Doctors said today that William J. Schroeder was "warm and pink and dry" in his second day with an artificial heart, and his wife and six children, in their first public statement, said they were "cautiously optimistic on the progress."

Though doctors kept Schroeder, 52, sedated most of the day, Humana Heart Institute International's chairman, Dr. Allan M. Lansing, reported that at times Schroeder had been "very alert." Lansing's initial assessment was that Schroeder's mental functions appear "excellent . . . . He moves everything; he responds appropriately, and he seems aware."

Still on a respirator and with a tube in his throat, Schroeder cannot talk. But Lansing said his patient was aware that he has survived.

"He didn't quite give the thumbs-up signal, but you could see that look in his eye," Lansing said.

The patient's eldest son, Mel, 30, spoke on behalf of the Indiana family in a videotaped interview.

"Dad wanted to go through with this, and we're all behind him 100 percent," he said.

Schroeder's wife of 32 years, Margaret, who spent time today with her husband, said it was his decision to go ahead with the experimental operation. "It was kind of left up to Bill to make up his own mind . . . . He said, 'I have no other thoughts other than go all the way.' And he just kept going."

In doing so, Schroeder, whose life was in danger because of an untreatable heart condition, became the world's second recipient of a permanent mechanical heart.

Margaret Schroeder said she had received a telegram of support and the "best of wishes" from Una Loy Clark, whose husband, Barney, pioneered the way two years ago and lived for 112 days after the implant.

Lansing said he was encouraged that Schroeder appeared to have weathered the unexpected storm Sunday night caused by excessive bleeding after the seven-hour heart-implant operation earlier in the day.

The crisis required a second operation, which Schroeder has not been told about, but Lansing said that the bleeding appears to have stopped and that Schroeder's vital signs are generally good.

"He is warm and pink and dry, indicating excellent circulation," Lansing said. That was in marked contrast to Schroeder's cold, clammy and gray appearance during the bleeding episode Sunday.

Given the trauma of two operations, the artificial-heart patient was described by Lansing as "just as well off . . . as we could hope." But he again warned of possible serious complications in the days to come, including infection and blood clots. He also noted that Schroeder was suffering from what seem to be relatively minor and manageable side effects of receiving massive blood transfusions Sunday night.

In an otherwise quiet day today, doctors inserted a tube in the left side of Schroeder's chest to drain blood that apparently accumulated Sunday night.

Lansing said the strain on Schroeder's body of processing the new blood was also creating an "understandable" increase in kidney function and a mild jaundice.

Schroeder's diabetes also seemed to be under control, according to the medical updates. His comfort was aided by an anesthetic, sufentanyl, which in small doses can make a patient rest, yet does not knock him out. In the process, the drug can erase short-term memory.

Schroeder, who is being watched constantly by at least three staff members in his special room in the coronary care unit at the Humana Hospital-Audubon, was listed in critical but stable condition today.

Lansing said Schroeder appeared to be "extremely stable," and that he does not expect to upgrade his condition for several days -- until the patient is "sitting up in bed and taking food by mouth."

The doctor decribed Schroeder's quarters as "very spacious, with a wonderful window all along the wall." When the patient fully awakens from the sedatives and is up in bed, he will be able to "see the sunshine, see the trees, see the changing colors of the leaves," Lansing said.

Schroeder's room is cluttered with monitoring equipment and with the cumbersome power system that keeps the artificial heart beating.

While most attention was still focused on Schroeder, Humana announced that other patients are being interviewed as potential candidates for artificial hearts.

"We have no plans to do another operation within the week," Lansing said, "but we are not stopping our search for other patients who may benefit from this."

Dr. William C. DeVries, the surgeon who operated on dentist Clark two years ago and was in charge of Sunday's surgery, has federal approval from the Food and Drug Administration to implant up to five more mechanical hearts.

Lansing said a patient from Tennessee was screened Sunday and a Minnesota man was seen today. But he said that neither appeared to require immediate intervention and that both probably would be sent home for further consideration.

Schroeder's surgery was undertaken because his chronic heart condition, a weakened heart muscle that restricted the flow of blood to the body, was worsening and he appeared to have a short time to live without the surgery, Lansing said.

Lansing, who has been chief medical spokesman since the operation, said with a smile that Schroeder "looks super" but "DeVries looks tired." DeVries has stayed with his patient and has not yet met with the news media.

The highly centralized media operation, accommodating the needs of more than 200 reporters, is housed several miles from the hospital in the downtown Commonwealth Convention Center.

Humana has spared little expense in of publicizing the artificial-heart operation, including providing a professional film crew and almost instant access to videotapes.

When the Schroeder family, said to be concerned about facing a throng of reporters, declined on Sunday to meet with the media at large, the Humana-hired film crew taped an interview that family members gave two reporters from their hometown of Jasper, Ind.

Another videotape prepared by Humana ended with DeVries, in his green scrubs and white mask, leaning close to his patient's face and whispering, "The operation is all over. You did really well. It went perfect . . . . Everything's just great."