Face-up Position Research Articles

Post-operative face-up or face-down positioning after silicone oil tamponade in retinal surgery: Results of a retrospective study.

To compare the complications related to silicone oil, and anatomical and functional outcomes in patients nursed in different postoperative positionings after pars plana vitrectomy with silicone oil injection in retinal surgery. The retrospective cohort study was conducted at the Department of Ophthalmology, King AbdulAziz Medical City, Riyadh, Saudi Arabia, and comprised data of patients who underwent pars plana vitrectomy with silicone oil tamponade from January 2016 to October 2022. The patients were divided into two groups depending on how they were nursed in the postoperative period. Group A patients were nursed in postoperative face-down positioning and group B patients were nursed in the face-up position. Complications related to silicone oil tamponade, visual outcomes and anatomical results were compared between the groups. Data was analyzed using SPSS 26. Of the 157, 97(62%) were males and 60(38%) were females. The overall mean age was 5320 years. Group A had 87(55.4%) patients, while group B had 70(44.6%). There were 185 eyes involved; 104(56.2%) in group A and 81(43.8%) in group B. Overall, mean postoperative follow-up duration was 2519 months. Migration of silicone oil in the anterior chamber was more common in group A (p=0.470). Pupil block glaucoma was seen in 2(1.9%) eyes in group A only.Silicone oil-related complications, functional outcomes and anatomical outcomes were non-significantly different between the grpups (p>0.05) except a weak significant difference with respect to redetachments after removal of silicone oil (p=0.047). There was no difference seen in terms of complications as well as anatomical and physiological outcomes related to silicone oil tamponade in face-down or face-up postoperative positioning after pars plana vitrectomy with silicone oil tamponade for complicated retinal detachment surgery.

The impact of short-term postoperative face-up position on unintentional retinal displacement after pars plana vitrectomy for rhegmatogenous retinal detachment.

To assess the effectiveness and safety of a rigorous short-term supine position in preventing inadvertent retinal displacement after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachment (RRD). We conducted a retrospective observational analysis of a case series at two ophthalmological surgical centers. We included eyes diagnosed with macula-off RRD that maintained a strict face-up position for three hours immediately after PPV with intraoperative perfluorocarbon liquid (PFCL) and 20% sulfur hexafluoride (SF6) tamponade. Fundus autofluorescence (FAF) imaging was performed at one month post-operatively to identify unintentional retinal displacement through the detection of retinal vessel prints (RVPs) on FAF imaging using an ultrawide-field (UWF) imaging system. A total of 29 eyes with macula-off RRD were included in the study. The average age of the participants was 59.62 years. RRD involved one quadrant in two eyes, two quadrants in fourteen eyes, three quadrants in seven eyes, and four quadrants in six eyes. UWF-FAF imaging at one month follow-up after complete reattachment of the retina revealed RVPs in seven out of the 29 eyes (24.13%), with a mean displacement of 0.22 mm. In every case the displacement occurred downward. Our results suggest that adhering to a strict face-up position for three hours after PPV with PFCL and gas tamponade for macula-off RRD may lead to a low frequency and severity of inadvertent post-operative retinal displacement.

Maternal knowledge of recommendations for safe infant sleep and intentions for implementation- a cross sectional analysis of data from the KUNO-Kids birth cohort study.

Despite major advances in prevention, sudden infant death syndrome (SIDS) remains an important cause of infant mortality. The aim of our study was to determine actual knowledge and intentions to implement SIDS prevention measures among new mothers and to identify potential knowledge gaps for improved postpartum counselling strategies. Data was collected in a standardized interview from participants of the KUNO-Kids birth cohort study before discharge from maternity ward. The mothers did not receive any specific teaching prior to the interview. The majority of 2,526 interviewed mothers wereable to actively report important recommendations for safe infant sleep, including the exclusive face-up position. However, 154 mothers (9%) intended to position thenewborn face-down sometimes or often. The most frequently envisaged sleeping furniture was a bedside sleeper (n=1,144, 47%), but 2.2% of mothers indicated that the intended default sleeping place for the newborn would be the parents' bed (which is discouraged by the recommendations). For 43% of the infants (n=1,079), mothers planned to have loose objects in the bed and 189 mothers (7%) intended to use a loose blanket. 22% of infants (n=554) will live in a household with a smoker. Multivariate regression showed a significant association of "good knowledge" with maternal age and with not being a single parent, whereas the household size was negatively associated. Although the majority of mothers in our birth cohort were aware of many recommendations for safe infant sleep, our data also uncovered weaknesses in SIDS prevention knowledge and point to specific areas with potential for improved counselling.

Supine positioning after vitrectomy for rhegmatogenous retinal detachments with inferior retinal breaks

BackgroundTo evaluate the effectiveness of face up position (FUP) following pars plana vitrectomy (PPV) and silicone oil injection in cases of rhegmatogenous retinal detachment (RRD) with multiple peripheral and inferior breaks.MethodThirty-two eyes of 32 patients with RRD due to multiple peripheral breaks were managed with PPV and silicone oil as endotamponade. Postoperatively, all patients were instructed to assume face up (supine) position for at least 10 days. Silicone oil was removed 3 to 6 months postoperatively in eyes with attached retina and the patients were followed up for 6 months.ResultsThirty eyes (94%) got a successful attachment of the retina and remained attached after silicone oil removal. One case showed lower redetachment under silicone oil while the other case showed recurrent RRD after silicone oil removal.ConclusionAlthough postoperative FUP is not a popular one, it is effective in the treatment of RRD with peripheral breaks whatever the number or the distribution of these breaks. This may in some way or another change the traditional trends of postoperative positioning after vitrectomy for RRD.

An attempt to evaluate intraductal components of breast cancer by dual energy computed tomography

Objectives: Evaluation of Intraductal Components (ICs) of breast cancer, such as ductal extension or segmental distribution, is essential before surgery. Evaluation is mainly performed using contrast-enhanced MRI as its sensitivity and detectability are superior to those of contrast-enhanced CT. Dual Energy CT (DECT) has been shown to have a high contrast enhancement effect with high resolution in soft tissues such as breast tissue. Thus, we assessed the utility of DECT for evaluating an IC of breast cancer. Methods: Fifty-five patients with a biopsy-proven breast cancer have undergone contrast-enhanced DECT and MRI for preoperative investigation. We compared the imaging findings of both modalities and correlated them with the pathological outcome. Results: Pathologically, an IC of breast cancer was identified in 26 patients. Existence of an IC was identified in 32 patients on DECT and 35 patients on MRI. The sensitivity, specificity and accuracy for detecting an IC were 76.9%, 58.6% and 67.3% with DECT and were 73.1%, 44.8%, and 58.2% with MRI, respectively. Conclusions: The appearance of ICs on DECT was highly correlated with the pathological outcome. The advantages of DECT include high detectability of an IC, clinically acceptable image quality, imaging in the face-up position (consistent with the surgical position) and simultaneous assessment of distant metastasis without radiation dose penalty. Thus, DECT is a useful supporting modality for the detection of an IC of breast cancer.

Autologous platelet concentrate in surgery for macular detachment associated with congenital optic disc pit.

PurposeTo evaluate the anatomical and functional results obtained with pars plana vitrectomy (PPV) plus autologous platelet concentrate (APC) as a treatment for macular detachment associated with optic disc pit (ODP).MethodsWe performed a prospective interventional study of 19 eyes of 19 consecutive patients with posterior macular detachment due to ODP. All patients underwent PPV, posterior hyaloid peeling, fluid–air exchange, injection of 0.05 mL of APC over the ODP and 15% perfluoropropane (C3F8) endotamponade. Postoperative measures included face-up positioning for 2 hours and then avoidance of the face-up position during the ensuing 10 days. All patients underwent complete ophthalmologic examination and optical coherence tomography preoperatively at 1 month, 3 months, 6 months, 9 months, and 12 months postoperatively and then annually. Outcome measures were best corrected visual acuity (BCVA) by logMAR, improvement of quality of vision, macular attachment, and resolution of intraretinal schisis-like separation.ResultsPreoperatively, the median BCVA was 0.70 (range: 0.30–1.70) and all patients showed improved visual acuity after surgery; BCVA was 0.22 (range: 0.07–0.52) at 12 months follow-up. All patients showed complete reabsorption of intraretinal fluid (median time: 3.5 months [range: 2–8 months]) and macular attachment at the end of follow-up (median: 60 months [range: 12–144 months]), with stable or improved visual acuity. No reoperations were needed and no major adverse events were recorded.ConclusionFor macular detachment associated with ODP, the combination of PPV, posterior hyaloid peeling, APC, and C3F8 tamponade is a highly effective alternative technique with stable anatomical and functional results.

Hood Nebulization: Effects of Head Direction and Breathing Mode on Particle Inhalability and Deposition in a 7-Month-Old Infant Model

Aerosol drug delivery to infants is a strong function of their behavior. Infants can be active during medication administration, changing head position or breathing mode. The objective was to evaluate the influence of the head direction and breathing mode on the hood drug delivery in a 7-month-old girl airway model by using an approach that couples imaging with computational fluid dynamics (CFD). Three head directions, i.e., face up, face side, and sitting (face front), and two breathing modes, i.e., oronasal and nasal breathing, were studied. The face-airway model was developed from computed tomography scans of a 7-month-old girl. Respiratory airflows and particle transport were simulated with the low Reynolds number κ-ω turbulence model and Lagrangian tracking approach. Three pharmaceutical aerosol sizes (1, 2.5, and 5 μm) via hood nebulization were considered under quiet breathing conditions (5 L/min). Both head direction and breathing mode can noticeably affect aerosol inhalability and lung delivery efficiency. A maximum of 20% difference in inhalability is observed among the three head positions. Facial-ocular depositions are predominantly influenced by head position, but not breathing mode. The facial-ocular deposition rate with the face-up position is about threefold that with the sitting position for 5-μm particles. Nasal breathing gives about 17.8% lower lung deposition and about 65% higher facial-ocular deposition than the oronasal breathing. The face-side position has less facial-ocular deposition than the face-up position, while still achieving similar lung delivery efficiency. Because aerosols deposited around the eyes may cause irritation to the eyes, the face-side position appears to be a better option than the face-up position for comfort and safety reasons.

Pilot randomised controlled trial of face-down positioning following macular hole surgery

This was a pilot randomised controlled trial (RCT) to investigate the effect of post-operative face-down positioning on the outcome of macular hole surgery and to inform the design of a larger definitive study. In all, 30 phakic eyes of 30 subjects with idiopathic full-thickness macular holes underwent vitrectomy with dye-assisted peeling of the ILM and 14% perfluoropropane gas. Subjects were randomly allocated to posture face down for 10 days (posturing group) or to avoid a face-up position only (non-posturing group). The primary outcome was anatomical hole closure. Macular holes closed in 14 of 15 eyes (93.3%; 95% confidence interval (CI) 68-100%) in the posturing group and in 9 of 15 (60%; 95% CI 32-84%) in the non-posturing group. In a subgroup analysis of outcome according to macular hole size, all holes smaller than 400 μm closed regardless of posturing (100%). In contrast, holes larger than 400 μm closed in 10 of 11 eyes (91%; 95% CI 58-99%) in the posturing group and in only 4 of 10 eyes (40%; 95% CI 12-74%) in the non-posturing group (Fisher's exact test P=0.02). Post-operative face-down positioning may improve the likelihood of macular hole closure, particularly for holes larger than 400 μm. These results support the case for a RCT.

Perioperative nursing of Descemet stripping with endothelial keratoplasty for bullous keratopathy

Objective To discuss nursing care of patients underwent corneal Descemet stripping endothelial keratoplasty to treat bullous keratopathy. Methods 22 patients who underwent corneal Descemet stripping endothelial keratoplasty to treat bullous keratopathy accepted strengthened psychological care, perfect preoperatively preparation, to sleep in face-up supine position, meanwhile complications were observed and treated carefully. Results 22 patients could persist in sleeping in face-up position for 4days postoperatively. Graft shift occurred in two cases. And after gas reinjection the grafts adhered very well. Intraocular pressure rose in 7 cases .After timely treated these 7 patients were cured and discharged. Conclusions Careful preoperative evaluation and preparation could reduce postoperative complication. Strict measures to keep patients sleeping in face-up supine position, timely observation and treatment of complications should be important to ensure the success of the operation. Key words: Descemet membrane; Corneal transplantation; Nuring

Macular Hole Surgery With Inner Limiting Membrane Peeling, Endodrainage, and Heavy Silicone Oil Tamponade

To evaluate the anatomical and functional outcomes in macular hole (MH) patients who underwent vitrectomy with inner limiting membrane (ILM) peeling, endodrainage, and heavy silicone oil (HSO) endotamponade. A retrospective case series with 54 consecutive eyes from 53 patients with idiopathic stage 3 or 4 MHs. Surgery with infracyanine green-assisted ILM peeling and endodrainage was performed. Patients who were phakic underwent a simultaneous phacoemulsification. At the end of the operation, a HSO tamponade was used in all cases. The patient maintained a face-up position for 24 hours postoperatively. The HSO was removed two to three months after initial surgery. Optical coherence tomography was performed preoperatively and postoperatively to determine the MH stage and the anatomical closure rate. The mean follow-up time was 6.6 months (range, 3.6 to 18.2 months). The overall median duration between the first symptoms and the surgery was four months (range, two to 37 months). The overall anatomical closure success rate after one surgery was 100%. The median preoperative visual acuity (VA) was 20/200 (range, 20/40 to 20/600) and increased to 20/50 (range, 20/20 to 20/300) postoperatively. The median increase in VA was five lines (mean, 4.8 lines; range, -3 to 12 lines). Of all 54 eyes, 30 (55 %) eyes had a final VA of 20/50 or better. These findings indicate that surgery for MH with ILM peeling, endodrainage, and HSO endotamponade appears to induce a high incidence of anatomical closure with good visual outcome.

Fluid Mechanics of the Human Eye: Aqueous Humour Flow in The Anterior Chamber

We consider and compare the various different kinds of flow that may take place in the anterior chamber of a human eye. The physical mechanisms responsible for causing such flows may be classified as follows: (i) buoyancy-driven flow arising from the temperature difference between the anterior surface of the cornea and the iris, (ii) flow generated by the aqueous production of the ciliary body, (iii) flow generated by the interaction between buoyancy and gravity while sleeping while sleeping in a face-up position, (iv) flow generated by phakodenesis (lens tremor), (v) flow generated by Rapid Eye Movement (REM) during sleep. Each flow is studied using a traditional fluid mechanics/asymptotic analysis approach. We also assess the veracity of a hypothesis that was recently advanced [see Maurice, D.M., 1998. The Von Sallman Lecture 1996: An ophthalmological explanation of REM sleep. Exp. Eye. Res. 66, 139-145, for details] to suggest that, contrary to previous opinion, the purpose of REM during sleep is to ensure corneal respiration in the absence of the buoyant mixing that routinely takes place due to (i) above during waking conditions.

Results of macular hole surgery with and without epiretinal dissection or internal limiting membrane removal

Purpose To evaluate the results of idiopathic macular hole surgery with or without epiretinal dissection or peeling of the internal limiting membrane (ILM). Design Retrospective consecutive nonrandomized comparative interventional trial. Participants One hundred seventy-two eyes of 162 patients with previously untreated idiopathic macular holes of <24 months duration. Intervention All eyes were treated with pars plana vitrectomy by 1 surgeon using 1 of 3 techniques: no epiretinal dissection (116 eyes), epiretinal dissection (27 eyes), or ILM peeling (29 eyes). Main outcome measures Closure of the macular hole and visual acuity. Results The macular hole was closed with 1 surgery in 92.9% of 56 eyes with epiretinal dissection/ILM peeling versus 79.3% of 116 eyes without dissection ( P = 0.03) and was closed with 1 surgery in 85.1% of 27 eyes in the epiretinal dissection group compared with 100% of 29 eyes in the ILM peeling group ( P = 0.05). Visual acuity improved 3 or more lines in 57.1% of 56 eyes in the epiretinal dissection/ILM peeling group compared with 38.8% of 116 eyes in the no dissection group 3 months postoperatively ( P = 0.03). Visual acuity improved 3 or more lines at 3 months in the no dissection group in 32.2% of 87 eyes placed faceup for 24 hours compared with 58.6% of 29 eyes placed immediately prone postoperatively ( P = 0.02). The visual and anatomic results of the no dissection and epiretinal dissection/ILM peeling groups were similar when comparing eyes in the no dissection group placed immediately prone with the epiretinal dissection/ILM peeling eyes also placed immediately prone. Visual improvement of 3 or more lines at 3 months occurred in 79.2% of 24 eyes in the epiretinal dissection group versus 44.8% of 29 eyes in the ILM peeling group ( P = 0.01) in eyes with successful macular hole closure. Visual acuity results were similar in all subgroups at the final examination after reoperations. Conclusions The faceup position for 24 hours using adjuvants reduced the initial anatomic and visual outcomes of macular hole surgery. Internal limiting membrane peeling improved the likelihood of successful macular hole closure but reduced the amount of initial visual improvement at 3 months compared with epiretinal dissection alone. Final visual acuities were similar in all groups.

Does head positioning influence anterior chamber depth in pseudoexfoliation syndrome?

Phacodonesis can occur in pseudoexfoliation syndrome because of impaired zonular support. This study investigates whether the increased mobility of the lens influences anterior chamber depth in patients with pseudoexfoliation while assuming a prone position. Central anterior chamber depth was measured in 39 patients with clinically apparent unilateral pseudoexfoliation and elevated intraocular pressure. Patients were placed in a face-up position for 5 minutes, at which time anterior chamber depth and axial length were measured by A scan, and intraocular pressure was measured by Tonopen (Oculab, La Jolla, CA) in both eyes. The measurements were repeated on both eyes after 5 minutes in a face-down position. No significant differences in intraocular pressure or axial length between the prone and supine positions were found in either eye. Anterior chamber depth in eyes with pseudoexfoliation decreased from a mean of 3.08 mm in the supine position to a mean of 2.95 mm in the prone position, whereas mean anterior chamber depth in the fellow eyes decreased from 3.01 mm to 2.97 mm. The decrease in anterior chamber depth when facing down in the eyes with pseudoexfoliation was significantly greater than in the fellow eyes. In patients with clinically apparent unilateral pseudoexfoliation, the lens seems to be more mobile in the affected eye. This results in a shallower anterior chamber when the head is placed in a prone position. Whether this fact might potentially lead to transient pupillary block when engaging in activities such as facing down while reading warrants further study.

Sudden death during restraint: a study to measure the effect of restraint positions on the rate of recovery from exercise.

A small number of mental health patients have died suddenly following violent behaviour and restraint by staff. The safety of certain restraint positions has been questioned. This study evaluates two control and restraint (C & R) positions commonly used by health service staff. A repeated measures design was used to study rate of recovery from exercise in volunteer staff, measured by pulse oximetry, comparing the restraint positions with a seated (control) position. It was found that the recovery time for pulse rate of subjects restrained in a face-down position was significantly longer than for subjects restrained in a face-up position. No significant findings were made in terms of comparison between the control position and the restraint positions, and no significant changes in oxygen saturation were noted during restraint. It is concluded that restraint position may be a factor in death during restraint, but only where other factors contribute to the overall situation.

Silicone oil tamponade to seal macular holes without position restrictions

Objective The authors performed a study to determine the effectiveness and safety of silicone oil as a substitute for gas to fill the vitreous cavity to treat macular holes. Design Multicenter, nonrandomized, interventional trial. Participants Thirty-seven consecutive patients chose vitrectomy with silicone tamponade instead of gas to treat 40 eyes with stage-2 to stage-4 idiopathic age-related macular holes. Stage-2 holes constituted 40% of the holes, and stage-3 and stage-4 holes made up 60%. Intervention All eyes were treated with vitrectomy, manual detachment of the posterior vitreous face (not done for stage-4 holes), autologous serum instillation, and silicone fill of the vitreous cavity. After insertion of the oil, the patients resumed normal activity with no restriction of head or eye position except to avoid faceup position. The oil was removed after approximately 6 weeks. Main outcome measures The authors considered the seal of the macular hole and the preoperative and postoperative logarithm of the minimum angle of resolution (logMAR) visions the most significant measures for comparison to other studies. Results Eighty percent of all holes and 86% of holes not treated previously were sealed with a single silicone tamponade of the vitreous cavity. The logMAR value of visual acuity improved an average of 0.26 (2.6 lines) to 0.61 (20/81) for all eyes and 0.34 (3.4 lines) to 0.52 (20/66) when the macular hole sealed. Completeness of fill of the vitreous cavity with silicone affected seal of the macular hole. Three of eight eyes in which open holes developed after oil removal had less than 90% fill of the vitreous cavity by silicone. Sixty-nine percent of lenses increased opacity one grade or were removed after silicone tamponade. There were no significant adverse effects arising from silicone tamponade. Conclusions Silicone oil tamponade of macular holes is effective and safe. Silicone may be optimal for the treatment of macular holes in persons who must travel, who cannot maintain facedown positioning, or who have monocular vision. The most important factor in the successful closure of the macular hole was the completeness of fill of the vitreous cavity with silicone oil.

Surface Design Factors in the Evaporative Cooling of Electronic Components

Variations in the size and orientation of a surface cooled by evaporation of a liquid are reflected in the measured heat transfer characteristics. Nucleate boiling curves from tests of Freon-113 in contact with two sizes of heated flat plates in different positions are used to demonstrate the comparative characteristics. For low levels of heat flux, the lowest surface temperatures are exhibited by the larger of the heated plates facing downward. At higher fluxes, the lowest temperatures observed are those of the larger plates facing upward. The slope of the boiling curve for any size plate becomes progressively greater as the plate is shifted from the face-down position through the vertical to the face-up position. The facility with which bubbles can escape from a heated surface is proposed as a significant determinant of heat transfer characteristics.

The prone position in intravenous urography for study of the upper urinary tract.

Intravenous urography is usually carried out with the patient recumbent, in the face-up position. Occasionally, for visualization of anterior and posterior borders of the kidney, oblique-supine and recumbent lateral views are used. An erect anteroposterior projection is sometimes added to the routine to determine mobility of the kidneys, emptying of the renal pelves and the ureters, and possible laxity of the pelvic floor. A recumbent postero-anterior study is not commonly included in intravenous urography, although such a view can in some instances add valuable information. Urine containing the commonly used contrast materials is of higher specific gravity than non-opacified urine because of the relatively high specific gravity of the medium. Thus, 50 per cent Hypaque solution has a specific gravity of 1.32, and 76 per cent Renografin solution has a specific gravity of 1.42. Baumrucker (1) determined urine specific gravities in a series of patients just before and at a fifteen-minute collection after the intravenous injection of Diodrast. In this group urine containing the contrast medium showed an increase in specific gravity ranging from 0.007 to 0.042. Hence, during the course of intravenous urography the specific gravity of the urine varies, depending on its content of the opaque agent. In the absence of mixing, layering of the heavier, opacified urine below the less opacified or non-opacified urine occurs. The upper pole of each kidney is more posteriorly placed than the lower; thus, the superior calyces, being more dependent than the inferior calyces in the supine position, will be more readily opacified by the heavier contrast-containing urine in this position; conversely, in the prone position, the lower group of calyces are more dependent and should be better opacified. Similarly, inasmuch as the ureter cephalad to the pelvic brim lies in a plane anterior to the renal pelvis because of the normal lumbar lordosis, the prone position might afford better visualization of the ureters during intravenous urography. The layering of urine during intravenous urography has been the subject of previous reports. Fey and Truchot (3) in 1936 observed a patient with marked unilateral hydronephrosis due to an aberrant vessel, in whom the erect film demonstrated layering in the dilated calyces. In the discussion of this case, it was suggested that the layering was due to the different specific gravities of the contrast-laden urine and the non-opacified urine. Fey, however, had seen the layering persist for over an hour and he concluded that diffusion would by then have caused complete mixing had the effect been due only to a difference in specific gravity.