Uncontrolled high blood pressure under total intravenous anesthesia with propofol and remifentanil: A case report

BACKGROUND

Although propofol generally reduces blood pressure, rarely, it causes hypertension. However, the mechanism by which propofol increases blood pressure has not been established, and so far, there are only a few reported cases.

CASE SUMMARY

A 46-year-old woman, diagnosed with thyroid cancer, was administered general anesthesia with propofol and remifentanil for a thyroid lobectomy. An increase in the concentrations of intravenous anesthetics further increased her blood pressure. The blood pressure remained stable when anesthesia was maintained with sevoflurane and remifentanil after the interruption of propofol administration.

CONCLUSION

We concluded that propofol administration was the cause of increased blood pressure.

Remifentanil inhibits the traumatic stress response in emergent trauma surgery

OBJECTIVE

The aim of this study was to explore whether remifentanil could inhibit the stress response in emergent trauma surgery more effectively than sufentanil.

PATIENTS AND METHODS

Sixty trauma patients for emergent surgery were randomly divided into remifentanil group (R group, n = 30) or sufentanil group (S group, n = 30). The patients in the R group were continuously intravenously infused with remifentanil, while those in the S group were administrated with sufentanil. The plasma contents of cortisol (COR), epinephrine (E), norepinephrine (NE), and blood glucose were measured before anesthesia induction (T1), 5 minutes after intratracheal intubation (T2) and 5 minutes (T3), 30 minutes (T4), and 1 hour (T5) after surgery, respectively. The blood pressure (BP) and the heart rate (HR) at these time points were recorded as well.

RESULTS

The results showed that the patients in the R group had more stable hemodynamics during the surgery and had a significantly lower HR at T2-T5 than those in the S group. The plasma levels of norepinephrine at time points T3-T5 and levels of cortisol at T4-T5 in the R group were significantly lower than those in the S group (P < 0.05).

CONCLUSIONS

The results in the present study indicated that remifentanil could inhibit the stress response in emergent trauma surgery patients more effectively than sufentanil.

Sepsis-induced liver dysfunction was ameliorated by propofol via suppressing hepatic lipid peroxidation, inflammation, and drug interactions

AIMS

Our previous study showed that propofol can protect against sepsis-induced insults through suppressing liver nitrosation and inflammation. This study further evaluated the mechanisms of propofol-caused protection from sepsis-induced liver dysfunction.

MAIN METHODS

Male Wistar rats were subjected to cecal ligation and puncture (CLP) and then exposed to propofol. Levels of hepatic oxidative stress and lipid peroxidation were consecutively measured. Expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-4 messenger (m)RNA or proteins were quantified. Effects of propofol on microsomal pentoxyresorufin O-dealkelase (PROD) and ethoxycoumarin O-deethylase (ECOD) activities were determined.

KEY FINDINGS

Administration of propofol to CLP-treated rats significantly attenuated sepsis-induced insults. CLP caused augmented serum aspartate aminotransferase and alanine aminotransferase activities and concurrently triggered liver damage. In contrast, treatment with propofol protected against CLP-induced liver dysfunction. As to the mechanisms, the CLP-induced increases in oxidative stress and lipid peroxidation levels and TNF-α and IL-1β mRNA and protein expressions were subsequently attenuated by propofol. Furthermore, administration of CLP-treated rats with propofol augmented levels of IL-4 in the liver. Phenobarbital treatment of liver microsomes in CLP-treated rats produced less amplification of PROD and ECOD activities, and a smaller amount of 4-hydroxypropofol was metabolized from propofol by liver microsomes. In contrast, more drug interactions occurred with propofol, which decreased PROD and ECOD activities in liver microsomes of CLP-treated rats.

SIGNIFICANCE

Taken together, the present study showed that propofol can protect against sepsis-induced liver dysfunction through suppressing hepatic oxidative stress, lipid peroxidation, inflammation, and drug biotransformation and interactions in the liver.

Ring-oxidative biotransformation and drug interactions of propofol in the livers of rats

Propofol, an intravenous anesthetic agent, is widely used for inducing and maintaining anesthesia during surgical procedures and for sedating intensive care unit patients. In the clinic, rapid elimination is one of the major advantages of propofol. Meanwhile, the biotransformation and drug interactions of propofol in rat livers are still little known. In this study, we evaluated the ring-oxidative metabolism of propofol in phenobarbital-treated rat livers and possible drug interactions. Administration of phenobarbital to male Wistar rats significantly increased levels of hepatic cytochrome P450 (CYP) 2B1/2 and microsomal pentoxyresorufin O-dealkylase (PROD) activity. Analyses by high-performance liquid chromatography and liquid chromatography mass spectroscopy revealed that propofol was metabolized by phenobarbital-treated rat liver microsomes into 4-hydroxypropofol. In comparison, PROD activity and 4-hydroxy-propofol production from propofol metabolism were suppressed by orphenodrine, an inhibitor of CYP2B1/2, and a polyclonal antibody against rat CYP2B1/2 protein. Furthermore, exposure of rats to propofol did not affect the basal or phenobarbital-enhanced levels of hepatic CYP2B1/2 protein. Meanwhile, propofol decreased the dealkylation of pentoxyresorufin by phenobarbital-treated rat liver microsomes in a concentration-dependent manner. Taken together, this study shows that rat hepatic CYP2B1/2 plays a critical role in the ring-oxidative metabolism of propofol into 4-hydroxypropofol, and this anesthetic agent can inhibit CYP2B1/2 activity without affecting protein synthesis.

Propofol and remifentanil at moderate and high concentrations affect proliferation and differentiation of neural stem/progenitor cells

Propofol and remifentanil alter intracellular Ca²⁺ concentration ([Ca²⁺]_i) in neural stem/progenitor cells by activating γ-aminobutyric acid type A receptors and by reducing testosterone levels. However, whether this process affects neural stem/progenitor cell proliferation and differentiation remains unknown. In the present study, we applied propofol and remifentanil, alone or in combination, at low, moderate or high concentrations (1, 2–2.5 and 4–5 times the clinically effective blood drug concentration), to neural stem/progenitor cells from the hippocampi of newborn rat pups. Low concentrations of propofol, remifentanil or both had no noticeable effect on cell proliferation or differentiation; however, moderate and high concentrations of propofol and/or remifentanil markedly suppressed neural stem/progenitor cell proliferation and differentiation, and induced a decrease in [Ca²⁺]_i during the initial stage of neural stem/progenitor cell differentiation. We therefore propose that propofol and remifentanil interfere with the proliferation and differentiation of neural stem/progenitor cells by altering [Ca²⁺]_i. Our findings suggest that propofol and/or remifentanil should be used with caution in pediatric anesthesia.