The effect of a single intravenous dose of metamizol 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic parameters and postoperative pain after heart surgery

Antipyretic Use in Noncritically Ill Patients With Fever: A Review

Antipyretics are one of the most frequently used agents in medicine. Numerous pharmacological agents, such as acetaminophen, non-steroidal anti-inflammatory agents (NSAIDs), salicylates, and selective cyclooxygenase 2 (COX-2) inhibitors, and nonpharmacological treatment modalities, such as tepid sponging and cooling blankets, are available for temperature reduction. There is a scarcity of definitive clinical guidelines on the choice of various agents in noncritically ill febrile patients. Our review examined the various modalities available for antipyresis and compared their safety and efficacy. The rationale for the choice of a particular pharmacological agent and route of administration were scrutinized. Our review also envisaged the perceived beneficial effects of antipyretics against the harmful side effects, including the evaluation of morbidity or mortality advantage conferred by antipyretics. The various toxicities associated with these agents were also highlighted.

The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study

The hemodynamic effects of intravenous (IV) paracetamol in patients undergoing cardiac surgery are unknown. We performed a prospective single center placebo controlled randomized study with parallel group design in adult patients undergoing elective cardiac surgery. Participants received paracetamol (1 gram) IV or placebo (an equal volume of 0.9% saline) preoperatively followed by two postoperative doses 6 hours apart. The primary endpoint was the absolute change in systolic (SBP) 30 minutes after the preoperative infusion, analysed using an ANCOVA model. Secondary endpoints included absolute changes in mean arterial pressure (MAP) and diastolic blood pressure (DPB), and other key hemodynamic variables after each infusion. All other endpoints were analysed using random-effect generalized least squares regression modelling with individual patients treated as random effects. Fifty participants were randomly assigned to receive paracetamol (n = 25) or placebo (n = 25). Post preoperative infusion, paracetamol decreased SBP by a mean (SD) of 13 (18) mmHg, p = 0.02, compared to a mean (SD) of 1 (11) mmHg with saline. Paracetamol decreased MAP and DBP by a mean (SD) of 9 (12) mmHg and 8 (9) mmHg (p = 0.01 and 0.02), respectively, compared to a mean (SD) of 1 (8) mmHg and 0 (6) mmHg with placebo. Postoperatively, there were no significant differences in pressure or flow based hemodynamic parameters in both groups. This study provides high quality evidence that the administration of IV paracetamol in patients undergoing cardiac surgery causes a transient decrease in preoperative blood pressure when administered before surgery but no adverse hemodynamic effects when administered in the postoperative setting.

Effect of selective β-adrenoceptor blockade and surgical resection of the celiac-superior mesenteric ganglion complex on delayed liquid gastric emptying induced by dipyrone, 4-aminoantipyrine, and antipyrine in rats

There is evidence for participation of peripheral β-adrenoceptors in delayed liquid gastric emptying (GE) induced in rats by dipyrone (Dp), 4-aminoantipyrine (AA), and antipyrine (At). The present study aimed to determine whether β-adrenoceptors are involved in delayed GE induced by phenylpyrazole derivatives and the role of the prevertebral sympathetic nervous system in this condition. Male Wistar rats weighing 220-280 g were used in the study. In the first experiment rats were intravenously pretreated with vehicle (V), atenolol 30 mg/kg (ATE, β₁-adrenergic antagonist), or butoxamine 25 mg/kg (BUT, β₂-adrenergic antagonist). In the second experiment, rats were pretreated with V or SR59230A 2 mg/kg (SRA, β₃-adrenergic antagonist). In the third experiment, rats were subjected to surgical resection of the celiac-superior mesenteric ganglion complex or to sham surgery. The groups were intravenously treated with saline (S), 240 µmol/kg Dp, AA, or At, 15 min after pretreatment with the antagonists or V and nine days after surgery. GE was determined 10 min later by measuring the percentage of gastric retention (%GR) of saline labeled with phenol red 10 min after gavage. The %GR (means±SE, n=6) values indicated that BUT abolished the effect of Dp (BUT+Dp vs V+Dp: 35.0%±5.1% vs 56.4%±2.7%) and At (BUT+At vs V+At: 33.5%±4.7% vs 52.9%±2.6%) on GE, and significantly reduced (P<0.05) the effect of AA (BUT+AA vs V+AA: 48.0%±5.0% vs 65.2%±3.8%). ATE, SRA, and sympathectomy did not modify the effects of treatments. These results suggest that β₂-adrenoceptor activation occurred in delayed liquid gastric emptying induced by the phenylpyrazole derivatives dipyrone, 4-aminoantipyrine, and antipyrine. Additionally, the released neurotransmitter did not originate in the celiac-superior mesenteric ganglion complex.

Inhibition of cyclooxygenase attenuates the blood pressure response to plantar flexion exercise in peripheral arterial disease

Prostanoids are produced during skeletal muscle contraction and subsequently stimulate muscle afferent nerves, thereby contributing to the exercise pressor reflex. Humans with peripheral arterial disease (PAD) have an augmented exercise pressor reflex, but the metabolite(s) responsible for this augmented response is not known. We tested the hypothesis that intravenous injection of ketorolac, which blocks the activity of cyclooxygenase, would attenuate the rise in mean arterial blood pressure (MAP) and heart rate (HR) evoked by plantar flexion exercise. Seven PAD patients underwent 4 min of single-leg dynamic plantar flexion (30 contractions/min) in the supine posture (workload: 0.5-2.0 kg). MAP and HR were measured on a beat-by-beat basis; changes from baseline in response to exercise were determined. Ketorolac did not affect MAP or HR at rest. During the first 20 s of exercise with the most symptomatic leg, ΔMAP was significantly attenuated by ketorolac (2 ± 2 mmHg) compared with control (8 ± 2 mmHg, P = 0.005), but ΔHR was similar (6 ± 2 vs. 5 ± 1 beats/min). Importantly, patients rated the exercise bout as "very light" to "fairly light," and average pain ratings were 1 of 10. Ketorolac had no effect on perceived exertion or pain ratings. Ketorolac also had no effect on MAP or HR in seven age- and sex-matched healthy subjects who performed a similar but longer plantar flexion protocol (workload: 0.5-7.0 kg). These data suggest that prostanoids contribute to the augmented exercise pressor reflex in patients with PAD.

The postoperative analgesic effect of morphine and paracetamol in the patients undergoing laparotomy, using PCA method

Objective:

postoperative pain increases the activity of the sympathetic system, causes hypermetabolic conditions, retains salt and water, increases glucose, fatty acid lactate and oxygen consumption, weakens the immunity system which delays wound healing.

Our object was comparison of the analgesic effect of morphine and paracetamol in the patients undergoing laparotomy, using PCA method.

Method:

Seventy patients who had undergone laparotomy were studied using double blind randomized clinical trial (35 patients received morphine and 35 paracetamol) in the Shahid Rajaee Center and Velayat Hospital (Qazvin, Iran). People using opioids, painkillers and sedatives regularly and in large doses and patients with a history of lung or liver problems did not participate in this project. The parameters of the severity of pain and nausea (VAS), hemodynamic changes (BP and HR), pruritus, arterial oxygen desaturation and patient satisfaction (VAS) of both groups were measured by a third party (trained colleague). The data was analyzed using SPSS 16 statistical software then descriptive results were extracted and ultimately the groups were compared using the following statistical tests: student’s T-test, chi 2 and Fisher’s exact test (P<0.05).

Findings:

The mean age of the participants was 45±12.5 years. Women constituted 24.3% of the patients and men 75.7%. The average pain severity for morphine and paracetamol groups (VAS) was 5.3±2.2and 6.37±1.7 after2 hours and reached 1.91±1.3 and 2.49±1.3 after 8 hours (after the operation) respectively. There was a significant difference between the groups after 2 and 4 hours in terms of pain severity (after 2 hours P=0.007 and after 4 hours P=0.047). However there was no significant difference between the average pain severity of the studied groups (after 6 hours P=0.4 and 8 hours P=0.08).

After 8 hours, the average nausea severity was the minimum in both groups being 1.71±1.6 and 1.43±1.1 in morphine and paracetamol groups respectively. Nausea severity was higher after 2 hours in paracetamol group. In morphine group, it was higher after 4, 6 and 8 hours. Difference between the groups was not significant. The average satisfaction level (VAS) for morphine and paracetamol groups reached from 5.29±2.3 and 4.2±2.4 after 2 hours, to 7.94±1.8 and 7.69±2.1 after 8 hours (after the operation), respectively. The average satisfaction level of patients was higher in morphine group in 2,4,6 and 8 hours and except for, after 4 hours (P=0.01), the satisfaction difference between both groups was not significant in other hours (P=0.06 after 2 hours, P=0.6 after 6 hours and P=0.5 after 8 hours)

Conclusion:

Morphine seems to be more effective at 2 and 4 hours, but after 4 hours they have similar effects, the satisfaction difference between both groups was not significant in the patients.

Intravenous paracetamol: a review of efficacy and safety in therapeutic use

Paracetamol is well established as a leading nonprescription antipyretic analgesic drug and is available in oral, rectal or intravenous forms. However, except for oral paracetamol, there is a marked discrepancy between the extent to which paracetamol is used and the available evidence for an analgesic effect in postoperative pain. This review mainly focuses on intravenous paracetamol. Its efficacy and safety are analyzed, as well as its use in therapeutics, alone or in combination. The morphine-sparing, additive and antihyperalgesia effects of intravenous paracetamol are also reviewed. The analyses are divided into several sections, comparing the efficacy of intravenous paracetamol with placebo, other forms of paracetamol or analgesic agents and analyzing its efficacy in multimodal therapy combined with NSAIDs or a morphinic agent.

[Non-opioid analgesics for perioperative pain therapy. Risks and rational basis for use]

Non-opioid analgesics play a central role in the management of postoperative pain. In this review, the pharmacology, the analgesic efficacy and the side-effects of non-opioid analgesics are summarized. First, the pharmacology of diclofenac, acetyl salicylic acid, dipyrone, acetaminophen and the COX-2 inhibitors is described. Second, the analgesic efficacy of non-opioid analgesics is analyzed for moderate pain (e.g. ambulatory surgery) and for moderate to severe pain (e.g. abdominal surgery-in combination with opioids). There is limited evidence for an additive analgesic effect of two non-opioid analgesics. Third, the major side-effects of non-opioid analgesics are discussed in relation to the pathophysiology, the frequency and the clinical relevance of these effects. In particular, side-effects on the gastrointestinal tract (ulcus formation), on coagulation (bleeding and thrombosis), on the renal (renal insufficiency), the pulmonary (bronchospasm) and the hematopoetic systems (agranulocytosis) are described. Recommendations for the clinical use of non-opioid analgesics for perioperative pain therapy are given.