Significance of post-exercise increment of urinary bicarbonate and pH in subjects loaded with submaximal cycling exercise

Effect of Carbohydrate-Electrolyte Solution Including Bicarbonate Ion Ad Libitum Ingestion on Urine Bicarbonate Retention during Mountain Trekking: A Randomized, Controlled Pilot Study

We investigated whether bicarbonate ion (HCO₃⁻) in a carbohydrate-electrolyte solution (CE+HCO₃) ingested during climbing to 3000 m on Mount Fuji could increase urine HCO₃⁻ retention. This study was a randomized, controlled pilot study. Sixteen healthy lowlander adults were divided into two groups (six males and two females for each): a tap water (TW) group (0 kcal with no energy) and a CE+HCO3 group. The allocation to TW or CE+HCO3 was double blind. The CE solution contains 10 kcal energy, including Na⁺ (115 mg), K⁺ (78 mg), HCO₃⁻ (51 mg) per 100 mL. After collecting baseline urine and measuring body weight, participants started climbing while energy expenditure (EE) and heart rate (HR) were recorded every min with a portable calorimeter. After reaching a hut at approximately 3000 m, we collected urine and measured body weight again. The HCO₃⁻ balance during climbing, measured by subtracting the amount of urine excreted from the amount of fluid ingested, was −0.37 ± 0.77 mmol in the CE+HCO3, which was significantly higher than in the TW (−2.23 ± 0.96 mmol, p < 0.001). These results indicate that CE containing HCO₃⁻ supplementation may increase the bicarbonate buffering system during mountain trekking up to ~3000 m, suggesting a useful solution, at least, in the population of the present study on Mount Fuji.

Exercise Is Medicine, But Does It Interfere With Medicine?

Exercise frequently is prescribed therapeutically, either on its own or combined with drugs. A drug's absorption, distribution, metabolism, and excretion can be affected by the user's anatomy and physiology, which are both changed by the myriad of complex adaptations to acute and chronic exercise. This article reviews the research that suggests exercise may influence a drug's plasma concentration, and thus its efficacy and safety.

Short-Term Changes in Algometry, Inclinometry, Stabilometry, and Urinary pH Analysis After a Thoracolumbar Junction Manipulation in Patients with Kidney Stones

OBJECTIVES

To determine the efficacy of a high-velocity low-amplitude manipulation of the thoracolumbar junction in different urologic and musculoskeletal parameters in subjects suffering from renal lithiasis.

DESIGN

Randomized, controlled blinded clinical study.

SETTINGS/LOCATION

The Nephrology departments of two hospitals and one private consultancy of physiotherapy in Valencia (Spain).

SUBJECTS

Forty-six patients suffering from renal lithiasis.

INTERVENTIONS

The experimental group (EG, n = 23) received a spinal manipulation of the thoracolumbar junction, and the control group (CG, n = 23) received a sham procedure.

OUTCOME MEASURES

Pressure pain thresholds (PPTs) of both quadratus lumborum and spinous processes from T10 to L1, lumbar flexion range of motion, stabilometry, and urinary pH were measured before and immediately after the intervention. A comparison between pre- and postintervention phases was performed and an analysis of variance for repeated measures using time (pre- and postintervention) as intrasubject variable and group (CG or EG) as intersubject variable.

RESULTS

Intragroup comparison showed a significant improvement for the EG in the lumbar flexion range of motion (p < 0.001) and in all the PPT (p < 0.001 in all cases). Between-group comparison showed significant changes in PPT in quadratus lumborum (p < 0.001), as well as in the spinous processes of all of the evaluated levels (p < 0.05). No changes in urinary pH were observed (p = 0.419).

CONCLUSION

Spinal manipulation of the thoracolumbar junction seems to be effective in short term to improve pain sensitivity, as well as to increase the lumbar spine flexion.

Urinary bladder partial carbon dioxide tension during hemorrhagic shock and reperfusion: an observational study

Introduction

Continuous monitoring of bladder partial carbon dioxide tension (PCO₂) using fibreoptic sensor technology may represent a useful means by which tissue perfusion may be monitored. In addition, its changes might parallel tonometric gut PCO₂. Our hypothesis was that bladder PCO₂, measured using saline tonometry, will be similar to ileal PCO₂ during ischaemia and reperfusion.

Method

Six anaesthetized and mechanically ventilated sheep were bled to a mean arterial blood pressure of 40 mmHg for 30 min (ischaemia). Then, blood was reinfused and measurements were repeated at 30 and 60 min (reperfusion). We measured systemic and gut oxygen delivery and consumption, lactate and various PCO₂ gradients (urinary bladder–arterial, ileal–arterial, mixed venous–arterial and mesenteric venous–arterial). Both bladder and ileal PCO₂ were measured using saline tonometry.

Results

After bleeding systemic and intestinal oxygen supply dependency and lactic acidosis ensued, along with elevations in PCO₂ gradients when compared with baseline values (all values in mmHg; bladder ΔPCO₂ 3 ± 3 versus 12 ± 5, ileal ΔPCO₂ 9 ± 5 versus 29 ± 16, mixed venous–arterial PCO₂ 5 ± 1 versus 13 ± 4, and mesenteric venous–arterial PCO₂ 4 ± 2 versus 14 ± 4; P < 0.05 versus basal for all). After blood reinfusion, PCO₂ gradients returned to basal values except for bladder ΔPCO₂, which remained at ischaemic levels (13 ± 7 mmHg).

Conclusion

Tissue and venous hypercapnia are ubiquitous events during low flow states. Tonometric bladder PCO₂ might be a useful indicator of tissue hypoperfusion. In addition, the observed persistence of bladder hypercapnia after blood reinfusion may identify a territory that is more susceptible to reperfusion injury. The greatest increase in PCO₂ gradients occurred in gut mucosa. Moreover, the fact that ileal ΔPCO₂ was greater than the mesenteric venous–arterial PCO₂ suggests that tonometrically measured PCO₂ reflects mucosal rather than transmural PCO₂. Ileal ΔPCO₂ appears to be the more sensitive marker of ischaemia.