Incidence and Natural History of Phrenic Neuropathy Occurring During Open Heart Surgery

doi:10.1378/chest.103.3.850

Chest

Volume 103, Issue 3, March 1993, Pages 850-856

https://doi.org/10.1378/chest.103.3.850 Get rights and content

Objective

To study the incidence of phrenic neuropathy following coronary artery bypass grafting and determine long-term outcome.

Design

Prospective observational.

Setting

Surgical ICU in a university hospital, out-patient follow-up.

Patients

Ninety-two consecutive patients undergoing open heart surgery.

Interventions

None.

Measurements

Chest radiographs (CXR) 48 to 72 h postoperatively, ultrasonography of diaphragm, phrenic nerve conduction studies, diaphragmatic electromyogram, each repeated every 1 to 3 months until normal.

Main results

Seventy-eight of 92 (78 percent) patients had abnormal radiographs, 42 of 78 (54 percent) with abnormal CXRs had abnormal diaphragm motion, 24 of 42 (57 percent) with abnormal motion had phrenic neuropathy. Patients with normal diaphragm motion improved faster than those without; patients with normal nerve conduction (and abnormal motion) improved faster than those with abnormal nerve conduction.

Conclusions

Phrenic neuropathy is relatively common if sensitive tests are utilized for diagnosis. Nerve conduction studies can predict duration of morbidity. Most patients have low morbidity and recover fully. Abnormal diaphragm motion alone is not diagnostic of phrenic nerve injury.

Section snippets

Study Design

Ninety-six consecutive patients undergoing open heart surgery at a tertiary care hospital between March 15, 1989 and August 28, 1989 were prospectively evaluated for inclusion in the study. Surgical technique was not dictated by the study; all patients received topical hypothermia with a target temperature of 12° to 15°C. In addition to the use of cold blood cardioplegia, an ice slush was loosely placed around both the anterior and posterior surfaces of the heart. All patients had the use of a

Patient Population

During the study period, 96 open heart surgery procedures were performed. Of these, four patients were excluded from initial analysis: three died of adult respiratory distress syndrome prior to being evaluated and one had a right upper lobectomy in addition to the coronary artery bypass grafting (CABG). Thus, 92 patients were included in the study. Seventy-eight of these 92 patients had CABG only, 63 with internal mammary artery (IMA) grafting (58 left, I right, and 4 bilateral IMA grafts). Two

DISCUSSION

While other studies on phrenic neuropathy have usually relied on single techniques for diagnosis, eg, CXR or phrenic NCS, we have taken a comparatively conservative approach to the diagnosis. We have required that CXR, sonography, and NCS all be abnormal for the diagnosis. Moreover, we chose a conservative value for the upper limit of normal for phrenic nerve latency, 10.0 ms, which is the upper range in the study of 50 control subjects by Markand et al.⁵ We did not use mean ± 2 SD (9.3 ms in

CONCLUSIONS

We examined 92 of 96 consecutive patients undergoing open heart surgery of which 78 had clinical or radiologic abnormalities suggestive of diaphragmatic dysfunction. Of these 78, 42 had sonographic abnormalities and underwent phrenic NCSs that were abnormal in 24 cases. Thus, 24 of 92 patients had initial radiologic, sonographic, and neurophysiologic evidence of phrenic neuropathy. Over the first postoperative year, sonography and NCSs normalized in patients with definite phrenic neuropathy,

REFERENCES (14)

P Wilcox et al.
Phrenic nerve function and its relationship to atelactasis after coronary artery bypass surgery
Chest
(1988)
RA Esposito et al.
The effect of pericardial insulation on hypothermic phrenic nerve injury during open-heart surgery
Ann Thorac Surg
(1987)
WE Wheeler et al.
Etiology and prevention of topical cardiac hypothermia-induced phrenic nerve injury and left lower lobe atelectasis during cardiac surgery
Chest
(1985)
ON Markand et al.
Postoperative phrenic nerve palsy in patients with open-heart surgery
Ann Thorac Surg
(1985)
JD Marco et al.
Topical cardiac hypothermia and phrenic nerve injury
Ann Thorac Surg
(1977)
JC Scannell
Discussion of McGoon DC, Mankin HT, Kirklin JW. Results of open heart operation for acquired aortic valve disease
J Thorac Cardiovasc Surg
(1963)
JN Davis
Phrenic nerve conduction study in man
J Neurol Neurosurg Psychiatry
(1967)

There are more references available in the full text version of this article.

Cited by (96)

Diaphragm Dysfunction After Cardiac Surgery: Reappraisal
2021, Journal of Cardiothoracic and Vascular Anesthesia
The aim of this study was to re-investigate the incidence, risk factors, and outcomes of postoperative diaphragmatic dysfunction (DD) with actual cardiac surgery procedures.
Single-center, retrospective, observational study based on a prospectively collected database.
Tertiary care cardiac surgery center.
Patients who underwent cardiac surgery between January 2016 and September 2019.
None.
The DD group included patients with clinically perceptible diaphragmatic paralysis, which was confirmed by chest ultrasound (amplitude of the diaphragm movement in time-motion mode at rest, after a sniff test). The primary endpoint was the incidence of DD. Among 3,577 patients included, the authors found 272 cases of DD (7.6%). Individuals with DD had more arterial hypertension (64.3% v 52.6%; p < 0.0001), higher body mass index (BMI) (28 [25-30] kg/m² v 26 [24-29] kg/m²; p < 0.0002), and higher incidence of coronary bypass grafting (CABG) (58.8% v 46.6%; p = 0.0001). DD was associated with more postoperative pneumonia (23.9% v 8.7%; p < 0.0001), reintubation (8.8% v 2.9%; p < 0.0001), tracheotomy (3.3% v 0.3%; p < 0.0001), noninvasive ventilation (45.6% v 5.4%; p < 0.0001), duration of mechanical ventilation (five [four-11] hours v four [three-six] hours; p < 0.0001), and intensive care unit and hospital stays (14 [11-17] days v 13 [11-16] days; p < 0.0001). In multivariate analysis, DD was associated with CABG (odds ratio [OR] 1.9 [1.5-2.6]; p = 0.0001), arterial hypertension (OR 1.4 [1.1-1.9]; p = 0.008), and BMI (OR per point 1.04 [1.01-1.07] kg/m²; p = 0.003).
The incidence of symptomatic DD after cardiac surgery was 7.6%, leading to respiratory complications and increased ICU stay. CABG was the principal factor associated with DD.
Diaphragmatic Dysfunction After Elective Cardiac Surgery: A Prospective Observational Study
2020, Journal of Cardiothoracic and Vascular Anesthesia
To determine the incidence of postoperative diaphragm dysfunction as diagnosed by ultrasonography.
Explorative prospective observational study.
University intensive care unit.
One hundred consecutive patients undergoing elective cardiac surgery.
Diaphragm ultrasound was performed the day before surgery during unassisted breath (D-1), at the first spontaneous breathing trial attempt (D_SBT), 24 hours after surgery (D+1), and at intensive care unit (ICU) discharge (D_ICU). Diaphragm displacement, inspiratory and expiratory thickness, and the thickening fraction were measured at all timepoints.
Primary outcome was assessing the rate of postoperative diaphragm dysfunction, defined as a thickening fraction <20% at D_SBT. Secondary outcomes were the number of difficult-to-wean patients, the need for rescue noninvasive ventilation, the reintubation rate, and the ICU length of stay.
Thirty-eight patients showed diaphragm dysfunction at D_SBT, which resolved over time. No differences in preoperative characteristics and comorbidities were found between patients who developed postoperative diaphragm dysfunction and patients without postoperative disorders. The duration of cardiopulmonary bypass (103 ± 34 v 55 ± 34 min; P < 0.001) was significantly associated with the development of postoperative diaphragm dysfunction. When compared with patients without postoperative diaphragm disorders, patients with diaphragm dysfunction were characterized by a higher rate of difficult weaning (32% v 5%; P < 0.001), lower extubation rate at 24 hours after surgery (50% v 92%; P < 0.001), and longer ICU length of stay (19 [16; 88] v 16 [15; 18] hours; P < 0.001).
The incidence of postoperative diaphragm dysfunction after elective cardiac surgery is high and might contribute to prolonging ICU length of stay.
Intraoperative neurophysiological monitoring of the phrenic nerve: utility and descriptions of the technique
2019, Cirugia Espanola
En procedimientos quirúrgicos de las regiones supraclaviculares y laterales cervicales, así como en cirugías cardíacas y mediastínicas, la función diafragmática puede comprometerse desde la base del riesgo de lesión del nervio frénico y/o la raíz C4. Son escasas las publicaciones que tratan la estimulación intraoperatoria de estas estructuras nerviosas para evaluar su funcionalidad y, en nuestro conocimiento, hasta ahora no se ha hipotetizado acerca de si es posible reducir las tasas de lesión situadas en hasta el 26% en algunos estudios de cirugía cardíaca.
Describimos la técnica empleada para la monitorización neurofisiológica del nervio frénico. Asimismo, se discute su utilidad y ventajas respecto a otras técnicas.
Concluimos que con la incorporación creciente de la monitorización neurofisiológica intraoperatoria en los últimos años, es posible su aplicación al nervio frénico en los procedimientos en los que se considere que existe riesgo de lesión del mismo y, con ella, puede ser factible la reducción de las tasas de lesión iatrógena.
In surgical procedures of the supraclavicular and lateral cervical regions, as well as in cardiac and mediastinal surgeries, diaphragm function can be compromised by the risk of injury to the phrenic nerve and/or the C4 root. There are few publications that treat the intraoperative stimulation of these nerve structures to evaluate their functionality and, to our knowledge, until now it has not been hypothesized about whether it is possible to reduce the injury rates, which reach 26% in some cardiac surgery studies.
We describe the technique used for the neurophysiological monitoring of the phrenic nerve. Also, its usefulness and advantages over other techniques are discussed.
We conclude that, with the increasing incorporation in recent years of intraoperative neurophysiological monitoring, its application to the phrenic nerve is possible in procedures with a risk of injury and, thus, the reduction of iatrogenic injury rates may be feasible.
Neurologic complications of cardiac and vascular surgery
2017, Handbook of Clinical Neurology
Citation Excerpt :
Patients with persistent symptoms should undergo further testing with NCS to delineate axonal or myelin involvement, as axonal injury is associated with longer recovery. Phrenic nerve injuries are usually asymptomatic, and the majority of patients recover within 3–6 months (DeVita et al., 1993). The required time for healing depends on the type of injury (e.g., demyelination versus axonal injury) and the regeneration distance.
This chapter will provide an overview of the major neurologic complications of common cardiac and vascular surgeries, such as coronary artery bypass grafting and carotid endarterectomy. Neurologic complications after cardiac and vascular surgeries can cause significant morbidity and mortality, which can negate the beneficial effects of the intervention. Some of the complications to be discussed include ischemic and hemorrhagic stroke, seizures, delirium, cognitive dysfunction, cerebral hyperperfusion syndrome, cranial nerve injuries, and peripheral neuropathies. The severity of these complications can range from mild to lethal. The etiology of complications can include a variety of mechanisms, which can differ based on the type of cardiac or vascular surgery that is performed. Our knowledge about neuropathology, prevention, and management of surgical complications is growing and will be discussed in this chapter. It is imperative for clinicians to be familiar with these complications in order to narrow the differential diagnosis, start early management, anticipate the natural history, and improve outcomes.
Exercise Therapy for a Patient With Persistent Dyspnea After Combined Traumatic Diaphragmatic Rupture and Phrenic Nerve Injury
2015, PM and R
Citation Excerpt :
Confirmation of an elevated hemidiaphragm by chest radiography and computed tomography is effective for the diagnosis of phrenic nerve dysfunction; however, for a more accurate diagnosis, the sniff test, ultrasonography, and a phrenic nerve conduction study also should be performed. Of these tests, the nerve conduction study is the gold standard [8,9]. In the present case, the phrenic nerve injury was accompanied by a diaphragmatic rupture; however, as previously noted, an elevated hemidiaphragm was identified on chest radiography and computed tomography at the time of injury, and the initial diagnosis was only of diaphragmatic rupture, which delayed the diagnosis of the phrenic nerve injury.
We present a case report of a patient with a history of diaphragmatic rupture who had persistent dyspnea for 9 months after primary surgical repair of a right diaphragmatic rupture caused by a car accident. A phrenic nerve conduction study was performed, which demonstrated a rare accompanying ipsilateral phrenic nerve injury with resultant hemidiaphragmatic paralysis. Aerobic exercise therapy for the purpose of improving endurance and dietary modification for weight reduction were prescribed and continued for 6 months. The exercise intensity was prescribed based on the percentage of maximum heart rate as confirmed by an exercise tolerance test. The duration of exercise was gradually increased. In this case, the long-persistent dyspnea was successfully alleviated via nonoperative management to the point that the patient could resume regular activities of daily living.
Injuries of the Nerves of the Thorax
2015, Nerves and Nerve Injuries: Pain, Treatment, Injury, Disease and Future Directions: Vol 2
Injuries of the nerves of the thorax are a known complication of thoracic surgery. Diagnosis is not always straightforward, often requiring a multidisciplinary approach and a combination of several investigation techniques. Electrodiagnostic studies are most accurate in terms of confirming the diagnosis, although regarding the thoracic nerves, they are challenging. They are also helpful in determining prognosis, which is variable, with respect to the mechanism of injury. Clinical outcome depends not only on recovery of the nerve function, but also on the extent of the lesion (unilateral vs. bilateral), comorbidities, and compensatory activity of other muscles. Thus, conservative therapy is applied in most instances, while surgical treatment is reserved for cases of severely disabling nerve injuries. In this chapter, we review the following nerves: phrenic, long thoracic, recurrent laryngeal, thoracodorsal, vagus, intercostals, and sympathetic trunk. Anatomy and function, clinical syndromes, etiology, diagnosis, prognosis, and management of nerve injuries are discussed.

View all citing articles on Scopus

: Manuscript received May 19; revision accepted September 22

View full text

Chest

Clinical InvestigationsIncidence and Natural History of Phrenic Neuropathy Occurring During Open Heart Surgery

Objective

Design

Setting

Patients

Interventions

Measurements

Main results

Conclusions

Section snippets

Study Design

Patient Population

DISCUSSION

CONCLUSIONS

Chest

Ann Thorac Surg

Chest

Ann Thorac Surg

Ann Thorac Surg

Discussion of McGoon DC, Mankin HT, Kirklin JW. Results of open heart operation for acquired aortic valve disease

J Thorac Cardiovasc Surg

Phrenic nerve conduction study in man

J Neurol Neurosurg Psychiatry

Clinical Investigations
Incidence and Natural History of Phrenic Neuropathy Occurring During Open Heart Surgery