Doppler Ultrasound Assessment of the Effects of Ketamine on Neonatal Cerebral Circulation

Abstract

The effects of a single dose of 5 mg-kg-(1) of ketamine administered intravenously to 10 critically ill preterm infants prior to epicutaneo-caval catheterization were analyzed using pulsedwave Doppler ultrasound. The infants weighed between 670 and 1,885 g and their gestational ages ranged from 26 to 33 weeks. Arterial pressure (MAP), cardiac output (CO), transcutaneous oxygen pressure (TCPO(2)), transcutaneous carbon dioxide pressure (TCPCO(2)), end-diastolic velocity (EDV), peak systolic velocity (PSV), mean arterial velocity (MAV) of the cerebral anterior artery as well as Pourcelot’s resistance index (PRI) were measured before and after injection of the drug. We observed a significant decrease in arterial pressure at 2 min after injection while heart rate and CO did not vary significantly. TCPO(2) and TCPCO(2), also remained unchanged throughout the period of measurement. EDV, PSV, and MAV did not vary significantly nor did PRI. As this drug provides major comfort to the baby during painful procedures and considerably facilitates difficult thin vessel catherization, we believe that it may be used in such conditions.

Ketamine for procedural pain relief in newborn infants

“…The heart rate decreased only after administration of 2 mg/kg ketamine, and there were no statistically or clinically significant changes in blood pressure after any doses of ketamine. In a previous study, in which 10 preterm infants, aged 1–10 days, received 5 mg/kg ketamine intravenously before central venous catheterisation, a significant but short lasting decrease in arterial blood pressure was observed two minutes after ketamine administration, but no changes in cerebral blood flow occurred 9. A moderate decrease in arterial blood pressure was also observed in another study in which 20 2 week old preterm infants received 2 mg/kg ketamine intravenously before surgical procedures 19.…”

“…As only a few studies have been carried out on the analgesic use of ketamine during the neonatal period,8 9 we designed this randomised trial to evaluate its suitability and the appropriate dose for relief of the brief discomfort and pain caused by tracheal suction in newborn infants during the recovery period of ventilator treatment when sedation or analgesia is usually avoided.…”

Use of Analgesic and Sedative Drugs in the NICU: Integrating Clinical Trials and Laboratory Data

“…Systemic and cerebral hemodynamic effects of ketamine were assessed when used as analgesic therapy for central vein catheterization. No impairment of hemodynamics could be shown (124). When used for short procedures, higher doses of ketamine (2 mg/kg) reduced heart rate (125) and 5 mg/kg reduced blood pressure without impairing cardiac output (124).…”

“…No impairment of hemodynamics could be shown (124). When used for short procedures, higher doses of ketamine (2 mg/kg) reduced heart rate (125) and 5 mg/kg reduced blood pressure without impairing cardiac output (124). Studies of infants undergoing cardiac catheterization have reported respiratory complications (126) and increased blood pressure (127).…”

“…Remifentanil decreased pain for PICC insertion (169) Thoracic rigidity requiring muscle blocker injection (alfentanil 20 g/kg) (167). Same time to complete the maneuver and procedure time as placebo (169) Acetaminophen Ն37 wks GA No effect for heel lance (170) Good hepatic tolerance (149) Ketamine Ineffective for tracheal suctioning (125) No cerebral hemodynamic adverse effect (5 mg/kg) (124) Repetitive painful stimuli may persistently alter pain processing in humans (171), and epidemiologic studies have revealed an association between peri-and neonatal complications and behavioral/emotional problems in childhood, anxiety/ depression, and even suicidal tendencies (172,173). Conversely, drug toxicity should not be underestimated and risk/ benefit balance must be evaluated when prescribing analgesia or sedation for neonates.…”