Corridors of Blood

Corridors of Blood is a 1958 British-American horror film directed by Robert Day. It starred Boris Karloff and Christopher Lee. The original music score was composed by Buxton Orr. The film was marketed with the tagline "Tops in Terror!" in the US where MGM only released it in 1962 as a double feature with an Italian import called "Werewolf in a Girls' Dormitory".
Plot.
An 1840s British surgeon, Dr. Thomas Bolton (Boris Karloff) experiments with anesthetic gases in an effort to make surgery pain-free. While doing so, his demonstration before a panel of his peers ends in a horrific mishap with his patient awakening under the knife; he is forced to leave his position in disgrace. To complicate matters, he becomes addicted to the gases and gets involved with a gang of criminals, led by Black Ben (Francis de Wolff) and his henchman Resurrection Joe (Christopher Lee). Unfortunately, this shady partnership leads Bolton to further ruin, culminating in his unwitting participation in murder — for which he becomes the first victim of a blackmail scheme.
Production.
After the success of "The Haunted Strangler", producer Richard Gordon looked at making a follow up with Boris Karloff. At one stage a colour remake of "Dracula" was discussed, as was an adaptation of "The Facts in the Case of M. Valdemar". Eventually producer John Scott discovered a screenplay by Jean Scott Rogers based on the early days of anesthesia, originally called "Doctor from Seven Dials".
Executive producer Richard Gordon and interviewer Tom Weaver talk about the making of "Corridors of Blood" on the audio commentary of the Criterion DVD, available as part of the 2007 set "Monsters and Madmen".
Release and reception.
The movie was made in 1958 but, because of upheavals at MGM at the time, was not released until 1962 on a double feature with an Italian import called "Werewolf in a Girls' Dormitory". 
According to MGM records, the film made a profit of $14,000. It was considered a commercial disappointment and was the last film from Amalgamated Productions.
Leonard Maltin awarded the film two and a half out of a possible four stars.