Prone positioning

Editor – I have read with interest the article ‘Prone positioning in COVID-19: What's the evidence’ by Rajan S Pooni.¹ He writes that prone positioning is a relatively safe intervention that has been shown to improve oxygenation in conscious ward-based patients. He, however, concedes that it is not a substitute for intubated and mechanically ventilated patients. He also says that the existing evidence base is too small to lead to a definitive conclusion.

Respiratory analeptics

Sophisticated ventilators are a somewhat recent development. They have their own limitations and may have adverse effects on patients.

What could have we done, say 50–60 years ago, when there were no ventilators? This is especially important in a situation where there is the possibility of collapse of the respiratory centre.² In such a situation there would perhaps be relatively little chance of it taking over while the patient is on a ventilator. The centre could perhaps be stimulated by using a respiratory analeptic.

Nikethamide (Coramine)

Some workers have administered nikethamide intravenously at the rate of 4 mL/min in 15 patients with acute respiratory failure: the patients showed increase in mental lucidity and respiratory drive; there were varying degrees of decrease in arterial partial pressure of carbon dioxide and improvement in minute ventilation.³ One of greatest paradoxes is treatment for the relief of hypoxaemia may lead to further depression of ventilation. With the use of nikethamide the hypoventilation induced by oxygen breathing was corrected. The average dose varied between 5 and 8 mL (250 mg/mL). In most cases, a dose of 5 mL was adequate The ratio between therapeutic and toxic levels was good. Oxygen was administered through a nasal catheter at the rate of 3 to 5 litres per minute.

If a patient does not respond or gets worse on nikethamide, one can always switch over to mechanical ventilation. This drug has been in use for a long time and continues to be widely available. There is always scope for further studies.⁴ Nikethamide and other respiratory analeptics deserve a relook and call for further research.