22 research outputs found
Is it time for an autoregulation-oriented therapy in head-injured patients?
No full textOptimization of cerebral perfusion
pressure (CPP) is a cornerstone
of the management
of head-injured patients in
intensive care. Unfortunately, there is
still no consensus on the best strategies
to manipulate CPP. Which should we
modify first: blood pressure or intracranial
pressure (ICP)? Which is the most
appropriate drug? What are the pressure
thresholds?
Recent guidelines suggest that “CPP
<50 mm Hg should be avoided, and that
minimally invasive, efficient, and accurate
methods of determining and following
the relationships between CPP
and autoregulation and between CPP
and ischemia in individual patients are
needed” (1).
For the last 20 yrs, the Cambridge
University group has been working
on techniques to measure cerebral
autoregulation in real time and has
proposed many indexes retrospectively
related with clinical and prognostic data
(2–6). In the current issue of Critical
Care Medicine, the retrospective, single-
center study by Aries et al (7) adds
new information for a bedside practical
identification of an “optimal” value
of CPP (CPPopt), which is measured as
the CPP corresponding to the best cerebral
vasoreactivity (8). The main result
has been to develop an algorithm for
the computerized, automated, and continuous
updating of CPPopt, derived
from a time window recording of 4 hrs.
In their study, vasoreactivity has beencalculated as a linear correlation coefficient
between spontaneous fluctuations
of mean arterial pressure and ICP (PRx).
Results are based on some theoretical
considerations:
Firstly, PRx is an index of vasoreactivity,
which means that variations of ICP
induced by CPP changes should be related
to cerebral blood volume variations. In
fact, if ICP is unchanged, cerebral blood
volume should also remain unchanged.
This is not always true, as the same authors
state. In case of decompressive craniectomy,
it is likely that spontaneous fluctuations
of CPP do not induce ICP increase,
even in the presence of significant raises
in cerebral blood volume. The same can
happen when cerebrospinal drainage is
present, or cerebral compliance is high.
Secondly, according to the authors, the
best PRx should correspond to CPPopt.
From a theoretical point of view, it is
reasonable to consider that the best CPP
for individual patients matches with the
best cerebral vasoreactivity, but prospective
validation studies are still lacking. In
particular, we do not know if patients with
high vasoreactivity present the best metabolic
and perfusion indexes. For example,
hypocapnia increases PRx, but may be
dangerous for head-injured patients and
may represent an important confounding
factor that needs to be taken into account
(9). An important step in the knowledge
of this phenomenon is represented by Jaeger
et al (10), who have found that brain
tissue oxygen pressure increases according
to CPP, only when measured CPP was
below or equal to CPPopt. When measured
CPP was higher than CPPopt, brain tissue
oxygen pressure did not change, becoming
independent from any increase in CPP.
Even if brain tissue oxygen pressure is just
a surrogate of cerebral blood flow, this
could suggest that driving CPP in excess
of CPPopt does not improve cerebral perfusion,
at least in the area where the brain
tissue oxygen pressure probe is inserted.
Furthermore, we do not know if drugs
such as mannitol, vasopressors, or other
variables, such as hyperthermia, hypothermia,
and fluctuations in sedation
could impact on PRx and eventually on
CPPopt extrapolation (11).
In addition, even if a correlation
between PRx and prognosis was reported
by several studies, it was only retrospectively
investigated (4–6). We do not know
if optimizing CPP could improve prognosis,
or if it simply reflects such a derangement
of physiological parameters that is
associated with poor outcome.
Beside these theoretical limitations,
there are important practical problems due
to technical acquisition of arterial blood
pressure and ICP and prospective artifact
exclusion. Furthermore, independently
from the quality of the pressure signal, in
a significant number of cases a correlation
between arterial blood pressure and ICP
was lacking, consequently PRx was not
available. In addition, technical difficulties
in identifying CPPopt with an automated
system are reported by the authors.
The purpose of this study is ambitious
and fascinating because it suggests
an autoregulation-oriented strategy
to identify individualized threshold of
CPPopt, which correlates with patients’
prognosis. Such an approach has been
already highlighted on head-injured
patients by Howells et al (12). In an
interesting article, they retrospectively
compared the effects of ICP- and CPPoriented
therapy in patients with continuous
monitoring of cerebrovascular
pressure reactivity. They found that
CPP-oriented therapy was superior to
ICP-oriented therapy when cerebrovascular
reactivity was normal, but it
was the reverse when cerebrovascular
reactivity was impaired. The authors
estimated that the correct CPP- or
ICP-directed treatment could have, on
average, increased the probability of a
favorable outcome from 45% to 64%.
This hypothesis is intriguing and needs
a prospective validation.
So far, no prospective randomized
study has been done, and therefore, no
definitive evidence supports the use
of this technology in general practice.
We look forward to an autoregulationoriented
prospective randomized multicenter
study in the near future
Echography in brain imaging in intensive care unit: State of the art
No full textTranscranial Sonography (TCS) is an ultrasound-based imaging technique, which allows the identification of several structures within the brain parenchyma. In the past it has been applied for bedside assessment of different intracranial pathologies in children. Presently, TCS is also used on adult patients to diagnose intracranial space occupying lesions of various origins, intracranial hemorrhage, hydrocephalus, midline shift and neurodegenerative movement disorders, in both acute and chronic clinical settings. In comparison with conventional neuroimaging methods (such as Computed Tomography or Magnetic Resonance), TCS has the advantages of low costs, short investigation times, repeatability, and bedside availability. These noninvasive characteristics, together with the possibility of offering a continuous patient neuro-monitoring system, determine its applicability in multiple emergency and non-emergency settings. Currently, TCS is a still underestimated imaging modality that requires a wider diffusion and a qualified training process
Anaesthesia for total knee arthroplasty: efficacy of single-injection or continuous lumbar plexus associated with sciatic nerve blocks--a randomized controlled study
No full textTotal knee arthroplasty (TKA) often results in marked postoperative pain. We compared in a randomized controlled study tramadol consumption, postoperative pain and patient satisfaction after primary TKA in patients who received a single injection lumbar plexus and sciatic nerve blocks or a continuous lumbar plexus and sciatic nerve blocks. Forty-four patients scheduled for unilateral total knee arthroplasty were allocated to the single shot group (group A) or to the catheter group (group B). All patients (in both groups) reported being satisfied with their anaesthetic management. Although pain scores and tramadol consumption appeared lower in the active infusion group, the differences did not reach statistical significance. This study confirms that either single injection or continuous infusion of Ropivacaine in lumbar plexus provides reliable and long-acting anaesthesia and analgesia
Racemic ketamine in adult head injury patients: use in endotracheal suctioning
No full textINTRODUCTION:
Endotracheal suctioning (ETS) is essential for patient care in an ICU but may represent a cause of cerebral secondary injury. Ketamine has been historically contraindicated for its use in head injury patients, since an increase of intracranial pressure (ICP) was reported; nevertheless, its use was recently suggested in neurosurgical patients. In this prospective observational study we investigated the effect of ETS on ICP, cerebral perfusion pressure (CPP), jugular oxygen saturation (SjO2) and cerebral blood flow velocity (mVMCA) before and after the administration of ketamine.
METHODS:
In the control phase, ETS was performed on patients sedated with propofol and remifentanil in continuous infusion. If a cough was present, patients were assigned to the intervention phase, and 100 γ/kg/min of racemic ketamine for 10 minutes was added before ETS.
RESULTS:
In the control group ETS stimulated the cough reflex, with a median cough score of 2 (interquartile range (IQR) 1 to 2). Furthermore, it caused an increase in mean arterial pressure (MAP) (from 89.0 ± 11.6 to 96.4 ± 13.1 mmHg; P <0.001), ICP (from 11.0 ± 6.7 to 18.5 ± 8.9 mmHg; P <0.001), SjO2 (from 82.3 ± 7.5 to 89.1 ± 5.4; P = 0.01) and mVMCA (from 76.8 ± 20.4 to 90.2 ± 30.2 cm/sec; P = 0.04). CPP did not vary with ETS. In the intervention group, no significant variation of MAP, CPP, mVMCA, and SjO2 were observed in any step; after ETS, ICP increased if compared with baseline (15.1 ± 9.4 vs. 11.0 ± 6.4 mmHg; P <0.05). Cough score was significantly reduced in comparison with controls (P <0.0001).
CONCLUSIONS:
Ketamine did not induce any significant variation in cerebral and systemic parameters. After ETS, it maintained cerebral hemodynamics without changes in CPP, mVMCA and SjO2, and prevented cough reflex. Nevertheless, ketamine was not completely effective when used to control ICP increase after administration of 100 γ/kg/min for 10 minutes
Contrast-enhanced ultrasound in renal cystic lesions: an update
No full text: This narrative review aims to describe the current status of contrast-enhanced ultrasound (CEUS) in characterizing renal cystic lesion. The imaging techniques usually performed for their evaluation are ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) with different criteria of application based on the individual case and the purpose of the examination. Generally, US, as a non-ionizing examination, is the first imaging modality performed and therefore the one that incidentally detects cystic lesions. CT is the most performed imaging modality for cystic lesion assessment before MRI evaluation. It provides better characterization and management and has been introduced into the Bosniak classification. In this context, CEUS is making its way for its characteristics and represents the emerging technique in this field. With these premises, the authors analyze the role of CEUS in the evaluation of renal cysts, starting with an explanation of the technique, describe its main advantages and limitations, and end with a discussion of its application in the Bosniak classification and management, following the current major guidelines
Aphrophorini Amyot & Serville 1843
No full textAphrophorini Amyot & Serville, 1843 † Aphrophora pitoni nom.nov. = Aphrophora maculata Piton, 1936a: 94 (from Eocene) primary homonym of Aphrophora maculata Capanni, 1894a: 292 (from Europe) and primary homonym of Aphrophora maculata Edwards, 1920a: 53 (a synonym of Aphrophora costalis Matsumura, 1903a: 36) Etymology: The species is named in honor of L.E. Piton, the author of the replaced name.Published as part of Dmitriev, Dmitry A., 2020, Nomenclatural changes in the suborders Auchenorrhyncha (Hemiptera) and Paleorrhyncha (Palaeohemiptera), pp. 25-53 in Zootaxa 4881 (1) on page 25, DOI: 10.11646/zootaxa.4881.1.2, http://zenodo.org/record/442571
Utility of ultrasound-guided transversus abdominis plane block for day-case inguinal hernia repair
No full textBackground: The transversus abdominis plane (TAP) block is a regional anesthesia technique that effectively reduces the pain intensity and use of analgesia in abdominal surgery. The aim of this study was to determine the utility of the ultrasound-guided TAP block in improving the efficacy of the ultrasound-guided ilioinguinal/iliohypogastric nerve (IIN/IHN) block for intraoperative anesthesia and postoperative pain control in day-case inguinal hernia repair (IHR).Methods: We conducted a descriptive study of patients undergoing elective primary unilateral open IHR. Fifty-nine patients were divided into two groups according to the anesthetic technique used: ultrasound-guided TAP block plus ultrasound-guided IIN/IHN block (TAP group) vs. ultrasound-guided IIN/IHN block alone (IIN/IHN group). The outcome measures were the adequacy of anesthesia during surgery and postoperative analgesia.Results: Four patients (12.5%) in the TAP group and 10 patients (37.0%) in the IIN/IHN group experienced inadequate anesthesia and needed systemic sedation (P < 0.05). No significant differences in additional local anesthetic volume were found between the two groups. Patients in the TAP group reported lower pain scores at the end of surgery (0.4 +/- 0.8 vs. 2.1 +/- 2.5, P < 0.01), at 2 hours after surgery (0.8 +/- 1.3 vs. 3.0 +/- 2.2, P < 0.01), at discharge (1.4 +/- 1.2 vs. 4.3 +/- 2.2, P < 0.01), and at 24 hours (1.5 +/- 1.1 vs. 4.5 +/- 2.3, P < 0.01).Conclusions: The combination of the TAP and IIN/IHN blocks is associated with better intraoperative anesthesia and lower postoperative pain scores compared with the IIN/IHN block alone
