Incidence and treatment of diaphragmatic paralysis after cardiac surgery in children

Objective: Diaphragmatic paralysis (DP) caused by phrenic nerve injury is potentially life-threatening in infants. Phrenic nerve injury due to thoracic surgery is the most common cause of DP in children. We retrospectively analyzed incidence, surgical details, management and follow-up of our patients with DP after cardiac surgery to develop an algorithm for the management and follow-up. Methods: Retrospective analysis of 43 patients with DP after cardiac surgery performed between 1996 and 2000. Results: Median age at cardiac surgery was 1 month (range 3 days to 9 years). Incidence of DP was 5.4%. A trend towards higher incidences of DP were observed after arterial switch operation (10.8%, P=0.18), Fontan procedure (17.6%, P=0.056) and Blalock-Taussig Shunt (12.8%, P=0.10). Median time from cardiac surgery to surgical plication was 21 days (range 7-210 days). Transthoracic diaphragmatic plication was performed in 29/43 patients, no plication was done in 14/43 patients. Patients in whom diaphragmatic plication was required were younger (median age 2 months, range 21 days to 53 months versus 17.5 months, range 4 days to 110 months; P≪0.001). Indications for plication were failure to wean from ventilator (n=22), respiratory distress (n=4), cavopulmonary anastomosis (n=2), and failure to thrive (n=1). All these symptoms resolved after diaphragmatic plication, however, 8/29 patients with plication and 2/14 without plication died. Cause of death was not related to diaphragmatic plication in any patient. Position of plicated diaphragm was normal in 18/21 surviving patients 1 month after plication. In 2/12 surviving patients without plication hemidiaphragm showed a normal position 1 year after surgery. The rate of pulmonary infections was not significantly different during 12-60 months follow-up. Conclusions: DP is an occasional complication of cardiac surgery. High incidences of DP were seen after arterial switch operation, Fontan procedure and Blalock-Taussig shunt (BT). Respiratory insufficiency requires diaphragmatic plication in most infants with DP whereas older children may tolerate DP. Transthoracic diaphragmatic plication is an effective treatment of DP and achieves relief of respiratory insufficiency in most patients. Spontaneous recovery from postsurgical DP is rar

Incidence and treatment of diaphragmatic paralysis after cardiac surgery in children

Objective: Diaphragmatic paralysis (DP) caused by phrenic nerve injury is potentially life-threatening in infants. Phrenic nerve injury due to thoracic surgery is the most common cause of DP in children. We retrospectively analyzed incidence, surgical details, management and follow-up of our patients with DP after cardiac surgery to develop an algorithm for the management and follow-up. Methods: Retrospective analysis of 43 patients with DP after cardiac surgery performed between 1996 and 2000. Results: Median age at cardiac surgery was 1 month (range 3 days to 9 years). Incidence of DP was 5.4%. A trend towards higher incidences of DP were observed after arterial switch operation (10.8%, P=0.18), Fontan procedure (17.6%, P=0.056) and Blalock-Taussig Shunt (12.8%, P=0.10). Median time from cardiac surgery to surgical plication was 21 days (range 7-210 days). Transthoracic diaphragmatic plication was performed in 29/43 patients, no plication was done in 14/43 patients. Patients in whom diaphragmatic plication was required were younger (median age 2 months, range 21 days to 53 months versus 17.5 months, range 4 days to 110 months; P≪0.001). Indications for plication were failure to wean from ventilator (n=22), respiratory distress (n=4), cavopulmonary anastomosis (n=2), and failure to thrive (n=1). All these symptoms resolved after diaphragmatic plication, however, 8/29 patients with plication and 2/14 without plication died. Cause of death was not related to diaphragmatic plication in any patient. Position of plicated diaphragm was normal in 18/21 surviving patients 1 month after plication. In 2/12 surviving patients without plication hemidiaphragm showed a normal position 1 year after surgery. The rate of pulmonary infections was not significantly different during 12-60 months follow-up. Conclusions: DP is an occasional complication of cardiac surgery. High incidences of DP were seen after arterial switch operation, Fontan procedure and Blalock-Taussig shunt (BT). Respiratory insufficiency requires diaphragmatic plication in most infants with DP whereas older children may tolerate DP. Transthoracic diaphragmatic plication is an effective treatment of DP and achieves relief of respiratory insufficiency in most patients. Spontaneous recovery from postsurgical DP is rar

An unexpected role for brain-type sodium channels in coupling of cell surface depolarization to contraction in the heart

Voltage-gated sodium channels composed of pore-forming α and auxiliary β subunits are responsible for the rising phase of the action potential in cardiac muscle, but the functional roles of distinct sodium channel subtypes have not been clearly defined. Immunocytochemical studies show that the principal cardiac pore-forming α subunit isoform Na(v)1.5 is preferentially localized in intercalated disks, whereas the brain α subunit isoforms Na(v)1.1, Na(v)1.3, and Na(v)1.6 are localized in the transverse tubules. Sodium currents due to the highly tetrodotoxin (TTX)-sensitive brain isoforms in the transverse tubules are small and are detectable only after activation with β scorpion toxin. Nevertheless, they play an important role in coupling depolarization of the cell surface membrane to contraction, because low TTX concentrations reduce left ventricular function. Our results suggest that the principal cardiac isoform in the intercalated disks is primarily responsible for action potential conduction between cells and reveal an unexpected role for brain sodium channel isoforms in the transverse tubules in coupling electrical excitation to contraction in cardiac muscle

Diaphragmatic eventration

In general, diaphragmatic eventration (DE) is defined as abnormal elevation of all (or a portion of) an attenuated (but otherwise intact) diaphragmatic leaf [1]. The term “eventration” was used first by Becklard in 1829 (through Petit probably described the condition in 1970). Bingham described plication of the diaphragm in 1954 [2, 3]. Based on etiopathogenesis, DE may be classified as “congenital” or “acquired” even though the clinical features and principles of management are similar for both forms

Diaphragmatic palsy after cardiac surgical procedures in patients with congenital heart

Paralysis of diaphragm on one or, exceptionally, both sides is a common cause of delayed recovery and excessive morbidity following pediatric cardiac surgery. The consequences of this complication after all forms of congenital heart surgery in newborns and young infants can be potentially serious. The impact of diaphragmatic palsy on the physiology after single ventricle palliations is particularly significant. It is necessary for all professionals taking care of children with heart disease to be familiar with the etiology, diagnosis, and management of this condition. Early recognition and prompt management of diaphragmatic palsy can potentially reduce the duration of mechanical ventilation and intensive care in those who develop this complication. This review summarizes the anatomy of the phrenic nerves, reasons behind the occurrence of diaphragmatic palsy, and suggests practical guidelines for management