Perfusion Index Derived from a Pulse Oximeter Can Detect Changes in Peripheral Microcirculation during Uretero-Renal-Scopy Stone Manipulation (URS-SM)

<div><p>Background</p><p>The objective of this study was to test the effect of removal of a ureteral obstruction (renal calculus) from anesthetized patients on the perfusion index (PI), as measured by a pulse oximeter, and on the estimated glomerular filtration rate (eGFR).</p><p>Patients and Methods</p><p>This prospective study enrolled 113 patients with unilateral ureteral obstructions (kidney stones) who were scheduled for ureteroscopy (URS) laser lithotripsy. One urologist graded patient hydronephrosis before surgery. A pulse oximeter was affixed to each patient's index finger ipsilateral to the intravenous catheter, and a non-invasive blood pressure cuff was placed on the contralateral side. Ipsilateral double J stents and Foley catheters were inserted and left indwelling for 24 h. PI and mean arterial pressure (MAP) were determined at baseline, 5 min after anesthesia, and 10 min after surgery; eGFR was determined at admission, 1 day after surgery, and 14 days after surgery.</p><p>Results</p><p>Patients with different grades of hydronephrosis had similar age, eGFR, PI, mean arterial pressure (MAP), and heart rate (HR). PI increased significantly in each hydronephrosis group after ureteral stone disintegration. None of the groups had significant post-URS changes in eGFR, although eGFR increased in the grade I hydronephrosis group after 14 days. The percent change of PI correlates significantly with the percent change of MAP, but not with that of eGFR.</p><p>Conclusion</p><p>Our results demonstrate that release of a ureteral obstruction leads to a concurrent increase of PI during anesthesia. Measurement of PI may be a valuable tool to monitor the successful release of ureteral obstructions and changes of microcirculation during surgery. There were also increases in eGFR after 14 days, but not immediately after surgery.</p></div

Interquartile range (IQR) of mean arterial pressure (MAP) in patients with Grade I, II, and III hydronephrosis.

<p>The MAP decreased after induction of anesthesia, but there were no further changes during stone evacuation.</p

The changes in PI, MAP, and eGFR in the 3 hydronephrosis groups. (compared with repeat measurement ANOVA and then Turkey HSD test each other).

<p>Legend 2. PI in three hydronephrosis groups increase significantly after anesthesia and increases further after releasing urinary obstruction.</p><p>Footnote 2. ¹Baseline vs Pre-URS vs Post-URS PI in each hydronephrosis group: all significantly different when compared each other by Turkey HSD test (p<0.01);</p>2<p>Baseline vs Pre-URS, Baseline vs Post-URS MAP in each hydronephrosis group: significantly different when tested by Turkey HSD test (p<0.01), Pre-URS vs Post-URS MAP: not significantly different; ³Pre-URS vs 14 days, Post-URS vs 14 days eGFR in grade I hydronephrosis: significantly different (p<0.05).</p><p>The changes in PI, MAP, and eGFR in the 3 hydronephrosis groups. (compared with repeat measurement ANOVA and then Turkey HSD test each other).</p

Interquartile range (IQR) of Perfusion Index (PI) in patients with Grade I, II, and III hydronephrosis.

<p>The PI increased after induction of anesthesia, and increased further after stone disintegration.</p

Relationships between baseline clinical parameters and the percent changes in MAP, PI, eGFR after stone disintegration.

<p>Legend 3. Percent changes in MAP, PI, and eGFR have no correlation with baseline MAP, PI, and eGFR. There was also no significant difference in percent change in PI, MAP, and eGFR between each grade of hydronephrosis. Percent change of MAP has negative correlation with percent change of PI.</p><p>Footnote 3. ^#Percent change of MAP: (post-URS MAP-pre-URS MAP)/pre-URS MAP; ⁺Percent change of PI: (post-URS PI-pre-URS PI)/pre-URS PI; ^↑Percent change of eGFR: (14 days eGFR-pre-URS eGFR)/pre-URS eGFR.</p><p>Relationships between baseline clinical parameters and the percent changes in MAP, PI, eGFR after stone disintegration.</p

Demographic data and the degree of hydronephrosis.

<p>Legend 1.No significant difference among these groups. Only eGFR 14 days after URS showed significantly different.</p><p>Footnote 1.abbreviation: eGFR, estimated glomerular filtration rate; ASA, American Society of Anesthesiologists; MAP, Mean arterial pressure; HR, heart rate; URS, ureteroscopy.</p><p>Demographic data and the degree of hydronephrosis.</p

Primary prevention of myocardial infarction with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in hypertensive patients with rheumatoid arthritis—A nationwide cohort study

<div><p>Background</p><p>Rheumatoid arthritis (RA) is regarded as a high risk factor for myocardial infarction. Hypertension is a major modifiable risk factor contributing to increased risk of myocardial infarction (MI). Dual blood pressure (BP)-lowering and anti-inflammatory effect of renin-angiotensin-system (RAS) inhibitors may possess protective effect from MI in RA population. However, treatment of hypertension with RAS inhibitors and MI in RA population remains unclear.</p><p>Methods</p><p>We investigated whether RAS blockade could decrease risk of incident MI in hypertensive patients with RA. We identified patients with RA and hypertension from the Registry for Catastrophic Illness, a nation-wide database encompassing almost all of the RA patients in Taiwan from 1995 to 2008. The primary endpoint was MI and the median duration of follow up was 2,986 days. Propensity score weighting and Cox proportional hazards regression models were used to estimate hazard ratios for MI.</p><p>Results</p><p>Among 27,335 subjects, 9.9% received angiotensin-converting enzyme inhibitors (ACEIs), 25.9% received angiotensin II receptor blockers (ARBs) and 20.0% received ACEIs or ARBs alternatively. The incidence of MI significantly decreased in patients treated with ACEIs (hazard ratio 0.707; 95% confidence interval 0.595–0.840), ARBs (0.641; 0.550–0.747) and ACEIs/ARBs (0.631; 0.539–0.739). The protective effect of ACEI or ARB therapy was significantly better in patients taking longer duration. The effect remained robust in subgroup analyses.</p><p>Conclusions</p><p>Therapy of ACEIs or ARBs is associated with a lower risk of MI among patients with RA. Hence, hypertension in patients with RA could comprise a compelling indication for RAS inhibitors.</p></div

Kaplan–Meier curves showing the incidence of myocardial infarction among patients with ACEI (blue), ARB (green) or ACEI/ARB (red) treatment and controls (black).

<p>The log-rank analysis showed significant different (P < 0.001).</p

Demographic and clinical characteristics of study subjects.

<p>Demographic and clinical characteristics of study subjects.</p

Incidence of acute myocardial infarction by prescriptions.

<p>Incidence of acute myocardial infarction by prescriptions.</p