. Author manuscript; available in PMC: 2015 Jun 23.

Published in final edited form as: J Occup Environ Med. 2014 Mar;56(3):313–318. doi: 10.1097/JOM.0000000000000095

TABLE 5.

Differences in Pre- and Postshift Blood and Urine Values of Participants by Sustained and Average Heart Rate

	Sustained^* Heart Rate > (180 − age)					Average Heart Rate > 115

	Yes (n = 24)		No (n = 32)			Yes (n = 11)		No (n = 45)

	Preshift Mean	Postshift Mean	Preshift Mean	Postshift Mean	P^†	Preshift Mean	Postshift Mean	Preshift Mean	Postshift Mean	P^‡
Blood
Sodium, corrected^§	138.0	137.3	137.9	139.1	<0.01^‖	138.4	138.4	137.8	138.3	0.66
Potassium	4.5	4.2	4.4	4.2	0.51	4.6	4.4	4.4	4.2	0.94
Chloride	109.0	107.9	108.3	108.5	0.07	109.0	109.0	108.5	108.1	0.92
CO₂	22.7	22.7	23.3	24.0	0.17	23.1	22.6	23.0	23.6	0.07
BUN	15.1	16.9	14.2	16.0	0.95	17.0	18.7	14.0	15.8	0.66
Creatinine	1.0	1.3	1.1	1.3	0.24	1.0	1.4	1.1	1.3	0.07
BUN/creatinine ratio	15.6	13.5	13.0	12.3	0.03^‖	16.6	14.0	13.5	12.6	0.04^‖
Glucose	114.0	112.2	105.5	102.7	0.90	106.0	103.7	109.9	107.5	0.99
Osmolality	287.7	286.9	286.7	289.6	<0.01^‖	288.7	289.4	286.8	288.2	0.66
Urine
Specific gravity	1.022	1.026	1.024^¶	1.029	0.93	1.026	1.031	1.022^¶	1.027	0.82

Values sustained for greater than or equal to 5 continuous minutes.

^†

Paired t test when comparing the difference in pre- and postshift blood and urine values between participants with and without a sustained heart rate greater than (180 − age).

^‡

Paired t test when comparing the difference in pre- and postshift blood and urine values between participants with and without an average heart rate greater than 115.

^§

Sodium is corrected for participants with glucose concentrations greater than 200 mg/dL, using the formula: corrected sodium = measured sodium + 0.016 (glucose − 100).

^‖

P ≤ 0.05 was considered statistically significant.

^¶

Data were missing for one participant in the preshift group.

BUN, blood urea nitrogen.