European Journal of Cardiovascular Medicine

Managing anaesthesia in low-birth-weight neonates presents a unique set of challenges. These neonates often have difficult airways and challenging intravenous access due to their small size and fragile vasculature^1,2. Hypothermia is another critical concern, as these patients are prone to rapid heat loss in the operating room^3,4. Additionally, neonatal physiology, characterized by limited cardiovascular and respiratory reserves, increases the risk of complications during anesthesia^5,6.

We present a case series which explores the use of intramuscular ketamine for induction of anaesthesia in low-birth-weight neonates as a primary aesthetic agent, focusing on its efficacy and safety in managing these vulnerable patients.

Case Series: We present case series of five low birth neonates who were anaesthetized with intramuscular inj ketamine for intravenous access and induction of anaesthesia. Written informed consent was obtained from patient’s mother in all five cases.

Case 1.  A 5-day-old, 2.0 kg female posted for Meningomyelocele excision and repair with no other congenital disorders was administered intramuscular ketamine 10 (5mg/kg) mg in the preoperative room, after 7 minutes she lost consciousness but maintained spontaneous respiration, was transferred to the operating theatre where an IV line was secured with 24 G cannula in right hand dorsum, then she received iv midazolam 0.1 mg and iv fentanyl 4 mcq and sevoflurane inhalation for induction. She was intubated with 2.5 OD endotracheal tube placed and then iv atracurium 1 mg (0.05mg/kg) was given for muscle relaxation, anaesthesia was maintained with oxygen, air, and sevoflurane and intermittent iv atracurium. She was extubated and shifted to recovery and then to the ward.

Case 2. 8 days old, 2.1 kg female Omphalocele posted for laparotomy and repair (Figure 1) without any other congenital abnormality. Patient was given intramuscular injection ketamine 10 mg in preoperative room, after 10 minutes she felt asleep and was shifted to operation theatre, then intravenous access was obtained with 24 G cannula, she was premedicated with iv inj glycopyrrolate 0.01 mg, inj midazolam 0.1mg and fentanyl 4 mcq. She was given sevoflurane inhalational induction and inj atracurium 1 mg for muscle relaxation. She was intubated with 2.5 OD endotracheal tube. Anaesthesia maintenance was with oxygen, air and sevoflurane. Surgery went uneventful and she was reversed with inj neostigmine with inj glycopyrrolate. Later she was shifted out from recovery.

Figure 1. 8 days old, 2.1 kg female child Omphalocele posted for laparotomy and repair

Case 3 A 10 days old 2.5 kg female with leaking csf mengiomylocele (Figure 2) posted for emergency excision and repair. Preoperative patient bilateral chest crepitation, with Xray picture of pneumonitis, she also had fever and raised leucocyte counts with room air saturation of 89 %. In operation theatre she was given inj. Ketamine 10 mg and after 10 mins iv access was secured in right hand forearm with 24 G cannula. Premedicated with fentanyl and intubated with 3 OD ETT. Anaesthesia was managed with oxygen, nitrous and sevoflurane. Procedure was uneventful without any complication. We were unable to extubate the patient on table due to respiratory compromise and was shifted to NICU. Later she was extubated next day.

Figure 2. A 10 days old 2.5 kg female with leaking csf mengiomylocele

Case 4. A 2 days old male, 2.4 kg male with type C Tracheoesophageal Fistula (TEF) posted for emergency repair. In preoperative examinations patient had bilateral diffuse rhonchi. Her Xray showed twisted nasogastric tube with gas in abdomen (Figure 3). He was nebulized with salbutamol and budesonide. On operation table he was given intramuscular inj. ketamine 12.5 mg, iv line was secured and premedicated with inj glycopyrrolate 0.01 mg and inj midazolam after loss of reflexes he was induced with inj propofol 5 mg and intubated with 3 OD ETT. Anaesthesia was maintained with oxygen, air and sevoflurane and inj vecuronium bromide. Intraoperative patient had sudden rise in peak pressure which was later managed by changing endotracheal tube as it was blocked due to mucus plugging. Patient also managed with inj dopamine infusion in view of low heart rate. Rest of the course was uneventful. At end of surgery child was reversed from muscle relaxation and extubated.

Figure 3 Xray Chest and Abdomen showed showing twisted nasogastric tube with gas in abdomen indicating TEF.

Case 5. A 1 day 2.4 kg male with mengiomylocele posted for emergency excision and repair. Preoperative examination was normal. In preoperative room he was given inj. Ketamine 10 mg and after 8 mins iv access was secured and patient was shifted to operating room. Premedication was done with inj glycopyrrolate and inj fentanyl later she was intubated with 3 OD ETT. Anaesthesia was managed with oxygen, air and sevoflurane. At the end of surgery patient was extubated and shifted to ward.

This case series evaluates the use of intramuscular ketamine for the induction of anesthesia in low-birth-weight neonates. This approach overcomes the difficulties of airway management, intravenous access and hemodynamic stability.

All patients were successfully managed without any complication except case 4 where we needed to replace the endotracheal tube, it may have happened because of the prior preexisting respiratory compromise due to nature of the defect.

Ketamine is a dissociative anaesthetic drug acting through antagonism of the N-methyl-D-aspartate (NMDA) receptors⁷. It produces a dissociative state with analgesia, sedation, amnesia, and immobility while maintaining respiratory function and airway reflexes. So, its utility in neonatal and paediatric anaesthesia is important⁸. It has been widely evaluated for procedural sedation⁹. But its utility its intramuscular route for securing IV access in neonates and induction of anaesthesia is less evaluated.

Intramuscular ketamine for induction proved to be effective in all cases, facilitating IV access. All patients maintained adequate respiration post-ketamine administration until further anaesthetic agents were administered. One patient required prolonged mechanical ventilation in NICU which was due to pre-existing infection, so one needs to be for vigilant with neonates with underlying conditions. Hemodynamic parameters were well-maintained in all the cases. In one instance, a patient required dopamine infusion due to low heart rate, as we know cardiac output is heart rate dependent in newborns due to deceased compliance and contractility of heart muscles¹⁰.

Ketamine's unique pharmacological profile makes it a very useful anaesthetic agent, which is useful in scenarios where obtaining intravenous access is difficult and maintained respiratory and cardiovascular stability is needed. Its utility in low-birth-weight neonates, as highlighted in the case series, underscores its value in paediatric anaesthesia for challenging cases. However, clinicians must remain vigilant regarding its psychotropic effects and potential for cardiovascular stimulation.

1. Subramaniam, Rajeshwari. Anaesthetic concerns in preterm and term neonates. Indian Journal of Anaesthesia 63(9): p 771-779, September 2019. doi: 10.4103/ija.IJA_591_19
2. Park RS, Peyton JM, Kovatsis PG. Neonatal Airway Management. Clin Perinatol. 2019 Dec;46(4):745-763. doi: 10.1016/j.clp.2019.08.008.
3. Nemeth M, Miller C, Bräuer A. Perioperative Hypothermia in Children. Int J Environ Res Public Health. 2021 Jul 15;18(14):7541. doi: 10.3390/ijerph18147541
4. Abiramalatha T, Ramaswamy VV, Bandyopadhyay T, Pullattayil AK, Thanigainathan S, Trevisanuto D, Roehr CC. Delivery Room Interventions for Hypothermia in Preterm Neonates: A Systematic Review and Network Meta-analysis. JAMA Pediatr. 2021 Sep 1;175(9): e210775. doi: 10.1001/jamapediatrics.2021.0775.
5. Saikia D, Mahanta B. Cardiovascular and respiratory physiology in children. Indian J Anaesth. 2019 Sep;63(9):690-697. doi: 10.4103/ija.IJA_490_19
6. Batton B. Neonatal Blood Pressure Standards: What Is "Normal"? Clin Perinatol. 2020 Sep;47(3):469-485. doi: 10.1016/j.clp.2020.05.008.
7. Forestner JE. Pharmacology of ketamine. J Urol. 1980 Apr;123(4):608-9. doi: 10.1016/s0022-5347(17)56064-4. PMID: 7365922.
8. Simonini A, Brogi E, Cascella M, Vittori A. Advantages of ketamine in pediatric anesthesia. Open Med (Wars). 2022 Jul 6;17(1):1134-1147. doi: 10.1515/med-2022-0509
9. Barrett W, Buxhoeveden M, Dhillon S. Ketamine: a versatile tool for anesthesia and analgesia. Curr Opin Anaesthesiol. 2020 Oct;33(5):633-638
10. Vrancken SL, van Heijst AF, de Boode WP. Neonatal Hemodynamics: From Developmental Physiology to Comprehensive Monitoring. Front Pediatr. 2018 Apr 5; 6:87. doi: 10.3389/fped.2018.00087.