NU654 Unit 2 Deterioration Case, Guillain-Barre Example

A Saturation That Never Fell: A Deterioration Recognition Case of Neuromuscular Respiratory Failure in Guillain-Barre Syndrome

[Student Name]

Purdue University Global

NU654: AGACNP Acute Care Diagnosis and Management III

Unit 2 Deterioration Recognition Case

[Instructor Name]

[Date]

The patient is composite; measurements and times are bracketed. All respiratory measurements were taken at the bedside by respiratory therapy.

The Patient

Mr. [C.] is a [52]-year-old man, [80] kg, admitted with ascending weakness [five] days after a diarrheal illness. Nerve conduction studies supported Guillain-Barre syndrome, and intravenous immunoglobulin began on [Day 1]. On [Day 3] he could not walk and had mild weakness of both arms. He was on a monitored neurology bed with vital capacity and negative inspiratory force ordered every [three] hours.

The Data

1. [07:00]. Vital capacity [2.8] L, [35] mL/kg. Negative inspiratory force [minus 45] cmH2O. Single-breath count [30]. Cough strong. Neck flexion [4] of 5. Heart rate [88], blood pressure [128/78], saturation [98] percent on room air.

2. [10:00]. Vital capacity [2.4] L, [30] mL/kg. Inspiratory force [minus 38]. Count [24]. Cough fair. Neck flexion [4]. Heart rate [92], pressure [134/80], saturation [97] percent.

3. [13:00]. Vital capacity [2.1] L, [26] mL/kg. Inspiratory force [minus 32]. Count [18]. Cough weak; saliva pooling at the corners of his mouth; new difficulty closing both eyes fully. Neck flexion [3]. Heart rate [104], pressure [152/94]. Saturation [97] percent.

4. [15:00]. Vital capacity [1.9] L, [24] mL/kg. Inspiratory force [minus 28]. Count [15]. Cough weak with pooled secretions; speaking in short phrases. Heart rate swinging between [62] and [118] over [ten] minutes; pressure [96/58] to [164/98]. Saturation [96] percent.

5. [18:40]. Vital capacity [1.4] L, [17.5] mL/kg. Inspiratory force [minus 20]. Count [10]. Using accessory muscles; paradoxical abdominal movement. Heart rate [112], pressure [148/90]. Saturation [95] percent. Rapid response called.

He was intubated electively in the ICU at [19:30], before any hypoxemia or cardiac arrest, and did well.

The Risk He Carried From Admission

His risk was high before the day began. The Erasmus GBS Respiratory Insufficiency Score uses three features available at admission: the number of days between the onset of weakness and admission, the strength of the limbs on the Medical Research Council sum score, and the presence of facial or bulbar weakness. Scores range from 0 to 7, and the chance of needing ventilation within a week rises from about 1 percent at the bottom of the scale to about 91 percent at the top (Walgaard et al., 2010). Mr. [C.] was admitted only [five] days after his weakness began, and his limb strength fell quickly over the first two days, which placed him in a middle band before any bulbar sign appeared. A score in that range does not decide when to escalate, but it tells the team to expect deterioration and to read every measurement against that expectation rather than hoping each one is the lowest.

First Pass: Respiratory Mechanics

Lawn and colleagues described markers of impending respiratory failure in severe Guillain-Barre syndrome: a vital capacity below 20 mL/kg, a maximal inspiratory pressure weaker than 30 cmH2O, a maximal expiratory pressure below 40 cmH2O, or a fall of more than 30 percent in any of these (Lawn et al., 2001). The first two thresholds form part of what is often taught as the 20/30/40 rule.

Read against those markers, Mr. [C.]'s mechanics crossed the first line at [15:00]. His vital capacity had fallen by 32 percent from the morning, from [2.8] to [1.9] liters, and his inspiratory force had become weaker than 30. By [18:40] his vital capacity was below 20 mL/kg.

Second Pass: Bulbar and Axial Signs

The same study found that bulbar dysfunction, bilateral facial weakness and rapid progression each made mechanical ventilation more likely. By [13:00], Mr. [C.] had pooled saliva and could not fully close his eyes; by [15:00] his cough could not clear secretions and his speech was broken into phrases. A weak cough matters for its own reason: a patient who cannot protect his airway can aspirate long before his lungs fail to oxygenate. Neck flexion strength, which tracks diaphragm strength in neuromuscular disease, fell from 4 to 3.

Third Pass: Autonomic Signs

At [15:00], his heart rate and blood pressure swung widely within minutes. Dysautonomia is common in severe Guillain-Barre syndrome and was the fourth feature Lawn and colleagues linked to progression to ventilation. It also raises the risk of intubation itself, because induction drugs can trigger severe hypotension or bradycardia in a patient whose autonomic control is unstable, which is one more reason to intubate early and electively rather than late and urgently.

Why the Saturation Misled

In neuromuscular respiratory failure, oxygen saturation is one of the last things to fall, because the lungs are healthy and the problem is the pump. Mr. [C.] kept his saturation by breathing faster and more shallowly, and a pulse oximeter cannot see the effort that costs. Carbon dioxide rises before oxygen falls, and when saturation finally drops, the patient is usually close to exhaustion or arrest. A ten-step guide to managing the syndrome advises regular monitoring of respiratory function with vital capacity and related bedside measures, precisely because clinical signs and oximetry can lag behind (Leonhard et al., 2019). The unit's monitor had shown a green number all afternoon.

Verdict: Escalation Belonged at [15:00]

At [15:00] four signals were present together: a vital capacity fall of more than 30 percent, an inspiratory force weaker than 30, bulbar weakness with an ineffective cough and dysautonomia. Any one of them warranted a call; together they were a clear indication for intensive care review and preparation for elective intubation. The call came at [18:40], three hours and forty minutes later, when the vital capacity had fallen below 20 mL/kg.

Earlier escalation was possible from [13:00], when the bulbar signs appeared and the capacity had fallen by 25 percent. Reasonable clinicians might have waited one more measurement at that point, which is why the verdict is set at [15:00] rather than earlier.

What Would Have Changed the Outcome, and What Should Change Now

In this case the outcome was good, because intubation at [19:30] was still elective. The risk was that the next measurement, at [21:40], would have come too late. Three changes follow for the unit:

1. Chart vital capacity in mL/kg and as a percentage of the day's first value, so crossing a threshold is visible without calculation.

2. Add bulbar signs, cough strength and heart rate variability to the three-hourly neuromuscular checks.

3. State in the order set that saturation is not a reason for reassurance in Guillain-Barre syndrome, and name the thresholds that require a call.

References

Lawn, N. D., Fletcher, D. D., Henderson, R. D., Wolter, T. D., & Wijdicks, E. F. M. (2001). Anticipating mechanical ventilation in Guillain-Barre syndrome. Archives of Neurology, 58(6), 893-898. https://doi.org/10.1001/archneur.58.6.893

Leonhard, S. E., Mandarakas, M. R., Gondim, F. A. A., Bateman, K., Ferreira, M. L. B., Cornblath, D. R., van Doorn, P. A., Dourado, M. E., Hughes, R. A. C., Islam, B., Kusunoki, S., Pardo, C. A., Reisin, R., Sejvar, J. J., Shahrizaila, N., Soares, C., Umapathi, T., Wang, Y., Yiu, E. M., . . . Jacobs, B. C. (2019). Diagnosis and management of Guillain-Barre syndrome in ten steps. Nature Reviews Neurology, 15(11), 671-683. https://doi.org/10.1038/s41582-019-0250-9

Walgaard, C., Lingsma, H. F., Ruts, L., Drenthen, J., van Koningsveld, R., Garssen, M. J. P., van Doorn, P. A., Steyerberg, E. W., & Jacobs, B. C. (2010). Prediction of respiratory insufficiency in Guillain-Barre syndrome. Annals of Neurology, 67(6), 781-787. https://doi.org/10.1002/ana.21976