Outset Medical Inc. closed its Nasdaq IPO Thursday with gross proceeds of approximately of $277.9 million. The IPO, which launched Tuesday, included nearly 10.3 million shares of common stock at $27 per share and the full exercise of underwriters’ option to purchase more than 1.3 million additional shares. Shares of the San Jose, Calif.-based company’s stock, which is trading under the ticker OM, soared to more than $60 on the first day of trading amid enthusiasm for its portable dialysis machine.