We have described a rat model that responds to repetitive episodic hypoxia (12-s infusions of nitrogen into daytime sleeping chambers every 30 s, 7 h/day for 35 days) with an increase in diurnal systemic blood pressure. We hypothesized that afferent information from the peripheral chemoreceptors may be necessary to produce diurnal blood pressure elevation in this hypoxia model. Carotid body denervation (CBD) was accomplished by severing both carotid sinus nerves in two groups of male Wistar rats (250-375 g). Group 4 CBD rats were subjected to intermittent hypoxia for 35 days (3-5% nadir ambient O2) as described above, whereas group 5 CBD rats remained unhandled in their usual cages. Additional sham-operated controls included group 2 sham-"hypoxia" rats, which were housed in chambers identical to the hypoxia rats but supplied with compressed air instead of nitrogen, group 1 (not denervated) rats, which remained unhandled in their usual cages, and group 3 sham-operated rats, which were subjected to 35 days of intermittent hypoxia identical to group 4 CBD rats. Femoral arterial baseline and end-of-study blood pressures were measured in conscious rats. The group 3 rats exposed to episodic hypoxia displayed a 13-mmHg increase in mean blood pressure, whereas the other groups showed no significant change from baseline. Left ventricular hypertrophy was evident in all rats exposed to episodic hypoxia, but right ventricular hypertrophy was evident only in the group 4 rats. All CBD rats developed increased hematocrit and hemoglobin, while the group 3 rats (non-CBD, episodic hypoxia) did not. The baroreceptor reflex at baseline was not depressed in the CBD rats.(ABSTRACT TRUNCATED AT 250 WORDS)

The contribution of peripheral arterial chemoreceptors to cardiovascular and renal responses to acute hypocapnic hypoxia is currently not well understood. We compared the effects of normobaric hypoxia on mean arterial blood pressure (MABP), heart rate, glomerular filtration rate (GFR), renal blood flow (RBF), and renal volume and electrolyte excretion in conscious unilaterally nephrectomized carotid body-denervated (n = 10) and sham-operated (n = 10) control rats. Thirty minutes of normobaric hypoxia (12.5% O2) resulted in significant reductions in arterial PO2 and PCO2 as well as decreases in MABP, GFR, RBF, and renal sodium, potassium, and water excretion. These effects occurred more rapidly and/or were significantly more pronounced in carotid body-denervated than in sham-operated rats. These data indicate that moderate acute hypocapnic hypoxia has profound effects on systemic and renal hemodynamics as well as on renal excretory function in conscious rats. We conclude that stimulation of the peripheral arterial chemoreceptors can partially offset the hypoxia-induced decreases in MABP, RBF, GFR, urine flow, and urinary sodium and potassium excretion, thereby helping to maintain cardiovascular as well as fluid and electrolyte homeostasis.

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A patient with a history of multiple jejunal diverticulosis (JD) presented with a non-peritonitic abdominal pain and leucocytosis. CT scan showed a thick-walled interloop collection within the left mid-abdomen with dilated bowels and mild diffuse air-fluid levels. Exploratory laparotomy revealed multiple diverticular outpouchings in the mid-jejunum, one of which was perforated, contained within the mesentery. Resection of the contained abscess and primary anastomosis were performed subsequently.

Among the myriad of challenges healthcare institutions face in dealing with coronavirus disease 2019 (COVID–19), screening for the detection of febrile persons entering facilities remains problematic, particularly when paired with CDC and WHO spatial distancing guidance. Aggressive source control measures during the outbreak of COVID-19 has led to re-purposed use of noncontact infrared thermometry (NCIT) for temperature screening. This study was commissioned to establish the efficacy of this technology for temperature screening by healthcare facilities. We conducted a prospective, observational, single-center study in a level II trauma center at the onset of the COVID-19 outbreak to assess (i) method agreement between NCIT and temporal artery reference temperature, (ii) diagnostic accuracy of NCIT in detecting referent temperature $$\ge 100.0\,^{\circ }{\mathrm{F}}$$ ≥ 100.0 ∘ F and ensuing test sensitivity and specificity and (iii) technical limitations of this technology. Of 51 healthy, non-febrile, healthcare workers surveyed, the mean temporal artery temperature was $$98.4\,^{\circ }{\mathrm{F}}$$ 98.4 ∘ F ($$95\%$$ 95 % confidence interval (CI) = $$[98.2,98.6]\,^{\circ }{\mathrm{F}}$$ [ 98.2 , 98.6 ] ∘ F ). Mean NCIT temperatures measured from $${1}\,{\mathrm{ft}}$$ 1 ft , $${3}\,{\mathrm{ft}}$$ 3 ft , and $${6}\,{\mathrm{ft}}$$ 6 ft distances were $$92.2\,^{\circ }{\mathrm{F}}$$ 92.2 ∘ F $$(95\%\ {\text {CI}}=[91.8\ 92.67]\,^{\circ }{\mathrm{F}})$$ ( 95 % CI = [ 91.8 92.67 ] ∘ F ) , $$91.3\,^{\circ }{\mathrm{F}}$$ 91.3 ∘ F $$(95\%\ {\text {CI}}=[90.8\ 91.8]\,^{\circ }{\mathrm{F}})$$ ( 95 % CI = [ 90.8 91.8 ] ∘ F ) , and $$89.6\,^{\circ }{\mathrm{F}}$$ 89.6 ∘ F $$(95\%\ {\text {CI}}=[89.2 \ 90.1]\,^{\circ }{\mathrm{F}})$$ ( 95 % CI = [ 89.2 90.1 ] ∘ F ) , respectively. From statistical analysis, the only method in sufficient agreement with the reference standard was NCIT at $${1}\,{\mathrm{ft}}$$ 1 ft . This demonstrated that the device offset (mean temperature difference) between these methods was $$-6.15\,^{\circ }{\mathrm{F}}$$ - 6.15 ∘ F ($$95\%\ {\text {CI}}=[-6.56,-5.74]\,^{\circ }{\mathrm{F}}$$ 95 % CI = [ - 6.56 , - 5.74 ] ∘ F ) with 95% of measurement differences within $$-8.99\,^{\circ }{\mathrm{F}}$$ - 8.99 ∘ F ($$95\%\ {\text {CI}}=[-9.69,-8.29]\,^{\circ }{\mathrm{F}}$$ 95 % CI = [ - 9.69 , - 8.29 ] ∘ F ) and $$-3.31\,^{\circ }{\mathrm{F}}$$ - 3.31 ∘ F ($$95\%\ {\text {CI}}= [-4.00,-2.61]\,^{\circ }{\mathrm{F}}$$ 95 % CI = [ - 4.00 , - 2.61 ] ∘ F ). By setting the NCIT screening threshold to $$93.5\,^{\circ }{\mathrm{F}}$$ 93.5 ∘ F at $${1}\,{\mathrm{ft}}$$ 1 ft , we achieve diagnostic accuracy with $$70.9\%$$ 70.9 % test sensitivity and specificity for temperature detection $$\ge 100.0\,^{\circ }{\mathrm{F}}$$ ≥ 100.0 ∘ F by reference standard. In comparison, reducing this screening criterion to the lower limit of the device-specific offset, such as $$91.1\,^{\circ }{\mathrm{F}}$$ 91.1 ∘ F , produces a highly sensitive screening test at $$98.2\%$$ 98.2 % , which may be favorable in high-risk pandemic disease. For future consideration, an infrared device with a higher distance-to-spot size ratio approaching 50:1 would theoretically produce similar results at $${6}\,{\mathrm{ft}}$$ 6 ft , in accordance with CDC and WHO spatial distancing guidelines.

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