VALUE OF PREMIXED NITROUS-OXIDE-AND-OXYGEN MIXTURES IN THE RELIEF OF POST-OPERATIVE PAIN. DOUBLE-BLIND TRIAL OF 25 PERCENT NITROUS OXIDE IN OXYGEN, 15 PERCENT NITROUS OXIDE IN OXYGEN, AND OXYGEN

Pancreatic Islet Cell Transplantation: A new era in transplantation

Transplantation of insulin-producing tissue offers a physiologic approach to restoration of glycemic control. Whereas transplantation of vascularized pancreatic grafts has recently achieved encouraging results, pancreatic islet cell transplantation holds the promise of low morbidity and reduced requirements for agressive immunosuppression for recipients. Islet cell transplantation was recently demonstrated to induce euglycemia with insulin independence.

Minor procedures in the accident and emergency department: can Entonox help?

The efficacy of Entonox as a supplement to local anaesthesia for minor surgical procedures was studied. Eighty-five patients undergoing surgery for the incision and drainage of a subcutaneous abscess using a local anaesthetic were involved in a trial to ascertain the level of pain associated with such procedures and to investigate the possibility of using on-demand Entonox to supplement the local anaesthesia provided. Patients received either the standard local anaesthesia, or, alternatively, the local anaesthesia was supplemented with oxygen or Entonox via on-demand apparatus. Patients indicated on three linear visual analogue scales their pain, anxiety and total discomfort, and also on a cartoon pain rating scale, at different stages during the operation. Results showed that there was no statistically significant reduction in pain provided by the Entonox, despite general patient approval. Both oxygen and Entonox showed some anxiolytic properties. Pure oxygen was also seen to produce a rise in heart rate, while both gases (pure oxygen and Entonox) caused an increase in diastolic blood pressure. It was also seen that the patient's short term memory of the pain experienced was unaffected by pure oxygen or Entonox.

Prehospital analgesia with nitrous oxide/oxygen

A pilot study of prehospital analgesia with 50% nitrous oxide and 50% oxygen was undertaken in patients experiencing severe pain from various sources. Under the supervision of an ambulance attendant N2O/O2 was administered through a face mask held by the patient and connected to a portable regulator/tank unit. Two types of units were evaluated -- Entonox (with premixed N2O and O2) and Nitronox (with separate cylinders of N2O and O2, the gases being mixed at the time of administration). Of the 72 patients 69 obtained worthwhile analgesia (marked or partial relief of pain) during treatment in the field or in the ambulance. There were no serious side effects, and those that did occur reflected N2O's expected action (e.g., giddiness). N2O/O2 is thus considered a safe and effective analgesic, suitable for use by ambulance personnel.

Nitrous oxide/oxygen analgesia in emergency care

A method of analgesia relatively new to North American emergency care involves the use of a homogeneous gas composed of 50% nitrous oxide and 50% oxygen (Entonox). The gas is administered by the patient, who holds the Entonox apparatus mask to his face and triggers gas flow by exerting negative inspiratory pressure (-1 cm. H(2)O). Worthwhile analgesia (i.e. marked or partial pain relief) was achieved in 95% of 110 emergency department patients experiencing significant pain from various sources.

Clinical effects of nitrous oxide and oxygen mixtures at sea-level and at 1700 metres altitude

The effects of nitrous oxide, at sea-level and at an altitude of 1700 m, were assessed on a subjective and objective basis. Only marginal differences were shown between the effects of the gas at sea-level and 1700 m. Since consciousness was impaired with 60 and 70% nitrous oxide it is suggested that the use of Entonox-oxygen mixtures should be considered for single-handed operators.

Entonox in the emergency department

The use Entonox (BOC Medishield) was examined in a large accident and emergency department and was found to give satisfactory relief from pain in 92 per cent of cases. This compares favourably with reports of its results in other applications.

Pain relief in hospital: the more widespread use of nitrous oxide

A trial was conducted of Entonox for pain relief in minor, but painful, procedures which are conducted in wards, accident centres, and radiological units. The gas was self-administered by the patient using a demand apparatus. The administration was supervised by qualified nurses, specially trained in the properties of Entonox and the inhalational unit. The results confirm that the gas is safe in the hands of these personnel. Gratifying pain relief occurred in most patients with almost complete freedom from undesirable side effects. It is suggested that patient comfort in hospital can be considerably improved by utilizing this method of analgesia to the full.

A clinical study of the value of a mixture of nitrous oxide and oxygen as an analgesic in relief of pain following thoracic surgery and its usage physiotherapeutically

When patients have been subjected to thoracic and abdominal surgery, the ability to cough and ventilate the lungs adequately is inhibited post-operatively by pain and apprehension. The use of anaesthetic agents to relieve pain on stretching the incision has been investigated previously, particularly with patients following abdominal surgery.