Immunomodulatory effects of anesthetics in obese patients

Table 1 Clinical studies of effects of anesthesia on immune cells and outcomes in obese patients

Ref.	Population	Interventions	Comparison	Outcome
Abramo et al[120]	Morbidly obese patients undergoing laparoscopic gastric bypass (n = 30)	TIVA Sevoflurane anesthesia Xenon anesthesia	Serum levels of IL-6, IL-10, TNF-α, and NO before anesthesia, at the end of surgery, and 12 h after the end of surgery	At the end of surgery, IL-10 and TNF-α levels were lower in patients anesthetized with xenon than in those given sevoflurane or TIVA
Roussabrov et al[121]	Obese patients undergoing short-duration gastric or uterine surgery (n = 36)	Ketamine (IV) pre- induction compared with no ketamine before general anesthesia	Serum levels of IL-1β, IL-2, IL-6, TNF- α, lymphocyte proliferation, and NK cell cytotoxicity	Results to those of previous studies in lean patients: No change in inflammation or immune response (11 studies), suppressed immune response (9 studies), or enhanced immune responses (1 study)

Summary of results from clinical studies comparing inhalational and intravenous anesthetics according to population, intervention, comparison, and outcomes. IV: Intravenous; IL: Interleukin; TNF: Tumor necrosis factor; NK: Natural killer cells; NO: Nitric oxide; TIVA: Total intravenous anesthesia.

Table 2 Animal studies of effects of inhalational anesthesia in obese or MetS animals

Ref.	Population	Interventions	Comparison	Outcome in obese animals	Outcome in lean animals
Song et al[123]	Animals fed high-fat vs low-fat diet	Myocardial ischemia and reperfusion	Ctrl x Sevoflurane preconditioning	No sevoflurane cardioprotection	Sevoflurane: ↓ infarct size; ↑endothelial nitric oxide synthase, myocardial nitrite and nitrate
van den Brom et al[124]	Animals fed western vs control diet	Sevoflurane 2% vs baseline on echocardiographic myocardial perfusion and function	Myocardial perfusion and systolic function	Sevoflurane: No additional effect on myocardial perfusion but impaired systolic function	Sevoflurane: ↑ microvascular filling velocity, no change in myocardial perfusion
Bussey et al[125]	Zucker type 2 diabetic Zucker obese vs lean counterpart animals	Conscious vs 2% isoflurane anesthesia	Hemodynamic effects (mean arterial pressure, heart rate) of α or β adrenoreceptor (AR) stimulation	Isoflurane exacerbated and prolonged α-AR sensitivity and normalized chronotropic β-AR responses	Maintenance of ↑ α-AR sensitivity, ↑ chronotropic β-AR heart rate and mean arterial pressure responses
Zhang et al[126]	Animals with hypercholesterolemia vs normocholesterolemic animals	60 min sevoflurane pre-treatment, 12 h before myocardial IR surgery	Expression of myocardial iNOS and eNOS	No cardioprotectant effects of sevoflurane, downregulation of eNOS. Interference with iNOS signaling pathway	Delayed sevoflurane cardioprotection: decreased infarct size and improved ventricular function
Yang et al[127]	Animals fed high-fat vs low-fat diet	60 min focal cerebral ischemia followed by 24 h of reperfusion 15 min sevoflurane postconditioning	Cerebral infarct volume, neurological score, motor coordination 24 h after reperfusion	Sevoflurane post-conditioning failed to confer neuroprotection; no neuroprotective effect of mitoKATP channel opener	Sevoflurane ↓ infarct size, improved neurological deficit scores; neuroprotective effect of mitoKATP channel opener
Yu et al[128]	Animals fed high-fat vs low-fat diet	Middle cerebral artery occlusion; Isoflurane post-treatment after 20 min in vitro ischemia or transient middle cerebral artery occlusion	Cell injury in hippocampal slices, brain infarct volume, neurological deficit	Attenuated isoflurane-induced neuroprotection; ↓ Akt signaling pathway	Isoflurane post-treatment ↓ injury

Summary of the results of experimental studies comparing inhalational anesthetics according to population, intervention, comparison, and outcomes. AR: Adrenergic receptor; eNOS: Endothelial nitric oxide; IR: Ischemia-reperfusion.