WALTHAM, Mass.--(BUSINESS WIRE)--As the 2007 peak hurricane season approaches, Fresenius Medical Care North America, operators of the nation’s largest network of dialysis clinics, is urging kidney failure patients to plan ahead for disasters. Kidney failure patients represent one of the most vulnerable segments of the population during a hurricane or other natural disaster. These patients typically need dialysis every two days; any substantial delay in dialysis care can be life-threatening.