced no significant increase in the rate of loss of tumour radioactivity. This suggested that, in the population of labelled cells, cell lysis following irradiation proceeded slowly. In contrast, KHT tumours showed a significant increase in loss rate following each radiation dose, although the increase was dose-independent. In all tumour systems, the constant rate of cell loss after radiation appeared to coincide with published reports of tumour growth responses after irradiation. The present data suggest that the manner of expression of radiation-induced cell killing results from the cellular proliferative status, i.e. whether a cell is cycling or non-cycling.

125IUdR loss as a measure of tumour cell loss: influence of reutilization and influx of labelled host cells.

Two potential artifacts, the reutilization of label released from the gut and the influx into solid tumours of labelled host cells, have been measured by occluding the blood flow to tumours during, and for 30 min after, injection of 125IUdR. Previous work has shown that occluded EMT6 and KHJJ tumours exhibit a substantial increase in label, to 30-40% of the total activity in non-occluded tumours within 4 days post-125IUdR injection. In B16 and RIF-1 tumours the influx of label is minimal. Almost all of this entry of 125IUdR results from the influx of labelled host cells. Significant influx was also demonstrated in Lewis lung and KHT tumours. Minimal changes in the extent of influx of labelled host cells were found following irradiation of EMT6 and RIF-1 tumours with 600 or 1400 rad. These doses also resulted in little or no additional loss of 125IUdR despite the fact that 60 to 95% of the tumour cells were killed. Thus, the lysis of the killed cells must proceed very slowly. The conditions necessary for the use of 125IUdR loss to assess cell killing, as opposed to cell lysis, are reviewed.