Date: 201912
Local time of day: 0001-0600
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: B787-900
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Human factors: Confusion; Physiological - Other
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Illness / Injury
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; General Physical Injury / Incapacitation
Contributing factors: Equipment / Tooling; Human Factors
Primary problem: Human Factors

Narrative: I was Pilot in Command of a 4 person crew. During my rest break; in the crew bunk asleep when I heard the interphone in the crew bunk area wake the First Officer; who was in the adjoining bunk. I heard him get up and leave; and when he didn't return; I got up. When I reached the forward galley area; I saw one of the First Officers laying on the galley floor with a bloody face; and several crew members attending to him. By that time; the IMK's were being retrieved; and any passenger physician was being requested from the cabin. Apparently; the First officer was feeling light headed in the cockpit performing his duties; and had arisen to go to the forward lavatory. While stepping into the lavatory; he again felt faint; fell; and hit his head and face on the toilet seat; giving himself a laceration on his nose. He was removed from the lav and placed in a lying position on the galley floor and given care by the crew; and a female passenger physician; including monitoring his pulse; Blood Pressure; and respiration.His care included oxygen from two walkaround bottles; cold compresses and liquids. The physician wanted to administer a basic IV; but was unable to find a suitable vein. I returned to the cockpit to continue flight duties with the First Officer. The First Officer became stable; coherent and lucid; and at their request; with the concurrence of the POC and the passenger physician; decided to continue to our destination; which; once we had contact with ARTCC; was given priority handling. When we were handed off to Approach; we were told to expect an arrival which required an unacceptable delay; so I [requested priority handling] and requested a different arrival and runway which was granted. We flew the arrival and approach with no further incidents; and taxied to our gate where EMT's met the aircraft and attended to the First Officer.The attending passenger physician was unhappy about the quality of the IMK BP monitors. They appeared unreliable; and were giving fluctuating readings which caused her skepticism about their accuracy. This confused the situation regarding his actual condition; and delayed an assessment of the urgency of the situation regarding his blood pressure. In that situation; a device that provided accurate information to the attending physician would have meant a better understanding of the nature of the situation.




Synopsis: B787 Captain reported that a First Officer was injured during the flight; resulting in a diversion.