When I'm on the night shift, all the department heads can't sleep.

The phone in the clean area was quiet for less than five minutes before the internal line in the observation area rang again.

Luo Wenbin first reported Xu Wenliang's blood oxygen level, which had just been retested, and then asked the nurse to enter the vital signs of the other two observation points into the workstation.

After receiving oxygen, Gao Limin's blood oxygen level remained around 95, and Shao Dequan's blood oxygen level also temporarily stabilized. Both of them were able to answer questions completely.

Xu Wenliang still cannot do without an oxygen mask, and his recovery is getting slower and slower after coughing.

"The second-line respiratory specialist has reviewed the latest blood gas analysis," Luo Wenbin's voice came through the intercom. "Continue with the current respiratory support, and reassess every half hour. If the blood pressure drops again, or if there is any change in consciousness, the second-line respiratory specialist should be brought down immediately."

Xu Mingzhe confirmed that the respiratory department had received reports of changes in the patient's condition and reminded Li Qian that Gu Shoucheng's outpatient sampling and assessment would continue to be arranged by the local authorities, and that relevant information would be kept separately in the list of people who had been in contact with him.

Qin Hai leaned against the worktable and glanced down at his watch.

The clock on the wall had just passed midnight, and there was still more than half of this full night shift left.

He handled a series of matters from evening onwards, including referrals, emergency treatment in the red zone, and the fever clinic; his voice sounded even hoarseer than usual.

"Lin Ye, go sit on that chair inside for ten minutes."

"I'm not sleepy."

"Who asked if you were sleepy?" Qin Hai moved the water glass on the table aside to make room for him. "The phone rang and someone called you. Standing here staring at the test results won't speed things up."

Lin Ye wanted to argue, but Xu Mingzhe chimed in, "Go ahead. If the test results change, you'll be in trouble."

Behind the cleaning area, there was a small duty room with a single bed and two folding chairs.

Lin Ye sat down on the chair near the door, still holding his phone in his hand, the screen showing his chat with Ma Hao.

The chair back was hard, and he only realized his shoulders were tense when he leaned back.

The door to the duty room was not closed properly, and the sounds of internal communication lines, monitoring alarms, and footsteps could still be heard from outside.

Normally he finds it noisy, but now it feels like someone is keeping track of the time for him, preventing him from actually falling into a deep sleep.

He originally wanted to send a message to his mother, but he deleted it halfway through typing.

At this time, the parents are probably already asleep, and there is still no clear conclusion to be reached.

Finally, he changed his alarm clock from 7:00 AM to 6:30 AM, intending to call his parents proactively after dawn so they wouldn't have to wait for his message after waking up.

Lin Ye had just closed his eyes when the landline phone rang outside the door.

He opened his eyes and checked his phone; only seven minutes had passed.

Outside the duty room, Li Qian had already answered the phone.

The on-duty staff in the laboratory first verified the name and sample number, and then reported the results of the routine multi-sample test.

The multi-sample tests of the three patients with abnormal images did not detect common pathogens in the panel, and Gao Yuan's sample also showed no obvious abnormalities.

Before the results were finished being reported, the other party suddenly paused.

"Director Xu, there's an error curve in the additional nucleic acid screening sample from Xu Wenliang. One target is amplifying, stuck near the critical value, and the interpretation column hasn't shown a conclusion yet. We're pausing the report and re-extracting and retesting."

Xu Mingzhe immediately went to the phone: "What about the other two?"

"The other two additional tests did not show the same curves on the first pass. Quality control was normal, but we cannot rule out low load, sampling differences, or occasional contamination. Therefore, these tests cannot be treated as positive, nor can they be treated as negative."

"Keep the original sample, and record the retesting process and time." Xu Mingzhe looked at Li Qian. "The infection control supervisor and the on-call supervisor should report now. Ask the second-line laboratory staff to review the sample, and then contact the local CDC staff on-call to prepare the sample for delivery as required by them."

Li Qian picked up another phone.

Qin Hai had already walked to the monitoring screen, while Xu Wenliang was still leaning against the raised headboard, the oxygen storage bag under the oxygen mask constantly inflating and rising gently with his breathing.

Luo Wenbin stayed by the bedside, having just changed his blood oxygen finger clip.

Lin Ye returned to his worktable and checked the sampling number and sample registration information he had just heard one by one.

The sampler, submission time, laboratory receiving time, and storage location all match up, and the three specimens have consistent serial numbers from sampling to receipt.

A light blue notification appeared in my field of vision.

[Risk Area: Increased Risk of Cluster Transmission of Specific Respiratory Pathogens]

[Key gaps: original sample verification results, newly collected sample results, testing status of people present at the same location, and laboratory contamination investigation]

Lin Ye handed the three sample registration records to Xu Mingzhe: "The three sets of data all point to the same event, but the sampling times are different. Xu Wenliang is in charge of reviewing them, and the original samples from Gao Limin and Shao Dequan also need to be kept. Should we collect a new sample from each of the three of them, and check with the local authorities first?"

Xu Mingzhe glanced at the numbers: "List the old and new numbers of the three people separately, and I'll ask them."

The local CDC quickly called back, confirming that the original sample had been retested by the hospital's laboratory. At the same time, respiratory specimens were re-collected for the three patients with abnormal imaging results, with Xu Wenliang given priority.

Each re-collected specimen was packaged in the laboratory according to the designated procedure. One copy was kept within the hospital for future reference, and the portion sent out, along with the testing records, was sent to the municipal CDC laboratory for verification.

Whether Gao Yuan will be retested will be determined after local personnel have verified his symptoms and the initial test results.

After finishing the call, Xu Mingzhe pressed the intercom in the observation area: "Luo Wenbin, prepare to resample. Xu Wenliang, go first. Stabilize him with respiratory support, and retest his blood oxygen immediately afterward. Gao Limin and Shao Dequan, do it separately, and don't take them out of their respective areas."

"Received. Xu Wenliang's blood oxygen level just dropped to 92 again, he's breathing 31 times per breath, he's conscious and able to answer."

"Have the second-line respiratory specialists come directly to the bedside. Wait for the sampling to be done; we'll proceed once respiratory support is established."

A few minutes later, the second-line respiratory specialist was admitted to a private room. After reviewing the latest blood gas analysis and monitoring trends, it was decided to pre-oxygenate the patient using an oxygen reservoir mask before sampling, and then immediately switch to high-flow humidified oxygen therapy after sampling.

The equipment and tubing were moved to the bedside, the isolation monitoring beds were coordinated, and preparations for airway upgrades were also kept in place.

Luo Wenbin agreed, and the nurses in the observation area began preparing new sampling tubes and labels.

Each tube required a re-verification of the name, bed number, and sampling time. The new specimens from the three individuals were sealed in separate bags, and the old and new numbers were compared on separate sheets.

Xu Jing was still waiting for news in the registration area on the outside.

She saw people in the clean area putting on protective gear again through the glass, and then she saw nurses carrying sampling items into the observation area. She couldn't sit still any longer, so she got up and went to the intercom.

"We already picked some once, why do we have to pick some again? My dad has trouble even speaking now, can we let him rest for a bit?"

Xu Mingzhe turned on the intercom and asked her to sit down first: "One of the tests in the first test needs to be re-verified. The sampling will be done under the supervision of the bedside doctor, once his breathing condition allows. There are no final conclusions yet, so don't report the illness to your family yet."

Which item?

"Respiratory pathogen nucleic acid screening. The laboratory needs to redo the test, and new samples also need to be sent for retesting."

Xu Jing sensed his reluctance to commit to a conclusion, and her voice immediately became anxious: "Then what about my mother? She stayed with my father last night."

"Her name and phone number have been registered. She should continue to stay at home, keep her phone on, and wait for the local authorities to contact her. As for your father, keep an eye on his oxygenation. The bedside doctor will supervise the sampling."

Xu Jing stood in front of the walkie-talkie for a while before finally sitting back down in her original chair.

She sent her mother a voice message, starting by saying that the doctor was redoing the tests, then pausing for a few seconds before telling her mother to stay home and not to silence her phone.

Qin Hai and Lin Ye put on their protective gear again and entered the handover position through the buffer zone.

Xu Wenliang's side was overseen by the second-line respiratory specialist and Luo Wenbin, while Lin Ye was responsible for verifying the old and new sampling numbers and times.

After the blood oxygen level under the oxygen mask stabilized at 93%, the nurse moved the mask down slightly and quickly completed the nasopharyngeal swab collection.

The patient coughed as soon as the swab entered the nasal cavity.

The nurse then reattached the mask securely.

The blood oxygen level on the monitor dropped from 93 to 90. Luo Wenbin stayed by the bedside, reminding Xu Wenliang to breathe slowly. Another nurse had already connected the high-flow oxygen therapy tubing.

The number took half a minute to return to ninety-two.

The second-line respiratory specialist instructed the nurses to immediately switch to high-flow humidified oxygen therapy and adjust the flow rate and oxygen concentration according to the doctor's orders.

A few minutes later, the blood oxygen level returned to 94, and the respiratory rate remained at around 30 breaths per minute.

The second-line respiratory specialist, watching the monitor, said: "Maintain high flow for now, and check blood gases again in half an hour. If oxygenation still doesn't improve, or breathing becomes more difficult, prepare to upgrade airway support immediately."

Luo Wenbin then instructed the nurses: "Send this one first. Gao Limin and Shao Dequan will be tested according to their respective conditions. Xu Wenliang will not be tested a third time tonight."

After Lin Ye completed the labeling, he reported the sampling time to the clean area.

New specimens are first sent to the laboratory via a designated channel. After being repackaged, the portion to be sent out is placed in a transport box, and the outer seal is checked by two people.

After the handover was completed, Qin Hai and Lin Ye returned to the buffer zone along the original route, removed their protective gear one by one, and performed hand hygiene before returning to the clean area.

The retesting of the original samples is still in progress, and the screenshots of the abnormal curves have only been sent to the second-line testing team and Xu Mingzhe.

Li Qian first checked the existing records for the personnel in the clean area, the medical staff who had entered the observation area, and the sample delivery routes, and then waited for the on-duty officer and the person in charge of infection control to determine the subsequent scope.

At 1:17 a.m., the sample delivery personnel signed the time on the handover form.

After delivering the sample boxes, Li Qian switched to a blank form, with the first column listing the current staff of the fever clinic.