Hypoxaemia and supplemental oxygen therapy in the first 24 hours after myocardial infarction: the role of pulse oximetry. Comparison of nasal prongs and nasopharyngeal catheter for the delivery of oxygen in children with hypoxemia because of a lower respiratory tract infection. Oxygen administration to hypoxic children in Ethiopia: a randomized controlled study comparing complications in the use of nasal prongs with nasopharyngeal catheters. Postoperative respiratory care: a controlled trial of early and late extubation following coronary-artery bypass grafting.
To assess the incidence and degree of hypoxaemia in patients with acute myocardial infarction and evaluate the nation-wide perception and usage of oxygen therapy.
                Postal survey of all coronary care units (CCU) in England of their use of prescribed oxygen and pulse oximetry. Prospective randomised study of 50 patients presenting within 24 hours of onset of myocardial infarction, half of whom received oxygen therapy. Oxygen saturation (SpO2) as continuously measured by pulse oximetry, and arrhythmias and ST segment changes were recorded on simultaneous 24-hour ambulatory Holter monitors.
                In 53% of UK coronary care units oxygen is not routinely prescribed but in only 3% is a pulse oximeter used to aid management. In patients presenting with acute myocardial infarction the incidence of hypoxaemia (SpO2 < 90%) was 70% and severe hypoxaemia 35% in those not given oxygen, compared with only 27% and 4% in patients given oxygen therapy. The only patient to receive oxygen on clinical grounds had an oxygen saturation of 71%. Severe hypoxaemia (SpO2 < 80%) occurred significantly less often (1 and 7 patients, p < 0.05) in patients given oxygen. There were no differences in arrhythmias or ST segment changes between groups.
                Hypoxaemia occurs frequently in patients in the first 24 hours after acute myocardial infarction. It is effectively and easily treated with supplemental oxygen which can be guided by pulse oximetry. This is rarely done. Measurements of oxygen saturation are therefore justified in all patients to guide oxygen therapy unless there is a decision to give all patients supplemental oxygen: this we believe to be unnecessary. To determine the best method of oxygen delivery for children in developing countries who have hypoxemia caused by acute lower respiratory tract infection.
                One hundred eighteen children between 7 days and 5 years of age with a lower respiratory tract infection and arterial hemoglobin oxygen saturation (Sao2) less than 90% were randomly selected to receive oxygen by nasopharyngeal (NP) catheter (n = 56) or nasal prongs (n = 62). A crossover study to determine the flow rate necessary to achieve an Sao2 of 95% was performed in 60 children.
                One hundred twelve children could be oxygenated by the allocated method; in six oxygenation was poor with either method. The mean duration of therapy was 87.5 hours for the prongs and 94.9 hours for the NP catheter (not significant). The median oxygen consumption was 2142 L for prongs and 1692 L for the NP catheter (not significant). In the crossover study the prongs needed, on average, 26% higher oxygen flow rates than the NP catheter to obtain an Sao2 of 95% (p = 0.003). Complete nasal obstruction was observed in 24 of the children (44%) in the NP catheter group and in 8 (13%) in the prongs group (p < 0.001). Eighteen children died, 11 with NP catheter and 7 with prongs (not significant).
                Because nasal prongs are less prone to complications, and oxygenation in children is equally effective, they are a more appropriate method than the NP catheter for oxygen delivery to children in developing countries with acute lower respiratory tract infections. Oxygen administration is one of the most important therapeutic interventions for a child with severe acute lower respiratory tract infection (ALRI). Inexpensive and efficient methods of oxygen administration are highly desirable in hospitals in developing countries. The objectives of this study were to compare the frequency and nature of complications when nasopharyngeal catheters or nasal prongs are used to deliver oxygen. One hundred and twenty-one children between the ages of 2 weeks and 5 years with hypoxia due to ALRI were randomized to receive oxygen via a catheter (61 children) or via nasal prongs (60 children). The two groups were similar in terms of diagnoses, clinical severity, oxygen saturation on admission and case fatality rates. There was no difference in the incidence of hypoxaemic episodes between the two groups. The oxygen flow rates required on the day of admission for adequate oxygenation (SaO2 > 90%) ranged from 0.8 litres per minute to 1.2 litres per minute. The required oxygen flow rate decreased during the course of treatment. Mucus production was more of a problem in the catheter group, and nasal blockage, intolerance of the method of oxygen administration and nursing effort were generally higher amongst the catheter group, but none of these differences was significant. Ulceration or bleeding of the nose was significantly more common in the catheter group (19.7% vs 6.7%, p < 0.05). Abdominal distension and nasal perforation were not seen in either group. This study suggests that nasal prongs are safer, more comfortable and require less nursing expertise than nasopharyngeal catheters for administration of oxygen to children. Sequelae of early versus late extubation of the trachea in patients following coronary-artery bypass grafting were compared prospectively in 38 patients randomly assigned to one of the two groups. The times to extubation were 2 +/- 2 and 18 +/- 3 hours after operation for the two groups. Comparisons were made between groups for the following five variables: time spent in the intensive care unit; drug utilization in the intensive care unit; cardiopulmonary morbidity; hemodynamic performance; patient stress (plasma norepinephrine levels). The anesthetic technique consisted of induction with thiopental, nitrous oxide, and halothane, followed by maintenance with nitrous oxide and halothane. Pancuronium was the only muscle relaxant administered. Patients whose tracheas were extubated early had muscle relaxants reversed prior to the application of extubation criteria. There was no significant difference between the groups in times spent in the intensive care unit, hemodynamic performances, or plasma norepinephrine levels; however, the patients whose tracheas were extubated early received less morphine and diazepam and suffered significantly less cardiopulmonary morbidity.
NP and NPC seem to be similar in effectiveness and safety when used in patients with LRTI. There is no single clinical sign or symptom that accurately identifies hypoxaemia. Studies identifying the most effective and safe oxygen delivery method are needed.