If you meant "sphygmia", it is an archaic term for pulse, often used in medical contexts in the past.
However, it's more likely you meant "sphyxia".
"Sphyxia" is not a real word, and it's possible it's a misspelling of one of these terms:
* "Dyspnea": This means difficulty breathing.
* "Apnea": This means the temporary cessation of breathing.
* "Hypoxemia": This means a low level of oxygen in the blood.
* "Asphyxia": This means a condition of suffocation or lack of oxygen.
Please clarify your question or check the spelling if you meant something else.