Re: of plague dogs and cryonics



Sbharris[atsign]ix.netcom.com wrote:
> "Topics are resuscitation, liquid ventilation, pharamaceutical drug
> delivery and microemulsions."
>
> >>Cryonics? (You didn't think I'd get that did you.)
> I think you'd have to do a lot of cat karma to make up for killing dogs
>
> so wealthy wackos could be frozen until some time in the future when
> they're rescusitated with just, er...slight brain and other organ
> damage. <<
>
> COMMENT:
>
> Hypothermia's a hot topic these days. Hypothermia induction for
> purposes of minimizing brain damage after resuscitation isn't cryonics.
>
>
> Circulation. 2005 Jun 21;111(24):3195-201. Epub 2005 Jun 13.
>
> Hypothermia improves defibrillation success and resuscitation outcomes
> from ventricular fibrillation.
>
> Boddicker KA, Zhang Y, Zimmerman MB, Davies LR, Kerber RE.
>
> Cardiovascular Center, College of Medicine, University of Iowa, Iowa
> City, USA.
>
> BACKGROUND: Induced hypothermia is recommended to improve neurological
> outcomes in unconscious survivors of out-of-hospital ventricular
> fibrillation (VF) cardiac arrest. Patients resuscitated from a VF
> arrest are at risk of refibrillation, but there are few data on the
> effects of already existing
> hypothermia on defibrillation and resuscitation. METHODS AND RESULTS:
> Thirty-two swine (mean+/-SE weight, 23.0+/-0.6 kg) were divided into 4
> groups: normothermia (n=8), mild hypothermia (35 degrees C) (n=8),
> moderate hypothermia (33 degrees C) (n=8), and severe hypothermia (30
> degrees C) (n=8). Hypothermia was induced by surrounding the animal
> with ice, and VF was electrically induced. After 8 minutes of
> unsupported VF (no CPR), the swine were defibrillated (biphasic
> waveform) with successive shocks as needed and underwent CPR until
> resumption of spontaneous circulation or no response (> or =10
> minutes). First-shock defibrillation success was higher in the moderate
> hypothermia group (6 of 8
> hypothermia versus 1 of 8 normothermia; P=0.04). The number of shocks
> needed for late defibrillation (> or =1 minute after initial shock) was
> less in all 3 hypothermia groups compared with normothermia (all
> P<0.05). None of the 8 animals in the normothermia group achieved
> resumption of spontaneous circulation compared with 3 of 8 mild
> hypothermia (P=NS), 7 of 8 moderate hypothermia (P=0.001), and 5 of 8
> severe hypothermia (P=0.03) animals. Coronary perfusion pressure during
> CPR was not different between the groups. CONCLUSIONS: When VF was
> induced in the setting of moderate or severe hypothermia, resuscitative
> measures were facilitated with significantly improved defibrillation
> success and resuscitation outcome. The beneficial effect of hypothermia
> was not due to alteration of coronary perfusion pressure, which
> suggests that changes in the mechanical, metabolic, or
> electrophysiological properties of the myocardium may
> be responsible.
>
> PMID: 15956132 [PubMed - in process]
>
> ===================================
> Crit Care Med. 2005 Feb;33(2):414-8.
>
> Hypothermia for neuroprotection after cardiac arrest: systematic review
> and
> individual patient data meta-analysis.
>
> Holzer M, Bernard SA, Hachimi-Idrissi S, Roine RO, Sterz F, Mullner M;
> on behalf of the Collaborative Group on Induced Hypothermia for
> Neuroprotection After Cardiac Arrest.
>
> Department of Emergency Medicine, General Hospital Vienna, Medical
> University of Vienna, Vienna, Austria.
>
> OBJECTIVE: Only a few patients survive cardiac arrest with favorable
> neurologic recovery. Our objective was to assess whether induced
> hypothermia improves neurologic recovery in survivors of primary
> cardiac arrest. DATA SOURCE: Studies were identified by a computerized
> search of MEDLINE, EMBASE, CINAHL, PASCAL, the Cochrane Controlled
> Trial Register, and BIOSIS. STUDY SELECTION: We included randomized and
> quasi-randomized, controlled trials of adults who were successfully
> resuscitated, where therapeutic hypothermia was applied within 6
> hrs after arrival at the emergency department and where the neurologic
> outcome was compared. We excluded studies without a control group and
> studies with historical controls. DATA EXTRACTION: All authors of the
> identified trials supplied individual patient data with a predefined
> set of variables. DATA SYNTHESIS: We identified three randomized
> trials. The analyses were conducted according to the intention-to-treat
> principle. Summary odds ratios were calculated using a random effects
> model and translated into risk ratios. More patients in the hypothermia
> group were discharged with favorable neurologic recovery (risk ratio,
> 1.68; 95% confidence interval, 1.29-2.07). The 95% confidence interval
> of the number-needed-to-treat to allow one additional patient to leave
> the hospital with favorable neurologic recovery was 4-13. One study
> followed patients to 6 months or death. Being alive at 6 months with
> favorable functional neurologic recovery was more likely in the
> hypothermia
> group (risk ratio, 1.44; 95% confidence interval, 1.11-1.76).
> CONCLUSIONS: Mild therapeutic hypothermia improves short-term
> neurologic recovery and survival in patients resuscitated from cardiac
> arrest of presumed cardiac origin. Its long-term effectiveness and
> feasibility at an organizational level need further research.
>
> Publication Types:
> Meta-Analysis
> Review
>
> PMID: 15699847 [PubMed - indexed for MEDLINE]
>
> ========================================
>
>
> Resuscitation. 2001 Aug;50(2):189-204.
>
> Rapid (0.5 degrees C/min) minimally invasive induction of hypothermia
> using cold perfluorochemical lung lavage in dogs.
>
> Harris SB, Darwin MG, Russell SR, O'Farrell JM, Fletcher M, Wowk B.
>
> Critical Care Research, Inc. Rancho Cucamonga, CA, USA.
> sbharris@xxxxxxxxxxxxx
>
> OBJECTIVE: Demonstrate minimally invasive rapid body core and brain
> cooling in a large animal model. DESIGN: Prospective controlled animal
> trial. SETTING: Private research laboratory. SUBJECTS: Adult dogs,
> anesthetized, mechanically ventilated. INTERVENTIONS: Cyclic lung
> lavage with FC-75 perfluorochemical (PFC) was administered through a
> dual-lumen endotracheal system in the new technique of 'gas/liquid
> ventilation' (GLV). In Trial-I, lavage volume (V-lav) was 19 ml/kg,
> infused and withdrawn over a cycle period (tc) of 37 s. (effective
> lavage rate V'-lav=31 ml/kg/min.) Five dogs received cold
> (approximately 4 degrees C) PFC; two controls received isothermic PFC.
> In Trial-II, five dogs received GLV at V-lav=8.8 ml/kg, tc=16 s,
> V'-lav=36 ml/kg/min. MEASUREMENTS AND MAIN RESULTS:
> Trial-I tympanic temperature change was -3.7+/-0.6 degrees C (SD) at
> 7.5 min, reaching -7.3+/-0.6 degrees C at 18 min. Heat transfer
> efficiency was 60%. In Trial-II, efficiency fell to 40%, but
> heat-exchange dead space (VDtherm) remained constant. Lung/blood
> thermal equilibration half-time was <8 s. Isothermic GLV caused
> hypercapnia unless gas ventilation was increased. At necropsy after
> euthanasia (24 h), modest lung injury was seen. CONCLUSIONS: GLV
> cooling times are comparable to those for cardiopulmonary bypass. Heat
> and CO(2) removal can be independently controlled by changing the mix
> of lavage and gas ventilation. Due to VDtherm of approximately 6 ml/kg
> in dogs, efficient V-lav is >18 ml/kg. GLV cooling power appears more
> limited by PFC flows than lavage
> residence times. Concurrent gas ventilation may mitigate heat-diffusion
> limitations in liquid breathing, perhaps via bubble-induced turbulence.
>
> PMID: 11719148 [PubMed - indexed for MEDLINE]

The first one and the third one are not really of much clinical
significance *except* insofar as they suggest that cooling *before*
cardiac arrest/VF occurs protects the brain. This isn't new -
hypothermia's been used in OR's for more than 20 years when significant
hypoxia is expected during surgery. Kids in particular have survived
extended periods of cardiac arrest when they have fallen through ice
etc. Drowing victims are often protected for a short period of time if
the water is relatively cool. So if you can cool the person down before
s/he arrests s/he'll have abetter chance of surviving....Not a whole
lot of use in the real world though, where cardiac arrest is usually
unexpected.

The second abstract doesn't have enough info to judge exactly what's
being researched. Without information as to the cause of the cardiac
arrest - after all hypothermia itself can cause cardiac arrest - it's a
bit difficult to judge whether or not the findings are of any clinical
significance.

Have you given up on your cryonics work? Is the real end goal of your
research no longer resusuitation after years/decades/centuries of
suspended animation through freezing?

.