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