Bronchial mucus hypersecretion in acute quadriplegia. Macromolecular yields and glycoconjugate composition

Timing of tracheostomy in acute traumatic spinal cord injury: A systematic review and meta-analysis

BACKGROUND

Patients with acute traumatic cervical or high thoracic level spinal cord injury (SCI) typically require mechanical ventilation (MV) during their acute admission. Placement of a tracheostomy is preferred when prolonged weaning from MV is anticipated. However, the optimal timing of tracheostomy placement in patients with acute traumatic SCI remains uncertain. We systematically reviewed the literature to determine the effects of early versus late tracheostomy or prolonged intubation in patients with acute traumatic SCI on important clinical outcomes.

METHODS

Six databases were searched from their inception to January 2020. Conference abstracts from relevant proceedings and the gray literature were searched to identify additional studies. Data were obtained by two independent reviewers to ensure accuracy and completeness. The quality of observational studies was evaluated using the Newcastle Ottawa Scale.

RESULTS

Seventeen studies (2,804 patients) met selection criteria, 14 of which were published after 2009. Meta-analysis showed that early tracheostomy was not associated with decreased short-term mortality (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.39-1.79; p = 0.65; n = 2,072), but was associated with a reduction in MV duration (mean difference [MD], 13.1 days; 95% CI, -6.70 to -21.11; p = 0.0002; n = 855), intensive care unit length of stay (MD, -10.20 days; 95% CI, -4.66 to -15.74; p = 0.0003; n = 855), and hospital length of stay (MD, -7.39 days; 95% CI, -3.74 to -11.03; p < 0.0001; n = 423). Early tracheostomy was also associated with a decreased incidence of ventilator-associated pneumonia and tracheostomy-related complications (RR, 0.86; 95% CI, 0.75-0.98; p = 0.02; n = 2,043 and RR, 0.64; 95% CI, 0.48-0.84; p = 0.001; n = 812 respectively). The majority of studies ranked as good methodologic quality on the Newcastle Ottawa Scale.

CONCLUSION

Early tracheostomy in patients with acute traumatic SCI may reduce duration of mechanical entilation, length of intensive care unit stay, and length of hospital stay. Current studies highlight the lack of high-level evidence to guide the optimal timing of tracheostomy in acute traumatic SCI. Future research should seek to understand whether early tracheostomy improves patient comfort, decreases duration of sedation, and improves long-term outcomes.

LEVEL OF EVIDENCE

Systematic Review, level III.

Effects of glossopharyngeal insufflation on pulmonary function in cervical cord injury patients

STUDY DESIGN

Quasi experimental.

OBJECTIVE

To evaluate the effect of glossopharyngeal insufflation on pulmonary function in cervical cord injury.

SETTING

Indian Spinal Injuries Centre, Vasant Kunj, Delhi, India.

METHODS

Thirty-one cervical cord injured (ISNCSCI A and B) subjects received respiratory rehabilitation for 4 weeks, with the experimental group performing glossopharyngeal insufflation along with respiratory rehabilitation. The groups were assessed at baseline and after 4 weeks for pulmonary function test, chest expansion, dyspnea, and chest tightness.

RESULTS

Significant differences were observed in IVC, IC, FVC, FEV1, MEF 75%, PEF, tidal volume, chest expansion, dyspnea, and chest tightness (p < 0.05).

CONCLUSION

Glossopharyngeal insufflation is a technique that can be used to improve the respiratory function after cervical cord injury.

A Primary Care Provider's Guide to Managing Respiratory Health in Subacute and Chronic Spinal Cord Injury

Respiratory complications following spinal cord injury (SCI) have remained the leading cause of death across the lifespan and are one of the most common reasons for hospitalization. Complications from altered respiratory physiology after SCI include atelectasis, pneumonia, venous thromboembolic disease, and sleep-disordered breathing. The risk for complications is greater with higher SCI levels and severity, and mortality from pneumonia is heightened compared to the general population. Optimal primary care for individuals with SCI includes appropriate surveillance for SCI-specific respiratory disease, key preventive care including promotion of influenza immunization and respiratory muscle training, and early identification and treatment of pneumonia with institution of aggressive secretion management strategies. The respiratory physiology and specific management of respiratory complications after SCI is reviewed.

Spinal cord injury and diaphragm neuromotor control

Introduction: Neuromotor control of diaphragm muscle and the recovery of diaphragm activity following spinal cord injury have been narrowly focused on ventilation. By contrast, the understanding of neuromotor control for non-ventilatory expulsive/straining maneuvers (including coughing, defecation, and parturition) is relatively impoverished. This variety of behaviors are achieved via the recruitment of the diverse array of motor units that comprise the diaphragm muscle.Areas covered: The neuromotor control of ventilatory and non-ventilatory behaviors in health and in the context of spinal cord injury is explored. Particular attention is played to the neuroplasticity of phrenic motor neurons in various models of cervical spinal cord injury.Expert opinion: There is a remarkable paucity in our understanding of neuromotor control of maneuvers in spinal cord injury patients. Dysfunction of these expulsive/straining maneuvers reduces patient quality of life and contributes to severe morbidity and mortality. As spinal cord injury patient life expectancies continue to climb steadily, a nexus of spinal cord injury and age-associated comorbidities are likely to occur. While current research remains concerned only with the minutiae of ventilation, the major functional deficits of this clinical cohort will persist intractably. We posit some future research directions to avoid this scenario.

Critical Care Management of Acute Spinal Cord Injury-Part II: Intensive Care to Rehabilitation

Spinal cord injury is devastating to those affected due to the loss of motor and sensory function, and, in some cases, cardiovascular collapse, ventilatory failure, and bowel and bladder dysfunction. Primary trauma to the spinal cord is exacerbated by secondary insult from the inflammatory response to injury. Specialized intensive care of patients with acute spinal cord injury involves the management of multiple systems and incorporates evidence-based practices to reduce secondary injury to the spinal cord. Patients greatly benefit from early multidisciplinary rehabilitation for neurologic and functional recovery. Treatment of acute spinal cord injury may soon incorporate novel molecular agents currently undergoing clinical investigation to assist in neuroprotection and neuroregeneration.

Respiratory problems and management in people with spinal cord injury

Spinal cord injury (SCI) is characterised by profound respiratory compromise secondary to the level of loss of motor, sensory and autonomic control associated with the injury. This review aims to detail these anatomical and physiological changes after SCI, and outline their impact on respiratory function. Injury-related impairments in strength substantially alter pulmonary mechanics, which in turn affect respiratory management and care. Options for treatments must therefore be considered in light of these limitations.

KEY POINTS

Respiratory impairment following spinal cord injury (SCI) is more severe in high cervical injuries, and is characterised by low lung volumes and a weak cough secondary to respiratory muscle weakness.Autonomic dysfunction and early-onset sleep disordered breathing compound this respiratory compromise.The mainstays of management following acute high cervical SCI are tracheostomy and ventilation, with noninvasive ventilation and assisted coughing techniques being important in lower cervical and thoracic level injuries.Prompt investigation to ascertain the extent of the SCI and associated injuries, and appropriate subsequent management are important to improve outcomes.

EDUCATIONAL AIMS

To describe the anatomical and physiological changes after SCI and their impact on respiratory function.To describe the changes in respiratory mechanics seen in cervical SCI and how these changes affect treatments.To discuss the relationship between injury level and respiratory compromise following SCI, and describe those at increased risk of respiratory complications.To present the current treatment options available and their supporting evidence.

Intramuscular diaphragmatic stimulation for patients with traumatic high cervical injuries and ventilator dependent respiratory failure: A systematic review of safety and effectiveness

BACKGROUND

Intramuscular diaphragmatic stimulation using an abdominal laparoscopic approach has been proposed as a safer alternative to traditional phrenic nerve stimulation. It has also been suggested that early implementation of diaphragmatic pacing may prevent diaphragm atrophy and lead to earlier ventilator independence. The aim of this study was therefore to systematically review the safety and effectiveness of intramuscular diaphragmatic stimulators in the treatment of patients with traumatic high cervical injuries resulting in long-term ventilator dependence, with particular emphasis on the affect of timing of insertion of such stimulators.

METHODS

The Cochrane database and PubMed were searched between January 2000 and June 2015. Reference lists of selected papers were also reviewed. The inclusion criteria used to select from the pool of eligible studies were: (1) reported on adult patients with traumatic high cervical injury, who were ventilator-dependant, (2) patients underwent intramuscular diaphragmatic stimulation, and (3) commented on safety and/or effectiveness.

RESULTS

12 articles were included in the review. Reported safety issues post insertion of intramuscular electrodes included pneumothorax, infection, and interaction with pre-existing cardiac pacemaker. Only one procedural failure was reported. The percentage of patients reported as independent of ventilatory support post procedure ranged between 40% and 72.2%. The mean delay of insertion ranged from 40 days to 9.7 years; of note the study with the average shortest delay in insertion reported the greatest percentage of fully weaned patients.

CONCLUSIONS

Although evidence for intramuscular diaphragmatic stimulation in patients with high cervical injuries and ventilator dependent respiratory failure is currently limited, the technique appears to be safe and effective. Earlier implantation of such devices does not appear to be associated with greater surgical risk, and may be more effective. Further high quality studies are warranted to investigate the impact of delay of insertion on ventilator weaning.

Respiratory management in the patient with spinal cord injury

Spinal cord injuries (SCIs) often lead to impairment of the respiratory system and, consequently, restrictive respiratory changes. Paresis or paralysis of the respiratory muscles can lead to respiratory insufficiency, which is dependent on the level and completeness of the injury. Respiratory complications include hypoventilation, a reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Vital capacity (VC) is an indicator of overall pulmonary function; patients with severely impaired VC may require assisted ventilation. It is best to proceed with intubation under controlled circumstances rather than waiting until the condition becomes an emergency. Mechanical ventilation can adversely affect the structure and function of the diaphragm. Early tracheostomy following short orotracheal intubation is probably beneficial in selected patients. Weaning should start as soon as possible, and the best modality is progressive ventilator-free breathing (PVFB). Appropriate candidates can sometimes be freed from mechanical ventilation by electrical stimulation. Respiratory muscle training regimens may improve patients' inspiratory function following a SCI.

Dysphagia and respiratory care in individuals with tetraplegia: incidence, associated factors, and preventable complications

Dysphagia occurs in a significant number of individuals with spinal cord injury (SCI) presenting to acute care and inpatient rehabilitation. This prospective study has found dysphagia in nearly 40% of individuals with tetraplegia. Tracheostomy, mechanical ventilation, nasogastric tube, and age are significant risk factors. The detrimental complications of dysphagia in SCI can cause significant morbidity and delays in rehabilitation. Thus, early and accurate diagnosis of dysphagia is imperative to reduce the risk of developing life-threatening complications. Incidence and risk factors of dysphagia and the use of the bedside swallow evaluation (BSE) and videofluoroscopy swallow study (VFSS) to diagnose dysphagia are presented. The often underappreciated role of respiratory therapists, including assist cough, high tidal volume ventilation, and the use of Passy-Muir valve, in the care of individuals with SCI who have dysphagia is discussed. Improved secretion management and respiratory stabilization enable the individuals with dysphagia to be evaluated sooner and safely by a speech pathologist. Early evaluation and intervention could improve upon morbidity and delayed rehabilitation, thus improving overall clinical outcomes.

Specialized respiratory management for acute cervical spinal cord injury:: a retrospective analysis

BACKGROUND

In individuals with cervical spinal cord injury (SCI), respiratory complications arise within hours to days of injury. Paralysis of the respiratory muscles predisposes the patient toward respiratory failure. Respiratory complications after cervical SCI include hypoventilation, hypercapnea, reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Ultimately, the patient must use increased work to breathe, which results in respiratory fatigue and may eventually require intubation for mechanical ventilation. Without specialized respiratory management for individuals with tetraplegia, recurrent pneumonias, bronchoscopies, and difficulty in maintaining a stable respiratory status will persist.

OBJECTIVE

This retrospective analysis examined the effectiveness of specialized respiratory management utilized in a regional SCI center.

METHODS

Individuals with C1-C4 SCI (N = 24) were the focus of this study as these neurological levels present with the most complicated respiratory status.

RESULTS

All of the study patients' respiratory status improved with the specialized respiratory management administered in the SCI specialty unit. For a majority of these patients, respiratory improvements were noted within 1 week of admission to our SCI unit.

CONCLUSION

Utilization of high tidal volume ventilation, high frequency percussive ventilation, and mechanical insufflation- exsufflation have demonstrated efficacy in stabilizing the respiratory status of these individuals. Optimizing respiratory status enables the patients to participate in rehabilitation therapies, allows for the opportunity to vocalize, and results in fewer days on mechanical ventilation for patients who are weanable.

[Aspiration pneumonia after spinal cord injury. Placement of PEG tubes as effective prevention]

BACKGROUND

Pulmonary infections are dreaded complications in acute spinal cord injuries. The prevention of pneumonia is essential for reducing mortality and the period of hospitalization. Swallowing disorders occur frequently in patients with cervical cord injuries and are accompanied by aspiration with a high risk of pneumonia.

PATIENTS AND METHODS

In this study the identification and analysis of patients with newly acquired cervical cord injuries were carried out with respect to respiratory complications, treatment and prevention.

RESULTS

A total of 27 patients with a cervical cord injury (tetraplegia) were identified. Of these 20 patients (74%) were identified with a swallowing disorder and a high risk of aspiration. Of these patients 11 (PEG group) received a percutaneous feeding tube (PEG tube), 9 patients (non-PEG group) with diagnosed dysphagia were treated without PEG tube. A total of 6 patients in the non-PEG group (67%) acquired pneumonia compared to 3 patients (27%) in the PEG group.

CONCLUSION

A swallowing disorder is a major risk factor for a pulmonary infection after a cervical cord injury. An early placement of a PEG tube has a preventive effect with respect to aspiration pneumonia in patients with dysphagia.

Muc5b is the major polymeric mucin in mucus from thoroughbred horses with and without airway mucus accumulation

Mucus accumulation is a feature of inflammatory airway disease in the horse and has been associated with reduced performance in racehorses. In this study, we have analysed the two major airways gel-forming mucins Muc5b and Muc5ac in respect of their site of synthesis, their biochemical properties, and their amounts in mucus from healthy horses and from horses with signs of airway mucus accumulation. Polyclonal antisera directed against equine Muc5b and Muc5ac were raised and characterised. Immunohistochemical staining of normal equine trachea showed that Muc5ac and Muc5b are produced by cells in the submucosal glands, as well as surface epithelial goblet cells. Western blotting after agarose gel electrophoresis of airway mucus from healthy horses, and horses with mucus accumulation, was used to determine the amounts of these two mucins in tracheal wash samples. The results showed that in healthy horses Muc5b was the predominant mucin with small amounts of Muc5ac. The amounts of Muc5b and Muc5ac were both dramatically increased in samples collected from horses with high mucus scores as determined visually at the time of endoscopy and that this increase also correlated with increase number of bacteria present in the sample. The change in amount of Muc5b and Muc5ac indicates that Muc5b remains the most abundant mucin in mucus. In summary, we have developed mucin specific polyclonal antibodies, which have allowed us to show that there is a significant increase in Muc5b and Muc5ac in mucus accumulated in equine airways and these increases correlated with the numbers of bacteria.

Physiotherapy secretion removal techniques in people with spinal cord injury: a systematic review

OBJECTIVE

To address whether secretion removal techniques increase airway clearance in people with chronic spinal cord injury (SCI).

DATA SOURCES AND STUDY SELECTION

MEDLINE/PubMed, CINAHL, EMBASE, and PsycINFO were searched from inception to May 2009 for population keywords (spinal cord injury, paraplegia, tetraplegia, quadriplegia) paired with secretion removal-related interventions and outcomes. Inclusion criteria for articles were a research study, irrespective of design, that examined secretion removal in people with chronic SCI published in English.

REVIEW METHODS

Two reviewers determined whether articles met the inclusion criteria, abstracted information, and performed a quality assessment using PEDro or Downs and Black criteria. Studies were then given a level of evidence based on a modified Sackett scale.

RESULTS

Of 2416 abstracts and titles retrieved, 24 met the inclusion criteria. Subjects were young (mean, 31 years) and 84% were male. Most evidence was level 4 or 5 and only 2 studies were randomized controlled trials. Three reports described outcomes for secretion removal techniques in addition to cough, whereas most articles examined the immediate effects of various components of cough. Studies examining insufflation combined with manual assisted cough provided the most consistent, high-level evidence. Compelling recent evidence supports the use of respiratory muscle training or electrical stimulation of the expiratory muscles to facilitate airway clearance in people with SCI.

CONCLUSION

Evidence supporting the use of secretion removal techniques in SCI, while positive, is limited and mostly of low level. Treatments that increase respiratory muscle force show promise as effective airway clearance techniques.

Fatal fever of unknown origin in acute cervical spinal cord injury: five cases

BACKGROUND/OBJECTIVE

Patients with traumatic upper thoracic and cervical spinal cord injuries are at increased risk for the development of autonomic dysfunction, including thermodysregulation. Thermoregulation is identified as an autonomic function, although the exact mechanisms of thermodysregulation have not been completely recognized. Quad fever is a hyperthermic thermoregulatory disorder that occurs in people with acute cervical and upper thoracic spinal cord injuries. First described in 1982, it has not been widely discussed in the literature.

METHODS

Case reports of 5 patients with cervical spinal cord injury (SCI).

RESULTS

Five of 18 patients (28%) with acute cervical SCI who were admitted during a 1-year period had fatal complications caused by persistent hyperthermia of unknown origin.

CONCLUSIONS

Patients with acute traumatic cervical and upper thoracic SCI are at risk for thermoregulatory dysfunction. Changes in the hypothalamic axis may be implicated, especially in the light of modification in hypothalamic afferent nerves, but this hypothesis has not yet been explored. Thermodysregulation may be an early sign of autonomic dysfunction. A comprehensive guideline is needed for the management of elevated body temperature in critically ill patients with cervical SCI, because this condition may be fatal.

Pulmonary function and spinal cord injury

Injury to the cervical and upper thoracic spinal cord disrupts function of inspiratory and expiratory muscles, as reflected by reduction in spirometric and lung volume parameters and static mouth pressures. In association, subjects with tetraplegia have decreased chest wall and lung compliance, increased abdominal wall compliance, and rib cage stiffness with paradoxical chest wall movements, all of which contribute to an increase in the work of breathing. Expiratory muscle function is more compromised than inspiratory muscle function among subjects with tetraplegia and high paraplegia, which can result in ineffective cough and propensity to mucus retention and atelectasis. Subjects with tetraplegia also demonstrate heightened vagal activity with reduction in baseline airway caliber, findings attributed to loss of sympathetic innervation to the lungs. Significant increase in airway caliber following inhalation of ipratropium bromide, an anticholinergic agent, suggests that reduction in airway caliber is not due to acquired airway fibrosis stemming from repeated infections or to abnormal hysteresis secondary to chronic inability of subjects to inhale to predicted total lung capacity. Reduced baseline airway caliber possibly explains why subjects with tetraplegia exhibit airway hyperresponsiveness to methacholine and ultrasonically nebulized distilled water. While it has been well demonstrated that bilateral phrenic nerve pacing or stimulation through intramuscular diaphragmatic electrodes improves inspiratory muscle function, it remains unclear if inspiratory muscle training improves pulmonary function. Recent findings suggest that expiratory muscle training, electrical stimulation of expiratory muscles and administration of a long-acting beta(2)-agonist (salmeterol) improve physiological parameters and cough. It is unknown if baseline bronchoconstriction in tetraplegia contributes to respiratory symptoms, of if the chronic administration of a bronchodilator reduces the work of breathing and/or improves respiratory symptoms. Less is known regarding the benefits of treatment of obstructive sleep apnea, despite evidence indicating that the prevalence of this condition in persons with tetraplegia is far greater than that encountered in able-bodied individuals.

Acute respiratory infections in persons with spinal cord injury

Respiratory disorders are the leading cause of death for persons with both acute and chronic spinal cord injury (SCI), and much of the morbidity and mortality associated with respiratory disorders is related to acute respiratory infections. Pneumonia is the best recognized respiratory infection associated with mortality in this population. Recent evidence supports some management strategies that differ from those recommended for the general population. Upper respiratory tract infections and acute bronchitis may be precipitating factors in the development of pneumonia or ventilatory failure in patients with chronic SCI. This review emphasizes management principles for treatment and prevention of respiratory infections in persons with SCI.

Respiratory management during the first five days after spinal cord injury

Respiratory complications are the most common cause of morbidity and mortality in acute spinal cord injury (SCI), with an incidence of 36% to 83%. Eighty percent of deaths in patients hospitalized with cervical SCI are secondary to pulmonary dysfunction, with pneumonia the cause in 50% of the cases. The number of respiratory complications during the acute hospital stay contributes significantly to the length of hospital stay and cost. Four factors (use of mechanical ventilation, pneumonia, the need for surgery, and use of tracheostomy) explain nearly 60% of hospital costs and may be as important a predictor of hospital cost as level of injury. Atelectasis (36.4%), pneumonia (31.4%), and ventilatory failure (22.6%) are the most common complications during the first 5 days after injury. Ventilatory failure occurs on average 4.5 days after injury. Transfer to an SCI center specializing in acute management of tetraplegia has been shown to significantly reduce the number of respiratory complications. This review concentrates on the first 5 days after injury, focusing on complications, predictive factors, prevention, and management of those complications.

Respiratory muscle training in persons with spinal cord injury: a systematic review

The purpose of this paper was to review the effectiveness of respiratory muscle training (RMT) on respiratory muscle strength and endurance, pulmonary function, quality of life, respiratory complications and exercise performance in persons with spinal cord injury. A MEDLINE (National Library of Medicine, Bethesda, MD, USA) database was used for selection of the literature (from 1980 to November 2004), and relevant references from peer-reviewed articles were retrieved as well. Studies investigating the effects of RMT (i.e. resistive breathing weight lifting or normocapnic hyperpnea) in persons with spinal cord injury were selected. Two independent reviewers investigated controlled studies for methodological quality by using a modification of the framework for methodological quality. Methodological quality ranged between 15 and 29 (maximal feasible score=40). Twenty-three papers were retrieved and six controlled trials were kept for further analysis. A meta-analysis and calculation of effect-size of each individual study and weighted summary effect-size was intended. However, unreported data and heterogeneity in outcome variables did not allow performing a meta-analysis. From the systematic review it is concluded that RMT tended to improve expiratory muscle strength, vital capacity and residual volume. Insufficient data was available to make conclusions concerning the effects on inspiratory muscle strength, respiratory muscle endurance, quality of life, exercise performance and respiratory complications.

Esophageal Dysfunction in Cervical Spinal Cord Injury: A Potentially Important Mechanism of Aspiration

BACKGROUND

Respiratory complications are a major cause of morbidity and mortality in patients with cervical spinal cord injury (CSCI). We hypothesized that patients with CSCI had esophageal dysfunction, predisposing them to aspiration. The purpose of this study was to characterize esophageal function in these patients.

METHODS

CSCI and similarly injured control (spinal cord injury below T1) subjects were prospectively enrolled from two trauma centers. All underwent esophageal manometry to measure lower (LES) and upper esophageal sphincter (UES) pressures. A subset of patients had detailed manometry and 24-hour pH studies performed to evaluate dynamic esophageal function.

RESULTS

Eighteen CSCI and five control subjects were enrolled. The groups were similar with regards to age, sex, injury mechanism, Injury Severity Score, and hospital stay. Resting LES and UES pressures were similar in CSCI and control patients and did not differ from established norms. Five CSCI and two control patients underwent detailed manometric assessment. Defective UES relaxation was observed in all CSCI patients but not controls. CSCI patients had increased UES relaxation pressures (18.4 +/- 5.3 versus 3.9 +/- 0.7 mm Hg; p = 0.01) and UES bolus pressures (23.8 +/- 2.2 versus 10.2 +/- 6.9 mm Hg; p = 0.006) compared with controls. Esophageal body and LES function were normal. Two of five CSCI patients had abnormal 24-hour pH studies.

CONCLUSION

Patients with CSCI demonstrate significantly disturbed dynamic function of the pharynx and UES while resting parameters remain normal. Because adequate UES relaxation is critical to the clearance of secretions and coordination of swallowing, this is an important potential mechanism of aspiration in patients with CSCI.

Effects of abdominal binding on breathing patterns during breathing exercises in persons with tetraplegia

STUDY DESIGN

Cross-sectional, experimental.

OBJECTIVES

To investigate and compare static lung volumes and breathing patterns in persons with a cervical spinal cord lesion during breathing at rest, ordinary deep breathing, positive expiratory pressure (PEP) and inspiratory resistance-positive expiratory pressure (IR-PEP) with and without an abdominal binder (AB).

SETTING

The outpatient clinic at the Spinal Unit at Sahlgrenska University Hospital, Goteborg, Sweden.

METHOD

The study group consisted of 20 persons with complete cervical cord lesion at C5-C8 level. Breathing patterns and static lung volumes with and without an AB were measured using a body plethysmograph.

RESULTS

: With an AB, static lung volumes decreased, vital capacity increased, breathing patterns changed only marginally and functional residual capacity remained unchanged during PEP and IR-PEP.

CONCLUSION

Evidence supporting the general use of an AB to prevent respiratory complications by means of respiratory training is questionable. However, the interindividual variation in our results indicates that we cannot rule out that some patients may benefit from the treatment.

Breathing patterns during breathing exercises in persons with tetraplegia

STUDY DESIGN

Cross-sectional, observational, controlled study.

OBJECTIVES

To survey breathing patterns during breathing at rest, ordinary deep breathing (DB), positive expiratory pressure (PEP) and inspiratory resistance-positive expiratory pressure (IR-PEP) among individuals with a cervical spinal cord lesion (SCL) compared with able-bodied controls.

SETTING

Sahlgrenska University Hospital, Göteborg, Sweden.

METHOD

Participants consisted of 20 persons with a complete SCL at the C5-C8 level (at least 1 year postinjury) and 20 matched, able-bodied controls. Breathing patterns and static lung volumes were measured using a body plethysmograph.

RESULTS

Compared to the controls, breathing patterns at rest among the people with tetraplegia were characterised by a decreased tidal volume, stable respiratory rate and total cycle duration resulting in decreased mean inspiratory and expiratory flow, and alveolar ventilation. All volume and flow parameters increased except respiratory rate, which decreased during DB and PEP. During IR-PEP, tidal volume increased less compared to PEP, and combined with a decreased respiratory rate the alveolar ventilation was lower than during breathing at rest. The functional residual capacity increased during PEP and IR-PEP in people with tetraplegia.

CONCLUSION

DB exercises with or without resistance during expiration or the whole breathing cycle affect the breathing pattern in persons with tetraplegia. DB was superior in increasing volumes and flow. PEP and IR-PEP increased FRC but IR-PEP decreased volumes and flows. However, large interindividual differences in the SCL group indicate the need for caution in generalising the results.

SPONSORSHIP

This work was supported in part by grants from the Memorial Foundation of the Swedish Association of registered Physiotherapists and the Association of Cancer and Road Accident Victims.

Effect of chondroitinase ABC on purulent sputum from cystic fibrosis and other patients

Cystic fibrosis (CF) patients develop chronic lung infections associated with airway obstruction by viscous and insoluble mucus secretions. Although mucus glycoproteins (mucins) are thought to be responsible for mucus plugs, other glycoconjugate components of airway secretions have not been systematically evaluated. The aim of the present study was to determine whether chondroitin sulfate proteoglycans (CSPG) contribute to the insolubility of CF sputum. Sputa obtained from 18 CF patients were incubated with chondroitinase ABC (ChABC) or buffer (control) for 18 h at 37 degrees C, and after centrifugation at 12,000 g, the volume of the insoluble pellet and turbidity of the supernatant were determined as measures of solubility. ChABC caused a 70-90% reduction in supernatant turbidity and a 60-70% decrease in pellet volume of the 13 purulent CF sputa, but had much less effect on the five nonpurulent CF sputa tested. Similar results were obtained with two non-CF purulent and two non-CF, nonpurulent sputa. Gel electrophoresis, Western blot, and slot blot immunoassays with antichondroitin sulfate and antimucin antibodies revealed that purulent sputa (CF and non-CF) contained more CSPG and less mucin than nonpurulent sputa. In vitro mixing experiments showed that mucin in nonpurulent sputa was reduced upon incubation with purulent sputa, presumably because of degradation or a loss of immunoreactive mucin epitopes from leukocyte and/or bacterial enzymes present in purulent sputa. Our results suggest that CSPG contribute more significantly than mucins to the insolubility of purulent tracheobronchial secretions from CF patients. Because purulent sputa from non-CF patients showed a similar pattern, our observations with CF sputa may have wider applicability.

Airway hyperreactivity in subjects with tetraplegia is associated with reduced baseline airway caliber

OBJECTIVES

We administered aerosolized histamine to 32 subjects with tetraplegia to determine whether there were differences in spirometric and/or lung volume parameters between responders and nonresponders.

RESULTS

Baseline pulmonary function parameters revealed mild to moderate restrictive dysfunction. We found that 25 subjects (78%) were hyperreactive to histamine (mean provocative concentration of a substance causing a 20% fall in FEV(1) [PC(20)], 1.77 mg/mL). Responders (PC(20), < 8 mg/mL) had significantly lower values for forced expiratory flow between 25% and 75% of the outflow curve (FEF(25-75)), FEF(25-75) percent predicted, and FEF(25-75)/FVC ratio. Among all 32 subjects, the natural logarithmic transformation performed on PC(20) values (lnPC(20)) correlated with FEF(25-75) percent predicted, FEV(1) percent predicted, and FEF(25-75)/FVC ratio but not with FVC percent predicted. Responders with PC(20) values < 2 mg/mL (n = 13) had significantly reduced values for FVC, FVC percent predicted, FEV(1), and FEV(1) percent predicted compared to those with PC(20) values between 2 mg/mL and 8 mg/mL. In addition, among responders, there was a significant correlation between lnPC(20) and FVC percent predicted. A significant relationship was found between maximal inspiratory pressure (PImax) and both FEV(1) percent predicted and FEF(25-75) percent predicted, but not between lnPC(20) and either PImax or maximal expiratory pressure (PEmax).

CONCLUSIONS

These findings demonstrate that subjects with tetraplegia who exhibit airway hyperreactivity (AHR) have reduced baseline airway caliber and that lower values for lnPC(20) are associated with parallel reductions in surrogate spirometric indexes of airway size (FEV(1) percent predicted and FEF(25-75) percent predicted) and airway size relative to lung size (FEF(25-75)/FVC ratio). The absence of an association between lnPC(20) and FVC percent predicted for the entire group or between lnPC(20) and either PImax or PEmax indicates that reduced lung volumes secondary to respiratory muscle weakness cannot explain the mechanism(s) underlying AHR. Among responders, however, a possible role for reduction in lung volume, as it pertains to increasing AHR, cannot be excluded. Proposed mechanisms for reduced baseline airway caliber relative to lung size in subjects with tetraplegia include unopposed parasympathetic activity secondary to the loss of sympathetic innervation to the lungs and/or the inability to stretch airway smooth muscle with deep inhalation.

Lobectomy for destroyed lung in quadriplegic patients

BACKGROUND

Sixty-seven percent of quadriplegic patients after spinal cord injury (SCI) develop respiratory complications, which leads to death in one third. Preventive measures may fail to avoid parenchymal destruction and possible septic complications.

METHODS

Three quadriplegic patients (C3-C6 level), with destroyed lower lobes and incontrollable septic symptoms, were subjected to lobectomy.

RESULTS

Neither operative morbidity nor mortality was observed. All patients were discharged home without ventilatory assistance, and were symptom-free.

CONCLUSIONS

When the endobronchial chronic infection calls for repeated fiberoptic bronchoscopies to clear the bronchial tree, the parenchymal destruction is limited to one lobe of the lung, and there is evidence of impending septic complications, lobectomy may be indicated in quadriplegics to eradicate the source of infection.

Anaesthesia for chronic spinal cord lesions

Increasing numbers of patients with spinal cord injury present for surgery or obstetric care. Spinal cord injury causes unique pathophysiological changes. The most important peri-operative dangers are autonomic dysreflexia, bradycardia, hypotension, respiratory inadequacy and muscle spasms. Autonomic dysreflexia is suggested by headache, sweating, bradycardia and severe hypertension and may be precipitated by surgery, especially bladder distension. Patients with low, complete lesions, undergoing surgery below the level of injury, may safely do so without anaesthesia provided there is no history of autonomic dysreflexia or troublesome spasms. An anaesthetist should be present to monitor the patient in this situation. General anaesthesia of sufficient depth is effective at controlling spasms and autonomic dysreflexia but hypotension and respiratory dysfunction are risks. There is a growing consensus that spinal anaesthesia is safe, effective and technically simple to perform in this group of patients. We present a survey of 515 consecutive anaesthetics in cord-injured patients and a review of the current literature on anaesthesia for patients with chronic spinal cord lesions.

Dysregulation of proteoglycan production by intrahepatic biliary epithelial cells bearing defective (delta-f508) cystic fibrosis transmembrane conductance regulator

Hepatic dysfunction in cystic fibrosis (CF) has been attributed to accumulation of viscous mucoid secretions in intrahepatic bile ducts. The purpose of our study was to compare glycoconjugate secretion by intrahepatic biliary epithelial (IBE) cells derived from normal livers and livers of CF patients with the delta F508 mutation of the cystic fibrosis transmembrane conductance regulator (CFTR). Confluent cells were incubated with 3H-glucosamine (GlcN) for 16 hours, and radiolabeled macromolecules were analyzed for the amount and type of glycoconjugates. Incorporation of 3H-GlcN into macromolecular glycoconjugates was two- to threefold higher in CF cells versus normals, as was uptake of 3H-Glcn into the cytoplasm of CF cells. Gel exclusion chromatography on Sepharose Cl 4B revealed that the secreted glycoconjugates from CF cells eluted entirely in the excluded fraction (molecular weight > 2 x 10(6)), while, in the normal cells, 60% of the glycoconjugates eluted as lower-molecular-weight species. The high-molecular-weight glycoconjugates in both CF and normal cells were identified as chondroitin sulfates, as evidenced by susceptibility to beta elimination, chondroitinase digestion, and amino acid composition. Western blotting of IBE cell secretions with a polyclonal antibody to chondroitin sulfate revealed proteoglycan bands at 100 and 210 kd. Our results indicate that secretion of chondroitin sulfate is markedly increased in CF biliary epithelium in vitro compared with non-CF cells. Increased uptake of precursor 3H-GlcN may contribute to enhanced glycosylation of chondroitin sulfate in CF cells.

Sulfation of chondroitin/dermatan sulfate by cystic fibrosis pancreatic duct cells is not different from control cells

Cystic fibrosis is associated with mutations of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated plasma membrane chloride channel. Cystic fibrosis patients have been reported to possess elevated sulfation of glycoconjugates, which may contribute to the pathogenesis of the disease. Sulfation of glycosaminoglycans by a cystic fibrosis pancreatic adenocarcinoma cell line homozygous for DeltaF508 (CFPAC-1), a control pancreatic cell line (PANC-1), two CFPAC-1 cell lines transfected with the gene for CFTR (PLJ-CFTR-4.7, TR20), and a mock-transfected CFPAC-1 control (PLJ-6) was investigated. Cells were radiolabeled with [35S]sulfate and [3H]glucosamine, and glycosaminoglycans secreted into the medium after 24 and 72 h were isolated. Chondroitinase ABC digestion of chondroitin/dermatan sulfate allowed the recovery of disaccharides which were analyzed for their degree of sulfation by strong anion-exchange HPLC. No differences in the extent of sulfation by any of the cell lines were noted. However, glycoaminoglycans synthesized by cystic fibrosis cells consistently exhibited twofold higher [35S]-sulfate:[3H]glucosamine ratios than the controls. We conclude that CFTR plays no role in the sulfation of chondroitin/dermatan sulfate by pancreatic cells and that isotope incorporation ratios alone are insufficient evidence of changes in sulfation levels.

Chronic cough with a history of excessive sputum production. The spectrum and frequency of causes, key components of the diagnostic evaluation, and outcome of specific therapy

STUDY OBJECTIVE

To determine (1) the spectrum and frequency of causes of chronic cough with a history of excessive sputum production (CCS) and (2) the response of these causes to specific therapy.

STUDY DESIGN

Prospective study utilizing the anatomic diagnostic protocol originally developed to diagnose chronic cough.

PATIENTS

Seventy-one immunocompetent adults who complained of expectoration of greater than 30 mL of sputum per day.

LOCATION

University hospital pulmonary outpatient clinic.

RESULTS

Patients were seen an average of 4.2 times over 4.6 months before a specific diagnosis was made. The cause of CCS was determined in 97%. It was due to one cause in 38%, 2 in 36%, and three in 26%. Postnasal drip syndrome (PNDS) was a cause 40% of the time, asthma 24%, gastroesophageal reflux disease (GERD) 15%, bronchitis 11%, bronchiectasis 4%, left ventricular failure 3%, and miscellaneous causes 3%. Among patients with a normal chest radiograph who were nonsmokers and not taking an angiotensin converting enzyme inhibitor; CCS was due to PNDS, or asthma, or GERD, or all three in 100% of cases. Chest radiograph, methacholine inhalation challenge, 24-h esophageal pH monitoring, bronchoscopy, and spirometry with bronchodilator each had a sensitivity and negative predictive value of 100%. Chest radiograph and barium swallow had positive predictive values of only 38% and 30%, respectively.

CONCLUSIONS

(1) The anatomic diagnostic protocol for cough is also valid for CCS; (2) the major causes of chronic excessive sputum production and chronic cough are so similar that CCS should be considered a form of chronic cough; (3) the evaluation of CCS is more complicated and takes longer than the evaluation of chronic cough; (4) the major strength of the laboratory diagnostic protocol is that it reliably rules out conditions; (5) the outcome of specific therapy is almost always successful; and (6) the term "bronchorrhea" can be misleading if it is applied to excessive sputum production before a specific diagnosis of its source is made since the most common cause of excessive sputum that is expectorated (PNDS) is a disorder of the upper respiratory tract. Therefore, nonspecific therapies theoretically aimed at reducing mucus production in the lower respiratory tract are not likely to be helpful.

Pulmonary Manifestations of Neurological Disease

Breathing is a complicated act that requires sophisticated control mechanisms. The nervous system coordinates 3 fundamentally important components of respiration. The central nervous system has a central pattern generator that, along with appropriate feedback mechanisms, establishes both the resiratory rate and the depth of respirations. The peripheral nervous system facilitates transmission of these respiratory commands to the ventilatory muscles. The nervous system also contributes to the control of airway size. Laryngeal function is coordinated with inspiration, and local nerves in the lung have a major role in determining bronchial patency. Finally, the nervous system acts in incompletely understood ways to regulate perfusion of the lungs and to match local pulmonary blood flow with ventilation. Failure of the nervous system to adequately control these 3 different aspects of respiration may result in lifethreatening illness. Understanding how the nervous system affects control of ventilation, airway patency, and pulmonary perfusion therefore will enable intensivists to recognize and manage the pulmonary complications of neurological disease.