Enhanced peri-operative care to improve outcomes for high-risk surgical patients in Brazil: a single-centre before-and-after cohort study.

Mortality and morbidity for high-risk surgical patients are often high, especially in low-resource settings. Enhanced peri-operative care has the potential to reduce preventable deaths but must be designed to meet local needs. This before-and-after cohort study aimed to assess the effectiveness of a postoperative 48-hour enhanced care pathway for high-risk surgical patients ('high-risk surgical bundle') who did not meet the criteria for elective admission to intensive care. The pathway comprised of six elements: risk identification and communication; adoption of a high-risk post-anaesthesia care unit discharge checklist; prompt nursing admission to ward; intensification of vital signs monitoring; troponin measurement; and prompt access to medical support if required. The primary outcome was in-hospital mortality. Data describing 1189 patients from two groups, before and after implementation of the pathway, were compared. The usual care group comprised a retrospective cohort of high-risk surgical patients between September 2015 and December 2016. The intervention group prospectively included high-risk surgical patients from February 2019 to March 2020. Unadjusted mortality rate was 10.5% (78/746) for the usual care and 6.3% (28/443) for the intervention group. After adjustment, the intervention effect remained significant (RR 0.46 (95%CI 0.30-0.72). The high-risk surgical bundle group received more rapid response team calls (24% vs. 12.6%; RR 0.63 [95%CI 0.49-0.80]) and surgical re-interventions (18.9 vs. 7.5%; RR 0.41 [95%CI 0.30-0.59]). These data suggest that a clinical pathway based on enhanced surveillance for high-risk surgical patients in a resource-constrained setting could reduce in-hospital mortality.

Anesthetic management during endocardial radiofrequency ablation of septal hypertrophy ­ a case report

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetic disorder present in up to 1/500 individuals, about 20­30% of them presenting with hypertrophic obstructive cardiomyopathy (HOCM) due to left ventricle outflow tract obstruction. This is an important cause of sudden cardiac death. Endocardial radiofrequency ablation of septal hypertrophy (ERASH) might be an attractive treatment for HOCM, particularly in patients who do not respond to trans coronary alcohol septal ablation (TASA). Aim: To describe technical aspects related to the procedure and anesthetic management of an ERASH case. Case REPORT: A 64-year-old woman with HOCM was scheduled for ERASH. She had worsening of dyspnea on exertion and generalized fatigue for the previous weeks after previous surgical myomectomy about 6 months ago. The anatomy was unfavorable for TASA and the patient was not willing to undergo another surgery. Preoperative transthoracic echocardiography (TTE) showed asymmetric mid-septal hypertrophy, systolic anterior motion with septal contact and left ventricular outflow tract maximum gradient of 68 mmHg at rest and 105 mmHg after the Valsalva maneuver. General anesthesia was performed. Pulse pressure variation, echocardiography parameters and passive leg raising test where used to guide fluid therapy. At the end of the procedure, analgesia was provided together with prophylaxis of nausea and vomiting. Extubation was uneventful and the patient was transported to the intensive care unit eupneic and hemodynamically stable. On the fourth postoperative day, TTE showed septal hypocontractility and maximum gradient reduction of 33% at rest (68 mmHg to 45 mmHg) and 31% after the Valsalva maneuver (105 mmHg to 73 mmHg). The patient was discharged from hospital at the sixth postoperative day. One month later, she reported progressive improvement of symptoms and expressed satisfaction with the results. CONCLUSION: Better understanding of the pathophysiology and natural history of HCM has enabled earlier diagnosis, as well as a more adequate therapeutic approach. Anesthesiologists should be aware of the pathophysiology of HOCM and must be prepared to anticipate the hemodynamic changes and cardiovascular instability that such patients may show perioperatively. ERASH is a promising therapeutic modality increasingly used for HOCM and anesthesiologists should become more familiar with it.

Simultaneous pancreas-kidney transplantation: evaluation of graft function, cholesterol, triglycerides, and immunosuppressive regimens.

AIMS: To evaluate pancreas graft function, use of insulin, cholesterol, triglyceride levels, prescription of lipid-lowering drugs, and immunosuppressive regimens among recipients of simultaneous pancreas-kidney transplants (SPKT), who had initial immunosuppression with tacrolimus, sirolimus, and corticosteroids. METHODS: From 2000 to 2007, we performed 73 SKPT, among which we conducted a retrospective data analysis on 51 medical records of patients who had been followed for at least 6 to 72 months. We excluded from the analysis eight recipients who died before 6 months: eight with early pancreas graft losses and six for continued follow-up in other centers. RESULTS: There were four pancreas graft losses after 6 months due in two diabetes mellitus recurrence, one posttuberculosis treatment, and one after use of nonsteroidal inflammatory medication. Mean plasma glucose levels ranged from 84 to 103 mg/dL, while glycosylated hemoglobin (HbA1) levels ranged from 5.7% to 6.2%. At 6, 12, 36, and 60 months, 80%, 91%, 86%, and 75% of recipients, respectively, had HbA1 lower than 6.5%. In the same period, 10%, 8%, 10%, and 11% of recipients became insulin-dependent. Mean cholesterol levels (mg/dL) at 6, 12, 36, and 60 month were 190, 180, 196 and 193, while triglyceride levels (mg/dL) were 162, 129, 106, and 113 respectively. Recipient's rate of lipid-lowering drug use was 18%, 21%, 20%, and 22% at 6, 12, 36, and 60 months. Mean serum creatinine levels (mg/dL) with standard deviations were 1.3 +/- 0.4, 1.5 +/- 0.4, 1.6 +/- 0.5, 1.8 +/- 0.9, at 6, 12, 36 and 60 months respectively. Nineteen recipients had sirolimus suspended and 14 recipients, tacrolimus suspended as well for various reasons. CONCLUSION: Mean plasma glucose levels were normal during the period. About 10% of recipients became insulin-dependent and 20% required lipid-lowering drugs. The immunosuppressive regimen protocol had to be changed in 60% of patients.

Assessment of porcine bone metabolism by dynamic.

UNLABELLED: The aim of this study was to quantify regional bone blood flow and [(18)F]fluoride ion influx with [(18)F]fluoride ion PET and correlate the results with specific static and dynamic indices of bone metabolism in healthy pigs. METHODS: During continuous ventilation (fractional concentration of oxygen in inspired gas = 0.3), dynamic PET scans 120 min in duration were obtained for 9 mini pigs after intravenous injection of 10.0 +/- 1.2 MBq (mean +/- SD) of [(18)F]fluoride ion per kilogram of body weight. Iliac crest bone biopsies were performed immediately before the PET scan to determine static and dynamic indices of bone metabolism (i.e., the mineral apposition rate) by bone histomorphometry. Kinetic rate constants describing influx (K(1)) and efflux (k(2)) of [(18)F]fluoride as well as chemisorption and incorporation of [(18)F]fluoride (k(3)) and reverse transport (k(4)) were determined for 6 vertebral bodies in each animal. Blood flow estimates (f) were derived from K(1) values corrected for the permeability-surface area product using a previously derived correction algorithm. A rate constant describing the net forward transport rate of fluoride (K(i)) and the fluoride volume flux (K(flux)) derived from a 2-tissue-compartment model was calculated and compared with the results of Patlak graphic analysis (K(pat)). RESULTS: A significant correlation was found between mineral apposition rate and K(i) (P < 0.005), K(flux) (P < 0.01), K(pat), K(1), and f (P < 0.05). The values of f, K(i), K(flux), and K(pat) did not correlate significantly with other static or dynamic histomorphometric indices or with age, serum alkaline phosphatase, or parathyroid hormone levels. The values of f and K(i) correlated linearly (y = 0.023 + 0.32x; r(2) = 0.74; P < 0.001). CONCLUSION: PET bone studies using [(18)F]fluoride ion provide quantitative estimates of bone blood flow and metabolic activity that correlate with histomorphometric indices of bone formation in the normal bone tissue of the mini pig. Therefore, it seem reasonable to assume that [(18)F]fluoride ion PET can reduce the number of invasive bone biopsies, thus facilitating follow-up of patients with metabolic bone diseases.

Introducing fluorine-18 fluoromisonidazole positron emission tomography for the localisation and quantification of pig liver hypoxia.

Fluorine-18 labelled fluoromisonidazole ([18F]FMISO) has been shown to accumulate in hypoxic tissue in inverse proportion to tissue oxygenation. In order to evaluate the potential of [18F]FMISO as a possible positron emission tomography (PET) tracer for imaging of liver tissue hypoxia, we measured the [18F]FMISO uptake in 13 domestic pigs using dynamic PET scanning. Hypoxia was induced by segmental arterial hepatic occlusion. During the experimental procedure the fractional concentration of inspired oxygen (FiO2) was set to 0.67 in group A (n=6) and to 0.21 in group B (n=7) animals. Before and after arterial occlusion, the partial pressure of O2 in tissue (TPO2) and the arterial blood flow were determined in normal flow and flow-impaired liver segments. Standardised uptake values [SUV=kBq tissue (in g) / body weight (in kg) x injected dose (in kBq)] for [18F]FMISO were calculated from PET images obtained 3 hours after injection of about 10 MBq/kg body weight [18F]FMISO. Immediately before PET scanning, the mean arterial blood flow was significantly decreased in arterially occluded segments [group A: 0. 41 (0.32-0.52); group B: 0.24 (0.16-0.33) ml min-1 g-1] compared with normal flow segments [group A: 1.05 (0.76-1.46); group B: 1.14 (0.83-1.57) ml min-1 g-1; geometric mean (95% confidence limits); P<0.001 for both groups]. After PET scanning, the TPO2 of occluded segments (group A: 5.1 (4.1-6.4); group B: 3.5 (2.6-4.9) mmHg] was significantly decreased compared with normal flow segments [group A: 26.4 (21.2-33.0); group B: 18.2 (13.3-25.1) mmHg; P<0.001 for both groups]. During the 3-h PET scan, the mean [18F]FMISO SUV determined in occluded segments increased significantly to 3.84 (3.12-4.72) in group A and 5.7 (4.71-6.9) in group B, while the SUV remained unchanged in corresponding normal liver tissue [group A: 1.4 (1.14-1. 71); group B: 1.31 (1.09-1.57); P<0.001 for both groups]. Regardless of ventilation conditions, a significant inverse exponential relationship was found between the TPO2 and the [18F]FMISO SUV (r2=0. 88, P<0.001). Our results suggest that because tracer delivery to hypoxic tissues was maintained by the portal circulation, the [18F]FMISO accumulation in the liver was found to be directly related to the severity of tissue hypoxia. Thus, [18F]FMISO PET allows in vivo quantification of pig liver hypoxia using simple SUV analysis as long as tracer delivery is not critically reduced.