Complex sentence: He then had a severe allergic reaction to the anesthetic causing him to lapse into a coma for 8 days, leaving hospital only on October 22, and could not work in his ministry for 4 months.
Split into simpler sentences: He then had a severe allergic reaction to the anesthetic, causing him to lapse into a coma for 8 days. He began to recover, leaving the hospital on October 22, but he could not work in his ministry for another 4 months.