# Situation: A 63-year-old man is in the surgical intensive care unit after a major bowel resection. He receives parenteral nutrition (PN) by infusion pump through a central venous catheter and intermittent hemodialysis (HD) through a tunneled dialysis catheter for kidney failure. Near the end of an HD session, he suddenly becomes short of breath, coughs, reports chest pain and becomes cyanotic, and his blood pressure falls to 82/50 mmHg. The nurse sees air in the blood line returning to him. What should the nurse do FIRST?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=630264  
> language: ko  
> subject: Nursing Practice V — Care of Clients with Maladaptive Patterns of Behavior; Care of Clients with Life-Threatening Conditions, Acute Multi-Organ Problems, High Acuity and Emergency Situations

## 문제

Situation: A 63-year-old man is in the surgical intensive care unit after a major bowel resection. He receives parenteral nutrition (PN) by infusion pump through a central venous catheter and intermittent hemodialysis (HD) through a tunneled dialysis catheter for kidney failure.

Near the end of an HD session, he suddenly becomes short of breath, coughs, reports chest pain and becomes cyanotic, and his blood pressure falls to 82/50 mmHg. The nurse sees air in the blood line returning to him. What should the nurse do FIRST?

## 보기

1. Clamp the blood lines and stop the blood pump **✔ 정답**
2. Turn him onto his left side with the head lowered
3. Apply 100% oxygen by nonrebreather mask
4. Call the attending physician to the bedside

**정답: 1**

## 해설

All four actions belong in the response to air embolism during hemodialysis, but the first is to stop more air from entering: clamp the blood lines and stop the pump. The nurse then places the client on the left side with the head down to trap air in the right heart, gives oxygen and calls for help.

## 심화 해설

Understanding the Emergency

During hemodialysis, blood is pumped through an extracorporeal circuit. If air enters that circuit—often through a loose connection, a cracked line, or an empty air-detector chamber—the blood pump can push that air directly into the patient’s venous circulation. Because this patient has a central venous catheter, the air travels quickly to the right heart and pulmonary circulation. Large or rapidly introduced volumes of air can obstruct right ventricular outflow or pulmonary vessels, producing sudden dyspnea, chest pain, cough, cyanosis, and hypotension [1][2]. The nurse’s observation of air in the blood line returning to the patient confirms the source of the problem.

Why the First Action Is Clamping and Stopping the Pump

The immediate priority is to stop additional air from entering the patient’s circulation. Clamping the blood lines and stopping the blood pump interrupts the driving force that is actively pushing air into the venous system [1][4]. Every second the pump continues, more air can enter, worsening the embolic burden. Positioning, oxygen, and calling for help are all important, but they do not stop the ongoing entry of air. In air embolism management, source control always precedes supportive measures.

Pathophysiology of Venous Air Embolism

Venous air embolism occurs when air enters the systemic venous circulation and travels to the right atrium and right ventricle. A large air bolus can create an air lock in the right heart, impairing right ventricular filling and reducing pulmonary blood flow. This leads to acute right heart strain, decreased left ventricular preload, and systemic hypotension [1]. If air crosses into the arterial circulation—through a patent foramen ovale or pulmonary capillary transit—it can cause cerebral air embolism, producing neurologic symptoms such as seizures or focal deficits [2]. In this patient, the cardiovascular collapse is the dominant early manifestation.

Sequence of Interventions After Clamping

Once the lines are clamped and the pump is stopped, the nurse should immediately reposition the patient. The recommended position is left lateral decubitus with the head lowered (Trendelenburg). This position traps air in the right atrium or right ventricle apex, away from the pulmonary outflow tract, and may reduce the air lock effect . High-flow 100% oxygen by nonrebreather mask should be applied to accelerate nitrogen washout from the air bubble, which reduces bubble size by creating a diffusion gradient favoring nitrogen absorption [2]. The physician must be called to the bedside for further management, which may include catheter-based aspiration of air or hyperbaric oxygen therapy [2].

| Action | Purpose | Timing |
| --- | --- | --- |
| Clamp blood lines and stop pump | Stops further air entry into venous circulation | Immediately first |
| Left lateral decubitus with head down | Traps air in right heart, away from pulmonary outflow tract | Immediately after clamping |
| 100% oxygen by nonrebreather | Reduces bubble size via nitrogen washout gradient | After positioning, as soon as available |
| Call physician to bedside | Enables advanced interventions such as aspiration or hyperbaric oxygen | Concurrently or as soon as possible |

Watch out! Do not delay clamping to reposition the patient first. Air continues to enter the bloodstream as long as the pump is running and the lines are open. Source control is the highest-priority intervention in any air embolism scenario [1][4].

Key point! The classic triad of sudden dyspnea, chest pain, and hypotension during hemodialysis—especially when air is visible in the returning blood line—should trigger immediate clamping of the blood lines and stopping of the pump before any other action.

Clinical Relevance for Hemodialysis Nursing

Air embolism during hemodialysis is rare but potentially fatal. Risk factors include central venous catheter dysfunction, loose connections, cracked tubing, and failure of the air detector alarm system [2][4]. The air detector is a safety device that should automatically stop the blood pump when air is sensed; however, if the detector is bypassed, misaligned, or malfunctioning, air can reach the patient. Nurses must routinely verify that all connections are secure, the air detector is functioning, and the saline bag is not empty before initiating dialysis. After catheter removal, patients should be instructed to remain supine and perform a Valsalva maneuver during dressing changes to prevent air entry through the open catheter tract [4].

Why the Other Options Are Not First

Turning the patient onto the left side with the head lowered is a critical intervention, but it is performed after the source of air is controlled. Applying oxygen is supportive and should follow positioning. Calling the physician is necessary but does not address the ongoing air entry. In a rapidly deteriorating patient, the nurse must act first to stop the cause of the deterioration, then initiate supportive and collaborative measures.References (research sources)

- [1]Fatal Cerebral Air Embolism Following Central Venous Catheter Mishandling in a Stroke Patient: A Case Report.Case reportRundblad LIS, Lukassen TG, Grynnerup AG, Abdulmunem SA, Iversen HK, West AS. (2026) · DOI: 10.1155/crcc/6367510

- [2]Cerebral air embolism following a hemodialysis session successfully treated with hyperbaric oxygen: a case report.Case reportBousbaa A, Renou M, Poulain C, Laurent P, El Esper N, Choukroun G (2024) · DOI: 10.1177/17562864241287457

- [4]Air embolism following removal of hemodialysis catheter.Research articleSahutoglu T, Sakaci T, Hasbal NB, Kara E, Ahbap E, Sevinc M (2017) · DOI: 10.1111/hdi.12456

## 임상 시나리오

Air Embolism During Hemodialysis: First ResponseStop the source before supportive care
When air is seen in the blood line returning to the patient, the immediate priority is to clamp the blood lines and stop the blood pump. This halts the driving force pushing air into the venous circulation. Every second the pump continues increases the embolic burden.

After source control, place the patient in left lateral Trendelenburg position to trap air in the right heart, then apply 100% oxygen and call for help.

CautionDo not delay clamping to position the patient or call the physician. Air continues to enter as long as the pump runs, worsening obstruction of right ventricular outflow and pulmonary circulation.

## 핵심 개념

- **Venous air embolism** — Air entering venous circulation, traveling to right heart and pulmonary vessels, causing obstruction and hemodynamic collapse.
- **Extracorporeal circuit** — Blood pathway outside the body during hemodialysis, including tubing and dialyzer, where air can enter through loose connections or cracks.
- **Air lock** — Air bolus in right heart obstructing ventricular outflow or pulmonary circulation, leading to sudden dyspnea, hypotension, and cyanosis.
- **Source control** — First priority in emergency management: stopping the cause of injury before supportive measures.
- **Left lateral Trendelenburg** — Positioning patient on left side with head down to trap air in right heart, preventing pulmonary outflow obstruction.

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