Post-discharge follow-up using text messaging within an enhanced recovery program after colorectal surgery.

INTRODUCTION: Enhanced recovery after surgery programs (ERP) often lead to early discharge and return to home. In terms of risk management, extended surveillance is recommended. Surveillance using text messages (TM) has been validated for minor operations in ambulatory surgery. The goal of this study was to evaluate the feasibility of home surveillance by TM after colorectal surgery within an ERP. METHODS: This prospective multicenter study involved the University hospitals of Clermont-Ferrand, Grenoble, Marseille and Lyon Sud between November 2014 and September 2015. All patients underwent colorectal surgery within an ERP. Post-discharge, patients received TM (4 simple questions with regard to pain, bowel movements, temperature and phlebitis) on days 1, 3 and 5. If there was abnormal or lack of response, an automatic alert was sent to the attending physician via Internet and the patient was contacted immediately. RESULTS: One hundred and eleven patients were included. Responses were obtained within a median of 12 (1-422) minutes, and 90% of patients answered all TM. There were 48 alerts: 56% because of pain and 40% due to absence of response to the TM. Alerts led to in-hospital care for 4% of patients including three re-hospitalizations and two unplanned re-operations. The median satisfaction score (85% of patients responded) was 5 on a scale of 1 to 5. CONCLUSION: This study suggests the possibility, as for ambulatory surgery, to use test messaging for post-discharge home surveillance for patients undergoing colorectal surgery within an ERP.

Peripheral muscle endurance and the oxidative profile of the quadriceps in patients with COPD.

BACKGROUND: Based on previously reported changes in muscle metabolism that could increase susceptibility to fatigue, we speculated that patients with chronic obstructive pulmonary disease (COPD) have reduced quadriceps endurance and that this will be correlated with the proportion of type I muscle fibres and with the activity of oxidative enzymes. METHODS: The endurance of the quadriceps was evaluated during an isometric contraction in 29 patients with COPD (mean (SE) age 65 (1) years; forced expiratory volume in 1 second 37 (3)% predicted) and 18 healthy subjects of similar age. The electrical activity of the quadriceps was recorded during muscle contraction as an objective index of fatigue. The time at which the isometric contraction at 60% of maximal voluntary capacity could no longer be sustained was used to define time to fatigue (Tf). Needle biopsies of the quadriceps were performed in 16 subjects in both groups to evaluate possible relationships between Tf and markers of muscle oxidative metabolism (type I fibre proportion and citrate synthase activity). RESULTS: Tf was lower in patients with COPD than in controls (42 (3) v 80 (7) seconds; mean difference 38 seconds (95% CI 25 to 50), p<0.001). Subjects in both groups had evidence of electrical muscle fatigue at the end of the endurance test. In both groups significant correlations were found between Tf and the proportion of type I fibres and citrate synthase activity. CONCLUSION: Isometric endurance of the quadriceps muscle is reduced in patients with COPD and the muscle oxidative profile is significantly correlated with muscle endurance.

Angiotensin II relaxes microvessels via the AT(2) receptor and Ca(2+)-activated K(+) (BK(Ca)) channels.

Angiotensin II (Ang II) is one of the most potent vasoconstrictor substances, yet paradoxically, Ang II may dilate certain vascular beds via an undefined mechanism. Ang II-induced vasoconstriction is mediated by the AT(1) receptor, whereas the relative expression and functional importance of the AT(2) receptor in regulating vascular resistance and blood pressure are unknown. We now report that Ang II induces relaxation of mesenteric microvessels and that this vasodilatory response was unaffected by losartan, an AT(1) receptor antagonist, but was inhibited by PD123,319, a selective antagonist of AT(2) receptors. In addition, reverse transcriptase-polymerase chain reaction studies revealed high amounts of AT(2) receptor mRNA in smooth muscle from these same microvessels. Ang II-induced relaxation was inhibited by either tetraethylammonium or iberiotoxin, suggesting involvement of the large-conductance, calcium- and voltage-activated potassium (BK(Ca)) channel. Subsequent whole-cell and single-channel patch-clamp studies on single myocytes demonstrated that Ang II increases the activity of BK(Ca) channels. As in our tissue studies, the effect of Ang II on BK(Ca) channels was inhibited by PD123,319, but not by losartan. In light of these consistent findings from tissue physiology, molecular studies, and cellular/molecular physiology, we conclude that Ang II relaxes microvessels via stimulation of the AT(2) receptor with subsequent opening of BK(Ca) channels, leading to membrane repolarization and vasodilation. These findings provide evidence for a novel endothelium-independent vasodilatory effect of Ang II.

cAMP-dependent vasodilators cross-activate the cGMP-dependent protein kinase to stimulate BK(Ca) channel activity in coronary artery smooth muscle cells.

cAMP-dependent vasodilators are used to treat a variety of cardiovascular disorders; however, the signal transduction pathways and effector mechanisms stimulated by these agents are not fully understood. In the present study we demonstrate that cAMP-stimulating agents enhance the activity of the large-conductance, calcium-activated potassium (BK(Ca)) channel in single myocytes from coronary arteries by "cross-activation" of the cGMP-dependent protein kinase (protein kinase G, PKG). Single-channel patch-clamp data revealed that 10 micromol/L isoproterenol, forskolin, or dopamine opens BK(Ca) channels in coronary myocytes and that this effect is attenuated by inhibitors of PKG (KT5823; Rp-8-pCPT-cGMPS), but not by inhibiting the cAMP-dependent protein kinase (protein kinase A, PKA). In addition, a membrane-permeable analog, CPT-cAMP, also opened BK(Ca) channels in these myocytes, and this effect was reversed by KT5823. Direct biochemical measurement confirmed that dopamine or forskolin stimulates PKG activity in coronary arteries but does not elevate cGMP. Finally, the stimulatory effect of cAMP on BK(Ca) channels was reconstituted in a cell-free, inside-out patch by addition of purified PKG activated by either cGMP or cAMP. In contrast, channel gating was unaffected by exposure to the purified catalytic subunit of PKA. In summary, findings from on-cell and cell-free patch-clamp experiments provide direct evidence that cAMP-dependent vasodilators open BK(Ca) channels in coronary myocytes by cross-activation of PKG (but not via PKA). Biochemical assay confirmed this cross-activation mechanism of cAMP action in these arteries. This signaling pathway is a novel mechanism for regulation of potassium channel activity in vascular smooth muscle and other cells.

A novel transduction mechanism mediating dopamine-induced vascular relaxation: opening of BKCa channels by cyclic AMP-induced stimulation of the cyclic GMP-dependent protein kinase.

Dopamine dilates the coronary, renal and other vascular beds; however, the signaling pathway underlying this effect is unclear. In this study the signal-transduction process mediating dopamine-induced relaxation of porcine coronary arteries was investigated in isolated vessels and single arterial myocytes. Dopamine-induced relaxation of arteries was mediated through the DA- receptor and involved K+ efflux, and subsequent patch-clamp studies demonstrated that either dopamine or fenoldopam, a selective DA-1 agonist, increased the opening probability of the large-conductance, calcium- and voltage-activated K+ (BKCa) channel in coronary myocytes. Moreover, blockade of this channel by iberiotoxin prevented dopamine-induced coronary relaxation. Dopamine stimulation of BKCa channels was completely prevented by a DA-1-receptor antagonist, but was unaffected by propranolol. Furthermore, inhibiting adenylyl cyclase activity prevented stimulation of BKCa channel activity, whereas chlorophenylthio (CPT)-cyclic adenosine monophosphate (AMP), a membrane-permeable analog of cyclic AMP, mimicked the effects of dopamine. Interestingly, inhibiting the cyclic AMP-dependent protein kinase (PKA) did not affect the response to dopamine, whereas dopamine-induced channel activity was completely blocked by inhibiting the activity of the cyclic guanosine monophosphate (GMP)-dependent protein kinase (PKG). These findings demonstrate that activation of DA-1 receptors causes stimulation of BKCa channel activity by a mechanism involving cyclic AMP-dependent stimulation of PKG, but not PKA, and further suggest that this cross-reactivity mediates dopamine-induced coronary vasodilation.

Clinical, physiological and radiological features of asthma with incomplete reversibility of airflow obstruction compared with those of COPD.

OBJECTIVES: To compare clinical features, pulmonary function and high-resolution computed chest tomography (HRCT) findings of asthmatic patients with a component of incomplete reversibility of airflow obstruction (AIRAO) with those of patients with smoking-induced chronic obstructive pulmonary disease (COPD). METHODS: Thirteen patients with COPD (six males and seven females, mean age 59 years, mean smoking 50.5 pack-years) and 14 patients with AIRAO (six males and eight females, mean age 52 years) despite optimal treatment, with no significant smoking history (mean 1.5 pack-years) and no significant environmental exposure or any other respiratory disease, were studied. Patients had respiratory questionnaires, pulmonary function tests, allergy skin-prick tests and an HRCT to evaluate possible parenchymal or bronchial abnormalities. Eight patients in each group also had exercise tests. All patients were stable at the time of the study. RESULTS: As expected, atopy was more prevalent in AIRAO (n=13) than in COPD (n=1) patients. Mean forced expiratory volume in 1 s (FEV1) and forced vital capacity (percentage of predicted value) were 39% and 61%, respectively, in COPD patients and 49% and 71%, respectively, in AIRAO patients; FEV1 improved by 18% in COPD patients and and by 22% in AIRAO patients after use of inhaled salbutamol. Mean functional residual capacity was greater in COPD patients than in AIRAO patients (178% versus 144% of the predicted value), while the mean carbon monoxide diffusing capacity of the lungs (DLCO) was lower in COPD patients than in AIRAO patients (62% versus 89% of the predicted value). Exercise tolerance was similar in both groups, as were postexercise changes in arterial oxygen pressure (PaO2). Emphysematous changes were observed in COPD patients and AIRAO patients who had evaluable HRCTs (10 versus two patients, although very mild in asthma), bronchial dilations (zero versus six patients), bronchial wall thickening (two versus eight patients) and an acinar pattern (one versus five patients). Mean thickness of the large airway wall to outer diameter (intermediary bronchus) ratio was 0.176 in COPD and 0.183 in AIRAO (P>0.05). CONCLUSIONS: Asthma may lead to physiological features similar to COPD but may be distinguished by demonstrating a preserved DLCO and a higher ratio of airway to parenchymal abnormalities on HRCT scan.

Characteristics of bronchial asthma with incomplete reversibility of airflow obstruction.

BACKGROUND: Incomplete reversibility of airflow obstruction (IRAO) can be observed in some asthmatic patients without significant smoking history nor evidence of other respiratory condition. The characteristics of this group remain however to be defined. METHODS: We compared 18 asthmatic patients with persistent airflow obstruction, defined as an FEV1 < or = 75% predicted despite optimal corticosteroid treatment, to others with complete reversibility of airflow obstruction, paired for age and gender (CRAO, FEV1 > 80% of predicted). RESULTS: Mean duration of asthma was 31.6 years for IRAO patients and 17.7 for the CRAO group and mean baseline FEV1 was 48.6 +/- 2.6% and 89.3 +/- 3.4%, respectively. Patients with IRAO had more severe airflow obstruction and hyperinflation than those with CRAO, while lung compliance and CO diffusion were similar. Overall healthcare use was similar in the two groups, but those with IRAO had a greater global asthma-related discomfort, increased diurnal variation of airflow obstruction and used higher doses of inhaled corticosteroids than those with CRAO. Patients with IRAO had slightly increased airway wall thickness on high resolution chest tomography compared with CRAO. Baseline FEV1 however, was not correlated with the measured airway wall thickness. CONCLUSION: We found that asthmatic patients with IRAO have a more severe asthma and asthma of longer duration than asthmatic subjects with CRAO. Our data suggest that in asthma, IRAO may result from long-standing airway inflammation and associated structural changes, although this remains to be further documented.

Health risk assessment for inuit newborns exposed to dioxin-like compounds through breast feeding.

Inuit people living in the Arctic receive an unusually high dose of dioxin-like compounds through their traditional diet, which comprises large amounts of fatty tissues from various sea mammal species. During breast feeding, the mother transfers part of their body burden to its newborn. We estimated the impact of breast feeding on the body burden of Inuit from birth to age 75 years. Simulations performed with a toxicokinetic model revealed that breast feeding strongly influences body burden during childhood but not after age 20 years. Liver and adipose tissue concentrations expected in Inuit are well below those which induced severe adverse health effects in laboratory animals, e.g. cancer and reproduction. However, these concentrations approach levels generating subtle effects on reproductive systems.

Whole-cell and perforated patch recordings of four distinct K+ currents in acutely dispersed coeliac-superior mesenteric ganglia neurons of adult rats.

Properties and modulation of outward membrane currents in sympathetic neurons acutely dispersed from coeliac-superior mesenteric ganglia (C-SMG) of adult rats were examined using both the whole-cell variant of the patch-clamp technique and the perforated patch approach. Under voltage-clamp, four distinct outward currents were observed: a transient outward current (IA), a voltage-dependent sustained outward current consisting of a Ca(2+)-dependent component (IKCa) and a Ca(2+)-insensitive component (IKV), and a muscarinic agonist-sensitive outward current (IM). IA was isolated by digital subtraction, and characterized by very rapid activation at potentials more positive than -60 mV and by fast and complete voltage-dependent inactivation. Half inactivation potential (Vh) and slope factor (K) were -76 mV and 8.3 mV, respectively. IA was not affected by removal of external Ca2+, 1 mM tetraethylammonium ions, muscarinic agonists, or 8-bromo-cyclic AMP, but was suppressed by 4-aminopyridine (1 mM). Depolarizing pulses from of a holding potential of -50 or -60 mV to potentials more positive than -25 mV concomitantly activated two, independent sustained outward currents which decayed slowly; one exhibited voltage-dependent activation similar to the delayed rectifier current (IKV) and the other being triggered by Ca2+ influx into the cell (IKCa). The addition of tetraethylammonium ions (1 mM) strongly reduced the amplitude of the sustained outward currents. IM was characterized as a noninactivating time- and voltage-dependent outward current which activated at membrane potentials more positive than -60 mV and slowly turned off when the membrane was hyperpolarized back to -60 mV, and was suppressed by muscarinic agonists. The rank order of potency of the agonists tested was: oxotremorine > muscarine > bethanechol.

Increased maximal airway response to methacholine during seasonal allergic rhinitis in nonasthmatic subjects: relationships with airway wall thickness and inflammation.

This study was carried out to determine whether the increase in airway responsiveness induced by natural antigenic exposure in nonasthmatic subjects is associated with an increase in maximal bronchoconstrictor response (MBR), and if these changes could be due to an increase in airway wall thickness from allergen-induced increase in airway inflammation. In 11 nonasthmatic subjects with seasonal allergic rhinitis, a methacholine challenge was obtained monthly, during and out of pollen exposure. Each subject had a high-resolution chest tomography in and out of the pollen season, to determine the relative thickness of the right intermediary bronchus over its total diameter (T/D), as well as inflammatory cell counts, apparent basement membrane thickness as an indication of subepithelial fibrosis and epithelial desquamation in bronchial biopsy specimens. In season, the mean provocative concentration of methacholine producing a 20% decrease in forced expiratory volume in one second (PC20) decreased from 51.5 to 25.8 mg.mL-1, and the maximal post-methacholine fall in forced expiratory volume in one second (delta FEV1,max) or forced vital capacity (delta FVC) and the slope of the dose response curve (DRS) increased compared with out of season: delta FEV1,max 44 +/- 5 vs 25 +/- 5%; delta FVC 34 +/- 5 vs 16 +/- 4%; and slope of DRS 14.1 +/- 2.8 vs 6.9 +/- 1.3%/mg.mL-1. No significant change was observed in T/D ratio. The seasonal change in delta FVC was positively correlated with the delta FEV1,max (rs = 0.891) and the change in DRS (rs = 0.909), but not with the change in PC20, nor with changes in bronchial biopsy inflammatory features or T/D ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Interobserver variation in the computed tomographic evaluation of mediastinal lymph node size in patients with potentially resectable lung cancer. Canadian Lung Oncology Group.

OBJECTIVE: To measure the reliability of the assessment of mediastinal lymph node size in computed tomographic (CT) scans of the thorax. DESIGN: Observer agreement study in which radiologists, blinded to one anothers' interpretation, were randomized to read 30 scans each. POPULATION: Sixty scans from patients with apparently operable non-small cell carcinoma of the lung were read by radiologists responsible for clinical interpretation (clinical radiologists) and four radiologists with a special interest in thoracic CT (study radiologists). MEASUREMENTS: Radiologists measured the size of left and right superior mediastinal nodes, aortic nodes, and the subcarinal nodes and, on the basis of whether any nodes accessible to mediastinoscopy were greater than 1 cm, recommended whether mediastinoscopy be undertaken. Agreement was quantified using kappa, a measure of chance-corrected agreement. RESULTS: Among all radiologists, agreement on whether there were any nodes larger than 1 cm for right superior mediastinal nodes was 0.68; for left superior mediastinal nodes it was 0.28; for aortic pulmonary nodes it was 0.62; for subcarinal nodes it was 0.58; and for any node greater than 1 cm and accessible to mediastinoscopy it was 0.61. The agreement was very similar when the analysis was restricted to the study radiologists. CONCLUSION: Although the good level of overall agreement suggests that CT provides useful information in the evaluation of mediastinal lymph node size, the disagreement was sufficient that it likely contributes to suboptimal sensitivity and specificity of CT in detecting tumor spread reported in previous studies.

Surgical correction of nasal obstruction in the treatment of mild sleep apnoea: importance of cephalometry in predicting outcome.

BACKGROUND: A study was undertaken to determine if cephalometric radiographs could identify those who will benefit from nasal surgery in patients with a sleep apnoea hypopnoea syndrome (SAHS) and chronic nasal obstruction. METHODS: Fourteen patients with SAHS were enrolled. Those with normal posterior airway space and mandibular plane to hyoid bone distances on preoperative cephalometric radiographs were matched with those with abnormal cephalometry for the frequency of sleep disordered breathing and body mass index. Polysomnographic studies (all subjects) and nasal resistance measurements (n = 10) were performed one to three months before and two to three months after surgery (septoplasty, turbinectomy, and polypectomy). RESULTS: There was no difference in the baseline results of the polysomnographic studies between the two groups of patients. Nasal resistance decreased from a mean (SE) value of 2.9 (0.3) cm H2O/l/s before surgery to 1.4 (0.1) cm H2O/l/s after surgery in the normal cephalometry group and from 2.7 (0.3) cm H2O/l/s to 1.3 (0.3) cm H2O/l/s in the other group. The apnoea + hypopnoea index returned to normal (< 10 breathing abnormalities/hour) in all but one subject with normal cephalometric measurements, and sleep fragmentation improved with a decrease in the arousal index from 23.9 (3.3)/hour at baseline to 10.6 (2.5)/hour after surgery. Both of these parameters remained unchanged after surgery in the patients with abnormal cephalometry. CONCLUSIONS: Normal cephalometry is helpful in identifying patients with mild SAHS and nasal obstruction who will benefit from nasal surgery. The presence of craniomandibular abnormalities makes it unlikely that nasal surgery will improve sleep related breathing abnormalities.

Effects of surgical correction of nasal obstruction in the treatment of obstructive sleep apnea.

Negative upper airway pressure is thought to play a key role in the pathophysiology of obstructive sleep apnea. Because nasal resistance contributes to the increase of the transpharyngeal pressure gradient, we evaluated the effects of nasal surgery on sleep-related breathing abnormalities in 20 adults with obstructive sleep apnea. Polysomnographic studies were done before (baseline), and 2 to 3 mo after surgery (septoplasty, turbinectomy, and/or polypectomy). Nasal resistances were measured at these visits in 14 patients. Cephalometric measurements were obtained before surgery. Cephalometric abnormalities consisted in an increase in the distance from the mandibular plane to the hyoid bone (MP-H), a decrease in the space between the base of the tongue and the posterior soft tissues (PAS), a retroposition of the mandibule, and an increase in the length of the soft palate. Body weight did not change between the two studies. Nasal resistance decreased significantly after nasal surgery. The composition of the total sleep time spent in the rapid eye movement stage increased from 11.5 +/- 1.3% (mean +/- SEM) to 14 +/- 1.2% after surgery. For the group as the whole, there was no difference between baseline and postsurgical values in the frequency of respiratory disturbances (39.8 +/- 6.1, 36.8 +/- 5.9 n/h), the total apnea time (17.8 +/- 4.2, 15.4 +/- 2.8), the distribution of the apnea time within the different apnea types (obstructive and nonobstructive), and the severity of the nocturnal desaturations. Interestingly, apnea and apnea plus hypopnea indices returned to normal values (< 5 and 10, respectively) in four subjects with normal posterior soft tissues and mandibular plane to the hyoid bone distances.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibrovascular polyp of the esophagus with computed tomographic and pathological correlation.

The authors report a patient with a fibrovascular polyp of the esophagus. Radiologic and pathological features of this rare tumor include computed tomographic findings of a lesion of low density, situated intraluminally so that the findings may be relatively specific.