High- and low-level pressure support during walking in people with severe kyphoscoliosis.

To determine whether the level of pressure support (PS) provided during exercise influences endurance time in people with severe kyphoscoliosis, a double-blind randomised crossover study was performed. We hypothesised that high-level PS would be required to enhance endurance time in this population with high impedance to inflation. 13 participants with severe kyphoscoliosis performed four endurance treadmill tests in random order: unassisted; with sham PS; low-level PS of 10 cmH(2)O (PS 10); and high-level PS of 20 cmH(2)O (PS 20). Participants and assessors were blinded to the level of PS delivered during exercise. Endurance time was greater with PS 20 (median (interquartile range) 217 (168-424) s) compared with unassisted exercise (139 (111-189) s), sham PS (103 (88-155) s) and PS 10 (159 (131-206) s). In addition, isotime respiratory rate was decreased by 8 breaths x min(-1) (95% CI -11- -5 breaths x min(-1)) and isotime oxygen saturation increased by 4% (95% CI 1-7%) with PS 20 compared with unassisted exercise. People with severe kyphoscoliosis require high-level PS during walking to improve exercise performance. Investigation of high-level PS as an adjunct to exercise training or to assist in the performance of daily activities is warranted.

Bilevel ventilation during exercise in acute on chronic respiratory failure: a preliminary study.

To determine the immediate effects of bilevel non-invasive ventilation plus oxygen (NIV+O(2)) during exercise compared to exercise with O(2) alone in people recovering from acute on chronic hypercapnic respiratory failure (HRF), a randomised crossover study with repeated measures was performed. Eighteen participants performed six minute walk tests (6MWT) and 16 participants performed unsupported arm exercise (UAE) tests with NIV+O(2) and with O(2) alone in random order. Distance walked increased by a mean of 43.4m (95% CI 14.1 to 72.8, p=0.006) with NIV+O(2) compared to exercise with O(2) alone. In addition, isotime oxygen saturation increased by a mean of 5% (95% CI 2-7, p=0.001) and isotime dyspnoea was reduced [median 2 (interquartile range (IQR) 1-4) versus 4 (3-5), p=0.028] with NIV+O(2). A statistically significant increase was also observed in UAE endurance time with NIV+O(2) [median 201s (IQR 93-414) versus 157 (90-342), p=0.033], and isotime perceived exertion (arm muscle fatigue) was reduced by a mean of 1.0 on the Borg scale (95% CI -1.9 to -0.1, p=0.037) compared with O(2) alone. Non-invasive ventilation plus O(2) during walking resulted in an immediate improvement in distance walked and oxygen saturation, and a reduction in dyspnoea compared to exercise with O(2) alone in people recovering from acute on chronic HRF. The reduction of dyspnoea during walking and arm muscle fatigue during UAE observed with NIV+O(2) may allow patients to better tolerate exercise early in the recovery period.

Pattern of ventilation during manual hyperinflation performed by physiotherapists.

Summary The aim of this prospective observational study was to document patterns of ventilation during manual hyperinflation by physiotherapists. Manual hyperinflation with a Mapleson-F system was performed on the same patients on two consecutive days. Patterns of ventilation were recorded using a heated pneumotachometer, pressure transducer and custom designed data acquisition and analysis systems. The mean (SE) results were: inspiratory time 1.45 (0.10) s; volume delivered 1.23 (0.07) l; peak inspiratory and expiratory flow rate 1.51 (0.06) l.s(-1) and 3.26 (0.30) l.s(-1), respectively and I : E flow rate ratio 0.63 (0.05). All the physiotherapists achieved an increase in volume which was delivered within a safe and effective pressure range and without cardiovascular compromise. Most (26 out of 34 sessions) performed the technique in the way recommended for enhancing secretion clearance. This is the first study to document comprehensively the pattern of ventilation during manual hyperinflation and provides the basis for further clinical trials evaluating its effectiveness for secretion clearance and volume restoration.

The effects of three manual hyperinflation techniques on pattern of ventilation in a test lung model.

Manual hyperinflation (MHI) is used by physiotherapists as a treatment technique in intubated patients. This study investigated the effect of three different MHI techniques using a Mapleson-C circuit configuration with a CIG Medishield valve on volume delivered (Vt), peak inspiratory (PIFR) and expiratory flow rates (PEFR), and peak airway pressure (PAP) in a test lung model. The protocols differed in the degree of valve closure and inclusion of an inspiratory pause. For protocols 1, 2 and 3 the measures were Vt-1.33 (0.21), 2.74 (0.13), 3.55 (0.12) litres; PAP-14.30 (0.82), 24.00 (0.47), 30.20 (0.92) cmH2O and PIFR-1.13 (0.05), 1.51 (0.15), 1.32 (0.09) l/s respectively. All pair comparisons were statistically significant except for PEFR (l/s), which was significantly lower for protocol 1 [1.62 (0.06)], compared to protocols 2 [2.01 (0.25)] and 3 [2.10 (0.19)] but not between protocols 2 and 3. Circuit and technique choice should be considered in relation to the specific therapeutic aim of treatment.

Acute respiratory infection in patients with cystic fibrosis with mild pulmonary impairment: comparison of two physiotherapy regimens.

Chest physiotherapy is an essential part of the management of cystic fibrosis, yet comparatively few studies have investigated the commonly used forms of chest physiotherapy during acute respiratory exacerbations. Fifteen subjects with cystic fibrosis and predominantly mild pulmonary impairment completed a randomised cross-over trial with 24 hours between treatments. The active cycle of breathing techniques (ACBT) assisted by a physiotherapist was compared with the ACBT performed independently by the patient. Measurement outcomes included pulmonary function tests, indirect calorimetry and oximetry parameters. Energy expenditure was not significantly different between the two treatment regimens, though significant improvements in pulmonary function were apparent 24 hours following the therapist-assisted ACBT. In this group of subjects, neither form of treatment proved superior in terms of energy consumption, but a reduction in airways obstruction was observed as a carry-over effect following the therapist-assisted ACBT.

The effect of continuous positive airway pressures on lung volumes in tetraplegic patients.

Continuous positive airway pressure (CPAP) is widely advocated for the treatment of respiratory complications. However the effects of CPAP on the respiratory function of tetraplegic patients have not yet been investigated. The purpose of this study was to examine the effects of breathing with different levels of CPAP on the relationship between closing volume (CV) and functional residual capacity (FRC) in ten recently injured, but otherwise healthy tetraplegic patients with lesions between the fourth and eighth cervical segments. Lung volumes were measured before, during and after 32 min of zero end-expiratory pressure and 5 and 10 cm H2O of CPAP. FRC was measured by the open-circuit nitrogen washout method and CV was measured by the single breath nitrogen washout method. FRC was unaffected by zero end-expiratory pressure, but both 5 cm H2O and 10 cm H2O of CPAP caused significant increases in FRC. FRC returned to pre-CPAP values by the first minute after removal of 5 and 10 cm H2O of CPAP. We were unable to measure CVs in any subjects. It was concluded that 5 and 10 cm H2O of CPAP increase FRC in healthy tetraplegic individuals, but that these increases are rapidly lost with the subsequent removal of CPAP. These results suggest that CPAP may have a role in the treatment and prevention of respiratory complications in tetraplegics.

Pulmonary function tests after whole-lung irradiation and doxorubicin in patients with osteogenic sarcoma.

PURPOSE: Because of the scarcity of information regarding long-term follow-up of pulmonary function after whole-lung irradiation, a prospective study was started at the University of Florida in 1979 to evaluate pulmonary function after treatment with whole-lung irradiation and doxorubicin in patients with osteogenic sarcoma. PATIENTS AND METHODS: Between 1979 and 1984, 57 osteogenic sarcoma patients with no evidence of metastatic disease at diagnosis received adjuvant therapy consisting of whole-lung irradiation (with the heart shielded) followed by Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH). The whole-lung irradiation schema was 1,600 cGy in 10 fractions with 8-MV x-rays via anterior and posterior fields. This was followed by five cycles of Adriamycin for a total dose of 450 mg/m2. Pulmonary function tests (PFTs) consisting of spirometry, lung volumes, and diffusing capacity were obtained before the whole-lung irradiation, at 6 and 12 months after irradiation, and at yearly intervals thereafter. RESULTS: At the time of analysis, 28 of the 57 patients were available for study, with a mean follow-up of 42 months (range, 6 to 77 months). Follow-up pulmonary function testing revealed decreased forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1) during the first 6 to 12 months after whole-lung irradiation. These values returned to baseline during the second-year posttherapy and remained at baseline throughout the remainder of the follow-up period. Changes in lung volumes demonstrated a similar early trend, with significant decreases in total lung capacity (TLC) and functional residual capacity (FRC) at 6 to 12 months. These changes, however, did not improve significantly during the remainder of the follow-up period. Diffusing capacity of the lungs for carbon monoxide (DLCO) also reached a nadir at 6 to 12 months after whole-lung irradiation, with resolution by 2 years and maintenance of at least baseline values for the remainder of the follow-up period. CONCLUSIONS: Treatment with whole-lung irradiation and Adriamycin, as given in this study, caused no significant sequelae, as demonstrated by pulmonary function testing during the mean follow-up period of 42 months, although a mild, transient restrictive ventilatory defect occurred at 6 to 12 months after treatment.

Incisional or excisional neck-node biopsy before definitive radiotherapy, alone or followed by neck dissection.

An analysis of 508 patients (660 heminecks) with head and neck squamous cell carcinoma and clinically positive neck nodes who were treated with radiotherapy alone to the primary lesion (with or without a neck dissection) was conducted to determine if open neck-node biopsy before definitive treatment adversely affected the probability of control of neck disease, the risk of distant metastasis, or the cause-specific survival rate. The prognostic factors analyzed included biopsy status of the neck, N stage, neck treatment, node mobility, node location, T stage, primary site, and control of disease above the clavicles. Sixty-six patients who had undergone an open neck-node biopsy before definitive radiotherapy were compared with a control group of 442 patients who did not undergo a neck-node biopsy; no detrimental effect of the biopsy on neck control, distant metastasis, or cause-specific survival was demonstrated. We conclude that the potential adverse effect of violating the neck before definitive treatment cannot be demonstrated if radiotherapy is the next step in the patient's management.

Respiratory failure and sleep in neuromuscular disease.

Sleep hypoxaemia in non-rapid eye movement (non-REM) and rapid eye movement (REM) sleep was examined in 20 patients with various neuromuscular disorders with reference to the relation between oxygen desaturation during sleep and daytime lung and respiratory muscle function. All the patients had all night sleep studies performed and maximum inspiratory and expiratory mouth pressures (PI and Pemax), lung volumes, single breath transfer coefficient for carbon monoxide (KCO), and daytime arterial oxygen (PaO2) and carbon dioxide tensions (PaCO2) determined. Vital capacity in the erect and supine posture was measured in 14 patients. Mean (SD) PI max at RV was low at 33 (19) cm H2O (32% predicted). Mean PE max at TLC was also low at 53 (24) cm H2O (28% predicted). Mean daytime PaO2 was 67 (16) mm Hg and PaCO2 52 (13) mm Hg (8.9 (2.1) and 6.9 (1.7) kPa). The mean lowest arterial oxygen saturation (SaO2) was 83% (12%) during non-REM and 60% (23%) during REM sleep. Detailed electromyographic evidence in one patient with poliomyelitis showed that SaO2% during non-REM sleep was maintained by accessory respiratory muscle activity. There was a direct relation between the lowest SaO2 value during REM sleep and vital capacity, daytime PaO2, PaCO2, and percentage fall in vital capacity from the erect to the supine position (an index of diaphragm weakness). The simple measurement of vital capacity in the erect and supine positions and arterial blood gas tensions when the patient is awake provide a useful initial guide to the degree of respiratory failure occurring during sleep in patients with neuromuscular disorders. A sleep study is required to assess the extent of sleep induced respiratory failure accurately.

Does node location affect the incidence of distant metastases in head and neck squamous cell carcinoma?

An analysis of 455 patients with head and neck carcinomas and clinically positive neck nodes who were treated with radiation therapy alone to their primary tumors (with or without a neck dissection) was conducted to determine the relative role of several prognostic factors in the subsequent development of distant metastases (DM). The factors analyzed were N stage, node location (upper neck only vs. lower with or without upper neck), T stage, primary site (oral cavity, oropharynx, nasopharynx, hypopharynx, supraglottic larynx), modified AJCC stage, and neck treatment. All patients were treated between 1964 and 1985 and had a minimum follow-up of 2 years. The N stage and node location were the most significant prognostic factors in the subsequent development of distant metastases. The incidence of distant metastases increased with increasing neck stage (N1, 11%; N2, 18%; N3, 27%), and in four of five neck stages (N2B being the exception), the incidence of distant metastases was greater for those patients with metastatic adenopathy in the lower neck. The incidence of distant metastases by modified AJCC stage was 12/111 (11%) for Stage III, 34/146 (23%) for Stage IVA, and 41/198 (19%) for Stage IVB. The primary site and T stage had little influence on the subsequent development of distant metastases. A multivariate analysis of the clinical factors confirmed the importance of neck stage and node location in estimating the probability of distant metastases. Control of disease above the clavicles and the addition of a neck dissection also significantly affected the chance of developing distant metastases.

Noninvasive ventilatory support during sleep improves respiratory failure in kyphoscoliosis.

We investigated the effect on daytime respiratory function and quality of sleep, of providing adequate ventilation either by intermittent positive pressure ventilation (IPPV) or by continuous positive airways pressure (CPAP) both administered through a nose mask in a group of seven patients with severe thoracic kyphoscoliosis. All night control sleep studies were performed with and without ventilatory assistance. Patients underwent standard polysomnography including all night measurements of transcutaneous CO2 (tcCO2) and arterial oxyhemoglobin saturation (SaO2). Awake arterial blood gas tensions (ABGs), respiratory muscle strength (Pmus), and lung function tests were measured in the sitting position. Follow-up studies after three months of treatment showed normal sleep patterns, improvement in daytime ABGs, lung volumes, and respiratory muscle strength. We concluded that maintenance of nocturnal ventilation by either nasal CPAP or nasal IPPV in patients with nocturnal respiratory failure does significantly improve clinical measurements of respiratory function and quality of sleep.

The use of radiation therapy in the management of minor salivary gland tumors.

Between 1964 and 1985, 52 patients were treated with curative intent by radiation therapy alone or in combination with surgery for malignant tumors of minor salivary gland origin. All patients had a minimum follow-up of 2 years, and 80% had a minimum follow-up of 5 years. Twenty-six (50%) were adenoid cystic carcinomas; the remaining histologies included adenocarcinoma, mucoepidermoid carcinoma, and malignant mixed tumors. The most common sites of origin were in the oral cavity/oropharynx (49%) and the nasal cavity or paranasal sinuses (40%). Twenty-seven patients (52%) presented with an advanced or unresectable stage (AJCC Stage III or IV, extensive bone or nerve invasion, or tumor greater than 5 cm). Treatment was highly individualized; 50% of the patients received radiation therapy alone, and 50% received combined treatment with either postoperative or preoperative radiation therapy. Early-stage minor salivary gland tumors were controlled equally well with radiation therapy alone or with a combined approach. For the advanced tumors, a combined approach yielded significantly superior absolute local control rates as compared with radiation therapy alone (10/13 vs. 2/13). For adenoid cystic carcinoma, the local control rate at 10 years was 45% (actuarial); the tumor was not controlled locally in any patients with advanced/unresectable stage who were treated with radiation therapy alone. The absolute local control rate was 75% for 4 early-stage tumors treated with radiation therapy alone and 60% for 5 advanced tumors treated with a combined approach. The average time to local recurrence was 67 months for adenoid cystic carcinoma. Severe complications of radiation therapy occurred in 11 (27%) of 40 evaluable patients, with unilateral blindness being the most common. Seven of 9 patients who became blind had unresectable disease with close proximity to or invasion of the orbit. A time-dose analysis is also presented.

Treatment of alveolar hypoventilation in a six-year-old girl with intermittent positive pressure ventilation through a nose mask.

Persons with alveolar hypoventilation have abnormal daytime arterial blood gases and abnormal responses to hypercapnia and hypoxia in the absence of any identifiable lung or neuromuscular disease. The underlying defect in the control of breathing has not, however, been confirmed. We studied a 6-yr-old girl who was admitted in respiratory failure after a long history of disturbed breathing awake and asleep, which had been diagnosed as primary alveolar hypoventilation, (PaCO2 = 120). After several days of endotracheal intubation and assisted ventilation, her condition improved and she was extubated. At this time her ventilatory response to hypoxia was absent (VE/SaO2:0.1 l/min/% at a CO2 of 45) and there was a right-shifted response to hypercapnia (VE/PaCO2:2.6 l/min/mmHg). As obstructive sleep apnea was suspected, nocturnal nasal continuous positive airway pressure (CPAP) was tried; however, it was not effective in maintaining arterial oxyhemoglobin saturation. Definite central apneas were observed during sleep both with and without nasal CPAP, and there was an absence of snoring. Her condition deteriorated, and there was a progressive increase in her awake arterial CO2 levels for a period of 4 wk. The IPPV with 5 cm H2O of PEEP was administered through a nose mask during sleep and this maintained both oxygen saturation and transcutaneous CO2 levels within the normal range. After 10 days of nocturnal assisted ventilation, the hypercapnic response returned to the normal position (VE/CO2:2.1 l/min/mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of respiratory failure during sleep in patients with neuromuscular disease. Positive-pressure ventilation through a nose mask.

Severe nocturnal hypoxemia may occur in patients with respiratory muscle weakness caused by neuromuscular disorders. Negative pressure ventilators may be partially effective in these patients but can cause upper airway obstructive apneas. We examined the effectiveness of positive pressure ventilation through a nose mask in preventing nocturnal hypoxemia and compared it with negative pressure systems. We reasoned that nasal positive pressure would provide stability for the upper airway. Five patients with neuromuscular disorders underwent a series of all-night sleep studies under control conditions, negative pressure ventilation, and positive pressure ventilation through a comfortable nose mask. Sleep staging and respiratory variables were monitored during all studies. Daytime awake lung function, respiratory muscle strength, and arterial blood gases were also measured. The severe hypoxemia and hypercapnia that occurred under control conditions were prevented by positive pressure ventilation through a nose mask. Negative pressure ventilation improved NREM ventilation in all patients, but did not prevent severe oxyhemoglobin desaturation, which occurred during REM sleep. Negative pressure ventilation appears to contribute to upper airways obstruction during REM sleep as evidenced by cessation of air flow, reduced chest wall movements, falls in arterial oxyhemoglobin saturation, and hypercapnia. With treatment, daytime PaO2 improved from a mean of 70 to 83 mm Hg, and PaCO2 decreased from a mean of 61 to 46 mm Hg. We conclude that nasally applied positive pressure ventilation is a highly effective method of providing nocturnal assisted ventilation because it stabilizes the oropharyngeal airway.