[Can muscle relaxation prevent the development of pneumothorax in artificially ventilated newborn infants?]

A retrospective study was conducted on 37 ventilated newborn infants to find out whether muscle paralysis by pancuronium had prevented pneumothorax (pt) in those severely ill newborn infants. In the group of 21 newborns who developed pt, 17 (81%) had been paralyzed with pancuronium. In the group of 16 newborns without pt, 10 (61%) had received pancuronium (chi 2 = 1,568, ns). Thus, muscular paralysis had not prevented pt. Since the newborns in both groups were equally severely ill (mean compliance of the respiratory system 0.48 +/- 0.17 ml/cm H20 in the group with pt, 0.38 +/- 0.12 in the group without pt), we assume that pancuronium was unable to prevent pt in ventilated premature and full-term newborn infants. We therefore caution against the use of pancuronium as a paralytic drug known to have deleterious side effects.

Position may reduce or stop pneumothorax formation in dogs receiving mechanical ventilation

We have previously shown that in dogs with normal lungs, dependent placement of the puncture site reduced and/or stopped pneumothorax formation while breathing spontaneously. This experiment is now repeated in an acute injury model in dogs receiving either intermittent positive pressure ventilation (IPPV) or continuous positive pressure ventilation (CPPV). Pneumothorax was induced by percutaneous transthoracic insertion of a 20-gauge needle into the right lung. After a constant rate of pneumothorax formation was established (measured by evacuation of right pleural gas by chest tube), the dogs were alternated between 3 min with the puncture site up (left decubitus) or down (right decubitus). Only when the puncture was placed down did the rate of pneumothorax formation decrease (in every case), and this maneuver caused the leak to seal in 21 and 30% of the times with IPPV and CPPV, respectively. These results are consistent with the hypothesis that dependent placement of the puncture site allows reduction of both the alveolar size and alveolar to pleural pressure difference in the region surrounding the leak, thereby reducing and possibly stopping pneumothorax formation.

[Results of treatment of newborn infants with diaphragmatic hernias]

The article generalizes an experience with the treatment of 91 newborns with diaphragmatic hernias for the period from 1955 to 1985. The diagnostics has improved and greater amount of newborns were admitted to the clinic within the first day after birth. The frequency and character of postoperative complications were analyzed as well as causes of their appearance and effective measures for their prevention and structure of lethality. The tactics of resuscitation both before and after operation has been changed: the artificial ventilation of the lungs was performed without a positive pressure at the end of the expiration with the use of Tubarin and infusion of Dopamine. Lethality was 2 times reduced.

Complications of transthoracic needle biopsy decreased with isobutyl 2-cyanoacrylate: a pilot study

To explore the possibility of performing percutaneous lung biopsy safely in patients mechanically ventilated with positive-end expiratory pressure (PEEP), transthoracic needle biopsy was performed in 16 anesthetized mongrel dogs mechanically ventilated with 10 cm H2O of PEEP. To obtain the biopsy sample, a 25-gauge "skinny needle" was passed through a 20-gauge sheath and placed up to 6.25 cm deep. After satisfactory samples were obtained, both needles were withdrawn in the control group, but in the treated group, the outer sheath was used to inject 0.5 ml of isobutyl 2-cyanoacrylate to seal the needle track. Pneumothorax was present in 7 (87.5%) of 8 dogs in the control group and in 2 (25%) of 8 dogs in the treated group (p = .0147). Lung tissue exhibited an apparent foreign-body granulomatous inflammatory reaction. This technique could extend the benefits of transthoracic needle biopsy to mechanically ventilated patients, but further studies to prove the safety of isobutyl 2-cyanoacrylate are necessary.

Postcoital catamenial pneumothorax. Report of a case not associated with endometriosis and successfully treated with tubal ligation

A 39-year-old woman had a 7-yr history of recurrent right-sided pneumothoraces. These occurred within 1 to 2 days before or after the beginning of the menstrual cycle. The patient recalled often having developed the right-sided pleuritic pain of pneumothorax during or shortly after sexual intercourse. She had no symptoms or signs to suggest endometriosis. A trial of cyclic birth control pills was unsuccessful in preventing recurrent pneumothoraces. Finally, approximately a year ago, laparoscopic tubal ligation was performed. The patient has not had pneumothorax since. We conclude that in our patient, the catamenial pneumothorax was most likely related to transtubal passage of air during sexual intercourse. Passage from the peritoneum to the pleura presumably occurred through a congenital defect or fenestration of the right hemidiaphragm.

Prophylactic treatment of very premature infants with human surfactant

We undertook a randomized, controlled trial to determine whether human surfactant administered endotracheally at birth to very premature infants (gestational age, 24 to 29 weeks) would prevent the respiratory distress syndrome or reduce its severity. Thirty-one treated infants (birth weight, 938 +/- 286 g) were compared in a blinded fashion with 29 control infants (birth weight, 964 +/- 174 g). The lecithin/sphingomyelin ratio was less than 2 in all infants, and phosphatidylglycerol was not present in amniotic fluid or tracheal fluids at birth, indicating a deficiency of surfactant in the lungs. The principal dependent variables were neonatal death, the incidence of bronchopulmonary dysplasia, and the infant's requirement for respiratory support (and its complications). The surfactant-treated group had significantly fewer deaths than the control group (16 percent vs. 52 percent, P less than 0.001), fewer cases of bronchopulmonary dysplasia (16 percent vs. 31 percent), and significantly fewer cases of pulmonary interstitial emphysema (P less than 0.001) and pneumothorax (P less than 0.02). Prophylactic treatment with human surfactant also substantially reduced the period of neonatal intensive care. We conclude that treatment with human surfactant offers promise for improving the survival of very premature infants with a surfactant deficiency and for reducing the pulmonary sequelae of the respiratory distress syndrome.

Franz Kuhn. His contribution to anaesthesia

The history of tracheal intubation has been described before, but earlier accounts have overlooked several aspects and, in particular, the part played by Kuhn, who also deserves to be recognised for a number of other original contributions to anaesthesia.

[The importance of pressure registration in mask-balloon ventilation]

In positive pressure hand ventilation appropriate ventilatory pressures are essential for effectiveness and safety of treatment. Workers in a Neonatal Intensive Care Unit were asked to ventilate an imaginary patient. A diaphragm-manometer was used for measurements. This manometer was only visible to the investigator. Peak inspiratory pressure (PIP) and peak end expiratory pressure (PEEP) were recorded. Rather great differences in administered PIP were observed. Unintentionally, PEEP was given in many cases. It is concluded, that in positive pressure hand ventilation pressures should be monitored by measurement.

The eleventh rib transcostal incision: technique for an extrapleural approach

The transcostal extrapleural flank approach to the kidney requires an understanding of thoracic and abdominal wall anatomy to prevent injury to the pleura and subsequent pneumothorax. Isolation of the intercostal neurovascular bundle, division of the lumbodorsal fascia inferior to the rib bed and simultaneous dissection of the diaphragmatic insertion along the superior and posterior aspects of the 12th rib toward the lumbocostal arch are necessary surgical maneuvers before release of the diaphragm, exposure of Gerota's fascia and positioning of a flank retractor. Pneumothorax usually results from attempts to separate the pleura from the diaphragm, dissection within the intercostal space rather than along the diaphragmatic insertions and failure to release the diaphragm fully as far as the lumbocostal arch before placement of the retractor. Precise appreciation of the pericostal anatomy allows the urological surgeon to remain extrapleural during this commonly used flank incision.

Pancuronium prevents pneumothoraces in ventilated premature babies who actively expire against positive pressure inflation

Preterm infants who were making expiratory efforts against ventilator inflation were randomised to be paralysed with pancuronium or to receive no paralysing agent during ventilation. Pneumothoraces developed in all 11 unparalysed babies but in only 1 of 11 (p less than 0.0004) of those managed with pancuronium, which had no serious side-effects. In 34 infants excluded from the trial because they were not breathing against the ventilator, no pneumothoraces developed.

Position may stop pneumothorax progression in dogs

We attempted to see what the effect of position was on the rate of pneumothorax formation. In 6 anesthetized spontaneously breathing dogs in the left decubitus position, a chest tube was inserted into the right hemithorax. A right-sided pneumothorax was induced by percutaneous transthoracic insertion of a 20-gauge needle into the lung. Once a constant rate of pneumothorax formation occurred, the dogs were alternated between 3 min of no evacuation by the chest tube with the puncture site up (left decubitus) or down (right decubitus). The pneumothorax that accumulated was always evacuated immediately thereafter with the chest tube in the highest position (left decubitus). In every case, the rate of pneumothorax formation decreased with the puncture site down rather than with it up. Furthermore, this maneuver caused the site of leak to completely seal 11 of 21 times in which the puncture site was placed dependent. There was, however, no significant change in the rate of pneumothorax formation with the puncture site kept in the nondependent position. These results are consistent with the hypothesis that placing the site of pleural gas leak in the most dependent position causes a reduction in alveolar size as well as the alveolar to pleural pressure gradient in the region surrounding the leak. Both of these factors would tend to slow the rate of pneumothorax formation and allow sealing of the puncture site.

Tetracycline pleurodesis during active pulmonary-pleural air leak for prevention of recurrent pneumothorax

Pleurodesis with a sclerosing agent was attempted in an animal model in which a pneumothorax with an active air leak was created. Adult rabbits had a small left thoracotomy and then a 1-cm controlled cut in the lung surface. Animals served as control, or tetracycline was administered. The chest tube was removed after the air leak stopped. Animals were sacrificed after 20 days. Group A was control rabbits (6); group B had powdered tetracycline placed at thoracotomy; group C, tetracycline solution, 2 ml/kg, 25 mg/ml (4); and group D, tetracycline solution, 1 ml/kg, 50 mg/ml (10). Control rabbits showed few adhesions, and the pleura appeared to be normal by histologic examination. There was a spectrum of results with tetracycline, but with the concentrated tetracycline solution (group D) histologic examination showed uniform pleurodesis and thickening of the pleura. In group D it took no longer for the pulmonary air leak to seal than with the group A (control) rabbits. We conclude that concentrated tetracycline solution is effective in causing pleurodesis even when an active air leak is present. The lung, however, must be kept expanded so that symphysis can occur between the visceral and parietal pleura.

Prospective clinical comparison of two methods for mechanical ventilation of neonates: rapid rate and short inspiratory time versus slow rate and long inspiratory time

A prospective comparison was made of the clinical courses of two groups of neonates ventilated according to different protocols: one group at rates of 20 to 40/minute with a one-second IT, and the other at a rate of 60/minute and 0.5 second IT. Other ventilator settings were adjusted within protocol limits to maintain desired blood gas values. Mean starting and highest PIP were lower in the rapid rate group. The results showed no difference in mortality, failure to remain within protocol limits, time requiring respiratory treatment or FiO2 more than 0.6, and incidence of PDA or chronic lung disease. There was a difference (P = 0.011) in number of infants developing pneumothoraces (14% in the rapid group vs 35% in the slow group). Rapid rate ventilation can be used to decrease the incidence of pneumothorax, reserving long IT and higher PIP for infants who cannot be oxygenated or ventilated without them.

Pancuronium during mechanical ventilation speeds recovery of lungs of infants with hyaline membrane disease

Spontaneous breathing during mechanical ventilation in newborn infants may damage the lung. To find out whether the prevalence of lesions which might be due to trauma was reduced by muscle relaxation, fifty infants who required mechanical ventilation of hyaline membrane disease were randomly assigned to treated and control groups. The treated infants were kept muscle relaxed with pancuronium bromide until they needed a FiO2 of 0.40 or less during ventilation. The mean birthweight, gestational age, age at entry to the trial, duration of intubation and ventilation, FiO2 during the acute phase of the illness, and ventilator pressures were closely comparable in the two groups. Two of twenty-six treated infants and one of twenty-four controls died. Four treated and five control infants acquired pneumothoraces and/or interstitial emphysema. The length of time that the treated infants required added oxygen was significantly less than in the control infants. All treated infants were breathing room air spontaneously by one month of age whereas seven control infants were still dependent on added oxygen, needing an average FiO2 of 0.35 to achieve a mean PaO2 of 6.5 kPa (49 mm Hg). These seven infants required added oxygen until they were 5-18 (mean 10) weeks old. Muscle relaxation during mechanical ventilation for hyaline membrane disease speeds recovery of the lungs, probably owing to a reduction in traumatic damage.

Silver nitrate pleurodesis in spontaneous pneumothorax

Pleurodesis provoked by instillation of silver nitrate as prevention against recurrence in primary spontaneous pneumothorax has been used for many years in the Department of Thoracic Surgery, Gentofte Hospital, University of Copenhagen. The treatment was originally instituted on a theoretical empiric basis. In a prospective, controlled investigation of pleurodesis versus simple drainage the empiric observations have been confirmed. With simple drainage we found ipsilateral recurrence of pneumothorax in 45%, while no recurrences in the pleurodesis group were found during an observation period of 5-19 months. The difference was statistically significant. The therapeutical gain using pleurodesis was 45% +/- 30%. Silver nitrate pleurodesis results in a longer hospitalization, raises the number of pleurocentesis because of increased pleural effusion and results in more pain than simple drainage. It is, however, our experience that the considerable therapeutical gain more than compensates for these negative effects. We recommend pleurodesis as the treatment of choice in primary spontaneous pneumothorax in patients with only tiny blebs on the surface of the lungs.

Catamenial pneumothorax

A report is given of a 46-year-old woman, who had nine recurrencies of a catamenial right-sided pneumothorax. During anovulatory hormone treatment no recurrency was noted for the following 6 months.

Procedures in practice. Pleural aspiration and biopsy

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Prevention of pneumothorax in needle lung biopsy by breathing 100% oxygen

In an attempt to decrease pneumothorax after transthoracic needle lung biopsy we evaluated the effect of breathing 100% oxygen during the procedure. Fifty consecutive biopsies on 46 hospital patients were performed on subjects breathing either oxygen or compressed air. The selected gas, chosen randomly, was given for five minutes before the biopsy and continued for 30 minutes after. Twenty-six procedures were on air (group 1) and 24 on pure oxygen (group 2). Four subjects in group 2 were eliminated from analysis because they were unable to sustain the required oxygen breathing. Results showed fewer pneumothoraces with subjects breathing oxygen (four out of 20) than with those breathing air (11 out of 26). Three patients in group 1 required chest tube drainage for symptoms of dyspnoea, but none were required in group 2. The peak area of gas accumulation for each pneumothorax was smaller in group 2, with a mean surface area of 27·1 cm² (range 9·6-63·8), than in group 1 mean of 68·1 cm² (range 6·4-172·4). The rather surprising finding of fewer pneumothoraces in the oxygen group may be explained by rapid absorption of small leaks immediately after lung puncture. These results were statistically significant (p<0·05). We conclude that 100% oxygen breathing during transthoracic needle biopsy decreases the number and size of pneumothoraces and propose this simple technique to decrease the morbidity of transthoracic needle lung biopsy.

Muscle relaxation in mechanically ventilated infants

We evaluated the effect of muscle paralysis on gas exchange and incidence of pneumothorax in 35 severely ill infants on mechanical ventilation. Pancuronium (0.1 mg/kg) was given repeatedly until spontaneous respirations ceased in infants with inadequate gas exchange with FIO2 greater than 0.60, or peak inspiratory pressure greater than 30 cm H2O, or who were breathing out of phase with the respirator. Of 27 infants who had an alveolar-arterial oxygen gradient greater than 300 torr before paralysis, AaDO2 improved by greater than 100 torr within one hour of paralysis in only two infants; it worsened in two infants within the same period. By six hours postparalysis, 12 of 27 infants had improved, five of whom had had a worsening AaDO2 before administration of pancuronium. Changes in oxygenation were unrelated to changes in arterial carbon dioxide tension in most infants. Peak transpulmonary pressures after paralysis were lower than during spontaneous breathing, and may explain the low incidence of pneumothorax (3 of 35) during paralysis. Since those who improved could not be distinguished by birth weight, gestational age, or diagnosis, pancuronium might be worthy of trial in a mechanically ventilated infant with severe lung disease who is at risk for pneumothorax.

Bilateral tube thoracostomy to preclude fatal tension pneumothorax in patients with acute respiratory insufficiency

Two patients with acute respiratory insufficiency requiring prolonged mechanical ventilation are described. Both patients developed fatal unilateral tension pneumothoracies after the respiratory insufficiency appeared to be improving. The pneumothorax in each patient appeared to be the result of high inspiratory pressures resulting from high tidal volumes and positive end expiratory pressure. Currently, we recommend bilateral chest tube thoracostomies for those patients with inspiratory pressures greater than 40 cm H2O as a prophylaxis against this fatal complication.

Apical pneumatocele

Cervical herniation of the lung is a rare condition that results from congenital agenesis of Sibson Fascia. Occasionally, this may result from acquired causes like trauma. We report a rare case of a patient who was recently encountered in our Otorhinolaryngological Clinic and who posed an interesting problem of differential diagnosis. The management of such patients requires frequent checkups to safeguard against spontaneous pneumothorax. An otolaryngologist should not be caught unaware as the rhythmic "ballooning" of the supraclavicular area is quite characteristic with forced expiration.

Special new low resistance to flow tube and endotracheal tube adapter for use during fiberoptic bronchoscopy

This paper describes endotracheal tubes and adapters which are designed specially for fiberoptic bronchoscopy; the tubes are designed in such a way that they are wide at the upper part but are narrow and thin walled in the part of the tube which goes through and below the cords. By designing tubes in this manner, the resistance to flow of gas through the tube when the fiberoptic bronchoscope is in place is very much reduced and the safety of the whole precedure is enhanced. A special adapter for use under these circumstances is also described which utilizes a commercially available swivel tracheostomy adapter with a special silicone diaphragm fitted onto the top to enable the fiberoptic bronchoscope to be placed through the diaphragm and keep a sealed system. A plug is available for the hole in the diaphragm when the fiberoptic bronchoscope is not being used. Clinical and laboratory data show that these pieces of equipment perform the function for which they were designed.