- Email: [email protected]
SYRINGE PUMP SAFETY LOCK
188 the book Migraine and Epilepsy, which also reviews headaches as an epileptic manifestation or equivalent. We feel that a wider awareness of the features of postepileptic headache is important in everyday clinical neurology. In seeking the cause of unexplained blackouts a history of prolonged headache after the event may be a useful pointer to an epileptic origin; simple faints seem rarely to be followed by headaches. In our study 8 of the 9 patients with both migraine and epilepsy had pronounced postepileptic headache which had similar characteristics to their migraine pain and was associated with photophobia and gastrointestinal disturbance. This finding’ indicates that seizures can trigger migraine attacks and should be added to the list of precipitating factors such as exercise, diet, and
published in
hormonal variations.1 You state that "it is well known that... epilepsy is commoner in patients with migraine". This association is not established, some studiesincluding ours/ showing an incidence no greater than chance. The picture is further confused by the inclusion of electroencephalographic data in some, but not all, published studies. In view of our ignorance about the mechanism underlying migraine, it seems important that seizures can provoke a syndrome that closely resembles the headache phase of migraine. Postepileptic headache offers another model worthy of further study, to be added to earlier ones such as red wine and trinitrin-induced headaches.
Syringe pump with safety lock. plunger
*
Present address:
F. SCHON* J. N. BLAU
Neurology Department, Mayday Hospital, Croydon CR4 7YE.
1. Schon
F, Blau JN. Postepileptic headache and migraine. J Neurol Neurosurg Psychiatry 1987; 50: 1148-52. 2. D’Alessandro R, Sacquegna T, Pazzaglia p, Lugaresi E. Headache after partial complex seizures. In: Andermann F, Lugaresi E, eds. Migraine and Epilepsy. London; Butterworths, 1987. 273-78. 3. Barolin GS. Migraines and epilepsies: a relationship. Epilepsia 1966; 7: 53-66.
SYRINGE PUMP SAFETY LOCK
SIR,-Syringe pumps are a popular means of delivering drugs by infusion but accidents with the device have caused some anxiety among clinicians. A 4-month-old baby being ventilated because of respiratory failure was on a continuous infusion of d-tubocurarine in normal saline (1mg/ml) at a rate of 1 ml/h. Although it had apparently been set correctly the syringe pump delivered about 34 ml over a period not longer than 20 min. At the end of this period the baby became severely bradycardic, probably secondary to hypoxia caused by a sudden fall in pulmonary compliance. The baby became almost impossible to ventilate by hand and required external cardiac massage, adrenaline, frusemide, sodium bicarbonate, and hydrocortisone. The pump was examined by the manufacturer but no defect was found. To avoid frequent changes or refilling, syringes for infusion pumps are often loaded with drug sufficient for several hours or even days, and the pump is then set to deliver a concentrated infusion slowly (eg, 50 ml at 1 ml/h). This practice relies on the syringe pump being set correctly and then running accurately, and there is a danger of overdosing-for example, if the rate-setting controls are confusing; if the syringe is not securely attached to the drive mechanism, allowing free flow from the syringe;2 or if a pump, set correctly, malfunctions and delivers the infusion much too To limit the scale of overinfusion a simple mechanical quickly.3-<> safety lock has been designed and attached to a Vickers ’IP3 Treonic’ syringe pump (figure). A rigid barrier, which can be located at any one of several positions, prevents further movement of the syringe plunger. As the syringe plunger is depressed the barrier is moved down in stages ahead of it, but with only small movements each time. If a pump overrun develops or if free flow occurs the safety lock prevents the depression of the syringe plunger beyond the point at which the barrier was last set, so preventing a large overdose. The device will also limit the delivery of an infusion that has been set incorrectly at any excessive rate. If the syringe
by the
barrier
with the IP3 and similar
then, alarm sounds. However, if a slow infusion is being correctly delivered but staff fail to advance the barrier, some time will elapse before the alarm sounds, so it is important that regular, albeit limited, movements of the barrier are made if the infusion is not to
National Hospital for Nervous Diseases, London W9
is stopped
pumps, an
be interrupted.
Any electromechanical device can malfunction and my hope is that this device will make even safer an already useful and safe clinical tool. Staff find it easy to use and it provides peace of mind for doctors and nurses alike. Department of Paediatric Anaesthesia, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP
R.
J. BRAY
1. Anon. Evaluation of infusion pumps. Health Equipment Inf 1982; 106: 31. uncontrolled infusion. Safety Inf Bull 1986; 30.
2. Anon.
Syringe pumps: Department of Health and Social Security (DHSS). Infusion pumps: Vickers Treonic IP4 syringe drive. HN (hazard) 1984; no 16. 4. Anon. Infusion pump: Vickers Treonic IP4 and IP4H digital syringe driver. Safety Inf Bull 1984; 19. 5. DHSS. Infusion pump system: overinfusion resulting from liquid spillage. HN (hazard) 1985; no 4. 6. DHSS Vickers syringe diver pumps SP44, SP55. HN (hazard) 1987; no 2. 3.
ISOLATION OF HIV-2 IN CENTRAL AFRICA FROM AIDS PATIENT AND HER SYMPTOM-FREE
PARTNER
SiR,-HIV-2 does seem to be present in central Africal but until now we have been unable to isolate the virus. We report here the isolation of HIV-2 from a 25-year-old black woman and her 43-year-old white husband. The wife, who was pregnant, was an inpatient with full-blown AIDS; her husband was healthy. Both were seronegative for HIV-1 by ELISA but in an HIV-2 ELISA (Diagnostic Pasteur) both sera were positive. In western blots against HIV-1 antigens the sera reacted with the internal pl8-p25 protein only; however, they reacted strongly with the internal p 16-p26 proteins and envelope gpl60-gpl40 glycoproteins of HIV-2. Virus was isolated2 from peripheral blood lymphocytes from the woman and her husband and reverse transcriptase activity was 250 000 cpm/ml after 10 days. When cell-free virus was separated on polyacrylamide gel and transferred onto nitrocellulose, the viral antigens reacted in p26, p36, p55, p68 and gpl40 with the patient’s serum, with p26, p55 and gp 140 with an HIV-2 positive reference serum, and with p26 and p55 only with an HIV-1positive control serum. HIV-1infection is endemic in central Africa (eg, in Zaire and the Central African Republic’) but HIV-2 infection had not previously been described in this area. HIV-2 seems to originate from West Africa. (The woman with AIDS had had a 1 year sexual relationship with a man from Benin 8 years earlier, but we do not know whether he is positive for HIV-2.) Further studies are needed to pinpoint the
published in
hormonal variations.1 You state that "it is well known that... epilepsy is commoner in patients with migraine". This association is not established, some studiesincluding ours/ showing an incidence no greater than chance. The picture is further confused by the inclusion of electroencephalographic data in some, but not all, published studies. In view of our ignorance about the mechanism underlying migraine, it seems important that seizures can provoke a syndrome that closely resembles the headache phase of migraine. Postepileptic headache offers another model worthy of further study, to be added to earlier ones such as red wine and trinitrin-induced headaches.
Syringe pump with safety lock. plunger
*
Present address:
F. SCHON* J. N. BLAU
Neurology Department, Mayday Hospital, Croydon CR4 7YE.
1. Schon
F, Blau JN. Postepileptic headache and migraine. J Neurol Neurosurg Psychiatry 1987; 50: 1148-52. 2. D’Alessandro R, Sacquegna T, Pazzaglia p, Lugaresi E. Headache after partial complex seizures. In: Andermann F, Lugaresi E, eds. Migraine and Epilepsy. London; Butterworths, 1987. 273-78. 3. Barolin GS. Migraines and epilepsies: a relationship. Epilepsia 1966; 7: 53-66.
SYRINGE PUMP SAFETY LOCK
SIR,-Syringe pumps are a popular means of delivering drugs by infusion but accidents with the device have caused some anxiety among clinicians. A 4-month-old baby being ventilated because of respiratory failure was on a continuous infusion of d-tubocurarine in normal saline (1mg/ml) at a rate of 1 ml/h. Although it had apparently been set correctly the syringe pump delivered about 34 ml over a period not longer than 20 min. At the end of this period the baby became severely bradycardic, probably secondary to hypoxia caused by a sudden fall in pulmonary compliance. The baby became almost impossible to ventilate by hand and required external cardiac massage, adrenaline, frusemide, sodium bicarbonate, and hydrocortisone. The pump was examined by the manufacturer but no defect was found. To avoid frequent changes or refilling, syringes for infusion pumps are often loaded with drug sufficient for several hours or even days, and the pump is then set to deliver a concentrated infusion slowly (eg, 50 ml at 1 ml/h). This practice relies on the syringe pump being set correctly and then running accurately, and there is a danger of overdosing-for example, if the rate-setting controls are confusing; if the syringe is not securely attached to the drive mechanism, allowing free flow from the syringe;2 or if a pump, set correctly, malfunctions and delivers the infusion much too To limit the scale of overinfusion a simple mechanical quickly.3-<> safety lock has been designed and attached to a Vickers ’IP3 Treonic’ syringe pump (figure). A rigid barrier, which can be located at any one of several positions, prevents further movement of the syringe plunger. As the syringe plunger is depressed the barrier is moved down in stages ahead of it, but with only small movements each time. If a pump overrun develops or if free flow occurs the safety lock prevents the depression of the syringe plunger beyond the point at which the barrier was last set, so preventing a large overdose. The device will also limit the delivery of an infusion that has been set incorrectly at any excessive rate. If the syringe
by the
barrier
with the IP3 and similar
then, alarm sounds. However, if a slow infusion is being correctly delivered but staff fail to advance the barrier, some time will elapse before the alarm sounds, so it is important that regular, albeit limited, movements of the barrier are made if the infusion is not to
National Hospital for Nervous Diseases, London W9
is stopped
pumps, an
be interrupted.
Any electromechanical device can malfunction and my hope is that this device will make even safer an already useful and safe clinical tool. Staff find it easy to use and it provides peace of mind for doctors and nurses alike. Department of Paediatric Anaesthesia, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP
R.
J. BRAY
1. Anon. Evaluation of infusion pumps. Health Equipment Inf 1982; 106: 31. uncontrolled infusion. Safety Inf Bull 1986; 30.
2. Anon.
Syringe pumps: Department of Health and Social Security (DHSS). Infusion pumps: Vickers Treonic IP4 syringe drive. HN (hazard) 1984; no 16. 4. Anon. Infusion pump: Vickers Treonic IP4 and IP4H digital syringe driver. Safety Inf Bull 1984; 19. 5. DHSS. Infusion pump system: overinfusion resulting from liquid spillage. HN (hazard) 1985; no 4. 6. DHSS Vickers syringe diver pumps SP44, SP55. HN (hazard) 1987; no 2. 3.
ISOLATION OF HIV-2 IN CENTRAL AFRICA FROM AIDS PATIENT AND HER SYMPTOM-FREE
PARTNER
SiR,-HIV-2 does seem to be present in central Africal but until now we have been unable to isolate the virus. We report here the isolation of HIV-2 from a 25-year-old black woman and her 43-year-old white husband. The wife, who was pregnant, was an inpatient with full-blown AIDS; her husband was healthy. Both were seronegative for HIV-1 by ELISA but in an HIV-2 ELISA (Diagnostic Pasteur) both sera were positive. In western blots against HIV-1 antigens the sera reacted with the internal pl8-p25 protein only; however, they reacted strongly with the internal p 16-p26 proteins and envelope gpl60-gpl40 glycoproteins of HIV-2. Virus was isolated2 from peripheral blood lymphocytes from the woman and her husband and reverse transcriptase activity was 250 000 cpm/ml after 10 days. When cell-free virus was separated on polyacrylamide gel and transferred onto nitrocellulose, the viral antigens reacted in p26, p36, p55, p68 and gpl40 with the patient’s serum, with p26, p55 and gp 140 with an HIV-2 positive reference serum, and with p26 and p55 only with an HIV-1positive control serum. HIV-1infection is endemic in central Africa (eg, in Zaire and the Central African Republic’) but HIV-2 infection had not previously been described in this area. HIV-2 seems to originate from West Africa. (The woman with AIDS had had a 1 year sexual relationship with a man from Benin 8 years earlier, but we do not know whether he is positive for HIV-2.) Further studies are needed to pinpoint the