You will be shown the abstract of a medical clinical trial report. Your task is to extract all the findings from this report into a JSON array. Each finding should contain the following five elements:

- Intervention: The medical intervention being tested. This should be a text span copied from the input passage.
- Comparator: The baseline against which the intervention is being evaluated. This should be a text span copied from the input passage. If no comparator is reported, set to `null`.
- Outcome: The medical outcome whose effect is being measured. This should be a text span copied from the input passage.
- Effect: The effect of the intervention on the outcome, relative to the comparator. The effect should be one of the following three values: ("significantly increased", "significantly decreased", "no significant difference").
- Evidence: The evidence for the effect. This should be a text span copied from the input passage.

Please format your output as a JSON array. Each entry in the output should be an array containing the 5 elements listed above, in the following order: [<intervention>, <comparator>, <outcome>, <effect>, <evidence>].

For example, an output with two findings might read:
```
[["aspirin", "placebo", "headache severity", "significantly decreased", "Mean headache severity was significantly decreased in the aspirin group compared to the placebo group (p < 0.05)."], ["aspirin", "placebo", "weight loss", "no significant difference", "We did not observe any difference in weight loss between the group given aspirin relative to the control group"]]
```

There are 5 finding(s) in the abstract below. Please extract them. Output only the JSON array with these 5 findings. Do not include any additional text.

Abstract:
ABSTRACT.BACKGROUND:: Ketamine, a non-competitive NMDA (N-Methyl-D-Aspartate) receptor antagonist, is recognized as an intraoperative anesthetic agent. Increasing interest in the use of low-dose ketamine for postoperative analgesia has developed in part because of its NMDA-antagonistic properties, which may be important in attenuating central sensitization and opioid tolerance. Despite of many trial evaluations which have been done on the effect of low-dose ketamine in postoperative pain, the role of ketamine, as a component of perioperative analgesia, remains unclear. We evaluated the analgesic effect of low-dose ketamine during anesthesia induction in painful ophthalmic surgery.

ABSTRACT.MATERIALS AND METHODS:: After institutional approval and written informed consent, 88 patients undergoing retinal detachment, strabismus, and keratoplasty surgery aged 18-80 years old were randomly divided intoequal case and control groups. Anesthesia was induced with sodium thiopental, fentanyl, atracurium, and liducaine, and maintained with N2O, O2, and propofol. Ketamine 0.5 mg/kg was administered intravenously to patients in the case group during anesthetic induction. Mean blood pressure and pulse rate were listed in questionnaire every 5 minutes. The consumption of anesthetic, perioperative additional analgesic, extubation time, postoperative pain and nausea scores (based on Visual Analog Scale), vomiting frequency, and the recovery time were recorded.

ABSTRACT.RESULTS:: There were no differences in the recovery time (17.3 ± 3.4 in the case group vs. 16.3 ± 3 in the control group, P < 0.05), postoperative pain scores (5 ± 1 in the case group vs. 5.6 ± 2 in the control group, P < 0.05), the consumption of anesthetic (9376.9 ± 1245.8 in the case group vs. 9012.9 ± 1620 in the control group, P < 0.05), the analgesic requirements (1000 in the case group vs. 940.9 ± 135.6 in the control group, P < 0.05), and perioperative additional analgesic (63.4 ± 26.5 in the case group vs. 69.4 ± 25.6 in the control group, P < 0.05) between two groups. The extubation time in the case group (13.59 ± 4.83) was significantly shorter than in the control group (15.9 ± 3.6) (P = 0.01).

ABSTRACT.CONCLUSION:: This study demonstrates that a low dose administration of ketamine during anesthesia induction in retinal detachment, strabismus, and keratoplasty surgery improves the extubation time but have no effect on postoperative pain, nausea and vomiting, and perioperative additional analgesic requirements.

Findings:
[["Ketamine", "Control", "Recovery time", "no significant difference", "There were no differences in the recovery time (17.3 \u00b1 3.4 in the case group vs. 16.3 \u00b1 3 in the control group, P \u003c 0.05),"], ["Ketamine", "Control", "Post-Surgical Pain", "no significant difference", "There were no differences in the recovery time (17.3 \u00b1 3.4 in the case group vs. 16.3 \u00b1 3 in the control group, P \u003c 0.05), postoperative pain scores (5 \u00b1 1 in the case group vs. 5.6 \u00b1 2 in the control group, P \u003c 0.05),"], ["Ketamine", "Control", "Anesthetic usage", "no significant difference", "There were no differences in the recovery time (17.3 \u00b1 3.4 in the case group vs. 16.3 \u00b1 3 in the control group, P \u003c 0.05), postoperative pain scores (5 \u00b1 1 in the case group vs. 5.6 \u00b1 2 in the control group, P \u003c 0.05), the consumption of anesthetic (9376.9 \u00b1 1245.8 in the case group vs. 9012.9 \u00b1 1620 in the control group, P \u003c 0.05),"], ["Ketamine", "Control", "Usage of analgesics", "no significant difference", "the analgesic requirements (1000 in the case group vs. 940.9 \u00b1 135.6 in the control group"], ["Ketamine", "Control", "Time for extubation ", "significantly decreased", "The extubation time in the case group (13.59 \u00b1 4.83) was significantly shorter than in the control group (15.9 \u00b1 3.6) (P = 0.01)."]]