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PubMed1979

[Assessment of residual lesions after a chest trauma (author's transl)].

The correct assessment of residual respiratory lesions after a chest injury requires clinical examination, roentgenographic examination in two planes, lung function tests including ergo-spirometry and blood gas analyses before and after exercise. Oxygen consumption during exercise should be one of the criteria whereby to judge any reduction in working capacity. Improvements in respiratory function have been observed as late as two years after the accident.

Blood Gas Analysis↗
PubMed1978

[The lungs in congenital diaphragmatic hernias (author's transl)].

In congenital diaphragmatic hernias, the presence of abdominal viscera in the thoracic cavity will arrest the development of the ipsilateral lung, and occasionally of the controlateral lung also. The lung may thus be either compressed or hypoplastic in varying degrees. Its state of development conditions the prognosis of this disease. In severe forms, known as "High Risk" forms, presenting in the 3 first days of life with respiratory distress, the lung is very often hypoplastic, the number of bronchial, bronichiolar and vascular generations is diminished. The airways pulmonary function in medium and long term has been studied in 10 children over a period of 3 to 15 years. The clinical radiological, scannery and fonctional lung study results present not unfrequently signs of overdistention, of obstructive disease, and pulmonary bronchectasis on the side of the hernia. The evolution could be explained by the normal post natal multiplication of airways as well as by an increase of their size in such a manner as to occupy the whole thoracic cavity.

Age Factors↗
PubMed1993

Exercise-induced diaphragmatic fatigue in healthy humans.

1. Twelve healthy subjects (33 +/- 3 years) with a variety of fitness levels (maximal oxygen uptake (VO2, max) = 61 +/- 4 ml kg-1 min-1, range 40-80), exercised at 95 and 85% VO2, max to exhaustion (mean time = 14 +/- 3 and 31 +/- 8 min, expired ventilation (VE) over final minute of exercise = 149 +/- 9 and 126 +/- 10 l min-1). 2. Bilateral transcutaneous supramaximal phrenic nerve stimulation (BPNS) was performed before and immediately after exercise at four lung volumes, and 400 ms tetanic stimulations were performed at 10 and 20 Hz. The coefficients of variation of repeated measurements for the twitch transdiaphragm pressures (Pdi) were +/- 7-10% and for compound muscle action potentials (M wave) +/- 10-15%. 3. Following exercise at 95% of VO2, max, group mean Pdi twitch values were reduced at all lung volumes (range -8 +/- 3 to -32 +/- 5%) and tetanically stimulated Pdi values were reduced at both 10 and 20 Hz (-21 +/- 3 and -13 +/- 2%, respectively) (P = 0.001-0.047). Following exercise at 85% VO2, max, stimulated Pdi values were reduced at all lung volumes and stimulating frequencies, but only significantly so with the twitch at functional residual capacity (-15 +/- 5%). Stimulated Pdi values recovered partially by 30 min post-exercise and almost completely by an average time of 70 min. 4. The fall in stimulated Pdi values post-exercise was significantly correlated with the percentage increase in diaphragmatic work (integral of Pdi min-1) from rest to end-exercise and the relative intensity of the exercise. 5. The integral of Pdi min-1 and the integral of Po min-1 (Po, esophageal pressure) rose together from rest through the fifth to tenth minute of exercise, after which integral of Pdi min-1 plateaued even though integral of Po min-1, VE and inspiratory flow rate all continued to rise substantially until exercise terminated. Thus, the relative contribution of the diaphragm to total respiratory motor output was progressively reduced with exercise duration. 6. We conclude that significant diaphragmatic fatigue is caused by the ventilatory requirements imposed by heavy endurance exercise in healthy persons with a variety of fitness levels. The magnitude of the fatigue and the likelihood of its occurrence increases as the relative intensity of the exercise exceeds 85% of VO2, max.

Adult↗
PubMed1996

[Function of the diaphragm during exercise].

We examined the control of respiratory muscles with emphasis on the diaphragm during exercise at 30%, 60% and 90% of maximal working capacity in normal subjects. Control of the diaphragm was quantified by plotting transdiaphragmatic pressure (Pdi), its electromyographic activity (Edi) and its power (Wdi = Pdi x Dab/Ti) vs. workload and Pdi, an index of shortening velocity of diaphragmatic fibres (Dab/Ti) and Wdi vs. Edi. We observed that increase in Pdi (approximately 2-fold) from rest to heavy exercise was inadequately small comparing to increases in minute ventilation (approximately 9-fold) and Edi (approximately 4.5-fold). We hypothesized and confirmed that Wdi might increase even though Pdi decreased due to increasing Dab/Ti and expresses more closely diaphragmatic contribution to inspiratory effort during exercise than Pdi. Significantly augmented shortening velocity of the diaphragm suggests that it acts predominantly as a flow generator during exercise. It is strongly assisted in this task by abdominal muscles. The responsibility for generating inspiratory pressures falls on the inspiratory rib cage muscles. This arrangement may however impair diaphragm's performance even in healthy subjects as indicated by reduced Pdi twitch after exercise.

Adult↗
PubMed2001

Use of rapacuronium in a child with spinal muscular atrophy.

We report the case of an 18-month-old girl with spinal muscular atrophy (SMA) that received 1 mg x kg(-1) rapacuronium for laryngospasm during induction of anaesthesia. Within 15 min, we observed some diaphragmatic recovery and, after emergence from anaesthesia, the child demonstrated adequate respiratory efforts. However, the child showed diminished strength of the upper extremity muscles. Since the preoperative workup had revealed bulbar symptoms and laryngeal function could not be easily assessed, the patient was kept intubated until upper extremity strength had returned to preoperative levels. Small doses of midazolam had been given to reduce the patient's anxiety but the patient was extubated within 5 h without any complications. Train of four (TOF) monitoring of the right adductor pollicis muscle, performed during anaesthetic recovery, was equivocal. In SMA, muscle groups are differentially affected so that TOF responses may be inconclusive and not reflect the state of the upper airway muscles. To our knowledge, this is the first report of use of a nondepolarizing neuromuscular blocking agent in a child with SMA.

Anesthesia, Inhalation↗
PubMed1988

Separate resistive loading of the respiratory phases during mild hypercapnia in man.

Eleven human subjects were studied during steady state, controlled mild hypercapnia with resistive loading of either inspiration (RI) or expiration (RE). Minute ventilation and frequency were significantly reduced by RI (P = less than 0.01) and even more so by RE (P = less than 0.001). Tidal volume was unchanged. Both RI and RE reduced mean flow in the loaded phase - an effect relatively greater with RE. Neither RI nor RE altered mean flow in the unloaded phase. Although mean inspiratory flow was unchanged with RE, mouth occlusion pressure (P0.1) was increased (P = less than 0.01). Functional residual capacity (seven subjects) was increased with RE, but not with RI (P = less than 0.05). Five additional subjects were similarly studied with and without RE in whom transdiaphragmatic pressure (PDi) and peak diaphragmatic EMG (EMGDi) were examined. Changes in ventilation, breathing pattern and P0.1 were similar to those described above. Neither PDi nor EMGDi were significantly altered by RE, but with RE, diaphragmatic EMG activity began 50-190 ms before inspiratory flow. In conclusion, ventilation is reduced more by RE than by RI due to greater respiratory phase time. Moderately heavy RE does not augment inspiratory drive as reflected by mean flow, PDi or EMGDi. With RE and increased FRC, P0.1 does not accurately reflect inspiratory drive because of dissociation between EMG and flow.

Adult↗
PubMed1996

Zone of apposition in the passive diaphragm of the dog.

We determined the regional area of the diaphragmatic zone of apposition (ZAP) as well as the regional craniocaudal extent of the ZAP (ZAPht) of the passive diaphragm in six paralyzed anesthetized beagle dogs (8-12 kg) at residual lung volume (RV), functional residual capacity (FRC), FRC + 0.25 and FRC + 0.5 inspiratory capacity, and total lung capacity (TLC) in prone and supine postures. To identify the caudal boundary of the ZAP, 17 lead markers (1 mm) were sutured to the abdominal side of the costal and crural diaphragms around the diaphragm insertion on the chest wall. Two weeks later, the dogs' caudal thoraces were scanned by the use of the dynamic spatial reconstructor (DSR), a prototype fast volumetric X-ray computer tomographic scanner, developed at the Mayo Clinic. The three-dimensional spatial coordinates of the markers were identified (+/- 1.4 mm), and the cranial boundary of the ZAP was determined from 30-40 1.4-mm-thick sagittal and coronal slices in each DSR image. We interpolated the DSR data to find the position of the cranial and caudal boundaries of the ZAP every 5 degrees around the thorax and computed the distribution of regional variation of area of the ZAP and ZAPht as well as the total area of ZAP. The ZAPht and area of ZAP increased as lung volume decreased and were largest near the lateral extremes of the rib cage. We measured the surface area of the rib cage cephaled to the ZAP (AL) in both postures in another six beagle dogs (12-16 kg) of similar stature, scanned previously in the DSR. We estimated the entire rib cage surface area (Arc = AZAP + AL). The AZAP as a percentage of Arc increased more than threefold as lung volume decreased from TLC to RV, from approximately 9 to 29% of Arc.

Anesthesia, General↗
PubMed1998

Adverse reactions to peak flow monitoring. Report of 5 patients.

Five patients with adverse reactions to peak flow monitoring are presented: 2 patients had herniation of abdominal content, while the others presented with vasovagal syncope, minor depression and neurotic preoccupation with peak flow values, respectively. As a result, 3 of the 5 patients became noncompliant. For nonpsychological somatic adverse reactions, we calculated an incidence of 1.1 cases/1,000 patients started on peak flow monitoring. Adverse reactions with a psychological background may be more frequent. Clinicians should bear in mind that patients noncompliant with peak flow monitoring may have discontinued because of adverse reactions.

Adult↗
PubMed1985

Ventilatory muscle function during exercise in air and oxygen in patients with chronic air-flow limitation.

Ventilatory muscle function was examined at rest and during exercise on a cycle ergometer in 8 patients with moderate to severe chronic air-flow limitation (FEV1, 32 +/- 4% predicted) in air and in oxygen. The diaphragmatic electromyogram (EMG) was measured using an esophageal electrode. In addition, measurements of esophageal (Pes), gastric (Pga), and transdiaphragmatic (Pdi) pressures and abdominal wall movements were made. Patients exercised to exhaustion at a constant submaximal workload (80% of maximal power output) inspiring air or 40% O2 in random order on separate days. At end-exercise in air, tidal inspiratory Pes swings were 36 +/- 4% of static maximal inspiratory Pes, and inspiratory Pdi swings were 45 +/- 7% of the static maximal Pdi. Arterial oxygen saturation decreased from 91 +/- 2% at rest to 80 +/- 5% at end-exercise in air. During exercise in air, 5 patients demonstrated a persistent and greater than 20% fall in the ratio of high frequency (150 to 350 Hz) to low frequency (20 to 46 Hz) power (H/L) of the diaphragmatic EMG, indicating impending diaphragmatic fatigue, and 2 patients had paradoxical motion of the abdominal wall. Exercise time at the same constant work load increased from 3.0 +/- 0.6 min in air to 6.4 +/- 1.2 min in O2 (p less than 0.005). At the comparable time during exercise in O2 to end-exercise in air, minute ventilation was less by 13% (p less than 0.005), which was entirely attributable to a lower frequency of breathing. Mean inspiratory and expiratory flows and heart rate were all significantly lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed2003

Preferential diaphragmatic weakness during sustained Pseudomonas aeruginosa lung infection.

Infection with Pseudomonas aeruginosa plays a major role in the pulmonary inflammation and injury associated with cystic fibrosis. Lung inflammation may also lead to more widespread systemic effects on other organs. We tested the following hypotheses: (1) ongoing P. aeruginosa lung infection produces diaphragmatic and limb muscle weakness and (2) such muscle dysfunction is directly correlated with the level of pulmonary inflammation. Chronic bronchopulmonary infection with mucoid P. aeruginosa was induced in C57BL/6 mice. At Day 2 after infection, diaphragmatic force was decreased (37%) only in mice infected with a high dose of 1 x 10(6) cfu, whereas by Day 7 after infection, diaphragmatic force was similarly reduced (36%) even at a fivefold lower inoculating dose. No significant correlations were found between diaphragmatic weakness and pulmonary inflammation, as assessed by the number of neutrophils, macrophages, and lymphocytes in bronchoalveolar lavage fluid. Moreover, in marked contrast to the diaphragm, no effects of P. aeruginosa infection on contractile function were observed in prototypical slow- and fast-twitch hindlimb muscles. We conclude that sustained lung infection with P. aeruginosa induces preferential weakness of the diaphragm, which is not directly correlated with the degree of pulmonary inflammation induced under these conditions.

Animals↗
PubMed2004

Off-pump coronary artery bypass grafting in a high-risk dextrocardia patient: a case report.

We present an interesting but high-risk case of an obese male patient aged 56 years with dextrocardia and a left diaphragmatic hernia. Anterior myocardial infarction was diagnosed in 1994, and the patient later presented with a history of unstable angina. The diagnosis for this chronic smoker was triple-vessel disease, impaired left ventricular function, chronic renal failure, chronic bronchitis, impaired lung function, pulmonary hypertension, hypertension, diabetes, and chronic active gastritis (EuroSCORE of 10). The patient underwent successful off-pump coronary artery bypass grafting with 3 saphenous vein grafts to the left anterior descending, obtuse marginal, and right posterior descending arteries. He was discharged home 8 days later.

Coronary Artery Bypass, Off-Pump↗
PubMed2001

[B. V Petrovsky's scientific school at the turn of two centuries].

The paper shows how Academician B. V. Petrovsky's scientific school has been set up and how it has developed. Three stages of its development are identified: 1) the establishment and formation of the school on the basis of the department, the development of large areas of surgery (cardiovascular, thoracic, and esophageal surgeries) in 1951 to 1963; 2) the development of the school within the research institute-department system, the setting up of its branches, specialized services in the country, organizational and methodological management of its related research institutes in 1963 to 1989; and 3) the present period marked by the design and introduction of high technologies, the development of topical research problems (transplantation of the heart and liver, including related, miniinvasive surgery, computer-aided monitoring, telemedicine, as well as staff training). Four world's priorities of the school are noted. They included as follows: diaphragmatic plasty on a vascular pedicle for various abnormalities; the world's richest experience in surgically treating gunshot wounds of the large blood vessels during military actions; discovery of the physiological mechanisms of the function and properties of the valve-aorta complex of the human aortic root; the design and successful clinical application of nitinolic memory prostheses to endoprosthesis. The paper predicts how surgery will develop in the 21st century.

Academies and Institutes↗
PubMed2005

Laparoscopic nephrectomy: an early experience at Queen Mary Hospital.

OBJECTIVE: To report our early experience of laparoscopic nephrectomy. DESIGN: Prospective data collection. SETTING: Queen Mary Hospital, Hong Kong. PATIENTS: Transperitoneal laparoscopic nephrectomies were performed on 40 patients between July 1997 and December 2002. MAIN OUTCOME MEASURES: Demographic and perioperative data including operating time, blood loss, postoperative pain score, analgesic requirement, complications, time to resume oral intake, ambulatory state, and length of hospital stay. RESULTS: Laparoscopic nephrectomy was performed for 21 solid renal masses, five transitional cell carcinomas, and 14 non-functioning kidneys. Seven (17.5%) patients had previous abdominal surgery. The mean body mass index of the patients was 23.9 kg/m(2) and the mean operating time was 229 minutes. The mean estimated blood loss was 370 mL, and two patients required conversion to open surgery because of intra-operative bleeding. Other complications include diaphragmatic injury, port-site bleeding, chyle leakage, bleeding peptic ulcer, and myocardial ischaemia. The postoperative mean analgesic requirement was 26 mg of morphine sulphate equivalent. The mean time for patients to resume oral diet and full ambulation was 1.3 and 2.8 days, respectively, and the mean length of hospital stay was 6.7 days. The mean diameter of the solid renal tumour was 4.1 cm and the surgical margins of all resected specimen for malignant tumours were negative. CONCLUSION: Laparoscopic nephrectomy is a safe and efficacious approach for resection of benign non-functioning kidneys and malignant renal tumours.

Blood Loss, Surgical↗
PubMed1999

[Extracorporeal respiratory assistance (ECRA): initial experiences in Spain].

UNLABELLED: The attendance respiratory extracorporeal (AREC) is an oxygenation form for membrane extracorporeal with flow tidal and veno-venous cannula described by Chevalier et al. in 1990. We present our clinical experience so much with AREC in system veno-venous flow tidal as veno-arterial. From october of 1997 until the present time we have treated three patients by means AREC, in two patients with veno-venous system and in one veno-arterial. In all the cases bomb Collin-Cardio has been used with bladder for flow tidal and membrane of oxygenation of 0.8 m2, being inserted a system of alternative clamp of the branches of the circuit. The system AREC has been used in two patients with congenial diaphragmatic hernia, right in a case and left in the other one. The gestational age was of 38 and 36 weeks with a weight of 3,200 and 2,900 grams. Both patients were remitted from other centers by failure of the conventional treatment. In both cases the indication of AREC was the sharp deterioration of the general state with failure of the conservative treatment, being the previous oxygenation index of 109 and 112. The third patient precised veno-arterial AREC for ventricular failure during the correction of the congenital heart disease, this patient was 5 month old and the weight was 5,000 grams. The duration of AREC in the cases of congenital diaphragmatic hernia was of 14 and 10 days. In a patient the diaphragmatic hernia was corrected at the 55 hours of being in AREC. In the second case the hernia had been surgical corrected in another center. The exit of AREC in both cases carries out after a discreet improvement of the lung function. Both patients died at the 24 and 48 hours of the decannulation for cerebral hemorrhage and respiratory failure. The third patient stayed stable in veno-arterial AREC during 4 days, with hemodynamic support of 130 ml/kg/min, retiring the support to present absence of cerebral activity. CONCLUSIONS: With the derived limitations of the extreme severity of the treated cases and the current phase of beginning of the AREC team, we think that it is a useful and available technique in our country, for the handling of patient with cardiorespiratory failure while waiting for improvement of their base pathology.

Age Factors↗
PubMed1997

Surgery of the small intestine.

Although earlier reports describe a poor prognosis for small intestinal surgery in the horse, there is growing evidence that the short-term survival rate can exceed 80%. In addition to advancements in surgery and aftercare, early referral contributes considerably to the improved prognosis. Surgical procedures that restore anatomic and physiologic continuity to close to normal can minimize postoperative complications. Jejunojejunostomy carries a better prognosis than jejunocecostomy, probably because the latter involves anastomosis between two intestinal segments with dissimilar functions. Careful technique can reduce the prevalence of complications, such as postoperative ileus and serosal adhesions.

Anastomosis, Surgical↗
PubMed1996

Single lead DDD system: a comparative evaluation of unipolar, bipolar, and overlapping biphasic stimulation and the effects of right atrial floating electrode location on atrial pacing and sensing thresholds.

Single lead DDD pacing using unipolar or bipolar stimulation is limited by high atrial threshold. Overlapping biphasic (OLBI) waveform stimulation via atrial floating ring electrodes may preferentially enhance atrial pacing and avoid diaphragmatic pacing. Single lead DDD pacing with OLBI atrial pacing was studied in 12 patients (6 men and 6 women; mean age 74 +/- 7 years) with complete heart block. At implantation, atrial bipolar rings (area 27 mm2, separation 10 mm) were positioned at radiological defined high, mid, and low right atrial (RA) levels, and P wave amplitude and atrial and diaphragmatic pacing thresholds were determined in each position using unipolar, bipolar, and OLBI stimulation in random order. Although statistically insignificant, both the maximum and minimum sensed P wave amplitudes tended to be lower in the low RA position. Independent of the stimulation modes, minimum atrial pacing threshold occurred in the mid-RA. At mid-RA, the atrial pacing threshold was significantly lower with OLBI pacing compared with either unipolar or bipolar mode (3.9 +/- 2.2 V vs 6.7 +/- 3.5 V and 6.9 +/- 3.5 V, P < 0.05). Although the diaphragmatic thresholds were similar, OLBI pacing modes in the mid-RA and final location significantly improved the safety margin for avoidance of diaphragmatic pacing compared with unipolar mode. There was no correlation between atrial pacing and sensing threshold. At predischarge testing, all but one patient who developed atrial fibrillation had satisfactory atrial capture and a stable atrial pacing threshold (day 0: 2.6 +/- 1.1V vs day 2:3.2 +/- 1.3V, P = NS). However, diaphragmatic pacing occurred in four of 11 (36%) patients, especially in the upright position (sitting and standing). Our preliminary clinical results suggest that OLBI pacing via atrial floating ring electrodes can reduce the atrial pacing threshold. To optimize atrial pacing and sensing, the bipolar electrodes should be located at the mid-RA level first, although the high RA is an alternative. Despite significant improvements in the safety margin for diaphragmatic pacing with OLBI pacing, diaphragmatic stimulation remains a clinical problem.

Aged↗