Baseline measurements of heart rate ( HR ) , cardiac index ( CI ) , respiratory rate , systemic vascular resistance ( SVR ) , percentage of patients with second degree atrioventricular ( 2 ( o ) AV ) block , mean arterial pressure ( MAP ) , pH , and arterial partial pressures of carbon dioxide ( PaCO2 ) and oxygen ( PaO2 ) were obtained 5 minutes before administration of IV hyoscine ( 0.14 mg kg ( -1 ) ; group HIV ) , IM hyoscine ( 0.3 mg kg ( -1 ) ; group HIM ) , or an equal volume of physiologic saline IV ( group C ) .