Bilateral phrenic nerve injury after neck dissection: an uncommon cause of respiratory failure

The case of a patient with carcinoma larynx who developed diaphragmatic paralysis and post-operative respiratory failure due to bilateral phrenic nerve injury is reported. The use of portable ultrasonography for an early diagnosis of diaphragmatic paralysis is discussed.

Diaphragmatic paralysis: a complication of lung transplantation

BACKGROUND

Damage to the phrenic nerve, either unilaterally or bilaterally, is a well-documented complication of cardiac operation, but less commonly reported after lung transplantation.

METHODS

A retrospective review of 185 single and sequential single lung transplant procedures was performed at The Toronto Hospital. Objective confirmation (fluoroscopy or ultrasound) of diaphragmatic paralysis was found in 6 patients. Paralysis was unilateral in 5 patients (all were left sided) and bilateral in 1 patient.

RESULTS

The average length of ventilation was 8.2 +/- 9.2 days with an average intensive care unit stay of 11.2 +/- 10.6 days. Mean duration in the hospital was 37.5 +/- 11.1 days. The average length of intensive care unit stay and hospitalization were compared with all other sequential single transplantations performed from approximately the time of the first documented case of diaphragmatic paralysis. Intensive care unit stay and hospitalization for the other (no diaphragmatic paralysis) transplant recipients were significantly shorter (5.3 +/- 2.7 and 29.1 +/- 12.9 days, respectively; p < 0.05). One patient required noninvasive ventilatory assistance via bilevel positive airway pressure in the hospital. One other patient used bilevel positive airway pressure in the hospital and overnight for 6 months after discharge. All patients obtained acceptable lung function and were ambulatory upon discharge from the hospital.

CONCLUSIONS

Clinically detectable diaphragmatic paralysis is an infrequent complication of lung transplantation and is associated with longer intensive care unit stay and hospitalization, but is not associated with significant adverse outcomes.

Diaphragmatic paralysis following scalenotomy for thoracic outlet syndrome

Potential phrenic nerve injury that results in diaphragmatic dysfunction and respiratory insufficiency has important implications for the anesthesiologist who must insure adequate ventilation and gas exchange. A variety of traumatic injuries as well as some surgical manipulations have been identified with an increased frequency of diaphragmatic paralysis. We have observed the occurrence of this sequelae after scalenotomy for thoracic outlet obstruction, a previously unreported association.

The effect of unilateral intercostal nerve transfer upon lung function

Intercostal nerve transfer is a well-established technique in the treatment of some severe brachial plexus lesions in adults. There is, however, concern that in the presence of an ipsilateral phrenic nerve palsy it may lead to a significant compromise of respiratory function. 20 patients having intercostal nerve transfers had their lung function assessed pre-operatively and 6 weeks post-operatively. The patients were subsequently questioned about symptoms of respiratory dysfunction. There was no evidence that intercostal nerve transfer leads to a significant reduction in respiratory function in adults. It therefore appears safe to perform intercostal nerve transfers in adults following brachial plexus injuries even in the presence of an ipsilateral phrenic nerve palsy.

Diaphragmatic paresis in newborns due to phrenic nerve injury

Phrenic nerve lesions as a result of birth trauma have been reported as a cause of acute respiratory distress infrequently. We report recent diagnostic and therapeutic experiences in four newborns with birth-traumatic phrenic nerve injury: one bilaterally, and three unilaterally, all right-sided. In each case, mechanical ventilation was required for at least 16 days. Ultrasound examination of the diaphragm and phrenic nerve conduction studies turned out to be the diagnostic methods of choice. Spontaneous recovery occurred in two children and two became asymptomatic after operative treatment. One improved after plication of diaphragm and one after autologous nerve transplantation.

Right latissimus dorsi cardiomyoplasty in diaphragm eventration and cardiac malposition

Cardiomyoplasty recently has been introduced as a surgical therapy for long-lasting cardiac dysfunction in selected patients. We report the case of a patient affected by chronic heart failure, unresponsive to maximal medical therapy, with concomitant posttraumatic injury of the left phrenic nerve, left diaphragm eventration, and cardiac malposition (right displacement). In view of the progressive deterioration of the cardiac function, cardiomyoplasty was recommended, and the right latissimus dorsi muscle was used to perform the wrapping procedure. A 6-month follow-up showed significant functional, as well as hemodynamic, improvements in addition to a reduction in medical therapy.

Incidence of phrenic neuropathy after isolated lung transplantation. The Loyola University Lung Transplant Group

BACKGROUND

Isolated lung transplantation is a viable therapeutic option for many patients with end-stage pulmonary disease. Other intrathoracic surgical procedures have a well documented incidence of phrenic nerve dysfunction, although the incidence after lung transplantation has not been studied.

METHODS

Thirty-one patients who underwent lung transplantation were evaluated for evidence of phrenic nerve dysfunction and subsequent recovery. Risk factors contributing to the incidence of injury were examined. Phrenic nerve injury was defined by two separate diagnostic tests (Transcutaneous Phrenic Nerve Conduction Studies and Fluoroscopic evaluation of diaphragmatic movement) used in combination.

RESULTS

Of the 27 patients who were completely evaluated after the operation, eight had defining criteria for nerve injury--an incidence of 29.6%. Of those affected, the majority of injuries (89%) resulted in complete paralysis of the affected hemidiaphragm. The highest incidence of injury occurred in patients who underwent bilateral single lung transplantation (41%), with the right phrenic nerve being injured most often (78%). Fortunately, no significant postoperative morbidity was attributable to the occurrence of phrenic nerve injury when compared with those patients who did not sustain injury.

CONCLUSIONS

The analysis of possible risk factors resulted in the hypothesis that the likely mechanism of injury in these patients was due to stretching or direct instrumentation of the nerve, and thus measures should be instituted to minimize the possibility of injury.

A comprehensive electrophysiological evaluation of phrenic nerve injury related to open-heart surgery

A prospective electrophysiological study of phrenic nerve was performed in 59 subjects undergoing open-heart surgery. The nerve was stimulated percutaneously at the neck and the diaphragmatic response was recorded with surface electrodes placed over the 8th intercostal space. The latency, amplitude, duration and area of the evoked response were measured before and after the operation. Post-operatively no response was elicited in 2 patients bilaterally, in 5 from the left and in 2 from the right. Comparison of the post-operative with the pre-operative group values in the remaining subjects showed that the amplitude and area of the left phrenic were lower in the post-operative study, indicating that some of the nerve fibres were not conducting. There were no statistically significant differences between pre and post-operative values of latency or duration on the left or any of the parameters on the right. Our findings suggest that the amplitude and area of the diaphragmatic response are more sensitive than latency in detecting phrenic nerve paresis associated with open-heart surgery.

Phrenic nerve injury following scalenectomy in a patient with thoracic outlet obstruction

We present a case in which a patient with normal pulmonary reserve experienced orthopnea and hypoxia secondary to unilateral diaphragmatic paralysis following right scalenectomy. This operation was performed in an attempt to relieve neurovascular compromise at the thoracic outlet. To our knowledge, this association has not been previously described in the literature.

Retrograde replacement of the thoracic aorta

A technique is described for replacement of the entire thoracic aorta. In this "pull-through" technique, which utilizes hypothermic circulatory arrest, the graft is implanted in a retrograde fashion, thus providing protection for the spinal cord and brain and avoiding injury to the vagus and phrenic nerves.

Needle electromyographic evaluation of the diaphragm

Needle electromyography of the diaphragm is a useful tool in diagnosis and prognosis of patients with diaphragmatic dysfunction. Spontaneous activity, polyphasic motor units and decreased recruitment can be found in phrenic nerve and spinal cord injury. We describe a safe technique for studying the diaphragm using needle electrodes.

[Phrenic nerve injury following coronary artery bypass surgery: its clinical implication and management]

The hospital records of 80 patients undergoing coronary artery bypass surgery, including 19 patients using the "isolation pad", were reviewed to examine the prevalence of the phrenic nerve injury (PNI). All patients received ice slush for topical cooling during operation. The degree of the elevated diaphragm was evaluated objectively by "Diaphragmatic Elevation Index, DEI" calculated from the plain chest roentgenogram taken before and after the operation. Sixty-one patients without using the isolation pad were subdivided into 3 groups, mild (35), moderate (15), and severe (11) according to the degree of the elevated diaphragm, and compared along with those using the isolation pad. All groups could not be distinguished by clinical course. The degree of left diaphragmatic elevation was significantly high compared with that of right, but recovered significantly at discharge except 2 patients. Pulmonary complication was highly associated with the "severe" groups. Because PNI is often transient and of little clinical significance, it is sometimes neglected. But considering the high frequency of the development of pulmonary complication, proper protective measure should be undertaken. Utilization of the isolation pad was effective means in terms of protection of phrenic nerve.

Unilateral phrenic nerve paralysis from cutting down a Christmas tree

Stretch injury to the phrenic nerve is an unusual cause of unilateral diaphragmatic paralysis. In this case the injury occurred while the patient was lying on the ground and cutting down a Christmas tree with a hand saw.

Endocytotic activity of mouse skeletal muscle fibres after long-term denervation

The endocytotic activity of skeletal muscle fibres and its relation to the denervated endplate region has been studied using horseradish peroxidase (HRP) as marker for endocytosis. In muscles denervated for a short time period (10-20 days) HRP-uptake occurred in small segments of the muscle fibres near the centre of the muscle (endplate region). After long-term denervation (6-12 months) similar segments with high endocytotic activity were seen preferentially in more peripheral parts of the muscle fibres. Ultrastructural characteristics of segments with high endocytotic activity from long-term denervated muscle fibres include a proliferating transverse tubular system, HRP-containing bodies of different sizes with some very large vacuoles extending over several sarcomeres. These characteristics are similar to those described previously for HRP-uptake in the endplate region of short-term denervated muscle (Tågerud et al., J. Neurol. Sci., 75 (1986) 141) except that no recognizable endplate structures were observed in the present study. The results are discussed in relation to the fate of the denervated endplate and the receptive capacity for synapse formation in long-term denervated muscle.

Diabetes mellitus, internal thoracic artery grafting, and risk of an elevated hemidiaphragm after coronary artery bypass surgery

The elevated hemidiaphragm after coronary artery bypass grafting (CABG) that occurs in some patients is associated with internal thoracic artery (ITA) grafting as well as with the use of topical cardiac hypothermia. An increased incidence of elevated hemidiaphragm after CABG surgery in diabetic patients was observed. To determine the incidence and risk factors of elevated hemidiaphragm after CABG surgery and the relationship to preoperative diabetes, 200 consecutive patients undergoing CABG were studied; 29 (14.5%) had hemidiaphragm elevation postoperatively (25 on the left, 1 on the right, 3 bilateral). In the remaining 171 there was no hemidiaphragm elevation. Factors analyzed were age, gender, preoperative diabetes, duration of cardiopulmonary bypass (CPB) and aortic cross-clamping, minimum esophageal temperature during CPB, and use of the ITA graft. Univariate analysis showed a significant association between elevated hemidiaphragm and diabetes (P < 0.05), left ITA grafting (P < 0.01), and age (P < 0.05). Right ITA was not used for any patient. Multivariate analysis ruled out age, whereas preoperative diabetes and the use of the ITA remained the independent factors associated with elevated hemidiaphragm (odds ratio, 3.41; 95% confidence interval 1.41 to 8.18, and 2.86; 1.01 to 8.06, respectively). The relative risk of an elevated hemidiaphragm was 9.75 in diabetic patients with the ITA graft, as compared with nondiabetic patients without this graft. All 3 patients with bilateral diaphragm paralysis and a patient with a right hemidiaphragm elevation were diabetic. In conclusion, both diabetes and use of the ITA graft appear to be important risk factors for the development of elevated hemidiaphragm following CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of unilateral phrenic nerve denervation on diaphragm contractility in rat

We examined the early effects of phrenic nerve denervation on the diaphragm muscle 1, 3, 7 and 14 days after unilateral denervation in rats. In the denervated hemidiaphragms, force frequency curves at 3, 7 and 14 days decreased significantly by 51%, 50% and 38% respectively of the peak tension of the force frequency curves of the diaphragms of rats with sham operation. Twitch tensions increased significantly at 14 days, and contraction times and half relaxation times slowed significantly at 3, 7 and 14 days. The tensions of denervated diaphragms at 5 min during the fatigue runs was significantly increased at 14 days. As determined by histological staining, the mean cross sectional area of fast-twitch fibers (type II) decreased significantly from 2,742 (sham) to 1,599 microns (14 days), but that of the slow-twitch fibers (type I) did not change significantly during the same period. These findings suggest that, during the first two weeks of denervation, fast twitch fibers (type II) atrophy more rapidly than slow twitch fatigue resistant fibers (type I), as confirmed by the contractile properties and histological findings.

Phrenic nerve injury following stretch trauma: case reports

Phrenic nerve injuries from stretch trauma are uncommon. The setting in which they occur is often associated with more severe or obscuring injuries. Electrodiagnostic studies are helpful in establishing the presence of a phrenic nerve injury and in monitoring recovery as demonstrated by the two case reports described here. Mechanisms of injury, the anatomic factors associated with phrenic nerve injury, and management are discussed.

Fatal bilateral phrenic nerve injury following hypothermic open heart surgery

A 30-year-old woman underwent mitral valvotomy for severe mitral stenosis. Extracorporeal circulation by means of cardiopulmonary bypass and systemic hypothermia, in addition to local topical hypothermia using iced saline solution and slushed ice, was used. Fatal bilateral phrenic nerve paralysis with inability to wean her from the ventilator occurred. This report is presented to illustrate the pathophysiology, pathology, and means of possible prevention of such a potentially highly fatal injury following hypothermic open heart surgery.

[Postlaparoscopic pain syndrome. Results of a prospective, randomized study]

The so-called post-laparoscopic algesia is a specific impairment of about 63% of the patients who undergo laparoscopic surgical operations. This impairment takes the form of mild to moderate shoulder pain. Eliminating the causes of pain has a clear advantage over symptomatic treatment using analgetics, a fact worth a good consideration especially with the post-operative sojourn at the hospital becoming shorter and shorter. In a prospective controlled study, involving 42 patients subdivided into four groups namely, higher or lower insufflation pressures, chemically inert insufflation gas and control groups; the use of analgetics, lung function, operation duration, amount of insufflated gas, intraperitoneal pH-values and post-operative complications in the various subgroups were compared to each other with regard to post-operative pain perception. The results did not show any significant differences among the groups regarding the main parameters like pH-value or different insufflation pressures etc. These results led to the termination of the study based on the raised criteria since we anticipated the actual cause of the shoulder pain to be due to an unknown factor. By the evaluation of the individual data, it became apparent that, the pains increase with increasing gas consumption, a fact which led to assumption that the pains are caused by a physical effect such as the cooling of the peritoneum.

Rupture of the right diaphragm following blunt trauma in an infant: case report

Traumatic diaphragmatic rupture is a rare childhood injury and is often difficult to diagnose. This is particularly true in infants. We present the case of a 3-month-old infant with traumatic rupture of the right diaphragm that became clinically apparent only after extubation. The diagnosis can often be made on the basis of chest radiography and clinical signs. Surgical treatment is required. Some phrenic nerve injuries can be anticipated and late sequelae may result.

Clinically relevant diaphragmatic dysfunction after cardiac operations

Phrenic nerve injury and diaphragmatic dysfunction can be induced by cardiac operation. The clinical consequences are not well-established. We evaluated 13 consecutive patients over a 2-year period with unexplained and prolonged difficulties in weaning from mechanical ventilation. The mean time of measurement from the operation day was 31 +/- 19 days (range 8 to 78). With the same technique we also evaluated 12 control patients: four patients at day 1 after cardiac operation while they were still intubated; four normally convalescing patients at day 7 or 8 after cardiac operation; and four patients who required prolonged mechanical ventilation because of another identified cause after cardiac operation. Diaphragmatic function was evaluated at the bedside from esophageal and gastric pressure measurements. A low or negative ratio of gastric pressure swing to transdiaphragmatic pressure swing, indicative of diaphragm dysfunction, was found in all 13 patients (mean -0.39 +/- 0.64). The difference between the 13 patients and all control groups was found to be highly significant. Transdiaphragmatic pressure measured during a maximal voluntary inspiratory effort and transdiaphragmatic pressure measured during a short, sharp sniff were markedly diminished (28 +/- 18 cm H2O and 13 +/- 15 cm H2O, respectively) in the 13 patients, significantly different from values in the four control patients studied at day 7 or 8. Transdiaphragmatic pressure measured after magnetic stimulation in four patients was also markedly reduced (7 +/- 5 cm H2O) as compared with normal theoretic values. Aminophylline infusion had no effect on any of these parameters. In one of two patients evaluated a second time, about 5 weeks later, a marked improvement was observed. Estimating the prevalence of clinically relevant diaphragmatic dysfunction, we found it to be 0.5% when no topical cooling was used and 2.1% when iced slush with no insulation pad was added for myocardial protection (p < 0.005). The most striking finding was that the clinical course of the 13 patients was marked by severe intercurrent events, including cardiorespiratory arrest after early tracheal extubation in 5 patients, nosocomial pneumonia in 11, prolonged mechanical ventilation in all (58 +/- 41 days), and a fatal outcome in 3. We conclude that prolonged postoperative diaphragmatic dysfunction may cause severe life-threatening complications after cardiac operation and can be limited to some extent by avoiding the use of iced slush topical cooling of the heart.

Anatomical interrelation between the phrenic nerve and the internal mammary artery as seen by the surgeon

Paresis of the diaphragm (especially left-side paresis) is a relatively frequent finding following cardiac surgery. While, usually, it is a rather benign condition, in exceptional cases it may lead to severe impairment to death of the patient. The supposed causes of damage to the phrenic nerve include: local myocardial cooling by ice slush; opening of the pleural cavity in connection with local cooling; cross clamp length; total hypothermia; central venous cannulation; traction-related damage; mammary artery harvesting. Perhaps the commonest cause of damage to the phrenic nerve, i.e., the effect of local myocardial cooling by ice slush, and the mode of phrenic nerve protection have been studied in considerable detail. The authors focused their attention on the interrelation between the phrenic nerve and the proximal segment of the mammary artery. Using anatomical preparations, the authors demonstrate the very intimate relationship of the above entities. The interrelation of the two anatomical structures basically differs depending on whether the left or right side is concerned. 1) On the left: The phrenic nerve, on entering the thorax, runs between the subclavian artery and vein laterally from the mammary artery crossing it medially; it parts the latter and continues in mediastinal adipose tissue to run on the pericardium toward the diaphragm. 2) On the right: The phrenic nerve passes between the subclavian vein and artery medially from the mammary artery. For another 3-4 cm, it runs along the medial and dorsal edges of the mammary artery.(ABSTRACT TRUNCATED AT 250 WORDS)