Geoffrey Marshall developed an anaesthetic apparatus based on a machine designed by James Tayloe Gwathmey. It gave gas, oxygen and ether and had flowmeters. It became the standard model in Royal Army Medical Corps practice. In his investigation into shock, Marshall found that giving a mixture of gas and oxygen during surgery cut mortality rates from 90% to 25%.
Nitrous oxide cylinder
Nitrous oxide was used during the First World War (often without oxygen) for short operations. It was used with local anaesthesia for abdominal surgery and high leg amputations, and was particularly useful in surgeries on soldiers suffering from shock or exhaustion. Patients recovered from this type of anaesthetic quickly and, with no postoperative nausea, were able to eat soon after the operation. They also needed less postoperative care as it didn’t cause complications such as pneumonia or bronchitis, and patients were safe to transport relatively soon after surgery.
Copper cylinders may have been in use from 1853. However, they could be unsafe: without reducing valves to regulate the pressure inside the cylinder, it was possible for them to explode and the end of the cylinder to be blown off.
Nitrous oxide was produced in cylinders from 1870, and during the First World War both nitrous oxide and oxygen were supplied in this way. Metal was needed for munitions and was therefore in short supply so obtaining a supply of cylinder gases could be difficult.