U.S. consumer credit surged in April as Americans ramped up their use of credit cards, a potentially positive sign for consumer spending. Total consumer credit increased by $26.85 billion to $3.18 trillion, the Federal Reserve said on Friday. That meant consumer debt was growing at a 10.2 percent annual rate, the fastest pace of growth since July 2011. Analysts polled by Reuters expected a more modest increase during the month of $15.5 billion. Revolving credit, which mostly measures credit-card use, jumped by $8.8 billion.