Neuromuscular paralysis for newborn infants receiving mechanical ventilation

BACKGROUND

Ventilated newborn infants breathing in asynchrony with the ventilator are at risk for complications during mechanical ventilation, such as pneumothorax or intraventricular hemorrhage, and are exposed to more severe barotrauma, which consequently could impair their clinical outcome. Neuromuscular paralysis, which eliminates spontaneous breathing efforts of the infant, has potential advantages in this respect. However, a number of complications have been reported with muscle relaxation in infants, so that concerns exist regarding the safety of prolonged neuromuscular paralysis in newborn infants.

OBJECTIVES

To determine whether routine neuromuscular paralysis of newborn infants receiving mechanical ventilation compared with no routine paralysis results in clinically important benefits or harms.

SEARCH STRATEGY

MEDLINE (from 1966 to May 2000) and EMBASE (from 1988 to May 2000) were searched, as well as The Cochrane Controlled Trials Register (issue 2, 2000). References of review articles were hand searched. Language restriction was not imposed.

SELECTION CRITERIA

All trials using random or quasi-random patient allocation, in which the routine use of neuromuscular blocking agents during mechanical ventilation was compared to no paralysis or selective paralysis in newborn infants. Methodological quality was assessed blindly and independently by the two authors.

DATA COLLECTION AND ANALYSIS

Data were abstracted using standard methods of the Cochrane Collaboration and its Neonatal Review Group, with independent evaluation of trial quality, and abstraction and synthesis of data by both authors. Treatment effect was analysed using relative risk, risk difference and weighted mean difference.

MAIN RESULTS

Ten possibly eligible trials were identified, of which five were included in the review. All the included trials studied preterm infants ventilated for respiratory distress syndrome, and used pancuronium as the neuromuscular blocking agent. In the analysis of the results of all trials, no difference was found in mortality, air leak or chronic lung disease, but there was a significant reduction in intraventricular hemorrhage and a trend towards less severe intraventricular hemorrhages. In the subgroup analysis of trials studying a selected population of ventilated infants with evidence of asynchronous respiratory efforts, a significant reduction in intraventricular hemorrhage (any grade and severe IVH) was found, and a trend towards less air leak. In the subgroup analysis of trials studying an unselected population of ventilated infants, no differences were found for any of the outcomes.

REVIEWER'S CONCLUSIONS

For ventilated preterm infants with evidence of asynchronous respiratory efforts, neuromuscular paralysis with pancuronium seems to have a favourable effect on intraventricular hemorrhage and possibly on air leak. Uncertainty remains, however, regarding the long term pulmonary and neurologic effects, and regarding the safety of prolonged use of pancuronium in ventilated newborn infants. There is no evidence from randomized trials on the effects of neuromuscular blocking agents other than pancuronium. Therefore, the routine use of pancuronium or any other neuromuscular blocking agent in ventilated newborn infants cannot be recommended based on current evidence.

Experimental study on the in vivo behaviour of a new collagen glue in lung surgery

OBJECTIVE

To study the pneumostatic ability of a collagen polymerised with a polysaccharide (GAO) glue in lung surgery; its influence in pleuro-pulmonary adhesion formation; the pulmonary tissue reaction to it, its biodegradability, and the eventual alterations of pulmonary compliance induced by the glue.

METHODS

Two groups of ten rabbits (controls and treated) were operated under ventilatory assistance by thoracotomy to promote pleural adhesions, and injury to the lung. Repeated chest X-rays were carried out postoperatively. Lungs were examined histologically at day 40. In vitro tests were performed to study glue effects on pulmonary compliance.

RESULTS

Air leaks stopped 2 min after glue application. Persistent pneumothorax were likely seen in treated rabbits (ns). Glue induces a temporary reduction of pulmonary compliance. Glue did not increase adhesion formation, or interfere with the healing process.

CONCLUSIONS

For its properties, GAO seems to be a good and well-tolerated tool to reduce air leaks from the lung, without inducing residual pleural symphysis.

Selective use of chest tubes in thoracotomies for congenital cardiovascular procedures

BACKGROUND

Advantages and complications have been reported from the use of chest tubes (CT). To reduce the incidence of complications we have employed a selective use of CT in thoracotomy for congenital cardiovascular procedure; ie, in absence of air leaks and fluid to be drained, no CT was inserted.

METHODS

The lung was reexpanded and air evacuated during the chest closure. Early and 6 hours chest roentgenograms were performed on every patient. This study retrospectively reviews the results of this selective approach in 546 patients operated on between 1980 and 1998 mainly for patent ductus arteriosum ligation, pulmonary artery band, aortic coarctation, Blalock-Taussig shunt. Four hundred and eighteen patients did not receive a CT at the initial surgery (group I), and 128 patients received a CT either before or at surgery (group II).

RESULTS

40 patients in group I developed an air or fluid collection large enough to require a CT. Only one patient had complication, from an undetected hemothorax. Nine patients in group II required another CT, and one patient developed a pneumothorax upon pulling out the CT. No death in either group was related to the use or lack of use of the CT. A total of 378 CTs and collecting chambers were saved.

CONCLUSIONS

A selective approach to the use of CT in thoracotomies for cardiovascular procedures can be employed with minimal complications, more comfort for the patient, and cost savings.

Cannulation of the internal jugular vein: is postprocedural chest radiography always necessary?

OBJECTIVES

To determine whether clinical features can be used in a decision rule to prospectively identify a subgroup of internal jugular catheter placements that are correctly positioned and free from mechanical complications, thus obviating the need for routine postprocedural chest radiographs in selected patients.

DESIGN

Prospective cohort study.

SETTING

Tertiary care teaching hospital.

PATIENTS

A total of 107 consecutive patients who presented to our catheter service for internal jugular catheter insertion because of clinical indications between November 1995 and April 1996. Exclusion criteria were mechanical ventilation, an altered mental status, an age of <15 years, and a height of <152 cm.

INTERVENTIONS

Right or left internal jugular vein catheter placement followed by a postprocedural chest radiograph.

MEASUREMENTS

The operating physician completed a detailed questionnaire for each catheter insertion, designed to detect potential complications and to predict the necessity, or lack of necessity, for a postprocedural chest radiograph. The questionnaire documented patient characteristics, the number of needle passes, difficulty establishing access, operator experience, poor anatomical landmarks, number of previous catheter placements, resistance to wire or catheter advancement, resistance to aspiration of blood or flushing of the catheter ports, sensations in the ear, chest, or arm, and development of signs or symptoms suggestive of pneumothorax. After catheter insertion, chest radiographs were obtained to assess for mechanical complications and malpositioned catheters.

MAIN RESULTS

In 46 cases, the decision rule predicted either a complication or a malposition and, thus, the need for a chest radiograph. In 61 cases, neither was predicted (no chest radiograph was needed). Radiographs confirmed one complication (pneumothorax) and 15 catheter tip malpositions (nine in the right atrium and six in the right axillary vein). Among the 46 cases predicted to have a potential complication or malposition, there were one actual complication (pneumothorax) and six actual malpositions (three axillary vein malpositions and three right atrial malpositions). The positive predictive value of this decision rule is 15%. Among the 61 cases predicted to be free from complications or malpositions and not to require a postprocedural chest radiograph, there were nine unexpected malpositions (three axillary vein malpositions and six right atrial malpositions). The negative predictive value is 85%. The overall sensitivity of the decision rule for detecting complications and malpositions is 44%, and the specificity is 55%.

CONCLUSIONS

In experienced hands, internal jugular venous catheterization is a safe procedure. However, the incidence of axillary vein or right atrial catheter malposition is 14%, and clinical factors alone will not reliably identify malpositioned catheters. Chest radiographs are necessary to ensure correct internal jugular catheter position.

Cervical root stimulation at C5/6 excites C8/T1 roots and minimizes pneumothorax risk

Needle electrical cervical root stimulation may be performed lateral to the C5/C6 or C7/T1 spinous process interspaces. Pneumothorax has been reported following C7/T1 root stimulation. We evaluated the efficacy of a modified C5/C6 stimulation technique in exciting C8/T1 roots in 15 normal subjects and 36 patients with motor neuron disease (204 procedures). No instances of a 50% or greater amplitude decline occurred. C5/C6 interspace stimulation, therefore, may be used to excite C8/T1 roots while minimizing pneumothorax risk.

[Ultrasound guided forceps biopsy of the pleura]

AIM

Between cytology of pleural effusion and thorascopy there is a gap for another non invasive biopsy method to diagnose pleural diseases, especially since Adam's and Ramel's blind pleural biopsy is uncommon. Therefore it is suggestive to test feasibility and usefulness of pleural forceps biopsy.

METHOD

It is possible to take biopsies under ultrasound guidance with the help of a biopsy-forceps from the diaphragmatic pleura or pleural appositions through a 2.5 mm canula with a stop cock and a rubber vent. The specimen can be used for histological or immunohistochemical examinations. The procedure is coducted in a closed system to avoid pneumothorax. The puncture was done in 12 patients with a puncturable pleural effusion.

RESULTS

In 11 of 12 patients it was possible to get the final diagnosis. In one of three cases of mesotheliomas a rebiopsy was necessary. In 9 cases a malign tumor was diagnosed, effusion cytology was negative in 4 of 7 tumors. In 5 patients with a history of a former tumor pleural carcinosis was related three times correctly to the former cancer and twice to a secondary cancer. In one case a fibrous plaque was found. There were two patients with pleuritis, in one case a pulmonary tuberculosis was found 8 weeks later. In one patient with a mesothelioma inoculated metastasis were present in the sites of the punctures. In all pleural forceps punctures we got enough biopsy material for histological and immunohistochemical diagnosis.

CONCLUSION

The ultrasound guided forceps biopsy of the pleura is a very promising less invasive method to diagnose pleural tumors. Additional improvements of the equipment are possible. Definitive evaluation of the procedure especially in infectious pleural diseases requires a higher number of cases.

Buttressing staple lines with bovine pericardium in lung resection for bullous emphysema

The utility of buttressing an endoscopic mechanical stapler with strips of bovine pericardium in resection of pulmonary bullous areas was evaluated by comparing the duration of air leakage in two randomized patient groups, one with and one without buttressing. The duration of air leakage was not related to bulla size in either group but showed a linear relation with the radiologic emphysema score in both groups (p < 0.001) and was shorter when the stapler had been fitted with bovine pericardium, but significantly reduced (p = 0.019) only in patients with a high emphysema score. The duration of air leakage was thus related to emphysema score, and in patients with high scores was shortened by application of bovine pericardium to the stapler.

Infraclavicular brachial plexus block effects on respiratory function and extent of the block

BACKGROUND AND OBJECTIVES

Axillary block is devoid of severe respiratory complications. However, incomplete anesthesia of the upper limb is the main disadvantage of the technique. Theoretically, the more proximal infraclavicular approach would produce a more extensive block without the risk of pneumothorax. However, neither its effects on respiratory function nor a detailed characterization of the extent of neural block has been assessed. The goal of this study was to evaluate the possible changes in respiratory function and also the extent of the block after infraclavicular block.

METHODS

We performed an infraclavicular block with a mixture of 40 mL 1.5% plain mepivacaine and 4 mL 8.4% sodium bicarbonate in 20 patients. Forced expiratory volumes were measured before and 15 minutes after the injection of local anesthetic, and sensory and motor block were evaluated at 10 and 20 minutes.

RESULTS

We did not find significant differences from baseline in the forced expiratory volumes in any of the patients. Axillary and musculocutaneous nerve distributions had the lowest rate of sensory block at 20 minutes.

CONCLUSIONS

Infraclavicular block does not produce a reduction in respiratory function.

Successful management of spontaneous pneumothorax during general anaesthesia in a patient with eosinophilia

A 10-year-old male patient posted for left elbow arthrolysis developed pneumothorax during general anaesthesia. He had history of upper respiratory tract infection and high eosinophil count, which remained high in spite of treatment. In such patients, it is advisable to use steroid pre-operatively & intraoperatively to produce transient eosinopenia so that complications of eosinophilia are avoided.

Bilateral lung volume reduction surgery via median sternotomy for severe pulmonary emphysema

BACKGROUND

Lung volume reduction surgery either via sternotomy or by thoracoscopy has been demonstrated to be effective for selected emphysema patients in North America and Europe. The present study summarizes short-term results of bilateral lung volume reduction performed via median sternotomy for the first consecutive 39 patients with severe diffuse emphysema in Okayama, Japan, from July 1995 to February 1997.

METHODS

There were 35 men and 4 women, and the age range was 54 to 74 years with a mean age of 65 years. All were former heavy smokers and none of them had alpha1-antitrypsin deficiency. Only 9 patients (23%) showed a bilateral upper lobe pattern of emphysema. The operation was done through a median sternotomy, and the most emphysematous portions were excised bilaterally with a linear stapling device fitted with strips of bovine pericardium to prevent air leakage.

RESULTS

No operative death was encountered. The first 33 patients completed 3-month follow-up assessment, and their mean forced expiratory volume in 1 second had improved by 41% from 735 mL to 1,037 mL. Other parameters of pulmonary function tests, arterial blood gas analysis, 6-minute walking distance, and dyspnea scale also had improved significantly. These improvements lasted for at least a year.

CONCLUSIONS

Bilateral lung volume reduction surgery via median sternotomy is a safe and effective procedure for selected severe emphysema patients. Although the pattern of emphysema might be different between countries, the results in Japanese patients were similar to those previously reported in North American and European patients.

Pleural tenting during upper lobectomy decreases chest tube time and total hospitalization days

OBJECTIVE

A prolonged air leak after an upper lobectomy is a major determinant of morbidity and hospital stay. Creation of a pleural tent after upper lobectomy was used to investigate whether obliterating the usual postoperative intrapleural apical space with the parietal pleura would help shorten chest tube time.

METHODS

From August, 1994, through January, 1997, 48 consecutive patients undergoing an isolated upper lobectomy for a neoplasm were reviewed. Twenty-eight patients had creation of a pleural tent and 20 patients did not. Demographic and clinical profiles of both groups were not significantly different. Chest tubes were removed when there was no air leak for 48 hours and chest tube drainage was less than 75 ml per 8 hours.

RESULTS

The tented patients had significantly shorter mean air leak (tented 1.6 +/- 0.3 days vs nontented 3.9 +/- 1.2 days, p = 0.04), mean chest tube total drainage (tented 1619.5 +/- 95.5 ml vs nontented 2476.3 +/- 346.4 ml, p = 0.009), mean chest tube duration (tented 4.0 +/- 0.2 days vs nontented 6.6 +/- 1.0 days, p = 0.004), mean total hospitalization time (tented 6.4 +/- 0.4 days vs nontented 8.6 +/- 1.0 days, p = 0.02). No operative deaths occurred. Morbidity was not significantly different between groups.

CONCLUSIONS

(1) Creation of a pleural tent at the time of upper lobectomy appears to significantly reduce chest tube time and shorten hospitalization. (2) No morbidity or mortality was associated with this simple, quick procedure. (3) Surgeons should consider creation of a pleural tent at the time of upper lobectomy.

Needle-aspiration lung biopsy: a comprehensive approach to complication reduction

Complications in needle-aspiration lung biopsy are often related to technique. A step-by-step discussion of lung biopsy focusing on complication reduction is presented. Preparation, needle selection, biopsy approach, needle manipulations, sampling, postprocedure care, and complication management are discussed in detail.

Anaesthetic management of the severely injured patient: chest injury

Life-threatening haemorrhage is common in major chest and abdominal trauma (Figure 1). Management consists of rapid fluid transfusion via large bore intravenous cannulae and early surgical intervention if indicated. Refractory hypoxaemia is frequently present in the chest injured patient (Figure 2). Pneumothorax and haemothorax must be carefully sought, and chest drains used in their management. Hypoxaemia secondary to simple chest injury should be managed with oxygen administration and the provision of analgesia initially. Resistant hypoxaemia may necessitate intubation and ventilation.

Central venous cannulation: how to do it

Central venous cannulation is an important clinical tool for the hospital doctor. A sound knowledge of applied anatomy, relative contraindications and possible complications is required to decrease morbidity and mortality. This article seeks to provide the working knowledge required to perform and use central venous cannulation safely.

[A kit of disposable devices for transcutaneous puncture biopsy]

A kit of disposable devices has been devised for successful and safe puncture biopsy of abnormal formations deeply located in the lung, mediastinum, liver, breast, pleura. The use of the kit provides qualitative instant diagnosis, by decreasing the cost of studies, and rules out transmission of infections (hepatitis, AIDS), implantation of tumor cells into the puncture canal tissues, and reduces the incidence of traumatic pneumothorax and bleeding.

[Diagnostic percutaneous thoracic punctures. Assessment through a critical study of a compliation of 2406 cases]

The aim of this retrospective study of 2,406 diagnostic percutaneous thoracic needle aspirations under computer tomographic control was to assess the diagnostic value of this method, the technical problems and the complications and finally, to refine the indications. Percutaneous needle aspiration had been carried out after negative fibreoptic bronchoscopy. The authors review their technique and show the value of biopsy material which is only slightly traumatised. Computerised tomography and fine needle aspiration reduce the risk of pneumothorax and haemorrhage in a significant fashion. Personalized collaboration between the radiologist, physician and cytologist is a vital pre-requisite. The indications are discussed notably in cases of solitary pulmonary nodules and of mediastinal masses.