At least 18 and perhaps as many as 66 California prison inmate deaths in 2006 were preventable, according to a report released Wednesday by the receiver put in charge of the state's prison health care system by a federal judge.

The data is a "sobering reminder" of the deep disarray in which the prison health care system exists now after decades of disarray, said receiver Robert Sillen on Wednesday.

"When six inmates die of asthma in one year, we all know something is terribly wrong," Sillen said in a letter accompanying the report. "No one should die of asthma in California in 2006, and yet, in its prisons, that is the No. 1 cause of preventable death."

And none of this is new, he said.

"These tragic deaths depict the very problem that the court ordered the state to solve years ago, and that the receiver must now take on," Sillen wrote.

An analysis of California Department of Corrections and Rehabilitation's death review reports dated Aug. 20 found that of 381 inmate deaths -- not counting 43 suicides, one execution and one death review that was unavailable -- 18 were deemed preventable. Among them were:

-A two-year delay in diagnosis of testicular cancer in a 30-year- old patient with chronic pain; medical information was lost as this inmate was transferred between prisons, and by the time the cancer was diagnosed, it had spread beyond the point at which it could've been treated.

-A five-week delay in referral to a specialist for a patient with recurrent, severe abdominal pain, vomiting and known hernias; he died of an incarcerated hernia, in which the intestines became trapped outside the abdomen's muscular wall.

-Failure to diagnose a patient who complained nine times in three days of severe abdominal pain; he died of acute pancreatitis.

Another 48 deaths were deemed "possibly preventable," including deaths from heart attacks, AIDS, bowel perforations, drug overdoses, cancer and other causes. The most common lapses in these cases, the analysis found, were errors by individual caregivers -- failures to adequately evaluate "red flag" symptoms, to follow up on abnormal test results, to keep tabs on already-known medical problems and so forth. Next most common were delayed referrals for specialty care or special tests, followed by delayed responses to inmates' requests for care and poor communications including medical information being lost during inmates' transfers between prisons.

And even among the 315 deaths deemed non-preventable, more than half had lapses in care that may have contributed to earlier death or suffering.

Sillen wrote that his team of health care and corrections experts has developed a plan to address the shortcomings.

"It is clear that every aspect of the system contributes to its current problems and each area must be addressed," he wrote.

Senior U.S. District Judge Thelton Henderson of San Francisco tapped Sillen, formerly the Santa Clara Valley Health & Hospital System's executive director, in February 2006 to seize prison health care's reins after finding the state failed to fix it even since a class-action lawsuit's settlement in 2002.

Sillen answers only to the judge, has a free hand and a blank check -- on California taxpayers' dime -- to enact reform.

He has estimated it will take him five to 10 years to bring the system up to constitutional snuff, and perhaps that long again to transition its control back to the state.

The data in this new report reflects deaths that occurred during Sillen's first year on the job as he began overhauling the prison pharmacy system, raising medical staff salaries to market levels, reworking contracting and personnel practices, building an adequate emergency room at San Quentin State Prison, launching a project to build 5,000 new medical beds and 5,000 mental health beds in prisons across the state and more.