Réponse ventilatoire à l'hypercapnie et à l'hypoxie hypocapnique du chien sous différents niveaux d'anesthésie à l'Alfatésine

The authors have studied the response to hypercapnia and hypocapnic hypoxia in nine dogs anesthetised with Althesin, in correlation with three levels of anaesthesia defined by three different anaesthetic flow rates (A = 6.57 ± 2.00 μl . kg^?1 . min^?1; B = 13.88 ± 2.87 μl . kg^?1 . min^?1; C = 19.53 ± 5.34 μl . kg^?1 . min^?1). The animals were intubated. Ventilation was measured by means of a pneumotachograph. Arterial blood gases (pHa, PaCO₂, PaO₂) were measured before and at the end of each hypercapnia and hypocapnic hypoxia test. The results were compared with data in the literature concerning the dog awake. Increasing depth of anaesthesia leads to worsening hypoventilation and hypercapnia. As with other anaesthetic agents, the response to hypercapnia is more depressed the deeper the anaesthesia. On the other hand, unlike what has been described with other anaesthetic agents, hypoxia stimulates ventilation; the response to hypoxia is not abolished by the deeper states of anaesthesia. The possible mechanisms of this difference are discussed.     

Comparaison des effets de L’acidose respiratoire aigue et de L’acidose metabolique aigue sur le reflexe D’ouverture de la gueule du chien anesthesie

A few effects of carbon dioxide on pain threshold and acid-base balance are known. The purpose of this study was to investigate specifically the variations of analgesia in relation to hypercapnia during general anaesthesia and the respective roles played by carbon dioxide and [H⁺]. The nociceptive jaw opening reflex was studied on five beagle dogs anaesthetized with alfathesin administered at constant rate under acute hypercapnic conditions and acute metabolic acidosis. Acute hypercapnia did not decrease the jaw opening reflex significantly until a level was reached where Pa_co2 values modified blood [H⁺] (pH) significantly (10 ± 1.04 kPa corresponding to [H⁺] 91.5 ± 13.24 nmol/1 (pH 7.04 ± 0.06) p < 0.05). At [H⁺] 176.2 ±42.77 nmol/1 (pH 6.7 ± 0.13) (p < 0.01) the reflex was only 9.3 ± 3.9 per cent (p < 0.001) of its initial value. The infusion of decinormal solution of HC1 during constant capnia caused an abrupt drop of the reflex. There was a correlation between reflex and metabolic acidosis (p < 0.05). The authors conclude that modification of the jaw opening reflex occurs with extreme values of arterial [H⁺] incompatible with safe anaesthesia and they discuss the mechanisms involved.     

Isolated polio-like syndrome after tick-borne encephalitis presenting with acute hyperckemia

Tick borne encephalitis virus infection usually shows a biphasic course. In the first stage of illness symptoms are similar to a flu-like syndrome, then after a defervescence period, fever may represent with neurological manifestations ranging from mild meningitis to severe encephalomyelitis. We report the clinical case of an adult man presented with an acute proximal hyposthenia, severe hyperckemia, clinical and laboratoristic evidence of acute tick borne virus infection. This virus has a favourite tropism for the anterior horn cells of the cervical spine segment. Polio-like syndrome, usually affecting the upper limbs, is the clinical phenotype of an infection of the cervical motoneurons. Usually myelitis is associated to severe encephalitis and a complete diagnosis may be difficult in comatose patients. Rarely, an isolated polio-like syndrome may be the sole neurological complication of tick-borne encephalitis.     

Physical activity and sedentary behavior in relation to lung cancer incidence and mortality in older women: The Women's Health Initiative

Physical activity has been associated with lower lung cancer incidence and mortality in several populations. We investigated these relationships in the Women's Health Initiative Observational Study (WHI‐OS) and Clinical Trial (WHI‐CT) prospective cohort of postmenopausal women. The WHI study enrolled 161,808 women aged 50–79 years between 1993 and 1998 at 40 U.S. clinical centers; 129,401 were eligible for these analyses. Cox proportional hazards models were used to assess the association of baseline physical activity levels [metabolic equivalent (MET)‐min/week: none <100 (reference), low 100 to <500, medium 500 to <1,200, high 1,200+] and sedentary behavior with total lung cancer incidence and mortality. Over 11.8 mean follow‐up years, 2,148 incident lung cancer cases and 1,365 lung cancer deaths were identified. Compared with no activity, higher physical activity levels at study entry were associated with lower lung cancer incidence [p = 0.009; hazard ratios (95% confidence intervals) for each physical activity category: low, HR: 0.86 (0.76–0.96); medium, HR: 0.82 (0.73–0.93); and high, HR: 0.90 (0.79–1.03)], and mortality [p < 0.0001; low, HR: 0.80 (0.69–0.92); medium, HR: 0.68 (0.59–0.80); and high, HR: 0.78 (0.66–0.93)]. Body mass index (BMI) modified the association with lung cancer incidence (p = 0.01), with a stronger association in women with BMI < 30 kg/m². Significant associations with sedentary behavior were not observed. In analyses by lung cancer subtype, higher total physical activity levels were associated with lower lung cancer mortality for both overall NSCLC and adenocarcinoma. In conclusion, physical activity may be protective for lung cancer incidence and mortality in postmenopausal women, particularly in non‐obese women.     

Assessment of water enema computed tomography: an effective imaging technique for the diagnosis of colon cancer

Aim

The aim of this study was to assess the accuracy of water enema computed tomography (WECT) for the diagnosis of colon cancer.

Methods

A total of 191 patients referred for clinically suspected colon cancer were prospectively evaluated by WECT in a multicenter trial. Examination was contrast enhanced helical CT after colon filling through a rectal tube. For all the cases, final diagnosis was obtained by colonoscopy and/or surgery. CT data were interpreted both locally and at a centralized site by a specialized and general radiologist.

Results

Seventy-one patients were diagnosed with colon cancer. Overall, WECT sensitivity and specificity were 98.6 and 95.0%, respectively. Positive and negative predictive values were 92.1 and 99.1%, respectively. In a subgroup of 33 patients with unclean bowel, the sensitivity and specificity of WECT were 95.0 and 92.3%, respectively. The correlation between local radiologists and the specialized radiologist was excellent (Kappa = 0.87) as was the correlation between the general radiologist and the specialist (Kappa = 0.92).

Conclusion

This prospective analysis demonstrates that WECT is an effective, safe, and simple imaging technique for the diagnosis of colon cancer and can be proposed when a strong clinical suspicion of colon cancer is present, especially in frail patients.