Postoperative haemoglobin and anaemia-associated ischaemic events after major noncardiac surgery: A sex-stratified cohort study

STUDY OBJECTIVE

To determine the sex-specific associations between postoperative haemoglobin and mortality or complications reflecting ischaemia or inadequate oxygen supply after major noncardiac surgery.

DESIGN

A retrospective cohort study with prospective validation.

SETTING

A large university hospital health system in China.

PATIENTS

Men and women undergoing elective major noncardiac surgery.

INTERVENTIONS AND MEASUREMENTS

The primary exposure was nadir haemoglobin within 48 h after surgery. The outcome of interest was a composite of postoperative mortality or ischaemic events including myocardial injury, acute kidney injury and stroke within hospitalisation.

MAIN RESULTS

The study included 26,049 patients (15,757 men and 10,292 women). Low postoperative haemoglobin was a strong predictor of the composite outcome in both sexes, with the risk progressively increasing as the nadir haemoglobin concentration dropped below 130 g l-1 in men and 120 g l-1 in women (adjusted odds ratio [OR] 1.43, 95% CI 1.37-1.50 in men, and OR 1.45, 95% CI 1.35-1.55 in women, per 10 g l-1 decrease in postoperative nadir haemoglobin). Above these sex-specific thresholds, the change of nadir haemoglobin was no longer associated with odds of the composite outcome in either men or women. There was no significant interaction between patient sex and the association between postoperative haemoglobin and the composite outcome (Pinteraction = 0.673). Validation in an external prospective cohort (n = 2120) with systematic postoperative troponin and creatinine measurement confirmed our findings.

CONCLUSIONS

Postoperative haemoglobin levels following major noncardiac surgery were nonlinearly associated with ischaemic complications or mortality, without any clinically important interaction with patient sex.

Association between cumulative duration of deep anesthesia and postoperative acute kidney injury after noncardiac surgeries: a retrospective observational study

BACKGROUND

Bispectral index (BIS) is a processed electroencephalography monitoring tool and is widely used in anesthetic depth monitoring. Deep anesthesia exposure may be associated with multiple adverse outcomes. However, the relationship between anesthetic depth and postoperative acute kidney injury (AKI) remains unclear. We sought to determine the effect of BIS-based deep anesthesia duration on postoperative AKI following noncardiac surgery.

METHODS

This retrospective study used data from the Vital Signs DataBase, including patients undergoing noncardiac surgeries with BIS monitoring. The BIS values were collected every second during anesthesia. Restricted cubic splines and logistic regression were used to assess the association between the cumulative duration of deep anesthesia and postoperative AKI.

RESULTS

4774 patients were eligible, and 129 (2.7%) experienced postoperative AKI. Restricted cubic splines showed that a cumulative duration of BIS < 45 was nonlinearly associated with postoperative AKI (P-overall = 0.033 and P-non-linear = 0.023). Using the group with the duration of BIS < 45 less than 15 min as the reference, ORs of postoperative AKI were 2.59 (95% confidence interval [CI]:0.60 to 11.09, p = 0.200) in the 15-100 min group, and 4.04 (95%CI:0.92 to 17.76, p = 0.064) in the ≥ 100 min group after adjusting for preoperative and intraoperative covariates in multivariable logistic regression.

CONCLUSIONS

The cumulative duration of BIS < 45 was independently and nonlinearly associated with the risk of postoperative AKI in patients undergoing noncardiac surgery.

Contrasting patterns of genetic divergence in two sympatric pseudo-metallophytes: Rumex acetosa L. and Commelina communis L

BACKGROUND

Patterns of genetic divergence between populations of facultative metallophytes have been investigated extensively. However, most previous investigations have focused on a single plant species making it unclear if genetic divergence shows common patterns or, conversely, is species-specific. The herbs Rumex acetosa L. and Commelina communis L. are two pseudo-metallophytes thriving in both normal and cupriferous soils along the middle and lower reaches of the Yangtze River in China. Their non-metallicolous and metallicolous populations are often sympatric thus providing an ideal opportunity for comparative estimation of genetic structures and divergence under the selective pressure derived from copper toxicity.

RESULTS

In the present study, patterns of genetic divergence of R. acetosa and C. communis , including metal tolerance, genetic structure and genetic relationships between populations, were investigated and compared using hydroponic experiments, AFLP, ISSR and chloroplast genetic markers. Our results show a significant reduction in genetic diversity in metallicolous populations of C. communis but not in R. acetosa . Moreover, genetic differentiation is less in R. acetosa than in C. communis , the latter species also shows a clustering of its metallicolous populations.

CONCLUSIONS

We propose that the genetic divergences apparent in R. acetosa and C. communis , and the contrasting responses of the two species to copper contamination, might be attributed to the differences in their intrinsic physiological and ecological properties. No simple and generalised conclusions on genetic divergence in pseudo-metallophytes can thus be drawn.

Column switching in high-performance liquid chromatography with tandem mass spectrometric detection for high-throughput preclinical pharmacokinetic studies

A high-throughput liquid chromatography-tandem mass spectrometry method is described for the determination of multiple compounds in dog and rat plasma. After acetonitrile precipitation of plasma proteins, the analytes are pre-concentrated and back-flushed on a reversed-phase column for separation using a switching valve. The analytes are ionized using TurboIon Spray in a positive mode, and detected by multiple reaction monitoring. Automatic tuning software is used for fast method development. The data processing is greatly speeded up by using a powerful quantitation software package. Chromatography of multiple compounds takes only 4 min. The linear calibration curve ranges from 0.5 to 1000 ng/ml. This method was successfully used in the analysis of multi-compounds for preclinical pharmacokinetic studies.

[Report of 2 cases of extrinsic allergic alveolitis and review of relevant literature]

Two cases of extrinsic allergic alveolitis were reported. The antigens inducing the immunologic events are wheat powder, hair-dye liquid. The pathology, symptoms and chest radiograph features were presented. The best treatment is avoidance of antigen exposure and to use of corticosteroids. The chronic form of the disease often leads to irreversible pulmonary interstitial fibrosis.

Inhibition of nitric oxide synthesis increases the secretion of endothelin-1 in vivo and in cultured endothelial cells

The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin-1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (PAPm) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FIO2 = 0.10) was 25 +/- 3.1 kPa and 68.7 +/- 10.2 kPa.s/L respectively. NG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of PAPm and PVR during hypoxic ventilation to 36.6 +/- 4.7 kPa and 158.4 +/- 25 kPa.s/L and its effect lasted for 2-3 hours. Meanwhile, plasma endothelin-1 level in the femoral artery increased by 20.9 +/- 7.1, 25.6 +/- 7.7, 28.6 +/- 7.9 pg/ml at the 60th, 120th, 180th minute after the injection of L-NAME respectively (P < 0.05 vs hypoxic control before the injection). In cultured endothelial cells from umbilical veins, endothelin-1 level of culture medium in control group was 35.1 +/- 5.9 pg/10(5) cells/ml (n = 9). L-NAME increased endothelin-1 level to 42.8 +/- 4.9pg/10(5) cells/ml (n = 9, P < 0.05) in case of 10(-11) mol/L and to 43.0 +/- 4.7 pg/10(5) cells/ml in case of 10(-7) mol/L (n = 9, P < 0.05). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin-1 in vivo and in cultured vascular endothelial cells.

[The clinical significance serum N-POMC level in lung cancer patients]

Serum N-POMC level of 103 cases of lung cancer were measured in our hospital. The results were as follows: The lung cancer group, 50.5%, of patienst has an N-PONC level above the normal upper limit. The percentages of the N-POMC levels above the normal limit in lung cancers, such as: squamous-cell carcinoma, adenocarcinoma, SCLC and undifferentiated carcinoma were 52.2%, 50.0%, 47.3% and 57.1%, respectively. There was no statistically significant difference of N-POMC levels among these kinds of lung cancers, Eleven of 18 cases of SCLC patients in stage IIIb or IV, and 3 of 9 cases of SCLC patients in stage IIIa had N-POMC levels above the upper normal limit. Could serum N-POMC be one of the indexes for assisting the diagnosis and prognosis of lung cancer needs further investigation. Cases with carcinoid, thymoma and neurofibroma had higher N-POMC levels too. Six patients had Cushing syndrome.

[Inhibition of endogenous nitric oxide synthesis enhances acute hypoxic pulmonary vasoconstriction]

The objective of this study was to observe the role of endogenous nitric oxide, formed from L-arginine, in the regulation of acute hypoxic pulmonary vasoconstriction by inhibiting its synthesis with the false substrate NG-nitro-L-arginine methyl ester (L-NAME) in anesthetized dogs. L-NAME (1 mg/kg, 5 mg/kg, 15 mg/kg) significantly increased the mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FiO2 = 0.10) and its action lasted for 90-180 minutes. The maximum increase value (MIV) of hypoxic mPAP in three groups (4 dogs each group) is 1.1 +/- 0.2, 1.5 +/- 0.3, 1.6 +/- 0.4 kPa (1 kPa = 7.5 mmHg), respectively, while that of hypoxic PVR is 58.4 +/- 15.6, 99.3 +/- 28.8, 78 +/- 4.0 kPa.s/L (all P < 0.05 vs hypoxic control before the injection). The increase percent of hypoxic mPAP and PVR induced by L-NAME (15 mg/kg) was 45.23 +/- 5.78% and 133.2 +/- 35.22% 30 minutes after the injection, which was more remarkable than that of mPAP and PVR (18.83 +/- 5.63%, 84.13 +/- 22.67%, respectively) by L-NAME (1 mg/kg). L-arginine (0.5 g/kg) reversed the effect of L-NAME (5 mg/kg) on mPAP and PVR at hypoxic ventilation within one hour. L-NAME also markedly increased hypoxic mean arterial blood pressure at the dose of 15 mg/kg (MIV 2.7 +/- 0.7 kPa) and systemic vascular resistance at the three separate doses (MIV 354.4 +/- 99.7, 456.2 +/- 105, 361.5 +/- 70 kPa x s/L, respectively), meanwhile it remarkably decreased cardiac output and heart rate during hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Borrelia burgdorferi infection may be the cause of sarcoidosis

Serum antibody to Borrelia burgdorferi was measured in 33 patients with sarcoidosis which was confirmed clinically and pathologically. The results showed that 81.8% of the patients were positive for anti-B. burgdorferi antibody. In addition, a strain of B. burgdorferi was isolated from a patient's blood. Fifteen patients received ceftriaxone 2g per day or penicillin 12 million U per day. The antibody titers of the patients decreased to nearly normal levels rapidly. Serum angiotensin converting enzyme (SACE) turned to normal range after the treatment. According to the findings mentioned above, we consider that B. burgdorferi infection may be the cause of sarcoidosis and sarcoidosis might be a specific type of Lyme disease.

[An analysis of 30 cases of chylothorax and chyloperitoneum]

Thirty patients diagnosed as chylothorax and chyloperitoneum (13 of chylothorax, 9 of chyloperitoneum and 8 of both) in PUMC Hospital from 1923 to 1989 were reported. Thus, the incidence rate of these two diseases is rather low. The commonest causes were iatrogenic trauma (9 cases) and malignant tumor (7 cases). Other causes were tuberculosis (5 cases), lymphangioma (2 cases), Behcet's syndrome (1 case) and non-iatrogenic trauma (1 case). The etiology was not known in 5 cases. Acute episode was observed in patients with traumatic chylous effusion; it was usually manifested as dyspnea or abdominal distention. Patients with nontraumatic chylous effusion usually run a chronic course. The characteristics of chylous effusion were analyzed. Lymphangiography and lymphoscintigraphy with 99m TC-labeled dextran play important roles in diagnosis and treatment. It has been suggested that the changes in T-cell immunocompetence is important in determining whether the treatment should be conservative or operative. If chylous effusion is due to tuberculosis, antituberculosis treatment should be instituted.

[Clinical analysis of 90 cases of eosinophilia and pulmonary infiltrates with peripheral eosinophilia]

90 patients diagnosed as eosinophilia and pulmonary infiltrates with peripheral eosinophilia in PUMC Hospital from 1957 to 1986 were reported. The cause of the eosinophilia was unknown in 42% of the patients. Among these patients, hypereosinophilic syndromes (HES) were suspected in 11 patients. The most common presenting symptoms of HES were fever, skin lesions gastrointestinal symptoms and hepatosplenomegaly, the mean peripheral blood eosinophil count was as high as 25.6 x 10(9) cells/L. Biopsies of bone marrow and involved organs revealed extensive eosinophilic infiltration and severe necrosis. In the past ten years, eosinophilia and pulmonary infiltrates caused by parasitic infections obviously decreased. The most common parasites were ascaris Lumbricoides, Ancylostoma duodenale and Clonorchis sinesis. The other main causes which induced pulmonary infiltrates were allergic bronchopulmonary mycosis (ABPM) and chronic eosinophilic pneumonia. The prevalence of ABPM increased recently; early diagnosis and effective therapy could prevent the irreversible damage resulting in airways obstruction and fibrosis.

Damaging role of neutrophil elastase in the elastic fiber and basement membrane in human emphysematous lung

The immunolocalization of human neutrophil elastase (HNE) in the alveolar interstitium of 6 patients with emphysema was investigated by immunochemical electron microscopy. The results showed that HNE is localized in the azurophil granules of neutrophils, and extracellularly on the elastic fibers of alveolar interstitium and basement membranes of epithelium and endothelium. The damage of elastic fibers and basement membranes could be observed. The HNE level of the alveolar interstitium was obviously elevated and closely related to the severity of emphysematous lesions as shown by measuring the mean linear intercept (MLI) in 4 emphysematous lungs with chronic bronchitis (r = 0.84). This suggests that HNE might play an important role in the pathogenesis of emphysema. Although enlarged airspace and increased MLI data were observed in 2 patients, one with asthma and the other, an elderly patient, without lung diseases, the HNE level of alveolar interstitium is much less than that of the other 4 chronic obstructive pulmonary disease patients. This implies that the mechanism of the the airspace enlargement occurring in the 2 patients may be different from that of others. These findings support the hypothesis of elastase-antielastase imbalance on the pathogenesis of pulmonary emphysema.

[Mesothelioma and mesothelial hyperplasia]

Twenty cases of pleural mesothelioma (2 localized and 18 diffuse malignant pleural mesothelioma), 6 cases of diffuse malignant peritoneal mesothelioma and 1 case of mesothelial hyperplasia were reported. The prominent clinical manifestations of malignant mesothelioma was serosal effusion. The exudate was bloody, mucinous and of high specific gravity. It contained numerous mesothelial cells. The diagnosis is difficult because mesothelial hyperplasia and other malignant tumors may mimic mesothelioma in some clinical aspects. Roentgenography, CT scan, cytology of serosal fluid and biopsy world help to establish the diagnosis of mesothelioma. Immunohistochemical features of 4 cases of mesothelioma is negative immunostaining for carcino embryonic antigen (CEA) and positive for keratin antigen. In one case ultrastructural examination showed characteristic features of epithelial mesothelioma cells. The average survival period in case of chemotherapy and/or surgical intervention in patients of this series was 31.3 months. Mesothelial hyperplasia has rather good prognosis; but the strategy of therapy may be conservative.

[Multiple primary bronchial carcinoma. A case report of three separate synchronous primary cancers and a review of literature]

Fibreoptic bronchoscopy was performed in 677 patients with primary bronchial carcinoma during a period from October 1978 to January 1988. In one of them three separate synchronous bronchial carcinomas were found in the lungs. Two of these tumours were radiographically occult. The diagnoses of squamous cell carcinoma of the lung were verified histologically by materials obtained at fibreoptic bronchoscopy. This finding emphasizes the importance of careful bronchoscopic examination of the whole bronchial tree before surgical treatment of lung cancer. The literatures of 41 cases with multiple primary bronchial carcinoma were reviewed.