Early and late pulmonary complications of botulism.

Pulmonary complications of botulism were studied in an outbreak of 34 cases of type A botulism in New Mexico in 1978. Hospital record review, standardized questionnaires, and pulmonary function tests were used to define pulmonary complications during the acute illness and the patient's status one year later. Pulmonary involvement was documented in 81% of patients. Ventilatory failure occurred in 11, aspiration pneumonia in nine, and death in two patients. Difficulties in the diagnosis of ventilatory insufficiency were identified. At one year, most patients had residual symptoms, including easy fatigability in 68% and exertional dyspnea in 46%. However, only minor pulmonary function abnormalities were present. This study confirms the generally favorable prognosis of botulism and provides clinical guidance for the diagnosis and management of pulmonary complications in botulism.

Snoring in a Hispanic-American population. Risk factors and association with hypertension and other morbidity.

Snoring was investigated in a survey of respiratory disease in Hispanic-Americans of a New Mexico community. A population-based sample of 1222 adults was studied with questionnaires and measurements of height, weight, and blood pressure. The age-adjusted prevalence of regular loud snoring was 27.8% in men and 15.3% in women. Snoring prevalence increased with age and obesity in both men and women. Cigarette smoking was also associated with snoring, but chronic obstructive lung disease and alcohol consumption were not. Snorers more frequently had hypertension, ischemic heart disease, and excessive daytime sleepiness. In contrast to other studies, after adjustment for confounding factors, there was no effect of snoring on hypertension (odds ratio, 1.0; 95% confidence interval, 0.7 to 1.5), but an effect on myocardial infarction was still demonstrable (odds ratio, 1.8; 95% confidence interval, 0.9 to 3.6). The association of snoring with sleepiness suggests that respiratory disturbance of sleep related to upper airway obstruction, such as sleep apnea, occurs more frequently in snorers in this population.

Respiratory failure in myasthenia gravis due to vocal cord paresis.

Paroxysmal dyspnea and stridor in a patient with myasthenia were shown to be due to weakness of vocal cord abductors that improved with anticholinesterase therapy. Despite adequate inspiratory force, breathing was severely impaired by increased inspiratory resistance. The inspiratory flow-volume loop was useful in documenting the laryngeal obstruction and monitoring the effect of therapy. Reinterpretation of previous studies suggests that upper airway obstruction may often contribute to respiratory failure in patients with myasthenia.

T-sleep: an improved method for scoring breathing-disordered sleep.

We developed a new method to score sleep fragmented by respiratory events that we call the T-sleep (transitional sleep scoring) method. Five control polysomnograms from subjects without sleep-related breathing abnormalities were scored by the Rechtschaffen and Kales (R&K) method, and 10 polysomnograms from patients with severe obstructive sleep apnea were scored by both the R&K and the T-sleep method. Comparative analyses were performed on sleep variables of the control and apnea polysomnograms, and interscorer correlations were assessed for sleep and apnea variables. The interscorer correlations were high for both R&K control scoring and for apnea recordings scored by the T-sleep method. The number of sleep stage events documented for the 10 apnea recordings was significantly less for the T-sleep method than the R&K method (36, SD 17.0 vs. 332, SD 144.0; p = 0.0002). The T-sleep method was shown to be an effective, accurate and quick method for scoring sleep in patients with sleep-related breathing disorders.

Comparison of self- and spouse reports of snoring and other symptoms associated with sleep apnea syndrome.

We compared self- and spouse reports of snoring and other symptoms of sleep apnea syndrome ascertained from married couples in a community-based survey. Agreement between the two types of report varied between 70-98%, but was modest (kappa = -0.01-0.52) when adjusted for chance. For men, spouse reports yielded higher prevalence rates for snoring and for four other symptoms. For women, estimates of symptom prevalence were consistently lower by spouse report than by self-report. In multivariate analyses, the effect on snoring of gender and obesity increased and of age decreased when spouse reports were compared to self-reports. Snoring, according to spouse reports, was a significant risk factor for ischemic heart disease, but snoring according to self-reports showed a smaller effect and was not statistically significant. Snoring was not associated with hypertension when defined by either self- or spouse report. These observations suggest that questionnaire data of snoring and other symptoms of sleep apnea syndrome may be misclassified in part, and that such misclassification can affect estimates of prevalence and effects.

Atelectasis and neuromuscular respiratory failure.

Atelectasis occurred in 17 of 20 patients treated with assisted ventilation for respiratory failure due to neuromuscular disease. A retrospective review of chest roentgenograms and medical records indicated that atelectasis occurs early in the course of respiratory failure and has a predilection for the lower lobes. Atelectasis was associated with infection and persisted despite therapy, often for more than four weeks. This study demonstrates that atelectasis in this condition still occurs frequently despite modern practices of mechanical ventilatory assistance. Infection, occurring soon after intubation, is identified as the principal cofactor.

Treatment of snoring and obstructive sleep apnea with a dental orthosis.

A dental orthosis, designed to increase the size of the upper airway by advancing the mandible, was used in 68 patients to treat snoring and varying degrees of obstructive sleep apnea. The orthosis increased the posterior airway space, as assessed by lateral cephalograms. Seven months (range 2 to 25) after beginning use, 75 percent of patients were using the orthosis regularly. Snoring, by report, was improved in all patients but one (p less than 0.001) and was eliminated in 42 percent (95 percent confidence interval 30 to 55 percent). Sleep quality and sleepiness were also reported improved. Apneas and hypopneas, measured before and after use in 20 patients with obstructive sleep apnea, were reduced from an average of 47 to 20 events per hour (p less than 0.001). Oxygenation and sleep disturbance were also improved. Apnea-hypopnea frequency was reduced with treatment to less than 20/h in 13 patients. Residual frequencies greater than 20/h were associated with higher initial frequencies of apneas and hypopneas. Side effects of orthosis use were minor, and no serious complications were observed. The dental orthosis is an effective treatment for the symptom of snoring and can also effectively treat obstructive sleep apnea of moderate severity.

Continuous positive airway pressure for long-term treatment of sleep apnea.

Severe obstructive sleep apnea in a child with cleft palate and micrognathia developed after soft-palate repair. Continuous positive airway pressure applied to the nose during sleep corrected the abnormalities of sleep and breathing. Long-term treatment produced a remission of all symptoms. Proper technique was important. Continuous positive airway pressure was effective in treating obstructive sleep apnea in this child, and long-term treatment was implemented in the home.

Treatment of the obstructive sleep apnea syndrome.

The obstructive sleep apnea syndrome is a disorder of sleep and breathing that is being recognized with increasing frequency. The pathophysiologic consequences range from mild sleepiness to life-threatening cardiovascular and respiratory decompensation. The primary forms of treatment are directed at modifying the upper airway with either an operation or continuous positive airway pressure. Aside from tracheostomy, which is virtually always successful, other forms of treatment have met with varying results. Ancillary therapy, including oxygen, weight loss and drugs, is often helpful but seldom curative. Follow-up sleep studies are necessary to evaluate the effectiveness of treatment. Selecting therapy for a patient with obstructive sleep apnea requires a comprehensive evaluation including polysomnography, special examinations of the upper airway and assessing the cardiopulmonary status. Therapy is based on the severity of disease and must be tailored to each patient.

Use of the kinetic treatment table to prevent the pulmonary complications of multiple trauma.

The kinetic treatment table (KTT) has been developed to prevent and treat complications of immobility. Because atelectasis and pneumonia may be related to immobility, we studied the effect of the KTT on the prevention and treatment of pulmonary complications in a prospective randomized study of 30 patients with severe traumatic injuries. All were receiving mechanical ventilation and were randomly assigned to treatment with a KTT or a conventional bed. Both groups received conventional medical-surgical therapy while pulmonary function, chest roentgenograms, and the presence or absence of lung infection were monitored for one week. In the patients who began the study with a clear chest roentgenogram, atelectasis and pneumonia were significantly less frequent in those treated with a KTT (P less than .05). Thus, the KTT can reduce pulmonary complications in selected patients with multiple trauma. The effect of this benefit on overall outcome is uncertain.

Idiopathic hypoventilation syndrome: importance of preventing nocturnal hypoxemia and hypercapnia.

This report describes a young woman with unexplained chronic hypoventilation that was greatly exacerbated during sleep. Treatment with nocturnal O2 during a 2-yr period was associated with stable cardiovascular function but severe morning headaches and lethargy, presumably related to nightly bouts of hypercapnia and acidosis during sleep. A subsequent 2-yr period in which ventilation was assisted during sleep by means of a rocking bed, but supplementary O2 was not used, was associated with disappearance of the headaches and improved psychosocial function, but with the insidious development of signs of pulmonary hypertension and right ventricular hypertrophy. This patient's clinical course demonstrates the separate adverse effects of intermittent hypoxemia and hypercapnia and emphasizes the importance of preventing both hypoxemia and hypercapnia during sleep.