NU263 Unit 4 Cardiac Tamponade Hemodynamics Example

The Chest Tubes Went Quiet and the Pressures Met: A Hemodynamic Interpretation of Cardiac Tamponade in a Composite 66-Year-Old Man Six Hours After Bypass Surgery, Reading Pressure, Flow and Filling Together

[Student Name]

Purdue University Global

NU263: Medical-Surgical Nursing III

Unit 4 Hemodynamic Interpretation

[Instructor Name]

[Date]

The patient is composite; values and times are bracketed where illustrative, and reexploration and all medical decisions belong to the cardiac surgical team.

The Patient

[Mr. H.], composite, 66, had three bypass grafts at [0800]. In the intensive care unit from [1300] he was stable: chest tube drainage [150] mL an hour at first, then [180] and [200] mL an hour from [1500] to [1700]. The surgeon was informed and coagulation tests sent. At [1800] drainage fell to [20] mL, and at [1900] to [5] mL.

Two Profiles

[1600]: heart rate [88] in sinus rhythm; blood pressure [118/68], mean [85]; central venous pressure (right atrial) [8]; pulmonary artery wedge pressure [12]; cardiac index [2.6] L/min/m2; systemic vascular resistance [1,100]; urine [60] mL an hour; mixed venous oxygen saturation [68] percent. [1915]: heart rate [118]; blood pressure [92/74], mean [80], with the systolic falling by [14] mm Hg on inspiration; central venous pressure [18]; wedge [19]; cardiac index [1.7]; systemic vascular resistance [1,750]; urine [10] mL an hour; mixed venous saturation [52] percent. Feet cool. He is restless.

Pressure, Flow and Resistance

Mean pressure barely changed, from [85] to [80], yet the heart is pumping a third less blood. Pressure is held up because the vessels have clamped down: systemic vascular resistance has risen by more than half. A stable mean pressure hides a falling flow (Vincent & De Backer, 2013).

The pressure looked acceptable because his vessels were squeezing hard; the flow, the oxygen extraction and the urine all said the heart was failing to fill.

Filling Pressures That Meet

In tamponade, fluid or clot collects in the pericardial space and presses on all four chambers. Each chamber can fill only until its pressure matches the pressure outside it, so the pressures inside the right and left sides rise toward the same value. His central venous pressure rose from [8] to [18] and his wedge from [12] to [19]: high, and nearly equal. The heart is full of pressure but not of blood (Spodick, 2003).

A Systolic That Falls With Each Breath

A drop in systolic pressure of more than [10] mm Hg during inspiration, pulsus paradoxus, occurs because breathing in fills the right side, which in a tight pericardium pushes the septum toward the left and reduces left-sided filling. His fell by [14].

Oxygen the Tissues Are Taking Back

His mixed venous saturation fell from [68] to [52] percent. When flow falls, tissues extract more oxygen from each unit of blood, so less returns to the heart. Cool feet, restlessness and a urine output of [10] mL an hour are the bedside versions of the same message.

Quiet Chest Tubes

Chest tube drainage that was heavy and then suddenly stops is not always good news. Clot can block the tube while blood continues to collect around the heart. After cardiac surgery, tamponade may be caused by a localized clot and can lack classic signs such as muffled heart sounds, so the trend of the numbers matters most (Harding et al., 2023).

The Report

At [1920], the nurse called the surgeon: "Mr. H. may be tamponading. Chest tube output dropped from 200 an hour to 5. Heart rate 118, mean 80 with a paradox of 14, CVP and wedge both up to 18 and 19, cardiac index 1.7, urine 10 an hour, SvO2 52. I'm asking you to come now." The surgeon came within minutes, and he returned to the operating room, where clot was removed from around the heart.

Why Not Give More Fluid

A falling cardiac index and a soft pressure often prompt a fluid bolus. In tamponade, fluid may briefly raise filling and output, and it can buy time while the team prepares, but it does not treat the cause: the heart is compressed from outside. The rising and equal filling pressures in his profile argued against routine fluid as the answer. The definitive treatment was removing the blood and clot around the heart, which is why the nurse's report asked the surgeon to come rather than asking for a bolus order. Inotropes and vasopressors can also mislead, since they may raise the pressure while flow stays poor.

Keeping the Chest Tubes Open

On many cardiac units, nurses check chest tubes for patency each hour and follow the unit's protocol for clearing clot. A sudden fall in output should prompt a look at the tubing for kinks or clot and a call, not relief.

Recording the Trend

The nurse's flowsheet carried hourly values for heart rate, pressures, cardiac index, chest tube output and urine. Seen hour by hour, each number changed only a little. Seen as a trend from [1600] to [1915], they told a single story. Reviewing the trend, not just the latest value, is what made the report possible.

What the Nurse Watched Next

After reexploration: cardiac index, filling pressures, chest tube output and patency, urine and mixed venous saturation. Within two hours his index was [2.5], his central venous pressure [9] and his urine [50] mL an hour.

References

Harding, M. M., Kwong, J., Hagler, D., & Reinisch, C. (2023). Lewis's medical-surgical nursing: Assessment and management of clinical problems (12th ed.). Elsevier.

Spodick, D. H. (2003). Acute cardiac tamponade. New England Journal of Medicine, 349(7), 684-690. https://doi.org/10.1056/NEJMra022643

Vincent, J.-L., & De Backer, D. (2013). Circulatory shock. New England Journal of Medicine, 369(18), 1726-1734. https://doi.org/10.1056/NEJMra1208943