Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

PSYCHO-SOCIAL ASPECTS OF QUALITY OF LIFE IN WOMEN WITH ENDOMETRIOSIS

OBJECTIVES

The objective of this study was to assess the impact of endometriosis on the quality of life.

PATIENTS AND METHODS

Study group of 205 women, aged between 18-45 years old, hospitalized in the "Cuza-Voda" Hospital of Iasi, between 2013-2015. We used the Fertility Problem Inventory, the Endometriosis Health Profile and the Beck Depression Inventory.

RESULTS

We first realized a descriptive analyses of patients' health related quality of life - 60% of women reported higher infertility distress associated with relationship issues caused by difficulties to conceive. The descriptive analysis over the quality of life in patients with endometriosis suggests that the high level of stress related factors, are: the loss over the control of the symptoms, dyspareunia and altered emotional status. Regarding the sexual aspect of life, almost a quarter of the women complained about an altered sexual status, due to both fear of failing in conceiving and dyspareunia caused by the endometriosis. The descriptive analysis over the infertility related stress suggests that the factors associated with a high level of stress are: sadness, pessimism, feeling of failure, irritability, lack of confidence, self-hatred and fatigue.

CONCLUSIONS

Patients with endometriosis are dealing daily with a large spectrum of symptoms, including pain, dyspareunia, emotional instability and high levels of stress, which have a negative impact upon the quality of life, by lowering it on different levels. Also, within the present study we showed a significant presence of high infertility stress in patients of all ages that lead to depression and social anxiety.

Interpenetrating poly(urethane-urea)–polydimethylsiloxane networks designed as active elements in electromechanical transducers

Original interpenetrating polymer networks suitable for active dielectric elements in actuation devices were prepared by using a dual compatibilization pathway.

Goethite nanorods as a cheap and effective filler for siloxane nanocomposite elastomers

Composites based on PDMS and goethite nanorods are for the first time approached from the perspective of dielectric elastomers.

Superparamagnetic amorphous iron oxide nanowires self-assembled into ordered layered structures

The thermal decomposition of μ3-oxo trinuclear iron(iii) acetate in presence of dodecylamine and oleic acid, in trichloroacetic acid at 320 °C was optimized to obtain iron oxide nanoparticles with pure nanowire morphology.

Immunosuppressant regimen based on sirolimus decreases aortic stiffness in renal transplant recipients in comparison to cyclosporine

Whether or not a cyclosporine A (CsA)-free immunosuppressant regimen based on sirolimus (SRL) prevents aortic stiffening and improves central hemodynamics in renal recipients remains unknown. Forty-four patients (48 ± 2 years) enrolled in the CONCEPT trial were randomized at week 12 (W12) to continue CsA or switch to SRL, both associated with mycophenolate mofetil. Carotid systolic blood pressure (cSBP), pulse pressure (cPP), central pressure wave reflection (augmentation index, AIx) and carotid-to-femoral pulse-wave velocity (PWV: aortic stiffness) were blindly assessed at W12, W26 and W52 together with plasma endothelin-1 (ET-1), thiobarbituric acid-reactive substances (TBARS) and superoxide dismutase (SOD) and catalase erythrocyte activities. At W12, there was no difference between groups. At follow-up, PWV, cSBP, cPP and AIx were lower in the SRL group. The difference in PWV remained significant after adjustment for blood pressure and eGFR. In parallel, ET-1 decreased in the SRL group, while TBARS, SOD and catalase erythrocyte activities increased in both groups but to a lesser extent in the SRL group. Our results demonstrate that a CsA-free regimen based on SRL reduces aortic stiffness, plasma endothelin-1 and oxidative stress in renal recipients suggesting a protective effect on the arterial wall that may be translated into cardiovascular risk reduction.

Fixed combination of perindopril and indapamide at low dose improves endothelial function in essential hypertensive patients after acute administration

BACKGROUND

Fixed combination of angiotensin-converting enzyme inhibitors (ACEIs) with thiazide-type diuretics at low dose has been used as first-line therapy for the treatment of essential hypertension but their effect on conduit artery endothelial dysfunction remains unknown.

METHODS

Thirteen hypertensive patients were assessed after acute administration of a placebo, fixed combination of perindopril-indapamide at low dose: D1 (2 mg/0.625 mg) and twice this dose: D2 (4 mg/1.25 mg), during a double-blind, randomized, crossover study, and were compared with 13 matched controls. Mean arterial pressure (MAP), radial artery diameter (echotracking) and flow (Doppler) were measured during flow-mediated dilatation (FMD) induced by post-ischemic hyperemia (PIH). PIH was characterized by peak flow and duration of hyperemia (t(1/2)). Endothelium-independent dilatation was assessed by trinitrine.

RESULTS

In hypertensive patients compared with controls, basal radial artery diameter and flow, peak flow, and trinitrine responses were similar while MAP was increased (115 +/- 3 vs. 87 +/- 2 mm Hg), t(1/2) was decreased (11.1 +/- 1.9 vs. 17.2 +/- 2.2 s), and FMD was altered (radial diameter increase: 203 +/- 14 vs. 304 +/- 15 microm). Compared with placebo, only D2 decreased MAP (placebo: 115 +/- 3; D1: 112 +/- 4; D2: 103 +/- 4 mm Hg) and increased t(1/2) (placebo: 11.1 +/- 1.9; D1: 8.7 +/- 1.5; D2:13.0 +/- 1.9 s). Conversely, D1 and D2 increased FMD (placebo: 203 +/- 14; D1: 218 +/- 22; D2: 227 +/- 23 microm) with no change in basal diameter and flow, peak flow, and trinitrine responses.

CONCLUSION

These results demonstrate that a fixed combination of ACEI/diuretic at low dose significantly improves radial artery FMD in hypertensive patients and suggest a direct effect on conduit artery endothelium that may contribute to vascular protection.

Microcoil embolization for ablation of septal hypertrophy in hypertrophic obstructive cardiomyopathy

BACKGROUND

Percutaneous transcatheter occlusion with ethanol injection of septal arteries is an efficient treatment procedure of hypertrophic obstructive cardiomyopathy (HOCM). The aim of our study is to evaluate the feasibility and efficiency of septal artery embolization with microcoils.

METHODS

The microcoils were delivered through the guide-wire lumen of a 2mm-diameter coaxial balloon positioned inside the target vessel as distally as possible. One or more 0.018"-straight microcoils (Hilal straight coils, Cook, USA) were used for each target vessel until complete flow obstruction was noted. The intraventricular pressure gradient was measured before, during and after the procedure. Septal branch occlusion was finally documented by coronary angiography.

RESULTS

We treated 7 patients (pts) (male: 5 pts; mean age: 48 (10 years). All patients were symptomatic (NYHA class 3 or 4). The target vessels were successfully occluded in all patients, without complications. Moderate pain was recorded during and after the procedure and the CK level increased five- to ten-fold. The pressure gradient diminished during the procedure from 72 +/- 21 mm Hg to 30 +/- 15 mm Hg. The number of coils delivered ranged from 3 to 7 / patient. The embolized septal branches: 1 vessel in 5 patients; 2 vessels in 1 patient; 3 vessels in 1 case. After the procedure the pressure gradient, evaluated by transthoracic echocardiography, was 34 +/- 16 mm Hg and 42 +/- 12 mm Hg at 3 month-follow-up. Clinical improvement was recorded in all patients after the procedure (NYHA class 1 or 2). Temporary pacing was necessary in 3 patients during and immediately after the procedure but no patient needed permanent pacing.

CONCLUSIONS

Microcoil embolization is an efficient and safe approach for transcatheter ablation of septal hypertrophy in HOCM. This technique induced myocardial necrosis without the toxic effects of alcohol, reducing the risk of complications (permanent pace-maker implantation, ethanol flow to other myocardial regions).

[Hand skin heating: a new method for the evaluation of conduit artery endothelial function in insulin-dependent diabetic patients]

The presence of an altered endothelium-mediated flow-dependent dilatation (FDD) of peripheral conduit arteries in insulin-dependent diabetic patients without microangiopathy is still controversial. We studied 10 normotensive and non atherosclerotic insulin-dependent diabetic patients (D group) without complication (neuropathy, microalbuminuria or neuropathy) and 10 control subjects (C group) matched for age, sex and BMI. Radial artery diameter (RAD, echotracking) and flow (RAF, Doppler) were measured at baseline and during FDD in response to distal hand skin heating (from 34 to 44 degrees C). a method developed to increase RAF by stable steps by decreasing gradually hand skin vascular resistance. Endothelium-independent dilatation was evaluated by administration of glyceryl trinitrate (GTN: 0.3 mg spray). At baseline, there was no difference between group for RAF (C: 18 +/- 5 vs D: 18 +/- 2 mL/min; NS) and RAD (C: 2.51 +/- 0.12 vs D: 2.54 +/- 0.07 mm; NS). Heating induced in the diabetic group a smaller increase in RAF (C: 473 +/- 126% vs D: 262 +/- 63%; p<0.05) and RAD (C: 22.6 +/- 2.6% vs D: 16.1 +/- 1.8%; p<0.01). This last result remains significant when the increase in RAF was included into the analysis of RAD variation during heating (p<0.05). GTN-induced dilatation was similar in the 2 groups. Our results obtained by use of the hand skin heating method demonstrate the presence of an abnormal arteriolar skin reactivity and an altered peripheral conduit artery endothelium-dependent dilatation in uncomplicated insulin-dependent diabetic patients. The early identification of these anomalies, with negative prognostic value, could contribute to the management of these patients.

[Role of endothelium-derived nitric oxide in sustained flow-dependent dilatation of human peripheral conduit arteries]

Endothelial dysfunction is involved in the pathogenesis of cardiovascular diseases and is generally associated to the decrease in arterial nitric oxide (NO) availability. In humans, endothelial function can be evaluated by the post-ischaemic flow-dependent dilatation (FDD) of peripheral conduit arteries which is mainly mediated by the NO release when short duration of reactive hyperaemia are used (3 to 5 min ischaemia). However, recent studies suggest that the role of NO in this response decreases as the duration of the hyperaemic stimulation increases. The aim of the present study was thus, to evaluate, in healthy subjects, the role of NO in the FDD of conduct arteries in response to a sustained stimulation. Radial artery diameter (echotracking) and flow (Doppler) were measured, 7 cm under the elbow line, at baseline and during post-ischaemic hyperaemia (10 min wrist cuff inflation) in 10 healthy subjects (age: 24 +/- 1 years) in control period and after acute blockade of the endothelial NO-synthase by local infusion of NG-monomethyl L-arginine (L-NMMA, brachial artery, 8 mumol/min, 7 min). Endothelium-independent dilatation was studied by mean of sodium nitroprusside infusion (SNP: 5, 10 and 20 nmol/min, 3 min each dose before and after L-NMMA). L-NMMA administration decreased radial artery blood flow at base (Control: 14 +/- 2 vs L-NMMA: 10 +/- 1 ml/min, P < 0.05) and increased radial artery vasodilatation in response to SNP (P < 0.05) thus, demonstrating NO-synthase inhibition. Therefore, after L-NMMA there was a small decrease in radial FDD (Control: base: 2.52 +/- 0.05 mm, FDD: 11.3 +/- 0.6% vs L-NMMA: base: 2.51 +/- 0.04 mm: FDD: 9.0 +/- 0.9%; p < 0.05) without change in hyperaemia. In conclusion, our results demonstrate, in contrast to those obtained after short duration of hyperaemia, that the relative implication of NO in the flow-dependent vasodilatation of peripheral conduit arteries in humans decreases in response to sustained stimulation and suggest, in these experimental conditions, an associated flow-dependent vasodilating mechanism that is unaffected by the NO-synthase inhibition.

Restenosis in the coronary stent is an argument for the surgical myocardial revascularization

BACKGROUND

This study will evaluate the difference between the frequency of restenosis in myocardial revascularization procedures by stents and CABG by coronarographic control after clinical criteria (angina).

METHODS AND RESULTS

Out of the total of 6564 coronarographies performed (1999-2002) for diagnosis purposes, 3110 patients (44.8%) underwent myocardial revascularization procedures, PCI or CABG. PCI was performed in 981 patients (31%) and CABG in 1148 patients (37.3%). At the same time, we performed in our units 2067 surgical procedures, out of which 1148 (55%) revascularizations by CABG. The angiographic control for patients with myocardial revascularization by stent (55 patients) or CABG (50 patients) was performed by clinical criteria (angina reappears) on 105 patients. The restenosis we found in 47 patients (74.5%) treated by stent revascularization and in 29 patients from CABG procedures. In our study restenosis rate was 4.8% in patients with PCI and 2.5% in patients with CABG.

CONCLUSIONS

Both surgical (CABG) and percutaneous coronary artery revascularization (PCI) have proved to be extremely effective in the treatment of patients with multivessel coronary disease. In our study restenosis rate was smaller in the patients with CABG than in the PCI group, taking into account the fact that we did not use drug eluting stent (DES) on a large scale. Results from the series of randomized trials (SOS, SIRIUS, ERACI, ARTS, BARI, etc.) have shown that the restenosis phenomenon is an apparent advantage in patients with DES. Restenosis prevention is a complex phenomenon (inflammation, procoagulation, cellular migration, etc.) and DES appearance opens a new era in PCI.

Chronic ACE inhibition enhances the endothelial control of arterial mechanics and flow-dependent vasodilatation in heart failure

Reduced conduit arteries flow-dependent dilatation and altered compliance have been described during heart failure. However, the role of shear stress, the relation between endothelial dysfunction and mechanics, and the effect of chronic ACE inhibition on this relationship have not been investigated. The present study was designed to evaluate in heart failure patients the relationship between flow-dependent dilatation and radial artery mechanics at known shear stress levels and to assess the effect of chronic ACE inhibition. Sixteen stable congestive heart failure patients, who had never been treated with ACE inhibitors, participated in the study. Arterial pressure, cardiac output (bioimpedance), radial artery diameter (echo tracking) and flow (Doppler), total blood viscosity, and mean artery wall shear stress were assessed before and during a gradual increase in the forearm blood flow in response to gradual distal hand skin heating. Cross-sectional radial artery compliance and distensibility indexes were calculated at 34 degrees C, 40 degrees C, and 44 degrees C. The endothelium-independent vasodilatation was evaluated by use of glyceryl trinitrate. All parameters were assessed before and 24 hours after the last administration of perindopril (4 mg once daily) or placebo in a 2-month double-blind randomized study. Before treatment, there was no difference between the 2 groups for all parameters. After chronic ACE inhibition, systolic arterial pressure decreased at baseline from 126+/-11 to 118+/-10 mm Hg (P<0.05). During heating, the increase in diameter in response to shear stress was higher after ACE inhibition than after placebo (time/treatment interaction, P<0.05). Moreover, in contrast to placebo, at the same shear stress, there was a significant increase in compliance (3.23+/-0.79 x 10(-7) to 6.82+/-2.47 x 10(-7) m(2)/kPa, P<0.05) and distensibility (5.71+/-1.35 x 10(-3) to 8.87+/-1.88 x 10(-3)/kPa, P<0.05) during heating after ACE inhibition. The effect of glyceryl trinitrate did not change. The present study demonstrates that chronic administration of the ACE inhibitor perindopril increases the magnitude of the flow-dependent dilatation and restores the flow-dependent increase in compliance and distensibility of the radial artery evaluated at stable shear stress. In addition, the decrease in baseline systolic arterial pressure after ACE inhibitor suggests an associated increase in the distensibility of the proximal elastic conduit arteries.

Role of arterial smooth muscle tone and geometry in the regulation of peripheral conduit artery mechanics by shear stress

1. Although arterial blood flow is recognized as an important modulator of vascular tone and geometry, the effect of acute changes in shear-stress on conduit artery mechanics has not been fully investigated in humans because of technical limitations. 2. To assess, respectively, the effects of decreases and increases in flow and shear stress on radial artery tone and mechanics, arterial pressure (photoplethysmography), total blood viscosity, radial artery internal diameter, wall thickness (echotracking) and blood flow (Doppler) were measured in healthy volunteers (mean (+/-SEM) age 25 +/- 1 years) during a distal flow arrest (n=12) and hand skin heating (n=18). 3. Radial artery flow decreased from 31 +/- 4 to 7 +/- 1 10(-3) L/min during distal flow arrest (P < 0.001) and increased from 10 +/- 2 to 22 +/- 4 and 69 +/- 6 10(-3) L/min during heating (P < 0.001). At mean arterial pressure, these changes in flow were respectively associated with a parallel flow-dependent reduction and increase in diameter and midwall stress. There was no significant modification in mean elastic modulus. Compliance did not change when flow decreased and only increased at the highest level of flow. Finally, the cross-sectional compliance and incremental modulus were fitted as functions of midwall stress. The decrease in flow was associated with an upward shift of the modulus-midwall stress curve and a downward shift of the compliance-midwall stress curve. The increase in flow was associated with a downward shift of the modulus-midwall stress curve and an upward shift of the compliance-midwall stress curve at each level of wall shear stress. 4. By using two different procedures, we obtained similar results concerning the direct effects of increases and decreases in flow on stiffness of the arterial wall and on arterial compliance and demonstrated the presence of a flow-dependent regulation of arterial smooth muscle tone of peripheral conduit arteries in humans.

Divergent effects of verapamil and amlodipine at rest and during exercise

OBJECTIVE

To evaluate, in healthy volunteers, the effects of acute administration of two calcium antagonists with different pharmacological profiles, verapamil and amlodipine, on haemodynamics at rest and during exercise.

SUBJECTS AND METHODS

Six healthy volunteers (aged 20-29 years) were randomly assigned to receive single oral doses of amlodipine (5 mg), slow-release verapamil (240 mg) or a placebo during a double-blind cross-over study. Systolic (SAP), diastolic and mean arterial pressures (measured using a cuff sphygmomanometer), heart rate (HR), cardiac index (CI, bioimpedance), rate-pressure product (SAP x HR), and noradrenaline and adrenaline plasma levels were measured at rest before drug administration, and at rest and during graded bicycle exercise (steps of 50, 100 and 150 W during 3, 3 and 4 min, respectively) started 3 h after drug administration.

RESULTS

At rest arterial pressure, HR, rate-pressure product and catecholamine plasma levels did not change after verapamil or amlodipine administration, whereas CI significantly decreased after verapamil (from 3.9 +/- 0.4 to 3.3 +/- 0.4 l/min per m2) but not after amlodipine (3.9 +/- 0.3 and 4.1 +/- 0.5 l/m per m2) administration. During exercise the increases in SAP and HR were slightly but not significantly higher after amlodipine than after verapamil administration, rate-pressure product and CI were higher after amlodipine (22 +/- 1 x 10(3) mmHg x beats/min and 13 +/- 2 l/min per m2, respectively) than after verapamil (20 +/- 1 x 10(3) mmHg x beats/min and 10 +/- 2 l/min per m2, respectively) administration. Plasma levels of noradrenaline and adrenaline were similar at rest after each treatment and were slightly more increased after amlodipine administration during exercise.

CONCLUSIONS

In contrast to amlodipine, verapamil induced a slight myocardial depressive effect at rest and did not potentiate the myocardial effects of the sympathetic stimulation induced by exercise. The myocardial action of verapamil is such as to induce some decrease in myocardial oxygen demand, both at rest and during exercise.

Bioactive polymers: in vitro and in vivo study of controlled release neomycin

Neomycin is coupled on xanthan-a polysaccharide of microbial biosynthesis produced by Xanthomonas campestris-through ionic complexation. The kinetics of neomycin release, in vitro, at pH = 8.2 is studied. A controlled release of neomycin, following a zero order kinetics is observed, regardless of the eluent flow. Neomycin complexed on xanthan, administered in a unique daily dose to patients suffering from dysentery in the 100 cases taken in study, has shown a high clinical efficiency as compared with the treatments with ampicillin or furazolidone, administered for 5-10 days or longer.

[Infectious endocarditis in mitral valve prolapse]

The paper reports on 13 cases of infectious endocarditis in the patients with prolapse of the mitral valve admitted for a period of 10 years (1979-1989) into the Clinic of Cardiology of the Fundeni Hospital. These cases stand for 3.6% of the cases with prolapse of the mitral valve admitted during that period, and 5% of the patients with infectious endocarditis. Our study dealt only with the cases of the prolapse of the mitral valve, clinically and echographically documented before the appearance of the septic graft. The hemocultures were positive in all the patients (viridans streptococci in 84.61% cases). The symptomatology, the clinical objective data and the paraclinical results (phonocardiographic, echocardiographic, electrocardiographic, radiologic, investigations with isotopes), the response to the treatment (medical, surgical) and the evolution in time were analyzed. An increase was found during endocarditis in the number of patients with holosystolic murmurs (30.7% cases) versus those with click-telesystolic murmur, the appearance in 41.15% of the cases of valvular vegetations at the Echo examination, and in 15.38% cases of ruptures of cordages. Mitral insufficiency secondary to endocarditis became worse, in 30.76% cases. The treatment with antibiotics resulted in the healing of the infection in all the cases. The surgery was not necessary in any patient during the evolution of endocarditis. The surgery (valvular prosthesis) was made in 23.07% cases, which presented, after curing the septic graft, important mitral regurgitation with cardiac insufficiency refractory to the medical treatment. Prophylaxis of the infectious endocarditis in the prolapse of mitral valve with mitral regurgitation is necessary.

[An experimental model of data base organization in glaucoma with computer processing (a preliminary note)]

The authors report on an experimental model of data base set up for glaucoma with possibilities of statistical-mathematical processing. The application is designed for miniprocessors of the INDEPENDENT or CORAL type in FORTRAN 77. The paper presents the level structure of the display, and the ways of using the information under the form of assisted diagnosis and prognosis, according to which the attention is then directed to the rhythm and detailed content of the future examination.

Anatomoclinical correlations in coronary heart disease: recent advances and unanswered questions

An attempt is made to summarize the recent available information on anatomoclinical correlations in coronary heart disease. The paper focuses attention on: (a) the role in the pathogenesis of unstable angina pectoris, severe arrhythmias and sudden cardiac death, of repeated cycles of formation, disintegration and peripheral embolization of intramural thrombi or of thrombi developed on preexisting atherosclerotic plaques; (b) a still apparently unsolved problem: which comes first, coronary thrombosis or myocardial infarction? (c) the pathophysiological and clinical significance of the "border zone" of myocardial infarcts; (d) the importance, in the pathogenesis of coronary heart disease and particularly of sudden cardiac death, of obstructive lesions which occur in the vessels supplying the conduction system of the heart.

Calcified intracranial haematoma associated with chronic subdural hygroma

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