进胸膈神经全长切断后的肺功能变化观察

目的 研究全长膈神经移位术对肺功能的影响。方法 对15例行全长膈神经移位肌皮神经术的全臂丛根性撕脱伤病人的术后肺功能进行回顾性分析。11例共随访42～48个月，4例在随访过程中失访。结果 所有病例术后无呼吸功能障碍，胸部X线片中均出现不同程度的术侧膈肌麻痹和抬高（高1．0～1．5个肋间）。肺功能参数如肺活量、肺活量占预期值的百分比、残气量、肺总量、功能残余量、第1秒用力呼气量在术后1年均恢复到术前水平，但所有病例的最大吸气压值即使在术后4年仍比预期值有明显降低（平均降低20％）。结论 单侧膈神经完全切断后的肺功能参数均在术后1年内逐渐恢复到术前水平。     

进胸取膈神经移位术后肺功能的变化

目的　研究进胸取膈神经移位术后患者肺功能的变化。方法　对 5例进胸取膈神经移位患者术前及术后 (8～ 14个月 )肺功能的变化进行比较。结果　 5例在术后均未出现供氧不足症状。 3例出现膈肌抬高 ;术后肺活量 (VC)、肺活量预计值百分数 (VC % )分别比术前减少 17.3 %和 3 2 .3 % ,两者差异有显著性意义 (tvc=3 .49、tvc% =4.17,P <0 .0 5 )。其它项目如残气量 (RV)、肺总量 (TLC)、残气量 /肺总量比值 (RV/TLC)、用力肺活量 (FVC)、1s用力呼气量 (FEV1)、1s用力呼气量 /用力肺活量比值(FEV1/FVC)、5 0 %肺活量的最大呼气流量预计值百分数 (FEF 5 0 % )的变化 ,和术前相比均无明显差异。结论　进胸取膈神经移位术后成人的肺容量有部分丧失 ,但其丧失程度在机体可耐受范围内 ,不会导致呼吸功能障碍     

臂丛神经根性损伤膈神经移位术对青壮年患者早期呼吸功能的影响

目的研究臂丛神经损伤膈神经移位术对青壮年患者早期呼吸功能的影响.方法对16例接受膈神经移位治疗的患者,在术前、术后（10 d）进行肺功能指标的比较,同时定期进行门诊随访,观察呼吸系统自觉症状程度.结果13例术后出现了不同程度的供氧不足症状,16例全部出现一侧膈肌抬高,术后第10天肺活量（VC）、肺活量预计值百分数（VC%）分别比术前减少37.98%和26.88%,两者差异有统计学意义（tvc=11.532、tvc%=0,P＜0.01）.其它项目如残气量（RV）较术前轻度下降,肺总量（TLC）下降值达到术前肺总量的36.49%,残气量/肺总量比值（RV/TLC%）较术前上升了4.75%,上述各指标的差值均有统计学意义.1 s用力呼气量/用力肺活量比值（FEV1/FVC）和术前比基本无改变,但其差值有统计学意义.膈神经移位右侧（10例）与左侧（6例）术前、术后肺活量比较差异有统计学意义.术后随访8个月～2年,所有患者均无明显呼吸困难和胸闷等症状.结论膈神经移位术后对青壮年患者肺容量有较大的丧失,肺通气功能减弱和小气道阻力增加,但其丧失程度在机体自身代偿耐受范围内,不会导致急剧发生的严重呼吸功能障碍.建议对右侧臂丛神经根性损伤的患者,术前进行严格的肺、心功能检查,避免发生较为严重的并发症.     

Pulmonary and biceps function after intercostal and phrenic nerve transfer for brachial plexus injuries

This pseudo-randomized study was performed to compare the pulmonary function and biceps recovery after intercostal (19 cases) and phrenic (17 cases) nerve transfer to the musculocutaneous nerve for brachial plexus injury patients with nerve root avulsions. Pulmonary function was assessed pre-operatively and postoperatively by measuring the forced vital capacity, forced expiratory volume in 1 second, vital capacity, and tidal volume. Motor recovery of biceps was serially recorded. Our results revealed that pulmonary function in the phrenic nerve transfer group was still significantly reduced 1 year after surgery. In the intercostal nerve transfer group, pulmonary function was normal after 3 months. Motor recovery of biceps in the intercostal nerve group was significantly earlier than that in phrenic nerve group. We conclude that pulmonary and biceps functions are better after intercostal nerve transfer than after phrenic nerve transfer in the short term at least.     

Successful reinnervation of the diaphragm after phrenic nerve transection

A 16-month-old infant presented with bilateral diaphragmatic paralysis and respiratory failure after removal of a thoracic teratoma. Right diaphragmatic function recovered after end-to-end anastomosis of a transected phrenic nerve. We conclude that phrenic nerve repair can restore diaphragmatic function and should be attempted in selected cases of diaphragmatic paralysis due to phrenic nerve injury.     

青少年特发性脊柱侧凸患者术前肺功能影响因素分析及临床意义

目的 分析影响青少年特发性脊柱侧凸患者术前肺功能的相关影像学参数及其临床意义.方法 回顾性研究2009年7月～2012年8月本院收治的青少年特发性脊柱侧凸患者24例,术前肺功能检查、胸部CT扫描资料完整.分析肺功能结果与站立位全长X线片Cobb角、顶椎偏移、椎体旋转分度（Nash/Moe法）、顶椎肋椎角差值、矢状位T5-12后凸角和胸段累及椎体数目之间相关性.结果 患者年龄平均14.8岁,Cobb角平均52.8°;主弯Cobb角与术前肺活量占预计值百分比、第1秒最大呼气容积占预计值百分比、用力肺活量占预计值百分比、最大通气量占预计值百分比、肺总量占预计值百分比、一氧化碳弥散量占预计值百分比和一氧化碳弥散量呈负相关;顶椎偏移与肺总量占预计值百分比、一氧化碳弥散量占预计值百分比及一氧化碳弥散量呈明显负相关;站立位顶椎凸凹侧肋椎角差值分别与肺总量占预计值百分比、肺总量、一氧化碳弥散量占预计值百分比和一氧化碳弥散量呈负相关;Bending位顶椎凸凹侧肋椎角差值与肺总量、一氧化碳弥散量呈负相关;胸段累及椎体数≥7个组患者50％肺活量时最大呼气流量、75％肺活量时最大呼气流量、最大用力呼气中段流速占预计值百分比、最大通气量占预计值百分比及一氧化碳弥散量占预计值百分比数值,比胸段累及椎体数＜7个组患者有减少（P＜0.05）.结论 术前站立位主弯Cobb角愈大,主弯顶椎偏移增大,站立位以及Bending位顶椎凸凹侧肋椎角差值增加,肺功能下降.近胸弯≥30°组较之＜30°组,胸段累及椎体数≥7个组较之＜7个组,肺功能数值下降.     

Better pulmonary function and prognosis with video-assisted thoracic surgery than with thoracotomy

BACKGROUND: Data regarding pulmonary function and prognosis after video-assisted thoracic surgery lobectomy are limited. METHODS: From September 1992 to April 2000, 204 video-assisted thoracic surgery lobectomies were performed, and their preoperative and postoperative pulmonary function test results and prognoses were evaluated. RESULTS: The postoperative to preoperative ratio of pulmonary function tests (vital capacity and forced expiratory volume in 1 s) were better in video-assisted thoracic surgery lobectomy than in open thoracotomy (p < 0.0001). Furthermore, the 5-year survival rate of pathologic stage I lung cancers after video-assisted thoracic surgery was 97.0%, whereas that after open thoracotomy was 78.5% (p = 0.0173; Mantel-Cox). CONCLUSIONS: Pulmonary function and prognosis were far better after video-assisted thoracic surgery lobectomy than after open thoracotomy.     

Bilateral diaphragm paralysis after cardiac surgery with topical hypothermia.

Bilateral diaphragm paralysis is a rare but important complication of open heart surgery. Two cases were found among 360 prospectively studied patients undergoing open heart surgery during one year. Both patients had insulin dependent diabetes with peripheral neuropathy and this may have contributed to their diaphragm paralysis. The patients were studied postoperatively for one year with measurements of lung function, nocturnal oximetry, diaphragmatic function, and phrenic nerve conduction. Treatment with intermittent positive airway pressure ventilation by nasal mask was effective in both patients. After nine months one patient had recovered completely with normal phrenic nerve conduction and diaphragmatic function; the other continues most of his normal daytime activities, but still requires nasal positive airway pressure ventilation for six hours at night.     

Diaphragmatic plication offers functional improvement in dyspnoea and better pulmonary function with low morbidity

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was as follows: In adults with unilateral diaphragmatic paralysis, does diaphragmatic plication offer functional improvement in dyspnoea, better pulmonary function tests (PFTs) and return to activity? A total of 126 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, date and country of publication, patient group studied, surgical approach, study type, relevant outcomes and results of these articles are tabulated. Those articles reporting improvement in PFTs following plication, documented this benefit in the following parameters: mean forced vital capacity (range 17-40%), forced expiratory volume at 1 sec (range 21-27%), functional residual capacity (range 20-21%) and total lung capacity (range 16-19%). The percentage of postoperative improvement in shortness of breath as measured by a dyspnoea score was reported to be between 90 and 96% in the thoracotomy group and 100% in the Video Assisted Thoracoscopic Surgery (VATS) group, the dyspnoea score that was used in all the studies was a visual analogue scale between 0 and 10 where 0 is no dyspnoea and 10 is the worst dyspnoea a patient can have. One of the studies reported postoperative normalization in ventilation perfusion scan (VQ) scan parameters when compared with the preoperative mismatch. Complication rate was similar between the two groups, while the mortality rate was 4% in the thoracotomy group and 0% in the VATS group. The total number of patients included in all the studies combined was 161. All reports included in this review are observational studies (one cohort study and the remainder being case series); therefore, the risk of selection, information and publication biases are high and conclusions should be implemented with caution. We conclude that diaphragmatic plication can improve the functional status, shortness of breath and PFTs of patients with unilateral diaphragm paralysis. Patients undergoing a VATS approach appear to have more advantages in objective and subjective measures (including PFTs, dyspnoea score, length of hospital stay and postoperative complications). Further research with high-quality study designs is advised, focussing mainly on the long-term benefits and assessment of health-related quality of life.     

Phrenic nerve paralysis following lung transplantation

Phrenic nerve paralysis is a well-documented complication of cardiac operation, but there is less commonly reported after lung transplantation. A retrospective study of 49 lung transplantation was done at Okayama University Hospital. Phrenic nerve paralysis (unilateral in 3 patients and bilateral in 1) was found in 4 patients (8.2%). All of these paralyses were transiently recovered. The average length of ventilation, intensive care unit stay and hospitalization for recipients with phrenic nerve paralysis was not significantly longer than the other (no diaphragmatic paralysis) recipients, but there was a tendency to be longer. Diaphragmatic paralysis is most likely related to difficulty in detecting the phrenic nerve caused by adhesions, injury due to dissection, thermal injury by electrocartery, or local topical hypothermia using ice-slush. Therefore, it is important to take care of avoiding the injury of the nerve during the operation.     

Diaphragmatic Incisions Guided by Nerve Stimulator: A Respiratory Study

Thirty-four patients with hiatus hernia, divided into two groups, were operated upon by the transthoracic and transdiaphragmatic approach. In half of the patients (group I), the diaphragmatic incisions were made without the guidance of the nerve stimulator. In the other half (group II), the line of diaphragmatic incisions was guided by the nerve stimulator in order to avoid injury to the phrenic nerve. The pre- and postoperative respiratory function, arterial blood gas tensions, and diaphragmatic functional tests were statistically analysed in both groups. In group I, significant reductions in regional ventilation, perfusion and volume of the left lung, particularly the left basal field, were associated with a high incidence of diaphragmatic paralysis (10/17). Application of the nerve stimulator in group II resulted in significant improvement in the regional lung function after surgery and the diaphragmatic paralysis could be almost avoided (1/17). No statistical differences in the spirometric values could be demonstrated between the groups. However, a significant reduction in VC, FEV₁ and TLC was recorded when the subjects with diaphragmatic paralysis were compared with those with preserved innervation.     

Effect of lung transplantation on diaphragmatic function in patients with chronic obstructive pulmonary disease.

BACKGROUND--To date there are no data on the effects of lung transplantation on diaphragmatic function in patients with end stage chronic obstructive pulmonary disease (COPD). It is not known whether the relation between the transdiaphragmatic pressure (PDI) and lung volume is altered in recipients after transplantation as a result of changes in diaphragmatic structure caused by chronic hyperinflation. The effect of lung transplantation on diaphragmatic strength was determined in patients with COPD and the relation between postoperative PDI and lung volume analysed. METHODS--Diaphragmatic strength was assessed in eight double lung transplant recipients, six single lung transplant recipients, and in 14 patients with COPD whose lung function was similar to those of the transplant recipients preoperatively. PDI obtained during unilateral and bilateral phrenic nerve stimulation at 1 Hz (twitch PDI) at functional residual capacity (FRC) and during maximal sniff manoeuvres (sniff PDI) at various levels of inspiratory vital capacity (VCin) served as parameters for diaphragmatic strength. Sniff PDI assessed at the various VCin levels were used to analyse the PDI/lung volume relation. RESULTS--Lung transplantation caused a reduction in lung volume, especially in the double lung transplant recipients. As a consequence sniff PDI was higher in the double lung transplant recipients than in the patients with COPD at all levels of VCin analysed. However, sniff PDI values analysed at comparable intrathoracic gas volumes were not reduced in the patients with COPD when compared with those who underwent lung transplantation. Bilateral twitch PDI values were similar in the patients with COPD and in the lung transplant recipients. In the single lung transplant recipients unilateral twitch PDI values were similar on the transplanted and the non-transplanted side. The relation between PDI and lung volume was similar in the patients with COPD and in the lung transplant recipients. CONCLUSIONS--In patients with COPD lung transplantation leads to an increase the maximal sniff induced PDI values by placing the diaphragm in a more favourable position for pressure generation. Since patients with COPD and postoperative lung transplant recipients showed similar PDI/lung volume relations, this suggests that chronic pulmonary hyperinflation does not cause major functional alterations of the diaphragm.     

Phrenic and diaphragm function after coronary artery bypass grafting.

We studied respiratory mechanics and phrenic nerve and diaphragm function in 12 patients on the day before and eight to 13 days after coronary artery bypass grafting. The average vital capacity, functional residual capacity, and total lung capacity decreased by 20.5%, 9.5%, and 14.7% respectively after operation. Eleven patients showed less negative maximum inspiratory mouth pressures at any given lung volume after surgery and the magnitude of the change correlated with the reduction in total lung capacity. In 11 of the 12 patients the conduction times of the right and left phrenic nerves did not change substantially after operation and the ratio of inspiratory electrical activity (Edi) of left and right hemidiaphragms was similar before and after the procedure. One patient, however, showed a considerable increase in left phrenic nerve conduction time and a reduction in the left to right Edi ratio postoperatively. In three patients diaphragm function was also assessed by changes in transdiaphragmatic pressure during supramaximal phrenic nerve stimulation and voluntary increase in inspired volume; in none of the three patients did the transdiaphragmatic pressure swings show any significant change in the postoperative period. These data indicate that phrenic nerve paralysis only occasionally accounts for the postoperative loss of lung volume after coronary artery bypass grafting surgery. The mechanism of these abnormalities therefore remains to be determined.     

Comparative clinic study on vascularized and nonvascularized full-length phrenic nerve transfer

In order to understand whether the vascularizing procedure has any clinical value in nerve transfer and grafting, we compared nonvascularized and vascularized full-length phrenic never transfers in patients with a brachial plexus injury. Full-length phrenic nerve transfer to the musculocutaneous nerve had been conducted by the technique of video-assisted thoracic surgery in 15 patients. Three kinds of procedures were carried out. The first involved retaining the initial point of the phrenic nerve and dissecting the full-length distal nerve. The second involved keeping the cervical segment and isolating the thoracic segment of the phrenic nerve. The last involved vascularized phrenic nerve transfer. All these phrenic nerves were sutured to musculocutaneous nerves. After 28-35 months, the results of electrophysiology and function of the biceps brachii muscle were compared. All three procedures had no significant differences and led to the same functional recovery of the biceps brachii muscle after at least 28 months of follow-up. In conclusion, the vascularizing procedure had little clinical value, not only in full-length phrenic nerve transfer, but also in nerve grafting irrespective of the length of the gap, when the recipient bed had normal vascularity.     

Brachial plexus neurotization with donor phrenic nerves and its effect on pulmonary function

OBJECT: To examine possible side effects of neurotizations in which the phrenic nerve was used, pulmonary function was analyzed pre- and postoperatively in patients with brachial plexus injury and root avulsions. METHODS: Twenty-three patients with complete brachial plexus palsy underwent neurotization of the musculocutaneous nerve, with the phrenic nerve as donor material. Patients who suffered lung contusions as part of the primary injury were excluded from this study. In 12 patients (five left-sided and seven right-sided neurotizations) pre- and postoperative functional parameters were compared and additional body plethysmography was performed more than 12 months postsurgery. Of the 23, no patient experienced pulmonary problems postoperatively. Nonetheless, pulmonary functional parameters showed a vital capacity in percent of the predicted value of 9.8 +/- 6.3% (mean +/- standard deviation [SD]) in all patients examined, which was a significant reduction (p = 0.0002). In right-sided phrenic nerve transfers this reduction was significant, at 14.3 +/- 3.3% (mean +/- SD), whereas left-sided transfers showed a nonsignificant reduction of 3.6 +/- 3.5% (mean +/- SD). The observed decrease in vital capacity (VC) correlates with the maximal inspiratory pressure (Pi(max)) as an indication of clinical significance. CONCLUSIONS: When the right phrenic nerve is used as a donor in neurotization of the musculocutaneous nerve, the patient incurs a higher risk of reduced pulmonary VC. If possible, the left phrenic nerve should be preferred. The Pi(max) has to be determined preoperatively to avoid any further decrease in the already reduced pulmonary function due to the initial injury.     

Improvement of diaphragmatic function by a thoracic extradural block after upper abdominal surgery

The effects on diaphragmatic function of a thoracic epidural block were assessed in 13 patients after upper abdominal surgery (UAS). Lung volumes and tidal changes in chest wall circumferences and gastric (delta Pgas) and esophageal (delta Pes) pressures were measured pre- and postoperatively. Volume displacement of the abdomen divided by tidal volume (delta VAB/VT) and delta Pgas/delta Pes were taken as indices of the diaphragmatic contribution to tidal breathing. These respiratory variables were obtained in the postoperative period, before and after epidural injection of 0.5% plain bupivacaine to achieve a block up to the T4 segment. UAS was constantly associated with a decrease in VT, delta VAB/VT, delta Pgas/delta Pes, and forced vital capacity (FVC). Epidural block was associated with an increase in VT, delta VAB/VT, and FVC. delta Pgas and delta Pgas/delta Pes returned to their preoperative values. It is concluded that: 1) diaphragmatic dysfunction observed after UAS is partially reversed by thoracic epidural block; and 2) that inhibitory reflexes of phrenic activity arising from the abdominal compartment (abdominal wall and/or viscera) could be involved in this diaphragmatic dysfunction.     

Diaphragmatic paralysis: pathology at the reach of the pediatric surgeon

The phrenic nerve is the only motor nerve in the diaphragm. The injury will lead to a diaphragmatic paralysis or eventration with paradoxical movements during breathing. The aim of this review is to analyze the diagnostic criteria, surgical indications, and the patients that are not treated by surgery. We review 53 cases with diaphragmatic pathology in the last 5 years; 19 females and 20 males. One was a diaphragmatic rupture, 13 were diaphragmatic hernias, and 39 had diaphragmatic paralysis. Diaphragmatic paralysis was diagnosed by fluoroscopy in 97%, electromiography 5.1% or ultrasounds. The ethiology was 64% after cardiac surgery and 10% after thoracic oncologic surgery. The age at diagnosis was less than 1 month in 41% cases. In 29 patients the paralysis was well tolerated and were extubated between 24 h and 4 days after the diagnosis, frequently was in the first 48 h. 4 patients need a traqueostomy and 2 went to another hospital. In 5 we performed a diaphragmatic plication because the inability to be extubated or the persistence of respiratory distress. The paralysis was demonstrated by fluoroscopy. 2 patients are asymptomatic, 2 are in mechanical ventilation and 1 died (sepsis). The most frequent cause of diaphragmatic paralysis was related to cardiac or thoracic surgery. In general, is well tolerated, almost asymptomatic, the patients were extubated between 24 or 48 h. In pediatric population they are few cases that need surgical treatment. The patients that we operated on were less than 2 months old, because is at that age were the repercussion is more important. We must follow strict criteria, without precipìtation for the surgical indications.     

Diaphragmatic plication for unilateral diaphragmatic paralysis: a 10-year experience

Unilateral paralysis of the diaphragm due to nonmalignant disease is an uncommon disorder previously thought to have benign implications. Some patients, however, experience dyspnea and orthopnea with impairment of pulmonary function. Unilateral diaphragmatic plication was performed on 17 patients (16 men and 1 woman with a mean age of 53.7 years [range, 28 to 74 years]) during the last 10 years. Preoperatively each patient was shown to have paradoxical movement of the paralyzed diaphragm on sniffing and to have a reduction in forced vital capacity and lung volumes. These reductions were greater when the patient was in the supine position. All patients had moderate hypoxemia (mean arterial oxygen tension, 73.1 +/- 10.9 mm Hg). Plication was performed by imbricating the diaphragm in layers through a thoracotomy incision. After plication, all patients showed both subjective and objective improvement. Six patients were reassessed 5 or more years after plication (range, 5 to 7 years), and the improvement was maintained. Diaphragmatic plication is a safe and effective procedure for adult patients with dyspnea due to unilateral diaphragmatic paralysis; furthermore, the initial improvement is maintained.     

Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function

Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the effect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double-exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double-exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPO2) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty-one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 4-37% of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in 1s (FEV1) and peak expiratory flow (PEF) 3 and 8 h after the block without signs of dyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.     

Unilateral diaphragm paralysis: etiology, impact, and natural history

AIM: The etiology, clinical impact, natural history and best therapy of unilateral diaphragm paralysis (UDP) are incompletely understood. This condition is not amenable to pacing, which requires an intact phrenic nerve. METHODS: Clinical records of patients with UDP referred to our diaphragm center were reviewed. RESULTS: Thirty-six patients (28 male, 8 female) aged 1 month to 78 years (mean 47.8 years) with UDP evaluated from 1983 to February 2007 were reviewed. Etiology was postsurgical in 13 (36%), tumor (with surgery or radiation therapy) in 7 (19%), idiopathic in 6 (17%), trauma (motor vehicle accident or head injury) in 5 (14%), polio in 3 (8%), and viral in 2 (6%) patients. 28 patients (78%) were symptomatic; 8 (22%) carried a diagnosis of coexisting chronic obstructive pulmonary disease. Mean duration of paralysis was 57.9 months (range up to 261 months). The left diaphragm was involved in 23 cases (64%) and the right in 13 (36%). Mean forced expiratory volume (FEV1) was 1 915 mL (61.3% of predicted) and mean forced vital capacity (FVC) was 2 432 mL (62.9% of predicted). Mean pO2 was 69.9 mmHg (range 49 to 124), indicating considerable shunting through underventilated lung. Pulmonary infection affected 3 patients (8.4%). Diaphragm function returned in 17% of patients (mainly children) at mean of 10.3 months. Four incapacitated patients (11 %) were treated surgically, with resection of the hemi-diaphragm. Surgical exploration revealed neurogenic atrophy of the diaphragm muscle. All 4 resected patients showed clinical, oxymetric, and spirometric improvement. CONCLUSION: The conclusion is drawn that: 1) UDP may be traumatic, tumor-related, iatrogenic, or idiopathic; 2) UDP decreases pO(2) substantially and breathing capacity by more than 1/3; 3) spontaneous recovery is possible; 4) UDP is not intrinsically lethal; 5) occasional patients are incapacited; 6) diaphragm resection produces clinical improvement via lower lobe re-expansion; 7) the incapacity incurred by UDP is mild compared to the clinical spectrum of bilateral diaphragm paralysis.