Position statement for adult and paediatric spirometry in South Africa: 2022 update.

Spirometry is required as part of the comprehensive evaluation of both adult and paediatric individuals with suspected or confirmed respiratory diseases and occupational assessments. It is used in the categorisation of impairment, grading of severity, assessment of potential progression and response to interventions. Guidelines for spirometry in South Africa are required to improve the quality, standardisation and usefulness in local respiratory practice. The broad principles of spirometry have remained largely unchanged from previous versions of the South African Spirometry Guidelines; however, minor adjustments have been incorporated from more comprehensive international guidelines, including adoption of the Global Lung Function Initiative 2012 (GLI 2012) spirometry reference equations for the South African population. All equipment should have proof of validation regarding resolution and consistency of the system. Daily calibration must be performed, and equipment quality control processes adhered to. It is important to have standard operating procedures to ensure consistency and quality and, additionally, strict infection control as highlighted during the COVID-19 pandemic. Adequate spirometry relies on a competent, trained operator, accurate equipment, standardised operating procedures, quality control and patient co-operation. All manoeuvres must be performed strictly according to guidelines, and strict quality assurance methods should be in place, including acceptability criteria (for any given effort) and repeatability (between efforts). Results must be categorised and graded according to current guidelines, taking into consideration the indication for the test.

The utility of hand-held mobile spirometer technology in a resource-constrained setting.

BACKGROUND: Mobile phone-linked spirometry technology has been designed specifically for evaluating lung function at primary care level. The Air-Smart Spirometer is the first mobile spirometer accepted in Europe for the screening of patients with chronic respiratory diseases. OBJECTIVES: To prospectively assess the accuracy of the device in measuring forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) in a South African population, and to investigate the ability of the device to detect obstructive ventilatory impairment. METHODS: A total of 200 participants were randomly assigned to perform spirometry with either the mobile spirometer connected to a smartphone or the desktop spirometer first, followed by the other. The FEV1/FVC ratio as well as the absolute FEV1 and FVC measurements were compared, using each participant as their own control. A Pearson correlation and Bland-Altman analysis were performed to measure the agreement between the two devices. We defined obstructive ventilatory impairment as FEV1/FVC <0.7 measured by desktop spirometry in order to calculate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the Air-Smart Spirometer. RESULTS: There was a strong correlation between the absolute FEV1 and FVC values and FEV1/FVC ratio measured with the mobile Air-Smart Spirometer and more conventional pulmonary function testing, with r=0.951, r=0.955 and r=0.898, respectively. The Air-Smart Spirometer had a sensitivity of 97.6%, specificity of 74.4%, PPV of 73.0% and NPV of 97.8% for obstructive ventilatory impairment. CONCLUSIONS: The mobile Air-Smart Spirometer compared well with conventional spirometry, making it an attractive and potentially affordable tool for screening purposes in a primary care setting. Moreover, it had a high sensitivity and NPV for obstructive ventilatory impairment.

Guideline for office spirometry in adults, 2012.

BACKGROUND: Office spirometry remains an integral part of a comprehensive respiratory evaluation and is used to categorise the nature, severity and progression of respiratory diseases and to measure response to treatment. These updated guidelines are aimed at improving the quality, standardisation and usefulness of office spirometry in South Africa. RECOMMENDATIONS: All equipment should have proof of validation regarding resolution and the system's linearity (consistency). Moreover, equipment must be calibrated daily and quality controlled. It is also important to have standard operating procedures in place, including the documentation of ambient conditions and infection control measures. Adequate spirometry relies on a competent operator, accurate equipment, standardised operating procedures, quality control and patient co-operation. The indication for spirometry in a particular patient should be unambiguous and should be documented. Subjects should be appropriately prepared for testing, and patient details must be documented. Forced vital capacity (FVC) manoeuvres (either closed or open circuit) must be performed strictly according to guidelines, and strict quality assurance methods should be in place, including acceptability criteria (for any given effort) and repeatability (between efforts). Testing should continue until at least 3 acceptable curves are produced (with 2 fulfilling repeatability criteria). Other indices are derived from these efforts. CONCLUSION: Test results must be categorised and graded according to current guidelines, taking into account the indication for the test and the appropriateness of reference values.

Corticosteroids in the treatment of tuberculous pleurisy. A double-blind, placebo-controlled, randomized study.

Although several studies on tuberculous (TB) pleurisy suggest that the addition of corticosteroids to anti-TB therapy may have beneficial effects, these agents are not used routinely. To assess the effects of short-term oral prednisone therapy in TB pleurisy, 74 patients were randomly assigned in a double-blind fashion to treatment with either placebo or prednisone at a dose of 0.75 mg/kg/d for up to 4 weeks with gradual reduction over an additional 2 weeks. All subjects received a standard 3-drug anti-TB chemotherapy regimen for 6 months. TB pleurisy was diagnosed by histologic study and/or culture of pleural biopsy specimens obtained at thoracoscopy. Complete drainage of the effusion was performed simultaneously. Outcome measures were assessed periodically for 24 weeks, including indexes of morbidity and pleural thickening. After randomization, four patients were excluded from the final analysis. Of the 70 patients analyzed, 34 received prednisone and 36 received placebo. Demographic and clinical characteristics of the treatment groups were comparable at the time of hospital admission. Although a statistically significant improvement in symptoms occurred earlier in the prednisone group (8 weeks) than in the placebo group (12 weeks), between-group comparison showed no significant differences at any of the follow-up evaluations. The proportion of subjects in the prednisone group (53.1%) with residual pleural thickening at 6 months did not differ significantly from that of the placebo group (60%). Pleural effusions did not recur in any of the patients. Initial complete drainage of the effusion was associated with greater symptomatic improvement than any subsequent therapy. We conclude that standard anti-TB therapy and early complete drainage is adequate for the treatment of TB pleurisy. The addition of short-term oral prednisone therapy neither results in clinically relevant earlier symptom relief nor confers a beneficial effect on residual pleural thickening.

Desflurane analgesia for vaginal delivery.

The use of subanaesthetic concentration of inhalational anaesthetic for vaginal delivery offers many advantages to the mother and newborn. Desflurane, with the characteristics of rapid onset and minimal metabolism, may provide better analgesia and safety for labour pain control. Eighty healthy parturients were randomly assigned to receive either desflurane 1.0-4.5% and oxygen (n = 40) or nitrous oxide 30-60% in oxygen (n = 40). Analgesia was assessed using a score from 0 (no relief) to 4+ (excellent analgesia), amnesia for the delivery, blood loss were recorded. Neonates were evaluated by Apgar scores and neurologic and adaptive capacity scores (NACS). Data were analyzed for statistical significance using Student's t-test or Chi-square when appropriate. Analgesia scores were similar for both groups with more amnesia in desflurane group (23% vs 0% P < 0.05). Blood loss did not differ significantly, 364 ml for the desflurane group and 335 ml for the nitrous oxide group. There were no significant differences for neonatal Apgar score at 1 min or at 5 min or the NACS at 2 hr or 24 hr between the two groups. We conclude that desflurane in subanaesthetic doses is safe and effective inhalation agent for normal delivery but might be associated with amnesia.

Transnasal butorphanol: a new method for pain relief in post-cesarean section pain.

This study was undertaken to evaluate the efficacy and the safety of transnasal butorphanol (TNB) compared to intravenous butorphanol (IVB) in 186 patients experiencing moderate to severe post-cesarean section pain. Patients were randomly assigned to five groups in a double-blind fashion: Group I (n = 37) received 2 mg IVB, Group II (n = 38) 2 mg TNB, Group III (n = 36) 1 mg TNB followed by a repeat dose of 1 mg TNB at 60 min, Group IV (n = 38) 0.5 mg TNB followed by a repeat dose of 0.5 mg at 60 min, and Group V (n = 37) received placebo. All administrations were double dummy. Pain intensity and relief were noted and the incidence of side effects was recorded. Remedication with the same study drug was allowed up to 72 h. Onset of analgesia was more rapid in the 2 mg IV group compared to the three TN groups: 5 min vs 15 min, respectively. However, the 2 mg and the 1-1 mg TN groups had a longer duration of analgesia, approximately 4.5 h, compared to 3.0 h for the 2 mg IV group (P less than 0.05). Somnolence was dose related and was the most frequent side effect, and was less frequent when the TN dose was divided into 2 doses administered 1 h apart. Multiple doses of TNB and IVB were safe and clinically acceptable up to 3 days at all doses studied. There were no incidences of nasal mucosa irritation, or cardiovascular or respiratory depression. It is concluded that transnasal butorphanol represents a safe and effective alternative to injectable butorphanol for post-cesarean section pain and offers a better and longer duration of analgesia compared to IV butorphanol. The optimum dose seems to be 2 mg TN butorphanol and it is tolerated better when divided into 1 mg increments, given 1 h apart.

Mini-dose intrathecal morphine for the relief of post-cesarean section pain: safety, efficacy, and ventilatory responses to carbon dioxide.

To determine the safety, efficacy, and the ventilatory responses to carbon dioxide (CO2) of mini-dose intrathecal morphine, 33 healthy women who underwent cesarean section with spinal anesthesia using 0.75% bupivacaine in 8.25% dextrose were studied. Patients were randomly assigned to receive, in a double-blind fashion, either morphine 0.25 mg (group I, n = 11), morphine 0.1 mg (group II, n = 10), or saline (group III, placebo group, n = 12) in 0.5 ml volume mixed with the bupivacaine. In both groups I and II excellent postoperative analgesia with long duration was obtained (27.7 +/- 4.0 and 18.6 +/- 0.9 hours, respectively, X +/- SEM). All patients in group III required an analgesic (8 mg subcutaneous morphine) within 3 hours of spinal anesthesia. Seven patients in group I and four patients in group II developed mild pruritus that did not require treatment. Ventilatory responses to CO2 showed no evidence of depression attributable to either the 0.25 or 0.1 mg of morphine, but significant depression of the CO2 responses was observed in group III patients after administration of subcutaneous morphine. It is concluded that a dose as low as 0.1 mg of intrathecal morphine gives excellent analgesia with minimal to no side effects and that subcutaneous morphine is associated with marked depression of the ventilatory variables.